Obesity complicates pregnancy. Weight-loss surgery before pregnancy may help, but it can impair fetal development and cause a low-weight premature baby.
About half of all women who undergo weight-loss surgery are in their childbearing years. The surgery can help them conceive and lower their chance of gestational diabetes and hypertension. But it has other drawbacks. For one, the surgery can make it harder for a fetus to receive necessary micronutrients, according to a systematic review and meta-analysis presented at the European Congress on Obesity in Glasgow, Scotland during the spring of 2019.
The research compared more than 14,800 pregnancies in women with a history of weight-loss surgery against almost 4 million pregnancies in mothers who didn’t have the surgery. In the surgery group, babies were 57 percent more likely to be born premature, 41 percent more likely to go into a neonatal intensive care unit, 38 percent more likely to be stillborn or die within a week, and 29 percent more likely to have birth defects.
Women who had a gastric bypass were 2.7 times more likely to bear an underweight baby but had a quarter of the risk of bearing an overweight one.
The data may sound like an argument not to have weight-loss surgery if you plan to bear children. However, obesity has complications of its own. The probability of conception declines by 4 percent for each additional kg of weight once you hit a body mass index (BMI) of 29. Women with higher BMIs have a higher chance of gestational diabetes, preeclampsia, spontaneous miscarriage, and overweight babies or babies with defects. An estimated 11 percent of all neonatal deaths can be attributed to the consequences of maternal overweight and obesity. But no nutritional and lifestyle interventions have been proven to make a difference.
Children from obese mothers may also develop health complications later in life, such as hypertension, diabetes, or cardiovascular disease, due to epigenetic changes.
Weight-loss surgery has good results for women who can’t lose weight in other ways, particularly for diabetes. In one meta-analysis, more than 78 percent of bariatric surgery patients with diabetes were able to stop taking diabetes medication and maintain normal blood glucose levels two years later. About another 10 percent saw an improvement in their blood glucose control.
In an 18-year study of nearly 20,000 severely obese Americans, about half of whom had a gastric bypass, the surgically-treated group was dramatically less likely to die of cancer, heart disease, and diabetes.
If you do have surgery and want to bear a child, what can you do next to protect your health and the health of your baby? The authors of the recent meta-analysis presented in Scotland urged that weight-loss surgery patients receive nutritional counselling, including dietary supplements. Most advise holding off pregnancy for at least a year or two after the surgery in order to lose the maximum weight. But about 4 percent of women try to conceive, and another 41 percent have unprotected sexual intercourse in the first post-surgical year, research indicates. If you are taking a contraceptive pill, it may not be absorbed completely and thus be less effective after surgery.
Common nutrient deficiencies following bariatric surgery can be exacerbated by pregnancy symptoms like morning sickness or hyperemesis, gastroesophageal reflux, abdominal bloating, and pressure symptoms. It will be important to focus on a balanced diet, rather than expect to lose weight while pregnant. Instead expect to gain about 13 pounds if you have a BMI of 25 at the beginning. You will also need to be especially careful that your child is adequately nourished from breastfeeding.
December 27, 2019
Janet O’Dell RN