A 36-year-old primigravida presented at 19 weeks and 1 day of gestation with 24 hours of worsening acute right lower quadrant pain that awoke her from sleep. The pain was associated with nausea but no vomiting. She was afebrile and hemodynamically stable on arrival. Initial blood tests showed hemoglobin 129 g/L (reference 120–150 g/L) and leukocyte count 9.7 × 10^9/L (reference 4–11 × 10^9/L).
Her obstetric history was notable for a known multi-fibroid uterus; dating ultrasonography at 8 weeks 2 days reported the largest fibroid measuring 5.1 cm. The pregnancy was spontaneous. Relevant medical history included eczema, seasonal asthma, fatty liver, anxiety, and prior hysteroscopic polypectomy. She was not taking regular medications.
On presentation she underwent abdominal and pelvic ultrasonography, which identified a 6.5 × 7.3 × 5.7 cm exophytic fibroid located at the point of maximal tenderness. The appendix was not visualized. Estimated myometrial thickness and distance from the fibroid to the gestational sac ranged from about 5 to 12 mm. She was admitted for observation and analgesia with a working diagnosis of possible appendicitis.
Ultrasonography was used as the initial imaging modality. The team considered magnetic resonance imaging (MRI) for further diagnostic clarity, given its superior soft-tissue characterization, but MRI was not performed before clinical deterioration. The patient developed signs of peritonitis within 24 hours, including localized tenderness at McBurney point, prompting expedited operative evaluation.
The report emphasizes that ultrasonography is first-line in pregnant patients with acute abdominal pain and that MRI can be a useful adjunct when findings are inconclusive and the patient is clinically stable. CT with contrast remains the most accurate diagnostic test for appendicitis but is reserved for situations where the additional information will change management, given radiation exposure and theoretical fetal thyroid effects of iodinated contrast.
A diagnostic laparoscopy with planned appendectomy was performed using a supraumbilical open Hasson entry. On entry, moderate hemoperitoneum was found and approximately 200 mL of blood was evacuated. The uterus was equivalent to a 20-week size. A 7-cm subserosal fibroid at the right fundal region had ruptured through its capsule; blood was present on the serosal edges. No active arterial bleeding was observed at the time of surgery.
Because active hemorrhage was not seen, the surgical team chose expectant intraoperative management. An absorbable hemostatic powder was applied to the serosal edges of the ruptured fibroid. The appendix appeared grossly normal; nonetheless, an appendectomy was performed. The operative approach prioritized identifying and controlling bleeding while minimizing uterine trauma.
Postoperatively the patient reported improved pain. Repeat hemoglobin was 117 g/L. She ambulated and voided normally, had regular bowel function, and tolerated oral intake. The team observed her in hospital for three days to ensure ongoing stability, with contingency planning for laparoscopic myomectomy should clinical deterioration occur.
She was discharged on postoperative day 3 with hemoglobin 108 g/L and leukocyte count 7 × 10^9/L. Analgesia prescribed on discharge included acetaminophen and hydromorphone PRN. Pathologic examination of the appendix showed lymphoid hyperplasia without acute appendicitis or periappendicitis.
Serial ultrasonography during the remainder of pregnancy demonstrated progressive enlargement of the fibroid: 7 cm at 20 weeks, 9 cm at 25 weeks, and 11 cm at both 32 and 36 weeks. Despite the increase in size, the patient remained clinically well and did not require further analgesia. She underwent elective cesarean delivery at 38 weeks and 4 days for maternal request, delivering a healthy male infant in vertex presentation weighing 3.4 kg.
Acute abdominal pain in pregnancy presents unique diagnostic challenges because uterine enlargement and abdominal wall laxity can mask peritoneal signs and alter pain localization. A broad differential includes appendicitis, biliary disease, bowel obstruction, nephrolithiasis, ovarian pathology (cyst rupture or torsion) and complications of uterine fibroids such as degeneration, torsion, or, rarely, rupture.
Peritoneal signs such as rebound and guarding are not normal in pregnancy and should prompt expedited evaluation. Interpretation of laboratory tests is complicated by physiologic pregnancy changes: normal leukocyte counts may rise (physiologic leukocytosis with an upper limit up to ~15 × 10^9/L), and hemodilution causes physiologic anemia (hemoglobin <110 g/L can be normal), which can obscure classic laboratory indicators of infection or hemorrhage.
Abdominal and pelvic ultrasonography is the first-line imaging modality in pregnant patients with acute abdominal pain because it is safe and readily available. MRI provides higher sensitivity and specificity for soft-tissue characterization and can help differentiate torsion from degeneration of fibroids when patients are stable and MRI is accessible. CT with intravenous contrast has the highest diagnostic accuracy for appendicitis but carries radiation exposure and potential fetal thyroid effects from iodinated contrast; therefore it is recommended only when absolutely required to guide management.
Uterine fibroids are common benign tumors, affecting an estimated majority of females over a lifetime. In pregnancy most fibroids remain asymptomatic, but 10%–20% develop complications; the most frequent are pain from degeneration or torsion of a pedunculated fibroid. Risk factors for complications include fibroids larger than 5 cm and earlier gestational age when rapid growth may outstrip blood supply.
Degeneration results from ischemia within the fibroid, producing necrosis, inflammation, pain, leukocytosis and sometimes fever. Management of degenerating fibroids is usually conservative with intravenous fluids, analgesia and antiemetics; symptoms often resolve within 7–10 days. Surgery is reserved for hemodynamic instability from intracapsular bleeding or refractory pain. Hemorrhage most commonly arises from rupture of a superficial venous vessel overlying the fibroid; in the reported case, bleeding originated from capsular rupture rather than a discrete vessel.
Acute hemoperitoneum from spontaneous fibroid rupture in pregnancy is extremely uncommon, with just over 100 cases reported in the English-language literature since 1902. In severe or uncontrolled hemorrhage, myomectomy or, rarely, emergency hysterectomy may be required, particularly given the hypervascularity of the gravid uterus.
When operative management is required in pregnancy, timely diagnosis and multidisciplinary surgical planning are essential to reduce maternal and fetal morbidity and mortality. Laparoscopy can be performed safely in appropriately selected pregnant patients when undertaken by an experienced team and when uterine size and other factors permit.
Recommended intraoperative principles include maintaining low insufflation pressures to limit maternal hypercapnia, using an open (Hasson) entry technique to control the entry site and reduce uterine injury risk, and selecting hemostatic techniques that minimize operating time, uterine manipulation and thermal damage. A collaborative approach between gynecology and general surgery promotes comprehensive evaluation during diagnostic procedures and helps avoid being misled by fibroids when other intra-abdominal pathology is present.