Time to Limit Weight Gain in Pregnancy?Wednesday, April 16, 2008
Regular readers of my blog will have noticed several previous postings on the issue of maternal obesity and health risk for mother and infant.
This issue seems to be developing into a really “hot topic”, at least judging from the flurry of articles in the most recent alerts from CON/McMaster University’s OBESITY+ services.
The first was a nested case-control study comparing 251 mothers who developed gestational diabetes to matched normal controls, both selected from a multiethnic cohort of 14,235 women. In this study, Monique Heddersen and colleagues from Kaiser Permanente, Oakland, CA, demonstrated that women who gained significant amount of weight in the five years preceding their pregnancy, had a 2.5-fold higher risk of GDM compared to women with stable weight. Gestational diabetes has been linked to increased birth weights and later risk of obesity in the offspring (American Journal of Obstetrics and Gynecology, April 2008).
In the same issue of AJOG, Holly Hull from Columbia University, New York, NY, compared body weight and composition (air-displacement plethysmography) in 33 neonates born to mothers with a normal pregravid BMI to 39 neonates born to overweight/obese mothers with normal glucose tolerance. Babies born to normal BMI mothers had significantly less total and relative fat and more fat-free mass than babies born to overweight/obese mothers. Although preliminary, the authors interpret these data to suggest (and I agree) that the antecedents of future disease risk (eg, cardiovascular disease, diabetes, and obesity) occur early in life.
So what, if anything, can we do about this?
That question was addressed by Wolff and colleagues from the University of Copenhagen, who performed a randomized controlled trial in 50 obese mothers (pre-pregnancy BMI around 35) with or without restriction of gestational weight gain to 6-7 kg by ten 1-h dietary consultations. Not only did the women in the intervention group successfully limit their energy intake to restrict gestational weight gain to 6.6 kg (vs. a gain of 13.3 kg in the control group) but this was associated with a significantly reduced fasting glucose and insulin levels in the intervention group with no apparent harm to the babies. Thus, restriction of gestational weight gain in obese women is achievable and reduces the deterioration in the glucose metabolism. (International Journal of Obesity, March 2008)
Together these studies clearly support the importance of addressing obesity in mothers before and during pregnancy – an intervention that will hopefully prove beneficial to both mother and child.
So while weight management should probably soon become part of routine prenatal care, I do wonder how long it will take before we start seeing a whole new wave of “weight-loss-in-pregnancy” products and services from the ever vigilant and enterprising weight-loss industry.
Hopefully not too soon!