Intraoperative blood loss and gestational age at pregnancy termination

Objective: To establish the relationship of measured intraoperative blood loss to gestational age at pregnancy termination, and to determine which factors, if any, affect the risk of bleeding.Methods: A single-operator series of 363 consecutive women undergoing pregnancy termination between 5 and 24 weeks gestational age, as dated by ultrasound, was prospectively evaluated. All pregnancies under 13 weeks gestation were terminated by mechanical dilation and suction curettage without preoperative cervical ripening. All pregnancies between 13 and 24 weeks gestation were terminated by preoperative osmotic cervical dilation with laminaria tents and subsequent uterine evacuation by a combination of suction curettage, sharp curettage, and Bierer forceps extraction. All patients over 12 weeks gestation received a postoperative oxytocin infusion. Whenever possible, amniotic fluid and blood were collected and measured separately. Patients were excluded from the data analysis for pregnancy demise, PPROM, Potter's syndrome, or inability to separate blood establish their relationship. After adjustment for gestational age, the results were analyzed to determine if blood loss was related to maternal age, smoking history, body habitus, or operative indication.Results: A curvilinear relationship between blood loss and gestational age was observed. Mean blood loss at 24 weeks exceeded 800 mL. After adjustment for gestational age, no factors significantly affected blood loss at dilation and aspiration of first trimester pregnancies. In those patients undergoing dilation and evacuation in the second trimester, both simple and stepwise regression analyses showed obesity (BMI >/=32.3) to be significantly associated with increased blood loss (P <.05). Neither age, parity, previous cesarean section, nor smoking history were significantly associated with increased blood loss at dilation and evacuation.Conclusions: With advancing gestational age, intraoperative blood loss increases in curvilinear fashion. Termination providers should be advised that, although blood loss is unaffected by many factors, obese patients are at risk for increased bleeding at dilation and evacuation of pregnancies beyond 12 weeks gestation.