Risk remains even when mother's blood pressure stays within normal range.

When expectant mothers have elevated blood pressure during pregnancy, it may raise their children’s risk of developing childhood obesity, according to a study published in the Journal of Clinical Endocrinology & Metabolism.

“Our study is the first to demonstrate that among pregnant women, elevated blood pressure is associated with a greater risk of overweight and obesity for their children,” said the study’s first author, Ju-Sheng Zheng, PhD, of Qingdao University in Qingdao, China, and the University of Cambridge in Cambridge, U.K. “The risk still existed for children of women who didn’t have hypertension, but whose blood pressure during pregnancy was at the high end of the normal range.”

The prospective cohort study examined blood pressure levels and weight in 88,406 mother-child pairs who participated in the Jiaxing Birth Cohort in southeastern China between 1999 and 2013. The researchers analyzed the women’s blood pressure results from the three trimesters of pregnancy. During follow-up visits, the children were weighed when they were between the ages of 4 and 7. Among women who were hypertensive during the second trimester, their children were 49 percent more likely to be categorized as overweight or to have obesity compared to children of mothers who had lower blood pressure levels. Children of women with high blood pressure during the third trimester were 14 percent more likely to meet the criteria for overweight or obesity. The mother’s body size prior to pregnancy did not affect the association.

"The results indicate that all pregnant women and their doctors should monitor and try to limit a substantial increase in blood pressure in mid-to-late pregnancy,” Zheng said. “This may help reduce the likelihood of their children being affected by obesity.”

Other authors of the study include: Huijuan Liu and Yuhong Guan of the Jiaxing Maternity and Child Health Care Hospital in Jiaxing, China; Ken K. Ong and Yuan Huang of the University of Cambridge in Cambridge, U.K.; Tao Huang of the National University of Singapore in Singapore; Bo Yang of Wenzhou Medical University in Wenzhou, China; Fenglei Wang of Zhejiang University in Hangzhou, China; and Duo Li of Qingdao University and Zhejiang University.

The study is titled, “Maternal Blood Pressure Rise During Pregnancy and Offspring Obesity Risk at 4-7 Years Old: The Jiaxing Birth Cohort.”