Magnetic resonance imaging-guided surgical strategy for secondary abdominal pregnancy implanted in the broad ligament: A case report highlighting hemorrhage-control techniques.

A 28-year-old primigravida presented with amenorrhea for 13 weeks and intermittent lower abdominal pain for 40 days. She reported transient syncope and nausea but denied vaginal bleeding. Her past medical history was unremarkable, with no prior pelvic surgery or infertility treatment. The patient was admitted to Gansu Provincial Maternity and Child Care Hospital in October 2023. Investigations . (a) Transvaginal ultrasound: A viable male fetus (biparietal diameter: 19 mm; femur length: 10 mm) was identified in the left adnexa, with a placental thickness of 13 mm and heterogeneous endometrial thickening (16 mm) ( Figure 1(a) ). (b) Pelvic MRI: A 9-cm gestational sac was adherent to the left broad ligament, surrounded by an encapsulated hematoma and hypervascular parametrial vessels ( Figure 1(b) ). (c) Laboratory findings: Serum human chorionic gonadotropin (β-hCG): 34,731 mIU/mL; progesterone: 13.69 ng/mL. We have de-identified all patient details. Surgical management . During laparotomy, a 9-cm gestational sac was found in the pelvic cavity, with the placenta attached behind the left broad ligament and connected to the fimbrial end of the left fallopian tube. There was no active bleeding ( Figure 1(c) ). The surgical sequence was as follows: Investigations . (a) Transvaginal ultrasound: A viable male fetus (biparietal diameter: 19 mm; femur length: 10 mm) was identified in the left adnexa, with a placental thickness of 13 mm and heterogeneous endometrial thickening (16 mm) ( Figure 1(a) ). (b) Pelvic MRI: A 9-cm gestational sac was adherent to the left broad ligament, surrounded by an encapsulated hematoma and hypervascular parametrial vessels ( Figure 1(b) ). (c) Laboratory findings: Serum human chorionic gonadotropin (β-hCG): 34,731 mIU/mL; progesterone: 13.69 ng/mL. We have de-identified all patient details. Surgical management . During laparotomy, a 9-cm gestational sac was found in the pelvic cavity, with the placenta attached behind the left broad ligament and connected to the fimbrial end of the left fallopian tube. There was no active bleeding ( Figure 1(c) ). The surgical sequence was as follows: Imaging findings and intraoperative features of secondary abdominal pregnancy implanted in the left broad ligament. (a) Transvaginal ultrasound: left adnexal gestational sac (arrow) containing a viable fetus. (b) Pelvic magnetic resonance imaging (MRI): placental attachment to left broad ligament (arrow). (c) Intraoperative view: gestational sac adherent to broad ligament (arrow). Step 1 — Delivery after umbilical cord ligation: The umbilical cord was identified at its attachment site on the placental surface. The cord was cut and ligated 1 cm from the placental insertion site. The fetus (9.5 cm, male) was then completely delivered. Step 2 — Blunt placental dissection and vascular management: Given the patient's stable hemodynamic status and the absence of active bleeding during the initial examination, prophylactic uterine artery ligation and ovarian vascular ligation were not performed. First, the placenta was bluntly detached from the posterior lobe of the left broad ligament, with complete mobilization of the placental blood supply. The feeding vessels were sequentially ligated using No. 1 silk sutures. No temporary clamping, vasopressin, or hemostatic agents were used. Step 3 — Adjunctive hemostasis: After complete placental removal, focal electrocoagulation was performed only at identifiable bleeding points on the surface of the broad ligament. Because the fimbrial end of the left fallopian tube was connected to the placenta, a left salpingectomy was performed. Laparoscopic surgery was not selected in this case. Preoperative pelvic MRI revealed hypervascular parametrial tissue surrounding the gestational sac, which was firmly adherent to the broad ligament. Considering the potential risk of unexpected catastrophic intraoperative hemorrhage and the limited capacity for urgent hemostasis during minimally invasive surgery, exploratory laparotomy was considered the safer surgical option. The criteria for selecting complete blunt placental dissection rather than placental retention were as follows: (a) the placenta was attached to nonessential structures (broad ligaments, not attached to the intestine, bladder, or major pelvic blood vessels); (b) during the operation, it was found that the anatomical plane was easy to establish and there was no active bleeding; and (c) preoperative MRI showed no evidence of placental invasion into adjacent organs. The total duration of the surgery is 65 min. The estimated total blood loss was 50 mL. Postoperative hemoglobin decreased from 11.2 g/dL before surgery to 10.1 g/dL on postoperative day 1 Postoperative follow-up was actively performed: (a) Serum β-hCG declined from 5566 mIU/mL (postoperative day 1) to undetectable levels by week 2. (b) Gynecological ultrasound performed on postoperative day 5 showed no abnormalities. (c) No complications (e.g. infection or hemorrhage) were observed. (d) The patient is currently pregnant through natural conception. Her last menstrual period was 22 February 2025, and she is currently at 16 weeks of gestation. Compliance with reporting guidelines: The reporting of this case conforms to the Case Report (CARE) guidelines. 7 We have de-identified all patient details. Postoperative follow-up was actively performed: (a) Serum β-hCG declined from 5566 mIU/mL (postoperative day 1) to undetectable levels by week 2. (b) Gynecological ultrasound performed on postoperative day 5 showed no abnormalities. (c) No complications (e.g. infection or hemorrhage) were observed. (d) The patient is currently pregnant through natural conception. Her last menstrual period was 22 February 2025, and she is currently at 16 weeks of gestation. Compliance with reporting guidelines: The reporting of this case conforms to the Case Report (CARE) guidelines. 7 We have de-identified all patient details.

Abdominal pregnancy is traditionally defined as ectopic implantation within the peritoneal cavity, excluding the fallopian tubes, ovaries, and broad ligament. 1 However, the classification of broad ligament pregnancy remains controversial in the literature. Therefore, some authorities exclude broad ligament implantation from the definition of abdominal pregnancy because of its extraperitoneal location, 2 whereas others classify it as a variant of secondary abdominal pregnancy, particularly when it results from tubal rupture or abortion with subsequent trophoblastic implantation between the peritoneal folds of the broad ligament. 3 , 4 To resolve this inconsistency, the present report adopts the latter framework—broad ligament pregnancy as a subset of secondary abdominal pregnancy—consistent with recent case series and reviews. The incidence of abdominal pregnancy is approximately 1% of all ectopic pregnancies. 1 Despite advances in imaging, delayed diagnosis remains common, contributing to maternal mortality rates of 5%–20% in resource-limited settings. 5 Risk factors include pelvic inflammatory disease (odds ratio (OR) = 3.2), prior ectopic pregnancy (OR = 4.1), and assisted reproductive technologies (OR = 2.8). 6 Given the nonspecific clinical presentation and the potentially catastrophic hemorrhagic risk associated with broad ligament implantation, robust diagnostic tools are essential for timely and accurate preoperative assessment. Pelvic magnetic resonance imaging (MRI), in particular, offers superior soft-tissue contrast and vascular mapping capabilities, enabling precise localization of the placental attachment site and characterization of adjacent hypervascular parametrial structures. Because of its rarity and nonspecific presentation, abdominal pregnancy is frequently misdiagnosed as tubal pregnancy, resulting in delayed surgical intervention and increased hemorrhagic risk. We report a case of secondary abdominal pregnancy with a viable fetus at 13 weeks’ gestation that was successfully managed using an MRI-guided hemorrhage-control strategy, and we discuss the diagnostic challenges and surgical considerations.

Abdominal pregnancy remains a diagnostic and surgical challenge. MRI should be strongly considered for hemodynamically stable patients with equivocal ultrasound findings to facilitate accurate placental localization. Individualized surgical planning and meticulous placental management are critical to minimizing hemorrhagic complications and improving maternal outcomes.

Abdominal pregnancy is associated with significantly higher maternal mortality than tubal ectopic pregnancy, primarily because of the risk of catastrophic hemorrhage resulting from abnormal placental implantation. Fetal survival remains extremely low (<1%). 1 Abdominal pregnancy may be classified as primary or secondary. Secondary abdominal pregnancy refers to a condition secondary to tubal pregnancy rupture or miscarriage, and occasionally secondary to ovarian pregnancy or intrauterine pregnancy with a uterine-abdominal fistula. Advanced abdominal pregnancy is associated with maternal and infant mortality rates of 1%–20% and 40%–95%, respectively. 5 Risk factors include a history of pelvic inflammatory disease (OR = 3.2), previous ectopic pregnancy (OR = 4.1), use of assisted reproductive technology (ART) (OR = 2.8), and a history of fallopian tube surgery. 6 The patient in this case had no clear risk factors; however, adhesion between the left fimbrial end of the fallopian tube and the gestational sac was observed during surgery, which is a typical manifestation of secondary abdominal pregnancy, suggesting that abnormal fallopian tube function may be a potential cause. Due to abnormal placental attachment and insufficient blood supply during abdominal pregnancy, it is often difficult for the fetus to survive until full term. Patients often present with amenorrhea and early pregnancy symptoms, and the medical history frequently includes symptoms of tubal pregnancy miscarriage or rupture, or unexplained short-term anemia symptoms in early pregnancy, accompanied by abdominal pain and vaginal bleeding, which gradually improve later. 8 Subsequently, vaginal bleeding stops and the abdomen gradually enlarges. During fetal movement, pregnant women often experience abdominal pain, which gradually worsens as the fetus grows. Abdominal examination may reveal unclear uterine contours, but fetal limbs are easily palpable, the fetal position is abnormal, shoulder or buttocks may present first, the presenting part is high and floating, the fetal heart rate is abnormally clear, and placental murmurs are loud. Gynecological examination may reveal that the cervix has shifted upward, the uterus is smaller than expected for the gestational age and deviated to one side, although it may sometimes be difficult to palpate, whereas the fetus is located on the opposite side of the uterus. During the near due period, there may be a false delivery with contraction-like appearance, but the cervix does not dilate, and it is difficult to reach the presenting part of the fetus through the cervix. If the fetus dies, the signs of pregnancy disappear, menstruation returns, and the adhered organs and greater omentum surround the stillbirth. The fetus gradually shrinks and, over time, may dry out or become a stone fetus. If secondary infection occurs and an abscess forms, it may penetrate the mother's intestinal tract, vagina, bladder, or abdominal wall, resulting in the expulsion of fetal bones. The diagnostic criteria for primary abdominal pregnancy are (a) Both fallopian tubes and ovaries are normal, with no evidence of recent pregnancy; (b) No formation of uterine peritoneal fistula is present; and (c) The pregnancy exists only in the abdominal cavity, with no possibility of tubal pregnancy. 9 A factor that may promote the primary implantation of a fertilized eggs on the peritoneum may be the presence of endometriosis lesions in the peritoneum. Secondary abdominal pregnancy often occurs after miscarriage or rupture of fallopian tube pregnancy, and occasionally after rupture of an ovarian pregnancy or an intrauterine pregnancy with uterine defects (such as uterine scar rupture or a uteroperitoneal fistula). The embryo enters the abdominal cavity, and some villous tissue still adheres to the original implantation site, continues to grow, and subsequently attaches to the pelvic peritoneum and adjacent organ surfaces. 10 Although transvaginal ultrasound has been widely used in clinical practice, abdominal pregnancy remains extremely difficult to diagnose. On the one hand, the incidence of abdominal pregnancy is very low, and ultrasound physicians have limited experience with this condition, often misdiagnosing it as tubal pregnancy. On the other hand, the attachment sites of abdominal pregnancy are extremely extensive, and early ultrasound images lack specificity, making early diagnosis of abdominal pregnancy very difficult. Gerli et al. 11 first proposed the criteria for diagnosing abdominal pregnancy using transvaginal ultrasound: (a) No gestational sac is identified in the uterine cavity; (b) There is no clear enlargement of the fallopian tubes and cystic-solid adnexal masses; (c) The gestational sac is surrounded by the intestinal tract or separated by the peritoneum; and (d) The gestational sac demonstrates wave motion and mobility, especially when the pressure is applied to the posterior fornix with the transvaginal ultrasound probe. Previous studies have shown that the misdiagnosis rate of transvaginal ultrasound can reach 30%−40%, particularly in determining the location of placental attachment. 12 Although transvaginal ultrasound in this case indicated the survival of the fetus in the left adnexa region, the relationship between the placenta and the broad ligament was not clearly defined. Pelvic MRI clearly showed placental attachment behind the left broad ligament, and evaluated the distribution of the surrounding blood vessels and the extent of the encapsulated hemorrhage ( Figure 1(b) ), which is consistent with the conclusion of Rahaim et al. that MRI has a sensitivity and specificity of 91% and 88%, respectively, for placental localization, significantly better than ultrasound. This discovery highlights the important role of MRI in complex ectopic pregnancy, especially for patients with stable hemodynamics who require precise preoperative evaluation. Similar findings have been reported in other case series. Tsagias et al. used MRI during the planning stage of hysteroscopic resection for cornual ectopic pregnancy and concluded that MRI facilitates safe and effective treatment without impacting fertility potential. Abdominal pregnancy is relatively rare; however, because of the abundant blood vessels at the implantation site, rupture may lead to hemorrhagic shock, and fetal death within the abdominal cavity may lead to intra-abdominal infection, posing a serious risk to patients with abdominal pregnancy. The mortality rate is approximately eight times that of tubal pregnancy. Therefore, early diagnosis and treatment of abdominal pregnancy are particularly important, as they can significantly reduce maternal mortality and improve prognosis. Conservative treatment: For patients with early abdominal pregnancy, a small pregnancy tissue, and stable hemodynamics, drug therapy may be considered. This approach often involves using methotrexate to kill embryos, which can be combined with mifepristone tablets for antiprogestogen treatment. During conservative process, it is necessary to closely monitor abdominal pain, vaginal bleeding, and vital signs should be closely monitored. If conservative treatment fails, emergency surgical treatment is required. Surgical treatment is the main treatment for abdominal pregnancy, especially for patients with intra-abdominal bleeding or hemodynamic instability. Regarding the surgical approach, laparoscopy offers the advantages of a clear surgical field and fast postoperative recovery and can be used as the first choice. However, if the patient has unstable vital signs and requires rapid hemostasis by entering the abdomen, it is advisable to choose open surgery. The core principle of surgery for abdominal pregnancy is to balance the risk of bleeding and tissue preservation. Before surgery, it is necessary to fully assess the surgical risks, prepare sufficient blood, and if necessary, form a multidisciplinary team to safeguard the patient. The handling of the placenta during surgery should be particularly cautious, as arbitrary detachment may result in significant bleeding. It should be determined based on the location of placental attachment, fetal survival, and time of death. Surgery remains the definitive treatment. The principal intraoperative challenge is management of the placenta, as uncontrolled detachment may cause massive hemorrhage. Key surgical principles include (a) Preoperative assessment of placental implantation and vascular supply; (b) Adequate blood preparation; and (c) Multidisciplinary collaboration. A structured review of surgical strategies for broad ligament pregnancy reveals evolving management paradigms. Gao et al. reported a case series of six broad ligament pregnancies treated at a single institution since 2000 and concluded that early diagnosis enables prompt laparoscopic intervention while preserving the ureter and avoiding massive bleeding because of the proximity of the uterine artery. Belouad et al. 3 reported a 14-week broad ligament pregnancy managed by emergency laparotomy, emphasizing the importance of timely intervention. In our case, laparotomy was chosen because MRI demonstrated hypervascular parametrial tissue surrounding a relatively large (9 cm) gestational sac, with concerns that laparoscopic access would limit urgent hemostasis. The favorable outcome in our case (blood loss, 50 mL; no complications; and complete β-hCG normalization at 2 weeks) supports the value of MRI-guided surgical decision-making in this rare condition. Compared with published cases managed by placental retention, our approach of complete placental resection achieved a shorter β-hCG normalization period (2 weeks vs. up to 15 months) and avoided complications associated with retained placenta, including secondary hemorrhage, sepsis, and prolonged surgical wound drainage. Indrayanti et al. reported two cases of abdominal pregnancy in which the placenta was left in situ; one patient required methotrexate rescue on postoperative day 48 because of rising β-hCG levels, and the abdominal wound continued to seep for 12 months postoperatively. A systematic review of 314 cases of abdominal pregnancy further emphasized that leaving the placenta in situ necessitates prolonged follow-up and carries risks of infection and delayed hemorrhage. 13 By contrast, our case demonstrates that, with precise preoperative MRI mapping and a structured surgical protocol, complete placental resection can be safely achieved without these long-term sequelae. Intraoperative massive hemorrhage remains the most formidable complication of abdominal pregnancy surgery. Muroni et al. reported a case in which attempted placental excision during advanced-stage abdominal pregnancy resulted in massive hemorrhage (5000 mL) with hemorrhagic shock, necessitating repeat laparotomy. Similarly, Kunwar et al. 7 documented instances of life-threatening intra-abdominal hemorrhage following placental resection that was effectively managed with abdominal packing. These reports underscore the pivotal significance of preoperative placental localization and careful surgical planning. In contrast, our surgical strategy, grounded in preoperative MRI assessment, yielded a total blood loss of only 50 mL, suggesting that meticulous preoperative evaluation may substantially reduce the risk of hemorrhage. Compared with typical abdominal pregnancies reported in the literature, 14 this case has the following characteristics: (a) Long fetal survival cycle: fetuses survive at 13 weeks of gestation (most reported cases are ≤8 weeks), which may be related to the relatively abundant blood supply provided by the broad ligament attached to the placenta; (b) No serious complications: The patient did not experience major intra-abdominal bleeding or infection, thanks to early MRI diagnosis and timely surgical intervention; and (c) Rapid postoperative recovery, with serum β-hCG turned negative 2 weeks after surgery, possibly because of complete placental clearance and no residual chorionic tissue. These findings suggest that early MRI evaluation and tailored surgical management can improve outcomes in selected patients with abdominal pregnancy. Regarding future fertility, the patient in this case retained the uterus and right adnexa. The reason for performing left salpingectomy is that the umbrella end of the left fallopian tube is connected to the placenta. Complete removal of the placenta from the broad ligament without uterine incision or extensive destruction of the parametrial tissue preserved the anatomical integrity of the pelvic cavity. Importantly, the patient subsequently conceived naturally. Her last menstrual period was on 22 February 2025, and she is currently 16 weeks pregnant and undergoing follow-up. This favorable reproductive outcome suggests that surgical strategy of preserving the uterus and fertility during broad ligament abdominal pregnancy, performed under meticulous preoperative planning and controlled placental management, may not adversely affect future fertility. Nevertheless, long-term prospective studies are needed to better guide counseling regarding future pregnancy rates and the risk of recurrence. Based on this case and literature review, we propose the following decision algorithm. Complete placental resection is advantageous in the following situations: (a) placental attachment is limited to the broad ligament, fallopian tube, or omentum (nonessential structures); (b) Clearly identifiable avascular anatomical planes are present; (c) There is no active bleeding upon entry; and (d) Preoperative imaging demonstrates no evidence of placental implantation. On the contrary, placental retention should be considered when: (a) the adhesion of the placenta to the intestine, bladder, ureter, or major pelvic blood vessels; (b) Signs of placental implantation (e.g. loss of the cleavage plane, excessive blood vessels on MRI); and (3) Unstable hemodynamics hinder anatomy.

Supplemental material, sj-pdf-1-imr-10.1177_03000605261472344 for Magnetic resonance imaging-guided surgical strategy for secondary abdominal pregnancy implanted in the broad ligament: A case report highlighting hemorrhage-control techniques by Futang Ma, Zhenqiang Gong, Yaqin Zhao, Qing Liu and Fang Wang in Journal of International Medical Research