Intestinal Obstruction in the Third Trimester of Pregnancy: Maternal and Fetal Outcomes

Small bowel obstruction (SBO) is a rare yet life-threatening event in pregnancy. If not diagnosed and treated promptly, it can lead to an increase in maternal as well as foetal morbidity and mortality. In the majority of cases, small bowel obstruction is caused by adhesions from previous pelvic surgeries. We herein report a case of SBO in a 28-week pregnant woman, who had a previous history of laparotomy for ectopic pregnancy. She presented with severe epigastric pain and vomiting in the emergency department. On initial examination, the patient was clinically stable but with a distended abdomen. Abdominal ultrasound showed fluid-filled dilated small bowel loops, but was otherwise unremarkable. Conservative treatment was provided, and she was kept on nothing by mouth. Despite intravenous pain killers and antiemetics, the symptoms remained unsettled 72 hours after admission. A clinical suspicion of SBO was made, and an urgent MRI was carried out, suggesting small bowel obstruction. She underwent an immediate laparotomy. Intraoperatively, bands of omentum were found to be adherent to the distal ileum. The adhesions were resected, and the affected ileum showed no signs of ischaemia, so it was preserved. Her postoperative course was uneventful. She later had a caesarean section for intrauterine growth restriction at 37 weeks and delivered a 2.1 kg baby. Diagnosis of SBO is difficult, especially in the second and third trimesters, as the symptoms often are mistakenly attributed to the pregnancy itself. There is a reluctance in getting investigations such as a CT scan done due to the risk of exposure of the foetus to ionising radiation which can lead to a delay in diagnosis and treatment. MRI can safely be used in pregnancy as a modality to diagnose intestinal obstruction and to determine the aetiology. Once diagnosed, the optimal management mainly depends on the aetiology and the gestational age.