SCOTTSDALE, ARIZ. — A prospective observational study of 1,656 cesarean deliveries has produced a detailed portrait of factors leading to longer than usual operating times and the effects of long procedures on pregnancy outcomes.
Cesarean delivery is likely to be prolonged when a woman is older or overweight, according to data presented by investigator Everett F. Magann, M.D., at the annual meeting of the Central Association of Obstetricians and Gynecologists.
Dr. Magann reported that maternal age above 35 years and a body mass index of 30 kg/m
Dr. Magann suggested that obstetricians may want to consider requesting stronger backup when they perform a cesarean delivery on a woman who is older and overweight.
“Maybe call a partner in and get more experienced help,” he said, noting that longer procedures had negative effects on pregnancy outcomes.
“The most significant is that blood loss was increased, so you want to do your operation in a timely manner,” Dr. Magann of the Naval Medical Center in Portsmouth, Va., said in an interview.
He and his associates were surprised by two factors that turned out not to prolong cesarean delivery. “Surprisingly, endometriosis and wound separation were unrelated to the operation time,” they reported in a list of conclusions on the poster.
In the interview, Dr. Magann mentioned that the review also brought another surprise: “We didn't find [that] the longer you operate, the greater your risk of infection,” he said, noting that increased risk of infection is often assumed in this situation.
Women with preexisting hypertension or a low segment transverse scar from a previous cesarean operation were more likely to have longer procedures.
Other factors that contributed significantly to added time in the operating room were a uterus incision other than a transverse incision, having a first-year resident as the primary physician, and performance of a sterilization procedure during the operation.
Blood loss in excess of 1,000 mL was more than twice as likely (odds ratio 2.16) in operations lasting 30–60 minutes, compared with those lasting 30 minutes or less. The odds ratio rose to 6.93 in operations that lasted longer.
Patients whose cesarean delivery lasted longer than 60 minutes also were nearly three times more likely to have their umbilical artery pH level register below 7.1. In addition, their babies were nearly three times more likely to have Apgar scores below 7 at 5 minutes.
Risk of respiratory distress syndrome also increased with longer operating time; the odds ratio became 2.43 at 30–60 minutes and 4.07 after 60 minutes.
Nearly three-quarters (1,207/1,656) of women in the study were African American. Another 19% (315/1,656) were white. The women, more than half of whom were nulliparous, were 24.8 years old on average.
The investigators reported that 693 women had a previous cesarean delivery. About a third of this group (232 women) had at least two prior cesarean deliveries.
Complications occurred in 728 pregnancies (44%). Preeclampsia was the most common, occurring in 337 women. It was followed by gestational diabetes in 134 women, preterm premature rupture of membranes (76), congenital abnormalities (53), and intrauterine growth restriction (28).
Forty minutes was the median operative time in the study, which divided the women into three cohorts for the analysis. Only 386 deliveries (23%) were completed in 30 minutes or less. Nearly two-thirds (1,070 deliveries) took 31–60 minutes. The remaining 200 deliveries lasted longer than 60 minutes.
The study showed that the only factors associated with shortened delivery time were maternal age less than 18 years and fetal distress.