No Easy Path To Dropping Pounds After Pregnancy

Gaining excessive weight during pregnancy and retaining much of it after delivery is ones of the most common drivers of adult obesity in women. Emerging evidence supports the notion that both may well be detrimental to the health of mothers (and their kids). Unfortunately, it appears that behavioural intervention during pregnancy to reduce long-term weight retention is a lot more challenging that one may expect. This is the rather disappointing outcome of a randomised controlled trial by Suzanne Phelan and colleagues, published in the American Journal of Clinical Nutrition. The trial included 400 US Women, half of who were overweight or obese, randomly assigned to a behavioural intervention or control group beginning around the 13th week into their pregnancy. The intervention (Fit for Delivery) consisted of one face-to-face visit with an interventionist at the onset of treatment, the provision of body-weight scales, food records, and pedometers to promote adherence to daily self-monitoring, weekly postcards prompting healthy eating and exercise habits, personalized graphs of their weight gain with feedback, and supportive phone calls from the dietitian during the intervention. This intervention continued till delivery. Four out of five of the participants completed the 12-mo assessment. Overall the intervention did not increase the participants’ chances of achieving their prepregnancy weights. Even the completer analysis showed non-significant trends at best – this despite women in the intervention group reporting higher levels of dietary restraint and more frequent self-monitoring of body weight. Thus, this level if intervention, which far exceeds usual care during pregnancy for most women, does not appear to effectively reduce post-pregnancy weight retention. Incidentally, the only predictors of excessive weight retention were pre-pregnancy BMI and excessive gestational weight gain. Breastfeeding, age, parity, and delivery weeks were not. Thus, although excessive pregnancy weight gain and post-pregnancy weight retention are common problems with significant negative health impacts on both mother and child, it will apparently take far more than an additional visit with a dietitian and exercise counsellor or postcards and telephone reminders to impact body weight. I wonder if anyone else is not all too surprised by these findings? @DrSharma Edmonton, AB Phelan S, Phipps MG, Abrams B, Darroch F, Grantham K, Schaffner A, & Wing RR (2014). Does behavioral intervention in pregnancy reduce postpartum weight retention? Twelve-month outcomes of the Fit for Delivery randomized trial. The American journal of clinical nutrition, 99 (2), 302-11 PMID: 24284438 .

Stretching Beats Walking To Prevent Complications of Pregnancy

Preeclampsia, a potentially life-threatening complication of pregnancy, is more common in women with excess weight and there is now considerable evidence that the risk for this problem can be reduced with exercise. Interestingly, a previous randomised-controlled intervention in 124 pregnant women reported that simple stretching exercises, consisting of slow muscle movements that had neither aerobic nor muscle resistance components, performed 5 times a week starting at 18 weeks of gestation, very impressively reduced the risk of early signs of preeclampsia, compared to walking 40 mins 5 times a week (2.6% versus 14.6%). Now, a paper just published in the American Journal of Perinatology by Sowndramalingam Sankaralingam and colleagues from the University of Alberta, suggests that this difference may be due to a more positive effect of stretching exercises on reducing oxidative stress in blood vessels of these participants. Immunohistochemical analyses of blood vessels embedded in fat biopsy samples obtained during cesarean sections from some of the women who were randomized to either stretching ( N = 6) or walking ( N = 5) exercises in this larger study, showed remarkably higher expression of the antioxidant superoxide dismutase (SOD) and plasma transferrin levels, an antioxidant marker. In addition, plasma levels of transferrin continued to increase throughout gestation only among the stretchers. Thus the authors conclude that the beneficial effect of regular stretching exercises during pregnancy not only trump the benefits of walking may be attributable to the higher antioxidant protective effect of this low-intensity exercise during pregnancy. Incidentally, in the original study, walkers tended to exercised less than stretchers both overall and as pregnancy advanced, suggesting that stretching may be a better intervention as it is easier to perform and adhere to during pregnancy. While neither stretching nor walking had any effect on body weight, it is certainly worth considering that stretching exercises should perhaps be routinely prescribed and encouraged in women at risk for preecmlampsia. AMS Edmonton, Alberta Sankaralingam S, Jiang Y, Davidge ST, & Yeo S (2011). Effect of Exercise on Vascular Superoxide Dismutase Expression in High-Risk Pregnancy. American journal of perinatology PMID: 21815126

Early Pregnancy Weight Gain Predicts Gestational Diabetes

Gestational diabetes and excessive gestational weight gain have significant implications for the health of both mother and child. Anne-Sophie Morisset and colleagues from Laval University, Quebec City, Canada, now examined the relationship between weight gain early in pregnancy and the risk for gestational diabetes, in a paper just published in the Journal of Womens Health. The researchers examined data from medical records of women who delivered between January and December 2007 at the Laval University Medical Centre, which included 294 women (55 cases of gestational diabetes and 239 controls). Weight gain in the first trimester was significantly higher in patients who developed gestational diabetes than in controls (3.4 vs. 1.9  kg), whereas whereas weight gain in the third trimester was significantly lower in diabetes patients compared to controls (4.1 vs. 6.3 kg). Both prepregnancy BMI and first trimester weight gain were significant and independent predictors of diabetes suggesting that both preconception weight as well as weight gain during the first trimester may warrant greater clinical attention. This is particularly important given the discussions and concerns about the fetal development theory of epigenetic program, which many today believe to be one of the key drivers of childhood obesity. AMS Edmonton, Alberta Morisset AS, Tchernof A, Dubé MC, Veillette J, Weisnagel SJ, & Robitaille J (2011). Weight Gain Measures in Women with Gestational Diabetes Mellitus. Journal of women’s health (2002) PMID: 21332414

Excess Weight Gain in Pregnancy Leads to Bigger Babies

Readers of these pages are by now quite familiar with the increasing evidence showing that what happens to the fetus in utero may be a key determinant of obesity risk later in life. Thus, both small-for-gestational-age and large-for-gestational-age babies appear at increased risk for becoming obese kids (and adults). One of the important determinants of infant weight is the magnitude of maternal weight gain in pregnancy. But how strong is this relationship really? This question was now examined by David Ludwig (Harvard) and Janet Currie (Columbia) in a paper published last month in The Lancet. The researchers examined data from a population-based cohort study that included all known births in Michigan and New Jersey, USA, between Jan 1, 1989, and Dec 31, 2003, or a total of 513 501 women and their 1,164,750 offspring. Using a within-subject design to reduce confounding to a minimum, they noted a strong and consistent association between pregnancy weight gain and birthweight: infants of women who gained more than 24 kg during pregnancy were almost 150 g heavier at birth than were infants of women who only gained 8-10 kg. Women who gained more than 24 kg during pregnancy were more than twice as likely to give birth to an infant weighing more than 4000 g than women who only gained 8-10 kg. In light of the increasing evidence that larger infants are much more likely to become overweight and obese children (and later adults), this study certainly supports the need for efforts to prevent excessive weight gain during pregnancy. Targeting obesity prevention and treatment strategies to younger women and limiting excessive weight gain during pregnancy, may well be the single most effective way to prevent obesity in future generations. AMS Edmonton, Alberta Ludwig DS, & Currie J (2010). The association between pregnancy weight gain and birthweight: a within-family comparison. Lancet, 376 (9745), 984-90 PMID: 20691469

New Guidelines Advise Limiting Weight Gain in Pregnancy

Regular readers of these pages are aware of my concerns about how excess weight gain in pregnancy can adversely affect both mother and infant (click here for previous posts on this). This issue is now addressed in a comprehensive new guideline from the Institute of Medicine that reexamines this issue (click here for summary of guideline). This guideline follows on the heels of previous recommendation from the American Dietetic Association and the American Society for Nutrition, published last year. The report not only sets new levels for weight gain in pregnancy, but also addresses the issue of preconceptual weight given that one of the most important modifiers of pregnancy weight gain and its impact on a mother’s and her baby’s health is a woman’s weight at the start of pregnancy. The two major differences to previous guidelines are: firstly, the recommendations are now based on the WHO BMI categories rather than the now obsolete Metropolitan Life Insurance tables. Second, the new guidelines include a specific and relatively narrow range of recommended gain for obese women. It will remain to be seen how successfully these recommendation will be translated into practice. AMS Montreal, Quebec