written by Marie Aungst


You can try and hide from it but there’s no way around it, maternal weight gain affects both the mother and her fetus. Women today are heavier than they were two decades ago and an increasing number of mothers are entering pregnancy overweight or obese, and are often gaining too much weight during their pregnancy. There are several possible adverse affects to being overweight or obese before or during pregnancy. Labor and delivery complications are common in these individuals, as well as, delivery of large-for-gestational-age infants (LGA), birth defects, maternal complications (hypertension, gestational diabetes, preeclampsia), and even fetal and neonatal death. So it’s no surprise that in 2009, The Institute of Medicine (IOM) updated their 1990 recommendations for weight gain during pregnancy in their report, Weight Gain During Pregnancy: Reexamining the Guidelines. These new guidelines consider factors that affect pregnancy-related outcomes before conception, during pregnancy, and throughout the first year following delivery. 
A mother’s pre-pregnancy weight, pattern of weight gain, and total gestation weight gain can affect both the immediate and long term health of the infant and may predispose the mother to future health concerns (4). According to The Journal of Clinical Nutrition’s article, Maternal Obesity and Excess Pregnancy Weight Gain Increase Risks in Babies, a research study done by the researchers at the National Institutes of Health (NIH) and the New York State Department of Health, showed that women who are obese (BMI >30) tend to have 15% more babies with congenital heart defects and severely obese women (BMI >40) were shown to have an increase of 33% more babies with congenital heart defects than women within the normal BMI range. The Journal of Clinical Nutrition article also examined two other studies. One study found that women who were severely obese (BMI >40) had better fetal growth and a decreased risk of preterm birth when they had very little prenatal weight gain, while somewhat more weight gain was protective to better fetal growth in less obese mothers. The last study examined showed that a decreased weight gain during pregnancy in obese women was beneficial because it decreased the risk of childhood obesity in those babies (2).

The new IOM recommended ranges of weight gain are now based on pre-pregnancy Body Mass Index (BMI) since, as studies have shown, obese women don’t need to gain as much weight as healthy weight woman during pregnancy. This narrows the recommended amount of weight that an obese woman (BMI >30) should gain to a range of 11-20 pounds, which is a decrease from the old standard of at least 15 pounds of weight gain with no maximum limit. The new suggested weight gain for other pre-pregnancy weight groups are shown in table 1-1 (3).

Table 1-1


BMI                              Desired Weight Gain (lbs)        Energy                       

Underweight <18.5                   28-40                             + 340 cal/day 2nd trimester           

Average        18.5-24.9            25-35                            +452 cal/day 3rd trimester

Overweight   25-29.9               15-25           

Obese           >30                      11-20           

Twins                                       35-45                       


What about Gestational Diabetics? Gestational diabetes (GDM) typically occurs during the 2nd and 3rd trimesters. Gestational diabetes can lead to complications such as early delivery, c-sections, Type II Diabetes Mellitus, and an increased risk of baby developing diabetes and obesity later in life. The GDM weight gain guidelines are now also based on pre-pregnancy weight and are the same as those guidelines for non-gestational diabetics. If diagnosed with gestational diabetes, you should limit excess carbohydrates at meals and consume adequate calories to avoid maternal ketosis. Monitoring blood glucose levels is extremely important for gestational diabetics. Self-monitoring blood glucose (SMBG) goals in GDM are shown below in table 1-2 (1).


Table 1-2

                                                                        SMBG Goals

Fasting                                                                    60-90 mg/dl

1 hour post-prandial                                                <120 mg/dl             

 
            Implementation of the IOM’s new pregnancy weight gain guidelines calls for an extreme change. The possibility of discussing pre-pregnancy contraception options, and counseling on both healthy diet and physical activity may be the interventions that overweight women need to meet a healthy pre-pregnancy weight. IOM’s new guidelines, combined with other pre-pregnancy interventions could ultimately lead to an increased number of normal infant birth weights, possibly reduce the number of birth defects and postpartum weight retention, decrease childhood obesity, and improve overall long term health.

Works Cited

 

1. AADE Webinars. Gestational Diabetes: Successful Pregnancies. American Association of Diabetes Educators. 5 May 2010.

2.“Maternal Obesity and Excess Pregnancy Weight Gain Increase Risks in Babies.” Journal of Clinical Nutrition. June 2010. 22 June 2010  http://www.ajcn.org/misc/release1.dtl

3. Mitchell, David. “Physicians Urged to Offer More Counseling on Diet, Exercise.” IOM Updates Guidelines for Weight Gain in Pregnancy 2 June. 2009. 23 June 2010. http://www.aafp.org/online/en/home/publications/news/news-now/clinical-care-research/20090602iom-weight- 4. “Weight Gain During Pregnancy: Reexamining the Guidelines.” National Academies of the Sciences. May 28, 2009. 24 June. 2010 http://www.iom.edu/Reports/2009/Weight-Gain-During-Pregnancy-Reexamining-the-Guidelines.aspx