Preterm labor and Surg
As many as 2% of pregnant women undergo anesthesia for non-obstetric surgery during their pregnancy [Rosen, 1999]. The second trimester is considered the safest time to undergo nonobstetric surgery (once organogensis is completed), but there are still concerns of fetal hypoxia due to increasing metabolic demands and accidental induction of premature labor. In a study to evaluate the safety and timing of abdominal surgery during pregnancy, 77 gravid patients undergoing nonobstetric abdominal surgery were retrospectively reviewed for clinical presentation, perioperative management, preterm labor, and maternal and fetal morbidity and mortality. Preterm labor occurred in 26% of the second-trimester patients and 82% of the third-trimester patients. [Visser, et al., 2001].
It is generally thought that it is the pathology leading to surgery is more likely to induce preterm labor than the surgery itself. Outcomes studies in large numbers of women who underwent surgery during pregnancy show no increase in congenital abnormalities, but a greater risk of abortion, growth restriction, and low birth weight. This suggests that it is the surgical disease or procedure rather than the exposure to anesthesia that can increase the risk of preterm labor [Goodman, 2002].