Fetomaternal Haemorrhage and Anti-D dosing in Rhesus Negative Mothers Delivering at Moi Teaching and Referral Hospital

Fetomaternal Haemorrhage and Anti-D dosing in Rhesus Negative Mothers Delivering at Moi Teaching and Referral Hospital | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Fetomaternal Haemorrhage and Anti-D dosing in Rhesus Negative Mothers Delivering at Moi Teaching and Referral Hospital Fatma Ahmed Agil, Sahara Omar Shurie, Peter Itsura, Philliph Tonui This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9701884/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Fetomaternal haemorrhage (FMH) is the entry of foetal blood into the maternal circulation during pregnancy or delivery. If this occurs in a Rhesus-negative woman carrying a Rhesus-positive foetus, there is a risk of the mother being sensitized against the D antigen. The effect is seen in the subsequent Rhesus positive pregnancies, which may result in haemolytic disease of the foetus and newborn (HDFN). To prevent this sensitization, anti-D immunoglobulin is usually given. The dose given varies depending on the amount of FMH and the protocols adopted by different professional authorities. Objectives To quantify the size of Fetomaternal Haemorrhage and determine the average calculated dose of anti-D immunoglobulin required for postpartum prophylaxis in Rhesus-negative mothers delivering at Moi Teaching and Referral Hospital (MTRH), Eldoret, Kenya. Methods This was a cross-sectional study among Rhesus-negative postpartum women enrolled within 2–12 hours after delivery. The sample size of 99 was determined using the Kleihauer-Betke test. Participants were sampled consecutively, while data was collected using an interviewer-administered questionnaire, a clinical records review, and blood sample collections. The association between categorical independent variables and the occurrence of fetomaternal haemorrhage was assessed using Pearson’s Chi-Square test. Fisher’s exact test was used whenever the chi-square assumptions were violated. Results Out of 4,552 deliveries over the study period, 143 (3.1%) were Rhesus negative. Of the 143 women, 99 met the eligibility criteria and were enrolled. The mean age and gestational age at delivery were 26.4 (± 5.4) years and 39 weeks, respectively. Fetomaternal haemorrhage (range: 2.5-20ml) was detected in 35 (35.4%) of the women, 24 (68.6%) of whom had FMH of less than 10ml. The use of 100µg of anti-D immunoglobulin would have been sufficient for 89.9% (89/99) of the Rhesus-negative mothers in whom quantification of FMH was done. Conclusion The prevalence of Rhesus negativity among deliveries in MTRH was 3.1%. FMH of less than 10ml occurred in 89.9% of study participants, thus indicating that the majority of the cases of FMH could have been neutralized by 100µg of anti-D immunoglobulin. Sexual & Reproductive Medicine Fetomaternal Haemorrhage Rhesus Negative Mothers MTRH Figures Figure 1 Background The Rhesus blood group is an important human blood group system after the ABO system 1 . It consists of several antigens, namely D, C, c, and E with the D antigen being the most immunogenic 2 . Rhesus refers to the presence of the D antigen on the surface of the red blood cell thus denoting one as Rhesus positive if present and Rhesus negative if absent 1 . Being an antigen, the Rhesus factor can trigger an immune response with production of antibodies against it. This occurs when a Rhesus-negative individual is exposed to Rhesus-positive red blood cells 3 . Unlike the ABO system, where isoimmune anti-A and anti-B antibodies are naturally occurring, Rhesus isoimmunization is a two-step process that involves sensitization followed by immunization. In sensitization, red cells carrying the Rhesus antigen sensitize immune competent cells to produce anti-D antibodies. The critical volume required for sensitization is about 0.1ml of blood. Following subsequent exposure, immune cells produce specific anti-D antibodies more quickly and efficiently. The resultant effect is the destruction of the foetal Rhesus-positive cells by the maternal immune system via a type II hypersensitivity reaction. The antibodies produced remain throughout life. Entry of foetal red cells into maternal circulation during pregnancy or delivery is known as fetomaternal haemorrhage 4 . Potential obstetrical events that would result in fetomaternal haemorrhage include spontaneous or induced abortions, ectopic pregnancies, antepartum haemorrhage, external cephalic version, in utero interventions such as amniocentesis or cordocentesis, intrauterine foetal demise and abdominal trauma 3 . If fetomaternal haemorrhage occurs in a Rhesus-negative mother carrying a Rhesus-positive foetus, the mother is at risk of being sensitized against the D antigen. The mother’s immune system responds by producing antibodies against the D antigen present on the foetal red cells. The effect is seen in the subsequent D-positive pregnancies, whereby foetal red cells are destroyed resulting in hemolytic disease of the foetus and newborn with its spectrum of erythroblastosis foetalis, icterus gravis neonatorum and congenital anemia of the newborn. The accurate detection and quantification of foetal red blood cells in the maternal circulation are necessary for the prevention of Rhesus D isoimmunization among Rhesus D negative women. The anti-D immunoglobulin dose required by a patient is calculated based on the size of fetomaternal haemorrhage. Several quantification methods exist and the two well established tests are flow cytometry and Kleihauer Betke test. The Kleihauer Betke test is an acid elution blood test used to measure the amount of foetal haemoglobin within maternal circulation. It is the most widely used test as it is inexpensive and requires no specialist equipment. Flow cytometry on the other hand works by using monoclonal antibodies directed against haemoglobin F. It has greater precision and accuracy compared to the Kleihauer Betke test, but a longer turnaround time and is more expensive. The incidence of haemolytic disease of the foetus and newborn has been significantly reduced by the use of anti-D immunoglobulin prophylaxis from 13.2% to 0.2%. Assessing the amount of fetomaternal haemorrhage so as to give the right dose has further reduced the overall incidence to 0.14% 5 . This can further be reduced by strict compliance to guidelines concerning determination of fetomaternal haemorrhage and accordingly adjusting dosages of anti-D 6 . The current practice in the country is that an unsensitized Rhesus-negative mother who delivers a Rhesus-positive child is given a dose of 300µg of anti-D immunoglobulin. The amount of fetomaternal haemorrhage varies among patients thus the common practice of a 300ug dose could be an underdose or overdose depending on the amount of fetomaternal haemorrhage that has taken place. The origin of the dose of 300µg is from a study done more than fifty years ago in North America, with no clear indication as to why that particular dose was selected 7 . In 1971, the World Health Organisation suggested a standard dose of 200–300µg but stated that a 100µg dose was likely to have a success rate only slightly inferior to that of 200µg. Clinical experience in the United Kingdom has confirmed the efficacy of the 100µg dose, and this is the amount officially recommended for postpartum prophylaxis 8 . Similar studies done in Australia 9 and Ethiopia 10 have shown that most cases of fetomaternal haemorrhage can be neutralized by lower doses than the current standard of 300µg. Going by the unpublished Standard Operating Procedure (SOP) currently in use in MTRH, a Rhesus-negative unsensitized mother receives a dose of 300µg at 28 weeks and another 300µg after delivery of a Rhesus-positive baby. As of now, measurement of fetomaternal haemorrhage is not part of the SOP. It is assumed that the 300µg of anti-D immunoglobulin given will cover any amount of FMH that has taken place, despite the knowledge that the amounts vary based on patient and clinical factors 11 . No follow-up is done on these patients, and therefore, we have no reports of underdosing or overdosing. This study sought to quantify fetomaternal haemorrhage and calculate the required dose of postpartum anti-D immunoglobulin in Rhesus-negative mothers delivering at Moi Teaching and Referral Hospital. Methodology This was a descriptive cross-sectional study conducted at the Riley Mother and Baby Hospital (RMBH) wing of the Moi Teaching and Referral Hospital (MTRH). The study enrolled 99 Rhesus-negative mothers delivering at RMBH of MTRH. The study participants were enrolled over six months using a consecutive sampling technique. The Rhesus-negative mothers who were admitted to the labour ward had the indirect Coombs test done as per hospital protocol to determine whether they were isoimmunised or not. Those who were not isoimmunised and met the inclusion criteria were approached after delivery by the investigators and informed about the nature and purpose of the study as well as its potential risks and benefits. Those who gave informed consent were then recruited into the study. The study participants were then interviewed and had 2 mL of venous blood taken for fetomaternal haemorrhage estimation within 2 − 12 hours after delivery. The socio-demographic, clinical, and obstetric characteristics of the study participants were collected using an interviewer-administered structured questionnaire. Medical records were reviewed and relevant clinical data was abstracted and entered into the structured questionnaire. At the laboratory, thin blood slides were made, air-dried and fixed with 80% ethanol. The citrate phosphate buffer (pH 3.3) used for elution was warmed to 37°C and the slides were immersed in it for 5 minutes. The slides were then thoroughly washed with distilled water and air-dried completely. Thereafter, staining was done for 3 minutes with acid haematoxylin solution, after which the slides were rinsed with distilled water and counterstained with 0.1% eosin B solution for 4 minutes. A dry coverslip was placed on each slide and examined using oil immersion at 400X magnification. The foetal cells were differentiated from the maternal cells based on the intensity and intracellular distribution of pink staining. Each field had an approximate of 200 cells, thus 10 fields were examined to give a total cell count of about 2000. The number of foetal cells per slide was then expressed as a percentage of the 2000 cells counted. To calculate the amount of foetal blood in the maternal circulation, the American Association of Blood Banks formula of 2008 was used: FMH (ml) = (% of foetal cells by Kleihauer Betke/100) x 5000 The amount of anti-D immunoglobulin required to neutralize the foetal cells was then calculated taking into consideration that 10µg neutralizes 1ml of foetal whole blood (Crowther, 2010). The data was entered into an encrypted computer Microsoft Access Database which was later exported to R Core Team (2017), a language and environment for statistical computing, for analysis. Access to the data was restricted to the main investigator. Back-ups were made using encrypted memory disks to protect against loss of data. Categorical variables such as education level, marital status, occupation, and the monthly income category among others were summarized using frequencies and the corresponding percentages. Continuous variables such as age, duration of pregnancy were summarized using mean and the corresponding standard deviation (SD). Other continuous variables such as fetomaternal haemorrhage, and amount of anti-D dose given were summarized using median and the corresponding interquartile range (IQR) (i.e lower and upper quartiles). Continuous variables were assessed for Gaussian assumptions using histograms and normal probability plots. If the Gaussian assumptions were holding the variable was summarized using mean and SD, if not, median and IQR were used to summarize them. The prevalence of Rhesus-negative mothers delivering at the Moi Teaching and Referral Hospital was computed as the number of Rhesus-negative mothers who delivered divided by the total number of deliveries during the study period. The corresponding 95% confidence intervals (95% CI) was reported. The association between categorical independent variables with the occurrence of fetomaternal haemorrhage was assessed using Pearson’s Chi-Square test. Fisher’s exact test was used whenever the chi-square assumptions were violated. Continuous variables were compared between the participants who experienced fetomaternal haemorrhage and those who did not experience fetomaternal haemorrhage using an independent samples t-test if the Gaussian assumptions were held. Ethical clearance to conduct this study was obtained from the Institutional Research and Ethics Committee of Moi University School of Medicine and MTRH. Permission to conduct the research was granted by the hospital management. Written informed consent was obtained from each study participant before enrolment into the study. Participants’ privacy and confidentiality were ensured by consenting and interviewing participants in private, storing questionnaires and lab results in a locked cabinet and databases protected with passwords. Results A total of 4552 mothers delivered at the Moi Teaching and Referral Hospital during the months of April 2017– September 2017. Of the 4552, 143 were Rhesus negative thus giving a prevalence of 3.1% (95% CI: 2.7, 3.7). Of the 143 Rhesus-negative parturient women, 99 met the eligibility criteria and were included in the current study. The mean (SD) age was 26.4 (± 5.4) years with a range of 18–42 years (Table 1 ). Table 1 Socio-demographic characteristics of the participants Variable N Mean (SD) or n (%) Age (Years) 99 26.4 (5.4) Range (Min. – Max.) 18.0–42.0 Marital status Single 21 (21.2%) Married 99 77 (77.8%) Divorced 1 (1.0%) Education level Primary 22 (22.2%) Secondary 99 53 (53.5%) College 24 (24.2%) Occupation Unemployed 55 (55.6%) Self-employed 99 33 (33.3%) Employed 11 (11.1%) Monthly Household income (Kenya Shillings) < 10,000 99 69 (69.7%) ≥ 10,000 30 (30.3%) The average duration of the pregnancy was 39 weeks (SD: 1.9) days with a minimum and maximum of 33.7 and 43 weeks, respectively. The mothers had carried an average of 2.1 (± 1.1) pregnancies to viability. The least number of pregnancies carried was 1 and the most was 7. Data on blood group was captured, and the findings show that the most prevalent blood group was O negative at 49.5% and the least prevalent was AB negative at 2.0%. One fifth (22.2%) of the mothers had received routine antenatal anti-D prophylaxis at 28 weeks of gestation. None of the study participants reported a history of blunt abdominal trauma or abnormal per vagina bleeding during their pregnancy (Table 2 ). Table 2 Obstetric characteristics of study participants Variable N Mean (SD) or n (%) Gestation at delivery 99 39 (1.9) Range (Min. – Max.)(weeks) 33–43 Gravidity 99 2.1 (1.1) Range (Min. – Max.) 1.0–7.0 One 34 (34.3%) Two 31 (31.3%) Three 99 24 (24.2%) Four or more 10 (10.1%) Blood Group A- 26 (26.3%) B- 99 22 (22.2%) AB- 2 (2.0%) O- 49 (49.5%) Received anti-D at the 28th week of pregnancy 99 22 (22.2%) Had elevated blood pressure 99 5 (5.1%) Severity of the blood pressure 5 Mild 3 (60.0%) Severe 2 (40.0%) Mode of delivery Assisted vaginal delivery 1 (1.0%) Caesarean delivery 99 31 (31.3%) Spontaneous vaginal delivery 67 (67.7%) Had the placenta removed manually 99 4 (4.0%) Pregnancy outcome Fresh stillbirth 1 (1.0%) Single live birth 99 96 (97.0%) Twins live birth 2 (2.0%) Most of the study participants (64/99) did not have demonstrable FMH. Those that had FMH identified by the KHB test were 35.4% (35/99). The median FMH among the 35 mothers was 5.0 (IQR: 2.5, 10.0) ml with a range of 2.5-20mls. Fetomaternal haemorrhage of less than 10ml was seen in 68.6% (24/35). The remaining 11 had FMH ranging between 10ml-20ml (Table 3 ). Table 3 Distribution of FMH ≥ 10ml among study participants Size of FMH No. of participants (n = 11) 10.0ml 4 12.5ml 3 15.0ml 1 17.5ml 2 20.0ml 1 Large FMH, defined as that above 15ml, was only noted in 3 study participants. The largest size of FMH was 20ml of foetal whole blood. This was seen in a 29-year-old study participant who had undergone an emergency caesarian section, at term, for prolonged labour. The outcome in this case was a single live infant with a good APGAR score. Excessive FMH, defined as that exceeding 30ml, was not detected in any of the study participants. The amount of anti-D immunoglobulin that would have been required by the study participants was calculated taking into consideration that 10µg of anti-D immunoglobulin is required for every 1ml of foetal whole blood. The calculated amount of anti-D that would have been required against the size of FMH (Fig. 4). The median corresponding anti-D immunoglobulin dose that ought to have been administered to those who had FMH was 50.0 (IQR: 25.0, 100.0) µg with a minimum and a maximum of 25.0 and 200.0 ᶙg respectively. Discussion The prevalence of Rhesus-negative mothers delivering in our maternity unit was found to be 3.1%. This finding is consistent with a study among pregnant women attending the Aga Khan University Hospital in Nairobi at 3% 12 . Similar findings have also been demonstrated in Uganda in which the prevalence was found to be 3.8% 13 and in Nigeria where the prevalence was 4.5% 14 . The similarities in the prevalence could be because these studies were done in similar geographical regions in which majority of the population are of the same race. Different findings were reported by Szczepura in the United Kingdom and Haas in the Netherlands, in which the prevalence was 10% and 15% respectively. Rhesus negativity tends to have a racial predilection in its distribution such that it is higher in Caucasian populations and lower in other ethnic groups 15 , 16 . Entry of foetal blood into the maternal circulation occurs in approximately 75% of pregnancies but is only a concern if the size is large enough to cause foetal hemodynamic compromise or in instances of Rhesus incompatibility between the mother and foetus. Fetomaternal haemorrhage sufficient to cause isoimmunization occurs most commonly at birth in 15–50% of pregnancies 17 . Fetomaternal haemorrhage in this study was detected in 35.4% of the study participants. This finding is in line with one conducted in Kenya, which reported a 35.9% prevalence of fetomaternal haemorrhage. 2 This could be attributed to the similarity in the demographic regions in which the studies were conducted. However, a study in India demonstrated FMH in 92% 18 while in Ethiopia, it was estimated at 52%. 10 The variations could be due to different clinical factors that have a bearing on the occurrence of FMH, such as mode of delivery, the use of fundal pressure as reported in the Indian study, surgical technique and mode of placental delivery. 10 , 18 In this study, 89.9% of the 99 Rhesus-negative patients in whom FMH was tested had a FMH of less than 10ml, which is similar to the findings estimated at 92.5% 10 and 94.1%. 19 Excessive FMH (exceeding 30ml) was not detected in this study as was the case in a study conducted in India. 20 Supporting this low occurrence is a study in Ethiopia that showed excessive FMH in only 1.3%. 10 The occurrence of excessive FMH is considered rare, complicating about 0.7% of normal deliveries. 21 The similarities in the size of FMH have been observed despite differences in sample size and study types. This shows that majority of patients across different populations that have FMH have a minimal size of FMH. 21 The age difference between those who experienced FMH and those who did not was noted to be statistically significant, mean age: 29.0 (SD: 6.4) years vs. 25.1 (SD: 4.2) years, p -value = 0.002. While many studies on factors affecting FMH exist, their individual conclusions are contradictory. In line with this study in India, which established that as the maternal age increases, the risk of demonstrable FMH also increases. 20 However, other studies 22 , 23 demonstrated that maternal age does not affect the incidence of fetomaternal haemorrhage. All patients who had manual removal of placenta (4/99) had FMH. However, the numbers were too few to do a further analysis on. This is similar to a previous study 20 which reported that patients who had manual removal of placenta were more likely to have FMH. Manual removal of placenta is a known risk factor for the occurrence of fetomaternal haemorrhage with a plausible explanation being that tearing of the placental villi during extraction favors entry of foetal cells into the maternal circulation. 20 When comparing the mode of delivery, there were no significant differences in the mode of delivery between those who had FMH and those who did not. A study in Nigeria similarly found that the mode of delivery did not have a significant effect on the occurrence of FMH. 24 Anti-D dosing is ideally based on fetomaternal haemorrhage, taking into consideration that 10µg would neutralize 1ml of foetal whole blood or 0.5ml of packed foetal red cells. 25 A systematic review by Cochrane established that evidence on the optimal amount of anti-D for postpartum prophylaxis is limited. 25 The recommendations on the ideal dose vary in different countries and is usually guided by their respective professional associations. In Kenya, the guidelines recommend administration of a standard dose of 300µg, which is similar to guidelines in the United States of America. 17 FMH was demonstrated in only 35.4% (35) of the 99 sampled Rhesus-negative mothers. Of the 35 mothers, only 11 had FMH of 10ml and above. Taking this into consideration, individual doses of 100µg of anti-D would have been sufficient for prophylaxis in majority of the 35 mothers who had FMH. If we include those who did not have any detectable FMH, it means that individual doses of 100µg of anti-D would have been sufficient for prophylaxis in 89.9% of all the study participants. Conclusions and recommendations We report a low prevalence of Rhesus-negative mothers delivering at a national referral hospital in Western Kenya, which is congruent to those reported in the greater sub-Saharan region. However, fetomaternal haemorrhage was undetectable among most of this study’s participants. 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Neonatology 109:248–254 Ajayi AI, Nwokocha EE, Akpan W, Adeniyi OV (2016) Use of non-emergency contraceptive pills and concoctions as emergency contraception among Nigerian University students: results of a qualitative study. BMC Public Health 16:1046 Anti-D administration after childbirth for preventing Rhesus alloimmunisation - Crowther, CA – 1997 | Cochrane Library. https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000021/full Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9701884","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":639684978,"identity":"b08e2963-c28a-4bd2-abac-1a297d98d4f6","order_by":0,"name":"Fatma Ahmed Agil","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA50lEQVRIie2QvQrCMBRGI4Gb5WrXDP68giAUwcFXUQpO8Q1qEYRO6rM4dS6UxklcWxwDDuIgCOIgYqrObUbBnOH7QrgHbkKIxfKDsPmnscEWsW7erFQwpp8GlKNCQWOFABfd90W1wvbp5u7PmkDE9ZT5fSQsSTelCnqQL+UWgeyigZB6MZxMsjJlSDzIECRCbRX1BGiFo1uqoKMgfzy1QvHYE08ThXtwqIc+AiBV09BIUe6htY71J4NLp2uuDxVvQWd8zM+3YOh0lLqKW9B2WCJLlS9JEcDfaTBeEBRBL4bTFovF8me8AC8fQgxS+BJbAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0009-0007-7768-0955","institution":"Mbagathi County Hospital, Nairobi, Kenya","correspondingAuthor":true,"prefix":"","firstName":"Fatma","middleName":"Ahmed","lastName":"Agil","suffix":""},{"id":639691772,"identity":"38f7851c-b360-4073-ae37-d75ec70374f2","order_by":1,"name":"Sahara Omar Shurie","email":"","orcid":"https://orcid.org/0000-0002-9286-584X","institution":"Mbagathi County Hospital, Nairobi, Kenya","correspondingAuthor":false,"prefix":"","firstName":"Sahara","middleName":"Omar","lastName":"Shurie","suffix":""},{"id":639691773,"identity":"cdaafd25-72cc-4841-a4c0-acf45b0b3c62","order_by":2,"name":"Peter Itsura","email":"","orcid":"https://orcid.org/0000-0003-2446-6393","institution":"Department of Reproductive Health, School of Medicine, Moi University, Eldoret, Kenya","correspondingAuthor":false,"prefix":"","firstName":"Peter","middleName":"","lastName":"Itsura","suffix":""},{"id":639691774,"identity":"e9260f9d-e985-49a4-ae64-9cf6fe6545fc","order_by":3,"name":"Philliph Tonui","email":"","orcid":"","institution":"Department of Reproductive Health, School of Medicine, Moi University, Eldoret, Kenya","correspondingAuthor":false,"prefix":"","firstName":"Philliph","middleName":"","lastName":"Tonui","suffix":""}],"badges":[],"createdAt":"2026-05-13 09:52:57","currentVersionCode":1,"declarations":{"humanSubjects":true,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":true,"humanSubjectConsent":true,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-9701884/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9701884/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":109269644,"identity":"61b6941e-87c6-4018-9cbe-64c75dc289af","added_by":"auto","created_at":"2026-05-14 13:30:15","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":35388,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScatter graph showing individualized Anti-D doses.\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-9701884/v1/88998bc0758abb7b0e91b36c.jpeg"},{"id":109269646,"identity":"078c76f5-2c4d-4160-a1f7-73da9373f2b1","added_by":"auto","created_at":"2026-05-14 13:30:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":254346,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9701884/v1/6f74322a-019b-49ee-9bec-b6422a7da9fa.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eFetomaternal Haemorrhage and Anti-D dosing in Rhesus Negative Mothers Delivering at Moi Teaching and Referral Hospital\u003c/strong\u003e\u003c/p\u003e","fulltext":[{"header":"Background","content":"\u003cp\u003eThe Rhesus blood group is an important human blood group system after the ABO system \u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. It consists of several antigens, namely D, C, c, and E with the D antigen being the most immunogenic \u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Rhesus refers to the presence of the D antigen on the surface of the red blood cell thus denoting one as Rhesus positive if present and Rhesus negative if absent\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u003c/sup\u003e. Being an antigen, the Rhesus factor can trigger an immune response with production of antibodies against it. This occurs when a Rhesus-negative individual is exposed to Rhesus-positive red blood cells\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eUnlike the ABO system, where isoimmune anti-A and anti-B antibodies are naturally occurring, Rhesus isoimmunization is a two-step process that involves sensitization followed by immunization. In sensitization, red cells carrying the Rhesus antigen sensitize immune competent cells to produce anti-D antibodies. The critical volume required for sensitization is about 0.1ml of blood.\u003c/p\u003e \u003cp\u003eFollowing subsequent exposure, immune cells produce specific anti-D antibodies more quickly and efficiently. The resultant effect is the destruction of the foetal Rhesus-positive cells by the maternal immune system via a type II hypersensitivity reaction. The antibodies produced remain throughout life.\u003c/p\u003e \u003cp\u003eEntry of foetal red cells into maternal circulation during pregnancy or delivery is known as fetomaternal haemorrhage\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. Potential obstetrical events that would result in fetomaternal haemorrhage include spontaneous or induced abortions, ectopic pregnancies, antepartum haemorrhage, external cephalic version, in utero interventions such as amniocentesis or cordocentesis, intrauterine foetal demise and abdominal trauma \u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIf fetomaternal haemorrhage occurs in a Rhesus-negative mother carrying a Rhesus-positive foetus, the mother is at risk of being sensitized against the D antigen. The mother\u0026rsquo;s immune system responds by producing antibodies against the D antigen present on the foetal red cells. The effect is seen in the subsequent D-positive pregnancies, whereby foetal red cells are destroyed resulting in hemolytic disease of the foetus and newborn with its spectrum of erythroblastosis foetalis, icterus gravis neonatorum and congenital anemia of the newborn.\u003c/p\u003e \u003cp\u003eThe accurate detection and quantification of foetal red blood cells in the maternal circulation are necessary for the prevention of Rhesus D isoimmunization among Rhesus D negative women. The anti-D immunoglobulin dose required by a patient is calculated based on the size of fetomaternal haemorrhage. Several quantification methods exist and the two well established tests are flow cytometry and Kleihauer Betke test. The Kleihauer Betke test is an acid elution blood test used to measure the amount of foetal haemoglobin within maternal circulation. It is the most widely used test as it is inexpensive and requires no specialist equipment. Flow cytometry on the other hand works by using monoclonal antibodies directed against haemoglobin F. It has greater precision and accuracy compared to the Kleihauer Betke test, but a longer turnaround time and is more expensive.\u003c/p\u003e \u003cp\u003eThe incidence of haemolytic disease of the foetus and newborn has been significantly reduced by the use of anti-D immunoglobulin prophylaxis from 13.2% to 0.2%. Assessing the amount of fetomaternal haemorrhage so as to give the right dose has further reduced the overall incidence to 0.14% \u003csup\u003e5\u003c/sup\u003e. This can further be reduced by strict compliance to guidelines concerning determination of fetomaternal haemorrhage and accordingly adjusting dosages of anti-D \u003csup\u003e6\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe current practice in the country is that an unsensitized Rhesus-negative mother who delivers a Rhesus-positive child is given a dose of 300\u0026micro;g of anti-D immunoglobulin. The amount of fetomaternal haemorrhage varies among patients thus the common practice of a 300ug dose could be an underdose or overdose depending on the amount of fetomaternal haemorrhage that has taken place. The origin of the dose of 300\u0026micro;g is from a study done more than fifty years ago in North America, with no clear indication as to why that particular dose was selected \u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eIn 1971, the World Health Organisation suggested a standard dose of 200\u0026ndash;300\u0026micro;g but stated that a 100\u0026micro;g dose was likely to have a success rate only slightly inferior to that of 200\u0026micro;g. Clinical experience in the United Kingdom has confirmed the efficacy of the 100\u0026micro;g dose, and this is the amount officially recommended for postpartum prophylaxis\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Similar studies done in Australia\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e and Ethiopia\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e have shown that most cases of fetomaternal haemorrhage can be neutralized by lower doses than the current standard of 300\u0026micro;g.\u003c/p\u003e \u003cp\u003eGoing by the unpublished Standard Operating Procedure (SOP) currently in use in MTRH, a Rhesus-negative unsensitized mother receives a dose of 300\u0026micro;g at 28 weeks and another 300\u0026micro;g after delivery of a Rhesus-positive baby. As of now, measurement of fetomaternal haemorrhage is not part of the SOP. It is assumed that the 300\u0026micro;g of anti-D immunoglobulin given will cover any amount of FMH that has taken place, despite the knowledge that the amounts vary based on patient and clinical factors \u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. No follow-up is done on these patients, and therefore, we have no reports of underdosing or overdosing. This study sought to quantify fetomaternal haemorrhage and calculate the required dose of postpartum anti-D immunoglobulin in Rhesus-negative mothers delivering at Moi Teaching and Referral Hospital.\u003c/p\u003e"},{"header":"Methodology","content":"\u003cp\u003eThis was a descriptive cross-sectional study conducted at the Riley Mother and Baby Hospital (RMBH) wing of the Moi Teaching and Referral Hospital (MTRH). The study enrolled 99 Rhesus-negative mothers delivering at RMBH of MTRH. The study participants were enrolled over six months using a consecutive sampling technique. The Rhesus-negative mothers who were admitted to the labour ward had the indirect Coombs test done as per hospital protocol to determine whether they were isoimmunised or not. Those who were not isoimmunised and met the inclusion criteria were approached after delivery by the investigators and informed about the nature and purpose of the study as well as its potential risks and benefits. Those who gave informed consent were then recruited into the study. The study participants were then interviewed and had 2 mL of venous blood taken for fetomaternal haemorrhage estimation within 2 \u0026minus;\u0026thinsp;12 hours after delivery. The socio-demographic, clinical, and obstetric characteristics of the study participants were collected using an interviewer-administered structured questionnaire. Medical records were reviewed and relevant clinical data was abstracted and entered into the structured questionnaire.\u003c/p\u003e \u003cp\u003eAt the laboratory, thin blood slides were made, air-dried and fixed with 80% ethanol. The citrate phosphate buffer (pH 3.3) used for elution was warmed to 37\u0026deg;C and the slides were immersed in it for 5 minutes. The slides were then thoroughly washed with distilled water and air-dried completely. Thereafter, staining was done for 3 minutes with acid haematoxylin solution, after which the slides were rinsed with distilled water and counterstained with 0.1% eosin B solution for 4 minutes. A dry coverslip was placed on each slide and examined using oil immersion at 400X magnification. The foetal cells were differentiated from the maternal cells based on the intensity and intracellular distribution of pink staining. Each field had an approximate of 200 cells, thus 10 fields were examined to give a total cell count of about 2000. The number of foetal cells per slide was then expressed as a percentage of the 2000 cells counted.\u003c/p\u003e \u003cp\u003eTo calculate the amount of foetal blood in the maternal circulation, the American Association of Blood Banks formula of 2008 was used:\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eFMH (ml) = (% of foetal cells by Kleihauer Betke/100) x 5000\u003c/h2\u003e \u003cp\u003eThe amount of anti-D immunoglobulin required to neutralize the foetal cells was then calculated taking into consideration that 10\u0026micro;g neutralizes 1ml of foetal whole blood (Crowther, 2010). The data was entered into an encrypted computer Microsoft Access Database which was later exported to R Core Team (2017), a language and environment for statistical computing, for analysis. Access to the data was restricted to the main investigator. Back-ups were made using encrypted memory disks to protect against loss of data.\u003c/p\u003e \u003cp\u003eCategorical variables such as education level, marital status, occupation, and the monthly income category among others were summarized using frequencies and the corresponding percentages. Continuous variables such as age, duration of pregnancy were summarized using mean and the corresponding standard deviation (SD). Other continuous variables such as fetomaternal haemorrhage, and amount of anti-D dose given were summarized using median and the corresponding interquartile range (IQR) (i.e lower and upper quartiles). Continuous variables were assessed for Gaussian assumptions using histograms and normal probability plots. If the Gaussian assumptions were holding the variable was summarized using mean and SD, if not, median and IQR were used to summarize them.\u003c/p\u003e \u003cp\u003eThe prevalence of Rhesus-negative mothers delivering at the Moi Teaching and Referral Hospital was computed as the number of Rhesus-negative mothers who delivered divided by the total number of deliveries during the study period. The corresponding 95% confidence intervals (95% CI) was reported.\u003c/p\u003e \u003cp\u003eThe association between categorical independent variables with the occurrence of fetomaternal haemorrhage was assessed using Pearson\u0026rsquo;s Chi-Square test. Fisher\u0026rsquo;s exact test was used whenever the chi-square assumptions were violated. Continuous variables were compared between the participants who experienced fetomaternal haemorrhage and those who did not experience fetomaternal haemorrhage using an independent samples t-test if the Gaussian assumptions were held. Ethical clearance to conduct this study was obtained from the Institutional Research and Ethics Committee of Moi University School of Medicine and MTRH. Permission to conduct the research was granted by the hospital management. Written informed consent was obtained from each study participant before enrolment into the study. Participants\u0026rsquo; privacy and confidentiality were ensured by consenting and interviewing participants in private, storing questionnaires and lab results in a locked cabinet and databases protected with passwords.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eA total of 4552 mothers delivered at the Moi Teaching and Referral Hospital during the months of April 2017\u0026ndash; September 2017. Of the 4552, 143 were Rhesus negative thus giving a prevalence of 3.1% (95% CI: 2.7, 3.7). Of the 143 Rhesus-negative parturient women, 99 met the eligibility criteria and were included in the current study. The mean (SD) age was 26.4 (\u0026plusmn;\u0026thinsp;5.4) years with a range of 18\u0026ndash;42 years (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eSocio-demographic characteristics of the participants\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMean (SD) or n (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (Years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e26.4 (5.4)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRange (Min. \u0026ndash; Max.)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e18.0\u0026ndash;42.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMarital status\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSingle\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e21 (21.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMarried\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e77 (77.8%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDivorced\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1 (1.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEducation level\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePrimary\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e22 (22.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSecondary\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e53 (53.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCollege\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e24 (24.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOccupation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUnemployed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e55 (55.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSelf-employed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e33 (33.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEmployed\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e11 (11.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMonthly Household income (Kenya Shillings)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;10,000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e69 (69.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;10,000\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e30 (30.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe average duration of the pregnancy was 39 weeks (SD: 1.9) days with a minimum and maximum of 33.7 and 43 weeks, respectively. The mothers had carried an average of 2.1 (\u0026plusmn;\u0026thinsp;1.1) pregnancies to viability. The least number of pregnancies carried was 1 and the most was 7.\u003c/p\u003e \u003cp\u003eData on blood group was captured, and the findings show that the most prevalent blood group was O negative at 49.5% and the least prevalent was AB negative at 2.0%. One fifth (22.2%) of the mothers had received routine antenatal anti-D prophylaxis at 28 weeks of gestation. None of the study participants reported a history of blunt abdominal trauma or abnormal per vagina bleeding during their pregnancy (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eObstetric characteristics of study participants\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariable\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMean (SD) or n (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGestation at delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39 (1.9)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRange (Min. \u0026ndash; Max.)(weeks)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e33\u0026ndash;43\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGravidity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.1 (1.1)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRange (Min. \u0026ndash; Max.)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1.0\u0026ndash;7.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOne\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34 (34.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTwo\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31 (31.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThree\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24 (24.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFour or more\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10 (10.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlood Group\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e26 (26.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22 (22.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAB-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (2.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e49 (49.5%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReceived anti-D at the 28th week of pregnancy\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22 (22.2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHad elevated blood pressure\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5 (5.1%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSeverity of the blood pressure\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMild\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3 (60.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSevere\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (40.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMode of delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAssisted vaginal delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (1.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCaesarean delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e31 (31.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpontaneous vaginal delivery\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e67 (67.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHad the placenta removed manually\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4 (4.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePregnancy outcome\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFresh stillbirth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1 (1.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSingle live birth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e99\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e96 (97.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTwins live birth\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 (2.0%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eMost of the study participants (64/99) did not have demonstrable FMH. Those that had FMH identified by the KHB test were 35.4% (35/99). The median FMH among the 35 mothers was 5.0 (IQR: 2.5, 10.0) ml with a range of 2.5-20mls. Fetomaternal haemorrhage of less than 10ml was seen in 68.6% (24/35). The remaining 11 had FMH ranging between 10ml-20ml (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDistribution of FMH\u0026thinsp;\u0026ge;\u0026thinsp;10ml among study participants\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSize of FMH\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNo. of participants (n\u0026thinsp;=\u0026thinsp;11)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10.0ml\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12.5ml\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15.0ml\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17.5ml\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e20.0ml\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eLarge FMH, defined as that above 15ml, was only noted in 3 study participants. The largest size of FMH was 20ml of foetal whole blood. This was seen in a 29-year-old study participant who had undergone an emergency caesarian section, at term, for prolonged labour. The outcome in this case was a single live infant with a good APGAR score. Excessive FMH, defined as that exceeding 30ml, was not detected in any of the study participants.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe amount of anti-D immunoglobulin that would have been required by the study participants was calculated taking into consideration that 10\u0026micro;g of anti-D immunoglobulin is required for every 1ml of foetal whole blood. The calculated amount of anti-D that would have been required against the size of FMH (Fig.\u0026nbsp;4). The median corresponding anti-D immunoglobulin dose that ought to have been administered to those who had FMH was 50.0 (IQR: 25.0, 100.0) \u0026micro;g with a minimum and a maximum of 25.0 and 200.0 ᶙg respectively.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe prevalence of Rhesus-negative mothers delivering in our maternity unit was found to be 3.1%. This finding is consistent with a study among pregnant women attending the Aga Khan University Hospital in Nairobi at 3% \u003csup\u003e12\u003c/sup\u003e. Similar findings have also been demonstrated in Uganda in which the prevalence was found to be 3.8% \u003csup\u003e13\u003c/sup\u003e and in Nigeria where the prevalence was 4.5% \u003csup\u003e14\u003c/sup\u003e. The similarities in the prevalence could be because these studies were done in similar geographical regions in which majority of the population are of the same race.\u003c/p\u003e \u003cp\u003eDifferent findings were reported by Szczepura in the United Kingdom and Haas in the Netherlands, in which the prevalence was 10% and 15% respectively. Rhesus negativity tends to have a racial predilection in its distribution such that it is higher in Caucasian populations and lower in other ethnic groups \u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e,\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. Entry of foetal blood into the maternal circulation occurs in approximately 75% of pregnancies but is only a concern if the size is large enough to cause foetal hemodynamic compromise or in instances of Rhesus incompatibility between the mother and foetus. Fetomaternal haemorrhage sufficient to cause isoimmunization occurs most commonly at birth in 15\u0026ndash;50% of pregnancies \u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. Fetomaternal haemorrhage in this study was detected in 35.4% of the study participants. This finding is in line with one conducted in Kenya, which reported a 35.9% prevalence of fetomaternal haemorrhage.\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e This could be attributed to the similarity in the demographic regions in which the studies were conducted. However, a study in India demonstrated FMH in 92%\u003csup\u003e18\u003c/sup\u003e while in Ethiopia, it was estimated at 52%.\u003csup\u003e10\u003c/sup\u003e The variations could be due to different clinical factors that have a bearing on the occurrence of FMH, such as mode of delivery, the use of fundal pressure as reported in the Indian study, surgical technique and mode of placental delivery.\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e,\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eIn this study, 89.9% of the 99 Rhesus-negative patients in whom FMH was tested had a FMH of less than 10ml, which is similar to the findings estimated at 92.5%\u003csup\u003e10\u003c/sup\u003e and 94.1%.\u003csup\u003e19\u003c/sup\u003e Excessive FMH (exceeding 30ml) was not detected in this study as was the case in a study conducted in India.\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e Supporting this low occurrence is a study in Ethiopia that showed excessive FMH in only 1.3%.\u003csup\u003e10\u003c/sup\u003e The occurrence of excessive FMH is considered rare, complicating about 0.7% of normal deliveries.\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e The similarities in the size of FMH have been observed despite differences in sample size and study types. This shows that majority of patients across different populations that have FMH have a minimal size of FMH.\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eThe age difference between those who experienced FMH and those who did not was noted to be statistically significant, mean age: 29.0 (SD: 6.4) years vs. 25.1 (SD: 4.2) years, \u003cem\u003ep\u003c/em\u003e-value\u0026thinsp;=\u0026thinsp;0.002. While many studies on factors affecting FMH exist, their individual conclusions are contradictory. In line with this study in India, which established that as the maternal age increases, the risk of demonstrable FMH also increases.\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e However, other studies\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e,\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e demonstrated that maternal age does not affect the incidence of fetomaternal haemorrhage.\u003c/p\u003e \u003cp\u003eAll patients who had manual removal of placenta (4/99) had FMH. However, the numbers were too few to do a further analysis on. This is similar to a previous study\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e which reported that patients who had manual removal of placenta were more likely to have FMH. Manual removal of placenta is a known risk factor for the occurrence of fetomaternal haemorrhage with a plausible explanation being that tearing of the placental villi during extraction favors entry of foetal cells into the maternal circulation.\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e When comparing the mode of delivery, there were no significant differences in the mode of delivery between those who had FMH and those who did not. A study in Nigeria similarly found that the mode of delivery did not have a significant effect on the occurrence of FMH.\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e Anti-D dosing is ideally based on fetomaternal haemorrhage, taking into consideration that 10\u0026micro;g would neutralize 1ml of foetal whole blood or 0.5ml of packed foetal red cells.\u003csup\u003e25\u003c/sup\u003e A systematic review by Cochrane established that evidence on the optimal amount of anti-D for postpartum prophylaxis is limited.\u003csup\u003e25\u003c/sup\u003e The recommendations on the ideal dose vary in different countries and is usually guided by their respective professional associations. In Kenya, the guidelines recommend administration of a standard dose of 300\u0026micro;g, which is similar to guidelines in the United States of America.\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e FMH was demonstrated in only 35.4% (35) of the 99 sampled Rhesus-negative mothers. Of the 35 mothers, only 11 had FMH of 10ml and above. Taking this into consideration, individual doses of 100\u0026micro;g of anti-D would have been sufficient for prophylaxis in majority of the 35 mothers who had FMH. If we include those who did not have any detectable FMH, it means that individual doses of 100\u0026micro;g of anti-D would have been sufficient for prophylaxis in 89.9% of all the study participants.\u003c/p\u003e"},{"header":"Conclusions and recommendations","content":"\u003cp\u003eWe report a low prevalence of Rhesus-negative mothers delivering at a national referral hospital in Western Kenya, which is congruent to those reported in the greater sub-Saharan region. However, fetomaternal haemorrhage was undetectable among most of this study\u0026rsquo;s participants. The majority of the cases of FMH could have been neutralized using 100\u0026micro;g of Anti-D. There is need for quantification of FMH and individualized dosing of anti-D immunoglobulin in unsensitized Rhesus-negative mothers after delivery is recommended.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eAhmed M, Abdullatif M (2011) Fetomaternal Transfusion as a Cause Of Severe Foetal Anemia Causing Early Neonatal Death: A Case Report. Oman Med J 26:444\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOsaro E, Charles AT (2010) Rh isoimmunization in Sub-Saharan Africa indicates need for universal access to anti-RhD immunoglobulin and effective management of D-negative pregnancies. Int J Womens Health 2:429\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim YA, Makar RS (2012) Detection of fetomaternal haemorrhage. Am J Hematol 87:417\u0026ndash;423\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoelewijn JM, De Haas M, Vrijkotte TGM, Van Der Schoot CE, Bonsel G (2009) J. Risk factors for RhD immunisation despite antenatal and postnatal anti-D prophylaxis. BJOG 116:1307\u0026ndash;1314\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePollack W et al (1968) Results of clinical trials of RhoGAM in women. Transfus (Paris) 8:151\u0026ndash;153\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQureshi H et al (2014) BCSH guideline for the use of anti-D immunoglobulin for the prevention of haemolytic disease of the foetus and newborn. Transfus Med 24:8\u0026ndash;20\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAugustson BM, Fong EA, Grey DE, Davies JI, Erber WN (2006) Postpartum anti-D: can we safely reduce the dose? Med J Aust 184:611\u0026ndash;613\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUrgessa F, Tsegaye A, Gebrehiwot Y, Birhanu A (2014) Assessment of feto-maternal haemorrhage among rhesus D negative pregnant mothers using the kleihauer-betke test (KBT) and flow cytometry (FCM) in Addis Ababa, Ethiopia. BMC Pregnancy Childbirth 14\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSebring ES, Polesky HF (1990) Fetomaternal haemorrhage: incidence, risk factors, time of occurrence, and clinical effects. Transfus (Paris) 30:344\u0026ndash;357\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMwangi J (1999) Blood group distribution in an urban population of patient targeted blood donors. East Afr Med J 76:615\u0026ndash;618\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMbalibulha Y, Muwanguzi E, Mugyenyi G (2018) Rhesus blood group haplotype frequencies among blood donors in southwestern Uganda. J Blood Med 9:91\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOkeke TC, Ocheni S, Nwagha UI, Ibegbulam OG (2012) The prevalence of Rhesus negativity among pregnant women in Enugu, Southeast Nigeria. Niger J Clin Pract 15:400\u0026ndash;402\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFreeman K, Szczepura A, Osipenko L (2009) Non-invasive foetal RHD genotyping tests: A systematic review of the quality of reporting of diagnostic accuracy in published studies. Eur J Obstet Gynecol Reproductive Biology 142:91\u0026ndash;98\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSzczepura A, Osipenko L, Freeman K (2011) A new foetal RHD genotyping test: Costs and benefits of mass testing to target antenatal anti-D prophylaxis in England and Wales. BMC Pregnancy Childbirth 11:5\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eACOG Practice Bulletin 192 (2025) Management of Alloimmunization During Pregnancy: Correction. Obstet Gynecol 146:925\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOtieno JA, Kosgei RJ, Barasa CW, Ogutu O, Mukii RB (2025) Burden of Rhesus isoimmunization and pregnancy outcomes: a cross-sectional study conducted at Kenyatta National Hospital, Kenya. Pan Afr Med J 52:163\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSavithrisowmya S et al (2008) Assessment of fetomaternal haemorrhage by flow cytometry and Kleihauer-Betke test in Rh-negative pregnancies. Gynecol Obstet Invest 65:84\u0026ndash;88\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRisk factors for foetal-to-maternal transfusion in\u0026hellip; Journal of Perinatal Medicine \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ovid.com/journals/jperm/abstract/00005199-200432030-00010~risk-factors-for-foetal-to-maternal-transfusion-in-rh\u003c/span\u003e\u003cspan address=\"https://www.ovid.com/journals/jperm/abstract/00005199-200432030-00010~risk-factors-for-foetal-to-maternal-transfusion-in-rh\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnjili K, Anita K (2017) Study of Feto-Maternal Haemorrhage in Later Part of Pregnancy With Special Reference to Rh Negative Mothers\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGreer J (2013) \u0026amp; Wintrobe\u0026rsquo;s Clinical Hematology - Google Boeken. Wintrobe\u0026rsquo;s Clin Hematol 2312\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStudničkov\u0026aacute; M et al (2012) [The influence of maternal age, parity, gestational age and birth weight on fetomaternal haemorrhage during spontaneous delivery]. Ceska Gynekol 77:256\u0026ndash;261\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStroustrup A, Plafkin C, Tran TA, Savitz DA (2016) Demographic and Behavioral Predictors of Severe Fetomaternal Haemorrhage: A Case-Control Study. Neonatology 109:248\u0026ndash;254\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAjayi AI, Nwokocha EE, Akpan W, Adeniyi OV (2016) Use of non-emergency contraceptive pills and concoctions as emergency contraception among Nigerian University students: results of a qualitative study. BMC Public Health 16:1046\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnti-D administration after childbirth for preventing Rhesus alloimmunisation - Crowther, CA\u0026thinsp;\u0026ndash;\u0026thinsp;1997 | Cochrane Library. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000021/full\u003c/span\u003e\u003cspan address=\"https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000021/full\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Moi University","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Fetomaternal Haemorrhage, Rhesus Negative Mothers, MTRH","lastPublishedDoi":"10.21203/rs.3.rs-9701884/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9701884/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eFetomaternal haemorrhage (FMH) is the entry of foetal blood into the maternal circulation during pregnancy or delivery. If this occurs in a Rhesus-negative woman carrying a Rhesus-positive foetus, there is a risk of the mother being sensitized against the D antigen. The effect is seen in the subsequent Rhesus positive pregnancies, which may result in haemolytic disease of the foetus and newborn (HDFN). To prevent this sensitization, anti-D immunoglobulin is usually given. The dose given varies depending on the amount of FMH and the protocols adopted by different professional authorities.\u003c/p\u003e\u003ch2\u003eObjectives\u003c/h2\u003e \u003cp\u003eTo quantify the size of Fetomaternal Haemorrhage and determine the average calculated dose of anti-D immunoglobulin required for postpartum prophylaxis in Rhesus-negative mothers delivering at Moi Teaching and Referral Hospital (MTRH), Eldoret, Kenya.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis was a cross-sectional study among Rhesus-negative postpartum women enrolled within 2\u0026ndash;12 hours after delivery. The sample size of 99 was determined using the Kleihauer-Betke test. Participants were sampled consecutively, while data was collected using an interviewer-administered questionnaire, a clinical records review, and blood sample collections. The association between categorical independent variables and the occurrence of fetomaternal haemorrhage was assessed using Pearson\u0026rsquo;s Chi-Square test. Fisher\u0026rsquo;s exact test was used whenever the chi-square assumptions were violated.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eOut of 4,552 deliveries over the study period, 143 (3.1%) were Rhesus negative. Of the 143 women, 99 met the eligibility criteria and were enrolled. The mean age and gestational age at delivery were 26.4 (\u0026plusmn;\u0026thinsp;5.4) years and 39 weeks, respectively. Fetomaternal haemorrhage (range: 2.5-20ml) was detected in 35 (35.4%) of the women, 24 (68.6%) of whom had FMH of less than 10ml. The use of 100\u0026micro;g of anti-D immunoglobulin would have been sufficient for 89.9% (89/99) of the Rhesus-negative mothers in whom quantification of FMH was done.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eThe prevalence of Rhesus negativity among deliveries in MTRH was 3.1%. FMH of less than 10ml occurred in 89.9% of study participants, thus indicating that the majority of the cases of FMH could have been neutralized by 100\u0026micro;g of anti-D immunoglobulin.\u003c/p\u003e","manuscriptTitle":"Fetomaternal Haemorrhage and Anti-D dosing in Rhesus Negative Mothers Delivering at Moi Teaching and Referral Hospital","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-14 13:30:11","doi":"10.21203/rs.3.rs-9701884/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"1e0d4811-e271-405b-8055-ed629e6d50ae","owner":[],"postedDate":"May 14th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":68089116,"name":"Sexual \u0026 Reproductive Medicine"}],"tags":[],"updatedAt":"2026-05-14T13:30:11+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-14 13:30:11","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9701884","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9701884","identity":"rs-9701884","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}