Intra-abdominal hemorrhage following ultrasound-guided transvaginal oocyte retrieval: Retrospective analysis of 25 cases.

Lin Chen: Investigation, Data curation. Huanxiao Zhang: Data curation. Yanwen Xu: Writing – review & editing. Zengyan Wang: Supervision, Investigation, Conceptualization.

Patients with ultrasound-confirmed IAH requiring hospitalization within 7 days of OPU at Sun Yat-sen University First Affiliated Hospital (2010–2021) were included. Exclusion criteria: incomplete records or outpatient management. Cases were identified via keyword searches of hospital records, supplemented by manual chart reviews to ensure completeness ( Figure 1 ). Figure 1 The study flowchart Figure 1 Chen. Intra-abdominal hemorrhage following ultrasound-guided transvaginal oocyte retrieval: Retrospective analysis of 25 cases. AJOG Glob Rep 2025. The study flowchart The study received approval from the institutional ethical board of the First Affiliated Hospital of Sun Yat - sen University in 2022. The approval number is [2022]051. Given the retrospective nature of the study, the requirement for obtaining informed consent was waived. Clinical data, including demographics, symptoms, laboratory parameters (hemoglobin [Hb], hematocrit [Hct]), imaging findings, treatment modalities, and reproductive outcomes, were extracted from medical records. Postoperative monitoring protocols at the center include 2 hours of bed rest and ultrasound screening for abdominal symptoms before discharge, with inpatient referral for unstable cases. Normally distributed data are presented as mean±SD and compared via Student’s t-test; non-normally distributed data as median (IQR) with Mann-Whitney U-test. The categorical data were analyzed using the Chi-square test. Due to the small sample size (n=25), multivariate analysis was not performed, and univariate comparisons between conservative and surgical groups are reported.

Among 50,351 OPUs, 25 cases of IAH occurred (0.05%, 95% CI, 0.03%–0.07%). Patient characteristics included mean age 31.56±4.18 years, body mass index 19.63±2.65 kg/m², and a history of prior pelvic surgery (44%) or OPU (44%) in 60% (15/25) of cases. Mean oocyte yield was 12.92±8.70, with a median estradiol level of 1,766 (IQR: 1,058–3,828) pg/mL on human chorionic gonadotropin administration day ( Table 1 ). Table 1 Basic information of patients underwent intra-abdominal hemorrhage following OPU Table 1 No Age, year BMI, kg/m 2 PCOS Previous pelvic surgeries No. of previous OPU procedures E2, pg/mL No. of oocytes 1 32 20.94 No Yes 0 1,645 2 2 29 18.44 No Yes 0 1,522 17 3 25 19.70 Yes Yes 0 >5,000 25 4 34 17.10 No No 0 985 10 5 29 20.00 No No 0 2,411 6 6 32 17.00 No No 0 >5,000 20 7 34 19.14 No Yes 0 NA 13 8 35 19.00 No Yes 1 976 3 9 28 20.03 No No 0 2,869 14 10 26 16.65 No No 1 3,929 24 11 32 19.72 No No 0 >5,000 29 12 29 25.39 No Yes 0 535 2 13 27 20.20 No No 0 3,111 22 14 37 20.31 No No 5 1,733 11 15 38 14.02 No No 1 881 5 16 31 24.41 No No 0 2,553 18 17 31 18.80 No No 0 1,100 9 18 25 18.00 No No 0 3,828 12 19 36 18.20 No No 1 1,766 12 20 31 25.20 Yes No 4 >5,000 33 21 35 18.80 No Yes 1 1,711 11 22 42 21.20 No Yes 3 1,058 5 23 28 16.40 No Yes 3 3,217 9 24 32 18.36 No Yes 1 NA 10 25 31 21.00 No Yes 4 277 1 In total 31.56±4.18 19.5±2.64 2/25 11/25 11/25 1,766 (1,058, 3,828) 12.92±8.70 PCOS, polycystic ovary syndrome; Case No. 13 was diagnosed as bilateral ovarian endometriosis; Case No. 25 was a special patient and specific information was described separately. Chen. Intra-abdominal hemorrhage following ultrasound-guided transvaginal oocyte retrieval: Retrospective analysis of 25 cases. AJOG Glob Rep 2025. Basic information of patients underwent intra-abdominal hemorrhage following OPU PCOS, polycystic ovary syndrome; Case No. 13 was diagnosed as bilateral ovarian endometriosis; Case No. 25 was a special patient and specific information was described separately. The most frequently observed symptoms of IAH were abdominal distension and pain (present in 22 out of 25 patients), dizziness and/or syncope (16/25), nausea (12/25), vomiting (15/25), tenesmus (9/25), and weakness (4/25). The onset of these symptoms varied, ranging from immediately after oocyte pick-up (OPU) to 4 days later, with a median onset time of 1.25 (0, 6.25) hours. Notably, nearly half of the patients [48% (12/25)] showed distinct symptoms within the first hour after OPU, and 92% (23/25) experienced symptoms within 12 hours ( Table 2 ). Table 2 Clinical characteristics of patients Table 2 No Onset Time (h)* Symptoms Ultrasonic findings FBC before OPU FBC after OPU ΔHb (mg/dL) ΔHct (%) Treatment Admission (days) Reproductive outcomes Hb (mg/dL) Hct (%) Hb (mg/dL) Hct (%) 1 0 Progressive lower abdominal pain, dizziness, and tenesmus Pelvic hematoma and effusion 130 37.60 96 27.30 34 10.30 Laparoscopy 5 Not pregnancy in FET cycle 2 6 Lower abdominal distension and pain, apparent tenesmus Pelvic hematoma and effusion 127 37.30 102 29.50 25 7.80 Laparoscopy 4 Not pregnant in FET cycle, 1 embryo remained 3 0 Abdominal distension and pain, tenesmus, nausea and vomiting, dizziness and apsychia, progressive abdominal. Pelvic effusion 144 42.40 100 30.00 44 12.40 Laparotomy 6 Get live birth (twins) in a FET cycle 4 0 Intense abdominal pain, relieved after rest, abdominal distension, dizziness and weakness NA 124 38.30 89 25.90 35 12.40 Laparoscopy 6 Not pregnant in FET cycle, get live birth in another IVF cycle 5 13 Lower abdominal distension and pain, followed by dizziness, cold sweat, and tenesmus NA 129 38.90 83 27.40 46 11.50 Laparotomy 5 Not pregnant in FET cycle 6 3 Dizziness, nausea and vomiting Pelvic effusion 144 41.70 115 33.40 29 8.30 Laparotomy 7 Get single live birth in a FET cycle 7 3.5 Dizziness (progressive hemoglobin reduction that required surgical interventions) Ovarian hematoma 124 35.80 79 25.10 45 10.70 Laparoscopy 9 Get single live birth in a FET cycle 8 0 Progressive abdominal pain. Tenesmus, dizziness, sweating, repeated nausea and vomiting, Pelvic effusion 139 37.80 99* NA 40 NA Laparotomy 8 Oocytes unfertilized 9 0 Persistent lower abdominal pain, nausea and 10 vomiting Bilateral ovarian enlargement, pelvic effusion 121 37.80 106 32.70 15 5.10 Conservative 2 Get single live birth in a FET cycle 10 7 Abdominal pain, chest distress, nausea and vomiting Massive pelvic effusion 129 38.70 100 29.70 29 9.00 Conservative 7 Get single live birth in a FET cycle 11 7 Progressive lower abdominal pain and dizziness Peri-ovary hematoma and pelvic effusion 121 37.80 96 29.90 25 7.90 Conservative 4 Not pregnant in FET cycle, 2 embryos remained cryopreserved 12 0 Persistent lower abdominal pain, nausea, dizziness and weakness Bilateral ovarian enlargement 122 37.80 95 28.80 27 9.00 Conservative 4 Get live birth (twins) in a FET cycle 13 6.5 Abrupt lower abdominal pain Pelvic hematoma and effusion 137 40.20 136 39.20 1 1.00 Conservative 3 Get single live birth in a FET cycle 14 8 Persistent and unbearable abdominal distension and pain, apsychia Pelvic effusion 114 34.80 93 27.90 21 6.90 Conservative 4 1 embryo still remained cryopreserved 15 0 Abdominal pain, tenesmus, nausea and vomiting, apsychia Pelvic effusion 129 # 39.30 101 32.60 28 6.70 Conservative 3 Get single live birth in a FET cycle 16 0 Mild abdominal pain, chest distress and vomiting Pelvic effusion 139 # 41.80 137 40.90 2 0.90 Conservative 1 Get single live birth in a FET cycle 17 1.5 Intermittent and progressive lower abdominal pain, tenesmus, chest distress and apsychia Pelvic hematoma and effusion 128 38.90 96 30.00 32 8.90 Conservative 4 Get single live birth in a FET cycle 18 0 Lower abdominal pain, dizziness and weakness, nausea and vomiting Pelvic hematoma and effusion 140 # 43 108 32.80 32 10.20 Conservative 2 Get single live birth in a FET cycle 19 1 Lower left abdominal pain, dizziness and weakness, nausea and vomiting, tenesmus Pelvic hematoma and effusion 132 39.60 109 31.70 23 7.90 Conservative 8 Not pregnant in FET cycle 20 0 Progressive abdominal pain with vomiting, dizziness, nausea Pelvic effusion 132 41.30 126 38.50 6 2.80 Conservative 1 Not pregnant in FET cycle 21 1 Persistent lower pain, tenesmus, dizziness, progressive abdominal pain with vomiting Pelvic effusion 110 34.40 89 29.00 21 5.40 Conservative 5 All embryos still remained cryopreserved 22 4 Progressive lower abdominal distension and pain, dizziness, nausea and vomiting Pelvic hematoma 115 35.80 111 33.50 4 2.30 Conservative 5 Not pregnant 23 3 Abrupt and persistent lower abdominal pain and vomiting, progressive abdominal pain with vomiting Ovarian hematoma and pelvic effusion 133 42 90 27.60 43 14.40 Conservative 11 Get single live birth in a FET cycle 24 3.5 Dizziness and nausea Ovarian hematoma and pelvic effusion 128 39.60 99 34.30 29 5.30 Conservative 7 Not pregnant in FET cycle 25 4 days Fever, lower abdominal pain, repeated dizziness, and vomiting Mixed echo mass in adnexal area 119 34.20 97* 29.80* 22 4.40 Conservative 27 Oocytes unfertilized In total 1.50 (0, 6.25) / / / / / / 25.96±13.32 7.56±3.64 / 5 (3, 7) Live birth rate :52% (13/25) # Pre-OPU full blood count was performed on the day of HCG administration except case No. 15, 16 and 18; *post-OPU full blood count was performed within 24 hours after OPU except case 8 and case 25; case No. 25 had delayed onset of symptoms and was described separately. Chen. Intra-abdominal hemorrhage following ultrasound-guided transvaginal oocyte retrieval: Retrospective analysis of 25 cases. AJOG Glob Rep 2025. Clinical characteristics of patients Pre-OPU full blood count was performed on the day of HCG administration except case No. 15, 16 and 18; *post-OPU full blood count was performed within 24 hours after OPU except case 8 and case 25; case No. 25 had delayed onset of symptoms and was described separately. A particularly notable case was patient No. 25. There was a 4-day interval between her OPU procedure and the manifestation of IAH symptoms. Five years prior, she had undergone laparoscopic ovarian endometriosis cystectomy and developed pelvic inflammatory disease (PID) before starting in vitro fertilization (IVF) treatment. Additionally, she had previously undergone 3 uncomplicated OPU procedures. During the index OPU, one oocyte was retrieved, and approximately 40 mL of thick brown liquid was aspirated from her right ovary. Four days after the OPU, the patient presented with a constellation of symptoms, including fever, lower abdominal pain, recurrent dizziness, and vomiting. Her pre-OPU hemoglobin (Hb) level was 119 g/L. Although ultrasound revealed a heterogeneous adnexal mass measuring 5×5 cm, the 4-day delay in symptom onset, the presence of fever, and the significant decline in Hb level to 97 g/L strongly suggested IAH complicated by pelvic infection. This was in accordance with the European Society of Human Reproduction and Embryology (ESHRE) criteria for hemoperitoneum, which defines significant hemorrhage as a ΔHb >2 g/L. The patient was diagnosed with post-OPU IAH and pelvic infection. She was promptly initiated on treatment for anemia and received empirical antibiotic therapy, which was subsequently adjusted according to the results of blood culture and drug sensitivity tests. Notably, the patient did not require any blood transfusions. It took 27 days for her to fully recover and be discharged from the hospital. Unfortunately, the retrieved oocyte failed to fertilize, and the couple elected to discontinue their IVF treatment. Pelvic adhesion serves as a significant risk factor for OPU IAH. Potential pelvic adhesions were defined as history of laparoscopy/laparotomy (11 cases), prior OPU (11 cases), or endometriosis (1 case). Intraoperative confirmation of adhesions was obtained in 5/8 surgical patients. Overall, a substantial 68% (17 out of 25) of the patients were found to have potential pelvic adhesions, as detailed in Table 3 . Table 3 Intraoperative findings and surgical interventions Table 3 No Treatment Intervals between OPU and surgery,( h) Pelvic hemorrhage, (mL) Hemostasis method Blood transfusion 1 Laparoscopy 17 1,500 Electrocoagulation None 2 Laparotomy 16.5 1,200 Suture and electrocoagulation FP: 2 units 3 Laparoscopy 24 2,000 Suture pRBC: 4 units; FP: 4 units 4 Laparotomy 65 1,000 Suture and electrocoagulation None 5 Laparotomy 21 2,000 Suture pRBC: 4 units 6 Laparoscopy 34.5 1,000 Electrocoagulation after failed suture None 7 Laparotomy 50 1,300 Suture pRBC: 2 units 8 Laparotomy 11 2,500 Suture Platelet: 4 units pRBC: 4units FP: 4 units - 29.88±18.80 1,563±548 - - pRBC, packed red blood cell; FP, fresh plasma. Five patients were diagnosed with abdominal adhesions before OPU, which was verified during operations. Chen. Intra-abdominal hemorrhage following ultrasound-guided transvaginal oocyte retrieval: Retrospective analysis of 25 cases. AJOG Glob Rep 2025. Intraoperative findings and surgical interventions pRBC, packed red blood cell; FP, fresh plasma. Five patients were diagnosed with abdominal adhesions before OPU, which was verified during operations. A routine ultrasonic scan was conducted on all patients except 2 who presented with acute blood loss symptoms and thus underwent emergency surgery. In addition to ovaries enlarged as a result of ovarian stimulation, pelvic hematoma and/or effusion were detected in nearly every patient ( Figure 2 ). When comparing the hemoglobin (Hb) concentration within 24 hours post - OPU, before any treatment, to the pre - OPU baseline, the decrease was 25.96±13.32 g/L. Notably, the change (ΔHb) was significantly more pronounced in patients who received surgical treatment compared to those managed conservatively (including rest and the use of hemostatic drugs), with values of 37.25±7.78 g/L and 20.65±12.07 g/L respectively ( P <.01) ( Table 4 ). Furthermore, 21 patients showed a progressive decrease in Hb concentration after hospital admission. The overall decline in hematocrit (ΔHct) was 7.56±3.64%, and this decline was significantly greater in patients who underwent surgery than in those receiving conservative treatment (10.49%±1.85% vs. 6.36%±3.54%, P <.01) ( Table 4 ). Additionally, all patients had coagulation tests either before and/or after OPU. With the exception of a few tests showing mildly shortened activated partial thromboplastin time (APTT) and/or prothrombin time (PT), no obvious abnormalities were observed. Figure 2 Ultrasonic profiles of intra-abdominal hemorrhage following OPU OV, ovary (enlarged); UT , uterine; *: intra-abdominal hematoma. Figure 2 Chen. Intra-abdominal hemorrhage following ultrasound-guided transvaginal oocyte retrieval: Retrospective analysis of 25 cases. AJOG Glob Rep 2025. Table 4 Comparison of surgical vs. conservative management Table 4 Treatments Cases (%) Symptom onset (days) ΔHb (ng/mL) ΔHct (%) Admission (days) Pregnancy rate (%) Laparoscopy 32 (8/25) 3.19±1.609 37.25±7.78 10.49±1.85 6.25±0.590 50(4/8) Conservative 68 (17/25) 2.9±0.703 20.65±12.07 6.36±3.54 5.76±1.472 52.94(9/17) P values - .765 .002 .008 .828 .891 Chen. Intra-abdominal hemorrhage following ultrasound-guided transvaginal oocyte retrieval: Retrospective analysis of 25 cases. AJOG Glob Rep 2025. Ultrasonic profiles of intra-abdominal hemorrhage following OPU OV, ovary (enlarged); UT , uterine; *: intra-abdominal hematoma. Comparison of surgical vs. conservative management Surgical intervention was considered for patients with progressive hemoglobin reduction (>3 mg/dL), hemodynamic instability, or ultrasound evidence of ongoing bleeding. Conservative management was preferred for stable patients with mild symptoms ( Table 4 ). Treatment decisions were based on ultrasound evidence of hematoma/effusion progression, serial hemoglobin decline (>20 mg/dL within 24 hours), and clinical deterioration (e.g., hypotension, unrelenting pain). Conservative treatment included bed rest, intravenous hemostatic agents (e.g., reptilase 0.5 KU daily), bed rest, fluid resuscitation, and serial monitoring of Hb/Hct and ultrasound findings. Seventeen patients were managed conservatively, and none of them required blood transfusions. The remaining 8 patients, who had severe hemorrhage, needed laparoscopy or laparotomy to achieve prompt hemostasis. The time intervals between OPU and surgery ranged from 11 to 65 hours, with an average of 29.88±18.80 hours ( Table 3 ). The most frequently observed intraoperative findings were pelvic adhesions, lacerations, and/or active ovarian hemorrhage ( Figure 3 ). Figure 3 Intraoperative findings of intra-abdominal hemorrhage following OPU procedure UT , uterine; LOV , enlarged left ovary due to controlled ovarian stimulation, *: peri-ovary clotting. (A) A full view of the pelvis with clotting and hemorrhage remained. (B) Laceration on the lower polar of the left ovary. (C and D) Laceration on the lateral surface of the left ovary before and after suture. Figure 3 Chen. Intra-abdominal hemorrhage following ultrasound-guided transvaginal oocyte retrieval: Retrospective analysis of 25 cases. AJOG Glob Rep 2025. Intraoperative findings of intra-abdominal hemorrhage following OPU procedure UT , uterine; LOV , enlarged left ovary due to controlled ovarian stimulation, *: peri-ovary clotting. (A) A full view of the pelvis with clotting and hemorrhage remained. (B) Laceration on the lower polar of the left ovary. (C and D) Laceration on the lateral surface of the left ovary before and after suture. The assessment of hemorrhage volume was based on the examination and evaluation of blood accumulation in the abdominal cavity during laparoscopic surgery. On average, 1,563±548 mL of blood was aspirated from the pelvis. In all patients, satisfactory hemostasis was achieved through sutures or bipolar electrocoagulation, avoiding the need for partial or complete ovariectomy and thus preventing additional impairment of fertility. Only five of these patients required blood transfusions. Excluding the case of late - onset hemorrhage and infections mentioned above, the average hospital stay was 5.04±2.53 days, and there was no significant difference between the conservative and surgical treatment groups (5.76±1.42 days vs. 6.25±0.59 days, P >.05) ( Table 4 ). We also investigated whether IAH had a negative impact on reproductive success. All retrieved embryos were cryopreserved for future thawed embryo transfer. The clinical pregnancy rate, defined as the visualization of a fetal heartbeat via ultrasonic scan 5 weeks after embryo transfer, was 52% (13/25), leading to 13 live births. Among these 13 live births, no miscarriages or ectopic pregnancies were recorded, suggesting no increased risk of adverse pregnancy outcomes following IAH. The clinical pregnancy rates were similar among patients who received conservative and surgical treatments (50% vs 52.94%, P >.05) ( Table 4 ). After one or 2 failed frozen - thawed transfer cycles, 3 patients chose to suspend embryo transfer, and 2 patients did not attempt any further embryo transfers after OPUs. Currently, all remaining embryos are cryopreserved. Additionally, 2 patients experienced fertilization failure and decided to discontinue treatment. So far, 15 children have been born, all without birth defects. These success rates are within the expected ranges at the study institution, suggesting that IAH after OPU, regardless of whether it is treated conservatively or surgically, has a minimal impact on IVF outcomes.

IAH is a rare but potentially catastrophic OPU complication. Employing gentle techniques during follicle aspiration and rigorous postoperative monitoring, particularly in patients with adhesive disease, enables early diagnosis and avoids severe sequelae. Conservative treatment is first-line for stable patients, with surgery reserved for failed medical management. These findings inform clinical protocols to balance safety and reproductive success in IVF practice.

This study highlights the critical 12-hour post-OPU window for hemorrhage detection, with 92% of patients developing symptoms within this period—consistent with prior reports noting 93.3% of severe cases presenting within 24 hours. 11 Ultrasound remains the cornerstone of diagnosis, identifying pelvic hematoma or effusion in nearly all cases, while serial Hb/Hct monitoring aids in differentiating stable vs. progressive hemorrhage. In the current study, the incidence of IAH subsequent to OPU was determined to be 0.05%. This value is marginally lower than the range of 0.06% to 0.27% reported in previous studies, 4 − 6 , 10 , 11 and is also somewhat lower than certain reported rates, such as the 0.09% observed in a recent pooled analysis. 12 This discrepancy may reflect differences in patient selection, procedural techniques, or institutional protocols, highlighting the need for multicenter studies to further validate these findings. Stojnic et al. 13 found that 55.8% and 81.39% of patients developed symptoms within 8 hours and 24 hours after OPU, respectively. Abdominal pain or discomfort is common after OPU, whether or not complications arise. Liberty et al. noted that in non - complicated cases, pain subsided, while in complicated ones, it worsened within 24 hours. 10 These findings underscore the importance of post - OPU monitoring. The ESHRE working group recommends patients stay in the recovery area for about 2 hours under nurse supervision. 2 Since most hemorrhages occur within 12 hours after OPU and delayed IAH is possible, 14 , 15 , 16 , 17 patients must be educated on extended self - monitoring . A decline in a patient's condition, especially within the first 12 hours after OPU, warrants ruling out IAH or other complications. Ultrasound is the most accessible and sensitive diagnostic modality for detecting IAH. Both previous studies and our research consistently identify pelvic hematoma and/or effusion as the most common ultrasonic manifestations. 6 , 10 , 15 , 17 , 18 A complete blood count is valuable for diagnosis and treatment. Based on ultrasound and blood tests, various studies have reported different levels of hemoglobin change, pelvic effusion volume, and blood loss. 11 , 18 , 19 In our study, the hemoglobin level decreased by 26.50±13.32 mg/dL. In our study, the hemoglobin level reduction was 26.50±13.32 mg/dL. Initially, most patients had a declining hemoglobin concentration, likely due to ongoing bleeding or hemodilution from intravenous fluids. In the conservative treatment group, no instances of clot - related infection were detected. On average, symptoms resolved within 3 to 5 days. This finding underscores the safety of initiating conservative management, provided that patients are closely monitored. However, if there is a persistent hemoglobin drop and an expanding intra-abdominal hematoma, it indicates active bleeding and treatment failure, requiring laparoscopy or laparotomy. 6 , 10 , 18 , 20 It is crucial to note that these surgical procedures pose a risk of damaging ovarian reserves and fertility, as partial or complete ovariectomy may be required in certain cases. 4 , 11 , 13 , 21 , 22 As hemorrhage often stops spontaneously, surgery should typically be considered only if conservative therapy fails. Nonsurgical endovascular techniques have been used to manage life - threatening IAH 15 , 23 , 24 and remain a viable option for major IAH following OPU or other hemorrhagic conditions. Pelvic adhesions—present in 68% of cases (prior surgery/OPU or endometriosis)—emerged as a key risk factor. This finding aligns with literature linking prior abdominal/pelvic surgery to OPU-related hemorrhage, underscoring the need for pre-procedural imaging to assess anatomical distortion. 13 , 14 This is likely because pelvic adhesions impede the movement of the ovaries during follicle aspiration. Moreover, conditions such as endometriosis lead to extensive pelvic adhesions. In cases of endometriosis, repetitive punctures are often required, further elevating the risk of hemorrhage. Some studies 10 , 13 indicate that lean PCOS patients may be more prone to IAH after OPU. However, in this study, the mean BMI was 19.63±2.65 kg/m² (normal range), and only 2 PCOS patients were identified, one with pelvic adhesions. Thus, more research is required to elucidate the link between PCOS and IAH post - OPU. In addition to known risk factors, other potential causes of IAH after OPU are the GnRH agonist protocol for ovarian stimulation, coagulation disorders, and patient movement during OPU. A recent study shows the GnRH agonist downregulation protocol, along with a higher oocyte yield, raises the risk of post - OPU hemorrhage. 8 This is due to more punctures for more oocytes, a higher chance of ovarian lesions, and a longer procedure time. Also, IAH after OPU has been reported in patients with coagulation disorders like Von Willebrand disease and factor XI deficiency, 21 , 25 highlighting the need for routine coagulation screenings to take preventive measures. Okoshi et al. 26 described a case of severe ovarian hemorrhage possibly triggered by a violent cough during aspiration. In practice, patient movement when the aspiration needle is inserted can greatly increase the risk of hemorrhage or organ damage, as even a small movement can have serious results and cause pain, leading to more involuntary movements. 2 Thus, effective anesthesia is crucial to keep the patient still and reduce complications. To reduce the risk of post - OPU IAH, a 3 - stage approach is crucial. Pre - OPU: During COH, avoid excessive follicle growth; optimizing oocyte retrieval maximizes live - birth rates and lessens ovarian lesion risks. 27 , 28 Thoroughly review medical records to identify risk factors like coagulation disorder history, prior pelvic surgeries, and medications such as aspirin. Pre - OPU ultrasound, along with Color Doppler before aspiration, helps operators understand pelvic anatomy, distinguish vessels from follicles, and prevent vessel punctures. 29 Intra - OPU: Ensure patient, transducer, and needle immobility during follicle aspiration. Effective anesthesia is key to keeping the patient still and reducing complication risks. Keep the needle within the ovary to avoid repeated punctures that increase hemorrhage chances. Post - OPU: At our center, patients' vital signs are checked at least twice in the recovery room before discharge. Well - designed training programs and strict quality control systems are essential for residents to master OPU procedures, ensuring safe and effective practice. 30 , 31 , 32 A major strength of this study is its inclusion of patients undergoing both inpatient conservative and surgical treatments. This comprehensive approach allows for a more in - depth analysis of post - OPU IAH management and outcomes. Uniquely, the research defined the crucial 12 - hour post - OPU period as a key window for hemorrhage detection. Despite the presence of complications, the study also demonstrated a maintained live birth rate of 52%, providing valuable insights into the impact of IAH on reproductive outcomes. However, it is important to acknowledge the study's limitations. Because of the retrospective nature of the study and its focus on hospitalized cases, a comparison group was not included. Future research should consider incorporating a control group to gain more comprehensive insights into the incidence, risk factors, and outcomes associated with post - OPU IAH. This would help to strengthen the validity and generalizability of the findings, ultimately contributing to improved patient care in the field of assisted reproductive technology.

Ultrasound-guided transvaginal oocyte retrieval (OPU), introduced clinically in 1985, remains the gold standard for in vitro fertilization (IVF) due to its proven reliability, safety, and accessibility. 1 While this approach offers superior efficacy compared to transabdominal or laparoscopic methods, 2 understanding associated complications and risk factors is essential for patient safety. When retrieving oocytes, the aspiration needle has to pierce through the vaginal wall and reach the ovarian surface. During this process, it unavoidably damages the intricate vascular networks it traverses. This damage can lead to hemorrhage, which may range from mild to severe. Hemorrhage is a well-recognized OPU complication, arising from needle penetration of the vaginal wall and ovarian surface during follicle aspiration. While vaginal wall hemorrhage occurs in 8.6% of OPU cases, only 0.8% involve significant blood loss (>100 mL) requiring intervention. 3 In contrast, IAH—though less frequent (0.06%–0.27%) 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 —poses a silent risk, as it is not clinically apparent without imaging. Undetected minor hemorrhage can escalate to life-threatening intraperitoneal bleeding, underscoring the need for heightened vigilance. 6 , 8 , 10 While previous research describes the rarity of this complication, detailed clinical trajectories, risk factors like pelvic adhesions, and long-term reproductive impacts remain understudied. This study addresses these gaps through a single-center retrospective analysis. It retrospectively examines 25 cases of post - OPU IAH at a tertiary center. The study aims to delineate clinical courses, identify risk factors, and formulate preventive strategies.

The data underlying this article will be shared on reasonable request to the corresponding author.