Objective
To identify factors associated with peripartum hysterectomy performed within 30 days postpartum.
Methods
This was a population-based case-control study using Washington State birth certificate registry (1987-2006) linked to the Comprehensive Hospital Abstract Reporting System (CHARS). Cases underwent hysterectomy within 30 days postpartum. Controls were frequency matched 4:1. Exposures included factors related to hemorrhage, delivery method, multiple gestations, and infection. Incidence rates of peripartum hysterectomy and maternal and neonatal morbidity/mortality were assessed. Adjusted odds ratios (aOR) by maternal age, parity, gestational age, year of birth, and mode of delivery and 95% confidence intervals (CI) were computed.
Results
There were 896 hysterectomies. Incidence rates ranged from 0.25 in 1987to 0.82 per 1,000 deliveries in 2006 (χ2 for trend, p<0.001). Factors related to hemorrhage were strongly related to peripartum hysterectomy. Placenta previa (192 cases vs. 23 controls; aOR=7.9, 95% CI: 4.1– 15.0), abruptio placenta (71 vs. 55; aOR=3.2, 95% CI: 1.8–5.8), and retained placenta (214 vs. 28; aOR=43.0, 95% CI: 19.0–97.7) increased the risk of hysterectomy, as did uterine atony, uterine rupture, and thrombocytopenia. Having multiple gestations did not. As compared with vaginal delivery, vaginal delivery after cesarean (27 cases vs. 105 controls; aOR=1.9, 95% CI: 1.2–3.0), primary cesarean (270 vs. 504; aOR=4.6, 95% CI: 3.5–6.0), and repeat cesarean (296 vs. 231; aOR=7.9, 95% CI: 5.8-10.7) increased the risk of peripartum hysterectomy. Among the 111 women who had hysterectomy on readmission (12.8% of cases), hemorrhage- and infection-related factors were still strongly associated with peripartum hysterectomy.
Conclusion
Incidence rates of peripartum hysterectomy are increasing over time. The most important risk factor for peripartum hysterectomy is hemorrhage, most notably caused by uterine rupture, retained placenta, and atony of uterus.