High post-pregnancy BMI raises pelvic organ prolapse risk

Maintaining a normal body mass index (BMI) is important for good cardiovascular health and blood sugar control, but maintaining it after pregnancy can also be key to preventing pelvic organ prolapse, according to a new study by Yale School of Medicine researchers.

The findings are published in the journal Reproductive Sciences.

Yale researcher Dr. Marsha K. Guess and her colleagues collaborated with first author Dr. Yi Chen, from Wenzhou Medical College in Zhejiang, China to analyze data from a prospective study of 108 women. They evaluated the role of BMI on pelvic organ prolapse from the women’s pregnancy through the first year after delivering their first baby. The team recorded the participants’ BMI and gave them a pelvic organ prolapse assessment.

“We found that an important risk factor for prolapse for women one year after delivery was their BMI, regardless of their baseline BMI at the first trimester, or how much they gained during pregnancy,” said Guess. “Specifically, the higher the BMI one year after delivery, the higher the risk for having pelvic floor laxity and increased odds for early stage pelvic organ prolapse.”

Pelvic organ prolapse is a common condition among women who have given birth vaginally, affecting up to 50% of women over age 40. Hormonal changes, increased pressure, and the baby’s passage through the birth canal can damage connective tissue, muscles, nerves, and blood vessels. The vagina and the surrounding organs relax, lose their support, and fall from their normal positions, leading to a host of complications such as urinary incontinence and poor bowel control. It is thought that some women are genetically predisposed to having an abnormal repair process after delivery, which may also contribute to pelvic organ prolapse.

Increasing BMI in non-pregnant women has been found to be a risk factor for developing prolapse, but the mechanism is unknown. This study suggests that maintaining a healthy weight after delivery is also important for good pelvic floor support.

Guess and her team found that on average, women in their study gain 1.9 kg (4.2 pounds) between baseline and one year postpartum

“Our findings show that even small differences in BMI one year after delivery can lead to pelvic floor laxity in normal-weight women,” said Guess. “These results shed light on a potential critical, time-dependent opportunity to modify the risk of developing pelvic organ prolapse for some women.

“Getting women into a routine of healthy diet and exercise habits, and back to their baseline weight after delivery may play an important role in preventing the early stages of prolapse,” she noted.

Other authors on the study include Benjamin Johnson, Fangyong Li, William C. King, and Dr. Kathleen Connell.

The study was funded in part by the Ministry of Health of Zhejiang Province.