Objective: To compare between conservative management and appendectomy for acute appendicitis during pregnancy by trimester. Design: Retrospective cohort study. Setting: 632 acute-care hospitals in Japan. Population: Pregnant women diagnosed with acute appendicitis. Methods: We conducted a large nationwide study using a national inpatient database from July 2010 to March 2022. Comparisons were conducted using multivariable analysis with generalized estimating equations. Main Outcome Measures: Preterm labor, preterm delivery, or abortion, antepartum hemorrhage, duration of hospitalization, and duration of antibiotic use. Results: 3,158 individuals were eligible. Proportions of conservative management versus appendectomy by trimester were 507 (49.1%) vs. 525 (50.9%) in the first, 690 (44.6%) vs. 856 (55.4%) in the second, and 337 (58.1%) vs. 243 (41.9%) in the third. In the second trimester, appendectomy had a higher rate of preterm delivery, preterm labor, or abortion (OR 2.91; 95% CI 1.62–5.25). Antepartum hemorrhage occurred more frequently for appendectomy in the first (OR 2.12; 95% CI 1.31–3.43) and third (OR 2.43; 95% CI 1.79–3.31) trimesters. Appendectomy had longer duration of hospitalization in the second (2.15 days; 95% CI 1.14–3.17 days) and third (3.97 days; 95% CI 2.22–5.71 days) trimesters. Antibiotic use duration was shorter for appendectomy in the first (−1.20 days; 95% CI −1.51 to −0.90 days) and second (−0.61 days; 95% CI −0.90 to −0.32 days) trimesters. Conclusions: Clinical outcomes of acute appendicitis during pregnancy vary by trimester. Considering the appendectomy risks, conservative management may be viable depending on the clinical context and trimester.

Objective: To assess and compare the clinical aspects of uterine rupture by dividing the gestational age at uterine rupture occurrence into <37-week (preterm) and ≥37-week (term) groups. Design: Retrospective cohort study. Setting: 187 acute-care hospitals in Japan. Population: Pregnant women diagnosed with uterine rupture. Methods: We conducted a large nationwide study using a national inpatient database from July 2010 to March 2022. The patients’ characteristics, in-hospital procedures, and outcomes were investigated and compared between those who developed uterine rupture at preterm and term groups. Main Outcome Measures: Hysterectomy, complications, proportion of blood transfusions, and postoperative length of stay. Results: In total, 298 eligible patients were identified (161 in preterm group and 137 in term group). The incidence of placenta accreta spectrum was significantly higher in the preterm than term group (18.0% vs. 6.6%, respectively; P = 0.003). Vacuum delivery (19.0% vs. 0.6%, P < 0.001) and uterine fundal pressure (2.9% vs. 0.0%, P = 0.004) were more likely to be applied in the term than preterm group. The maternal need for mechanical ventilation (26.3% vs. 12.4%, P = 0.003), the incidence of disseminated intravascular coagulation (40.1% vs. 25.5%, P = 0.009), and the requirement for platelet transfusions (32.8% vs. 15.5%, P < 0.001) were greater in the term than preterm group. Additionally, the duration of the postoperative hospital stay was longer in the term group. Conclusions: This study shows that individual characteristics vary with the gestational age at uterine rupture and that the maternal morbidity rate is notably higher in term than preterm uterine ruptures.