Health Problems Follow Pregnancy Weight Gain

Most women gain weight during pregnancy — and they should. They are eating to sustain a growing fetus, and their bodies are carrying that developing baby.

Women should expect to gain between 25 and 35 pounds during the course of their pregnancy according to the National Institutes of Health. If they start out overweight, they will need to gain less; and if they are underweight, they may need to gain more.

When pregnancy weight gain lasts for a year or more postpartum, it can set in motion some serious health problems.

The average weight gain is typically two to four pounds during the first trimester and about a pound a week for the rest of the pregnancy. Though gaining weight is expected, your obstetrician will monitor you to be sure you aren't gaining too much or too little. Eating a well balanced diet and exercising regularly help ensure a healthy, full-term infant.

For many women, simply giving birth relieves them of much of the excess weight of pregnancy. And those who decide to breastfeed may find it helps take off even more pounds. But what happens if the “baby weight” persists after the baby is delivered?

A new study suggests that when the weight gain of pregnancy lasts for a year or more postpartum, it can set in motion some serious health problems — especially if the new mother goes on to have more children.

Previous studies have already shown that there is a cumulative impact when successive pregnancies result in retained weight over the years. And now we know that the overweight resulting from back-to-back pregnancies increases the risk of both metabolic and cardiac disease in a women’s life, according to a new study by researchers at Mount Sinai Hospital in Toronto.

The extra fat women are still carrying at six and 12 months post-delivery tends to be visceral fat that accumulates at the waistline. This is more dangerous because it is being deposited around internal organs, unlike subcutaneous fat that is simply under the skin on one's thighs or buttocks, for example.

The belly fat also carries a higher metabolic risk similar to the blood sugar issues that can cause gestational diabetes. The health risks to women's hearts are equallly serious.

The study followed about 200 pregnant women and tracked their metabolic and cardiac health status both when they were pregnant and at three and 12 months after giving birth.

Women were screened for glucose tolerance (a sign of a tendency toward diabetes) and questioned about their physical activity levels. Their blood pressure was checked, and their weight and waist circumference were measured. Researchers then compared these health indicators to their weights and looked to see how patterns of weight loss affected the results.

Women who did not lose the weight they had gained during pregnancy, or who even gained a few pounds during that first year, had elevated blood pressure and glucose levels at 12 months postpartum.

Most of the women — three-quarters of them — lost at least some of their excess baby weight by the end of their baby's first year.

But those women who did not lose the weight they had gained during pregnancy, or who even gained a few pounds during that first year, showed definite signs of heart- and diabetes-related health problems.

At 12 months postpartum those still carrying the excess weight had elevated blood pressure and glucose levels, even though these risky heart and diabetes measures hadn't been seen when they were checked at the three-month mark.

This suggests that the negative effects of the excess post-childbirth weight begin pretty early, despite the fact that new mothers are generally quite young. The effects of the metabolic changes accompanying post-pregnancy weight gain build as women age, especially if they have more children and if the weight is not lost.

The researchers, led by Ravi Retnakaran, an endocrinologist at Mount Sinai Hospital in Toronto and associate member at the Lunenfeld-Tanenbaum Research Institute, see this pattern of post-pregnancy weight gain as a red flag, signaling women at higher risk for cardio-metabolic disease.

The year after childbirth is an important window of opportunity for weight loss.

Women who reported more physical activity, particularly those who were involved in sports, were less likely to gain weight between three and 12 months after delivery and more likely to lose the weight they had gained during pregnancy.

The year after childbirth is an important window of opportunity for weight loss. The researchers recommend that new mothers having trouble losing the weight they gained during pregnancy be eligible for counseling and nutrition and exercise interventions to promote healthy weight loss and prevent the metabolic fallout that the excess belly fat can bring.

The study is published in Diabetes Care.