GUANGZHOU, Aug. 24 (Xinhua) -- Moms-to-be who control their weight gain between 22 and 26 weeks into pregnancy can significantly lower the risk of high blood pressure, a new study has found.
Unregulated weight gain during pregnancy is known to increase the risks of weight retention, hypertension, metabolic syndrome in women after delivery and affect babies' metabolism and cardiovascular health.
However, it had not been clear to scientists whether a "time window" exists within the 40 weeks of pregnancy during which weight gain has a notable result on blood pressure.
The study led by Niu Jianmin, a professor at Shenzhen Maternity and Child Healthcare Hospital, discovered a sharp rise of diastolic pressure closely linked to weight gain in mid-pregnancy.
While a steady weight increase of about 450 grams per week is normal for pregnant women, extra pounds they put on can be harmful. For every additional 200 grams per week, the risk for hypertension is increased by 20 percent, according to the study, whose findings are based on data collected from 1,112 women through all stages of pregnancy.
The study was published this week in the peer-reviewed American journal Hypertension. It also revealed a "rebound" curve of the diastolic pressure throughout pregnancy while the systolic pressure rose more slowly and steadily.
Hypertension is defined as having blood pressure higher than 140/90 mmHg. The top number is the systolic pressure, the bottom the diastolic.
Niu said as more Chinese couples opt for a second child due to the relaxed family planning policy, the number of older women becoming pregnant has greatly increased.
"Advanced maternal age is a high risk factor for hypertension in pregnancy, which is a major cause of maternal and infant mortality," he said. "That's why we need research into the matter for the health of mothers and children."
