Raise in the rates of cesarean delivery during recent decades have been reported in all regions of the world. Thus, many women carry uterine scars in their next pregnancies which may put them at higher risk for occurrence of complications such as uterine rupture (1-3). The advances in timely detection of abnormalities and conditions needing termination have led to increase in the second trimester termination of pregnancy (4). Due to high number of patients with previous history of cesarean section (C-section) who may need second trimester termination, it is essential to choose an appropriate method to avoid the risk of uterine rupture in at-risk patients. Growing trends toward the medical abortion approach has made surgical methods a choice only for the specific cases.
Medical abortion in the second trimester has gained more and more popularity over years with misoprostol being one of the most common agents used for this indication. Misoprostol as a synthetic prostaglandin E1 analogue was primarily used for the treatment of gastric ulcers but then it was approved for the induction of abortion with favorable safety and efficacy (5). Several complications including coagulation disturbances, vaginal bleeding and uterine rupture have been reported in the literature after misoprostol use for abortion (3, 6). Although uterine rupture is rare after using misoprostol, its higher rates in patients with scarred uterus and remarkable morbidity and mortality have turned misoprostol into a relative contraindication in this sub-group of patients (1, 3). While misoprostol in the patients with previous history of C-section must be used cautiously, its use is still so common in daily practice around the world. Hereby, we report three cases of uterine rupture subsequent to misoprostol use for the second-trimester pregnancy termination due to PPROM which have occurred over the past 5 years in our center (Yas Hospital, Tehran University of Medical Sciences, Iran) as a referral teaching hospital. Our center has a rate of up to 100-120 cases of misoprostol-based second-trimester pregnancy terminations monthly which makes it one of the most experienced hospitals in this field. Our hospital protocol for the pregnancy termination is based on FIGO misoprostol-only recommended regimens 2017. Another point to keep in mind is that mifepristone is not available for use in our country. Also due to controversy in using mechanical methods for cervical ripening in PPROM cases regarding increased risk of chorioamnionitis, insertion of cervical foley catheters or osmotic cervical dilators are prohibited for such patients in our hospital. In all cases presented here only misoprostol was used for the termination and oxytocin was not used due to low initial BISHOP score.

 

Case Presentation

The 1^st case- The patient was a 32 year-old woman, gravida3 in 21^st week of pregnancy. She was referred for pregnancy termination due to PPROM. She had a history of two terms cesarean deliveries. The first C-section was due to prolonged fetal heart rate (FHR) deceleration and the second was due to repeat in C-section 3 years before current pregnancy (both with low-transverse incisions). Her BISHOP score was 2 at admission. Anterior placental position was observed. To terminate the pregnancy, sublingual misoprostol was initiated for the patient with 100 ug followed by 200 ug doses with 4-hour intervals. At 4 hours after the last dose with a total dose of 900 ug misoprostol, the patient became agitated and painful with tachycardia of 100 bpm and temperature of 39.5°C. Contractions were not sensed with tocotransducers exactly. Along with these changes, the uterine fundus was palpated as floating in the abdomen suggestive of possible uterine rupture which was further confirmed by bedside emergent ultrasonography. The patient was transferred to the operating room just after initiating intravenous antibiotic with suspicion of chorioamnionitis, before she becomes heamodynamically unstable. In the operating room, the abdominal and pelvic cavity was cleared out from hemorrhage and clots with an estimated volume of 500ml. After extraction of dead fetus and placenta which was bulged out from previous hysterotomy scar, no active bleeding from hysterotomy scar margins was identified. The rupture was repaired as with a simple hysterotomy and uterus could be preserved successfully. After operation, no extraordinary bleeding was observed and the patient was discharged after 4 days without any complication.
The 2^nd case- The patient was a 27 year-old woman, gravida2 patient who was referred for pregnancy termination at 23^rd week of pregnancy due to PPROM and non-viable gestational age. The patient had positive history of one prior C-section with low-transverse incision at 5 years before the current pregnancy. Her BISHOP score was 0. The placenta was located in fundal anterior position. For pregnancy termination, sublingual misoprostol was started for the patient. Four doses of 200 ug were administered for the patient with 4- to 6-hour intervals. After reaching a total dose of 800 ug, the patient complained of severe abdominal pain without vaginal bleeding. Due to heamodynamic instability of the patient reflected with tachycardia of 130 bpm and hypotension, she was immediately sent to the operating room. During the operation, 500 ml of hemorrhage and clots were suctioned from abdominopelvic cavity. The rupture site was exactly on the previous C-section scar on uterus which was extended to the left lateral side of the uterus. The fetus and placenta were removed and uterus was preserved successfully. The patient was admitted at ICU after operation. She received combined parenteral antibiotic therapy due to possible antepartum chorioamnionitis. Post-operative ultrasonographic assessment showed no free fluid in the abdominal and pelvic cavities. The patient was discharged after 5 days with good general condition.
The 3^rd case- The patient was a 27 year-old woman, gravida3 patient with a history of one previous C-section with low-transverse incision at 29 weeks due to late decelaration of FHR 18 months before. In this admission, she was referred for pregnancy termination at 20-week gestation due to PPROM but she refused termination. After 3 days of observation in the ward she was sent to labor ward for the termination due to development of fever and mild tachycardia with prompted diagnosis of chorioamnionitis. Her BISHOP score was 3. The placenta was in anterolateral position. Besides starting intravenous antibiotic for her, pregnancy termination began with routine sublingual misoprostol dose for her gestational age as 400 ug every 5 hours. After total dose of 1200 ug the patient became tachycardic with 140 bpm and her hemoglobin level declined by 2 units. The patient was urgently sent to the operating room. After abdominal exploration and clearing out the abdominopelvic cavity of 1 liter of blood, clot, fetus and placenta, the rupture site which was exactly at the previous hysterotomy scar, was repaired as usual and uterine was preserved. Due to blood loss of more than 75%of mother’s estimated blood volume, blood transfusion was started for her during surgery. She was then sent to ICU for close heamodynamic monitoring and after receiving 2 units of packed cells and rise of hemoglobin level up to 9.5 mg/dL, the patient was sent to the general ward and dismissed from hospital 2 days later with good general conditions (Figure 1).

Figure 1. This picture refers to first case, in which fetus and placenta bulging out of uterine rupture site could be seen