By Kathryn Doyle
NEW YORK (Reuters Health) - Cesarean sections take longer, on average, when new mothers are obese, according to a recent study.
More time isn't necessarily a bad thing and may indicate that the doctor was taking extra care not to damage the woman's tissues, said lead author Dr. Shayna Conner.
"But, if a baby is in trouble and needs to be delivered quickly, a slower cesarean can potentially lead to complications," Conner, of Washington University School of Medicine in St. Louis, Missouri, told Reuters Health.
The anesthesia used during the procedure can affect blood pressure, researchers said, and blood pressure drops during delivery can slow the baby's heartbeat to a dangerous point.
Conner and her coauthors looked back at the records of every C-section performed at one hospital between 2004 and 2008 and divided the more than 2,000 mothers into four groups based on their body mass index (BMI), a measure of weight in relation to height, when the baby was born.
For men and women who aren't pregnant, a BMI of 30 and above is considered obese by the Centers for Disease Control and Prevention.
A five-foot, five-inch woman would have a BMI of 30 at 180 pounds, a BMI of 40 above 240 pounds and a BMI of 50 above 300 pounds.
Women in the study with a BMI under 30 had an average time from surgical incision to delivery of 9.4 minutes.
That compared to 11 minutes for women with a BMI between 30 and 40, 13 minutes for women with a BMI between 40 and 50 and 16 minutes for women with a BMI of 50 and above, according to results published in the American Journal of Obstetrics and Gynecology.
"An additional seven minutes from incision to delivery can potentially lead to complications with the baby in emergency situations," Conner said.
As women's BMI increased above 40, babies tended to have more problems at birth, such as more acidic blood in the umbilical cord, than babies of non-obese mothers. More acidic cord blood indicates that the baby is distressed, Conner said.
Two smaller previous studies did not find a link between longer delivery times and problems with the baby, she noted.
"Having observed many C-sections as a neonatologist, I've seen that patient obesity makes surgeons' work more complicated like many other medical maneuvers from IV insertion to surgery," said Dr. Ayala Maayan-Metzger of Sheba Medical Center at Tel Hashomer, Israel, who was not involved in the study.
Although it makes sense that longer delivery times mean a greater risk of problems with fetal blood flow, her own study on incision-to-delivery times in elective C-sections did not find a link to infants' health, Maayan-Metzger told Reuters Health by email.
The current study included emergency C-sections, where time may be more important, she said.
Women should be encouraged to attain a healthy weight prior to pregnancy and to gain the recommended amount of weight while pregnant, Conner said. According to the Institute of Medicine, that is 25 to 35 pounds for normal weight women and 11 to 20 pounds for obese women.
Conner said doctors should also try to optimize care for heavier women, such as by exploring different surgical techniques tailored to their needs.
"Cesarean deliveries are performed every day across the nation, and can be life-saving, but they are major surgery and do pose an increased risk to obese women," she said.
"Obese women can do their part by working to achieve a healthy weight prior to pregnancy, and physicians can work to find techniques and interventions to help decrease these risks."
SOURCE: http://bit.ly/133XuXq American Journal of Obstetrics and Gynecology, online July 15, 2013.