Antepartum nonobstetrical surgery at ≥23 weeks' gestation and risk for preterm delivery

We sought to describe the influence of antepartum nonobstetrical surgical procedures performed at viable fetal gestational ages (GAs) on incidence of preterm delivery.

This was a retrospective case series of patients requiring nonobstetrical surgery at ≥23 weeks' gestation at the Mayo Clinic during the interval 1992 through 2014. Data were abstracted for maternal demographic variables, operative procedure, anesthetic type, whether intraoperative fetal monitoring was employed, and both GA and method of delivery.

In all, 111 patients underwent 121 operative procedures at a mean GA of 29.2 weeks (range, 23-37 weeks). The majority of procedures were completed under general anesthesia (88/121, 73%), with intraoperative fetal monitoring performed in 14 cases (14/121, 12%); fetal loss occurred during a single unmonitored procedure. Outcome data were available for the majority of patients (86/111, 78%) with preterm delivery occurring in 41% (35/86) at a mean GA of 36.9 weeks (range, 25-41 weeks). Mean interval from procedure to delivery was 7.7 weeks, with 9 patients (9/86, 10%) delivering within 1 week of surgery. Neither procedures requiring entry into the abdominal cavity (P = .65) nor GA at time of procedure (P = 1.0) statistically influenced the risk of preterm delivery.

Nonobstetrical surgical procedures performed at or beyond fetal viability increased the incidence of preterm delivery regardless of surgical site or timing of procedure, however the risk of intraoperative or immediate postoperative obstetrical complications was relatively low.