Gaining too much weight or too little during pregnancy can lead to increased childhood cardiometabolic risk factors, including adiposity, hypertension and insulin resistance, according to findings published in Diabetologia.
“The risk of obesity and diabetes increase in offspring of mothers who have obesity or diabetes. This intergenerational cycle of diabetes and obesity may be an important contribution to the escalating obesity and diabetes seen in many parts of the world,” Ronald C.W. Ma, MD, professor and head of the division of endocrinology and diabetes in the department of medicine and therapeutics at The Chinese University of Hong Kong, told Endocrine Today. “Prospective mothers who plan to become pregnant need to be aware of the risks and long-term impact of gaining excessive weight during pregnancy. ‘Eating for two’ is a myth that needs to be dismissed.”
Ma and colleagues examined data from 905 mother-child pairs of Chinese ancestry that reached full-term pregnancies and used 2009 Institute of Medicine recommendations for gestational weight gain to determine when participants gained too much or too little during pregnancy. Self-reported weight was used to calculate BMI before pregnancy, and medical records provided weight at delivery. The participants returned 7 years after delivery to record the anthropometric indices of the children. These assessments took place between 2009 and 2013.
The researchers noted a mean BMI of 20.9 kg/m2 for participants before pregnancy. Weight gain after delivery averaged to 15.2 kg, with 41.8% of the women meeting the Institute of Medicine guidelines (n = 378), 41% exceeding recommended weight gain (n = 371) and 17.2% falling below (n = 156).
In models adjusted for child sex, age and height, significantly higher BMI (P = 1.3 x 10-7), diastolic blood pressure (P = 1.4 x 10-3), diastolic BP percentile (P = 9.7 x 10-4), systolic BP percentile (P = .0185), fasting plasma insulin (P = .0146), 2-hour insulin (P = 1.2 x 10-3), homeostatic model assessment of beta-cell function (P = 4.2 x 10-4), HOMA-insulin resistance (P = .039) and pancreatic beta-cell function (P = 6.6 x 10-4) and Matsuda insulin sensitivity index (P = 6 x 10-4) were found among the children born to mothers who gained more weight than recommended compared with those who met recommendations. Children born to mothers with inadequate gestational weight gain also had higher diastolic BP percentile (P = .0186), 2-hour insulin area under the curve (P = .0158), pancreatic beta-cell function (P = 7.9 x 10-3) and Matsuda insulin sensitivity index (P = .0477) compared with those with recommended amount of weight gain.
“Our findings suggest that the effect of maternal [gestational weight gain] on childhood cardiometabolic risk is not confined to the upper and lower extremes of [gestational weight gain], but rather this relationship is a U-shaped continuum,” the researchers wrote.
“It is often too late to try to intervene during pregnancy,” Ma said. “It is best to try to optimize body weight before pregnancy in order to achieve the best outcome. Young women need greater awareness of the importance of healthy diet and lifestyles and the health risks of obesity.”
Conclusions from the study have limitations, especially as it pertains to the Chinese population, the researchers wrote. The Institute of Medicine recommendations are based on “standard BMI thresholds,” which have yet to be determined in China.
“The definition based on prepregnant BMI for overweight and obesity in [Asia] is different,” Wing Hung Tam, MD, professor in the department of obstetrics and gynecology at The Chinese University of Hong Kong, told Endocrine Today. “We need [a] large population study to tell what kinds of weight gain is most appropriate for the underweight, normal weight, overweight and obese mothers.” – by Phil Neuffer