STOCKHOLM – Women had a more than six-fold increased risk of developing diabetes more than a decade after they gave birth if they were overweight or obese at the start of their pregnancy, according to the results of a large epidemiological study.
The odds ratio for the development of diabetes was 6.4 (95% confidence interval, 3.5-11.6, P < .001) comparing women who had a body mass index above 25 at the start of pregnancy with those who were of a lower body weight.
The heavier women also were more likely to be obese (OR, 21.9; 95% CI, 16.3-29.5; P< .001), have developed cardiac (OR, 2.7; 95% CI, 1.5-4.9; P= .001) or other endocrine (OR, 2.3; 95% CI, 1.5-3.4; P< .001) diseases 10-17 years later.
Sara Freeman/Frontline Medical News
Dr. Ulrika Moll
“A high pre-pregnancy BMI significantly increases the risk of several diseases later in life, including diabetes and cardiac disease,” Dr. Ulrika Moll of Lund University, Sweden, said at the annual meeting of the European Association for the Study of Diabetes.
The amount of weight gained during the pregnancy did not appear to matter, with no increase in the risk of cardiac or endocrine disease, even in women who gained more than the recommended weight set by the Institute of Medicine (IOM) guidelines. The IOM recommends that that women who are overweight should gain no more than 7–11.5 kg and those who are obese no more than 5-9 kg during their pregnancy. The mean maternal weight gain was 14.7 kg in the overweight group and 8.9 kg in the obese group.
Gaining more than 15 kg versus ≤15 kg during pregnancy did double the likelihood of women being overweight or obese in later life. A larger weight gain appeared to be protective against development of later psychiatric disease (OR, 0.6; 95% CI, 0.4-0.9; P= .03).
“A high weight gain during pregnancy did not have any implications on metabolic diseases within 10 years in our cohort,” Dr. Moll said. “These results have implications for the urgency of identification and care of the young women of childbearing age who struggle with being overweight or obese.”
Previous studies have shown that women who are overweight before they are pregnant and those that gain excessive amounts of weight during their pregnancies are more likely to experience poor outcomes, such as developing gestational diabetes or hypertension, needing a Cesarean section, giving birth prematurely, or having a larger baby. There was also some evidence that a high BMI at the start of pregnancy increases the risk form heart attack or stroke.
The aim of the current study was to see if a high maternal body weight at the start of pregnancy and a high or low gestational weight gain were associated with diseases later in life. Dr. Moll and associates used a population-based cohort of 23,524 women from southern Sweden and 30,559 records from the Swedish Medical Birth Register to find women who had at least one pregnancy and had completed a self-reported health questionnaire 10-17 years afterwards.
A total of 13,608 women were identified who had a mean pre-pregnancy BMI of 21.9, a follow-up BMI of 24.6 , and a mean gestational weight gain of 14.5 kg. Women were divided into groups based on their pre-pregnancy BMIt (≤25 or >25) and amount of they weight gained during their pregnancy (≤15 or >15 kg).
At follow up, the crude rates of diabetes, cardiac, and endocrine diseases were 1.6%, 3.3%, and 7.1%. There was a 0.4% rate of stroke and 2.3% rate of psychiatric disease; 37% of women were overweight, and 9.4% were obese.
In an interview, Dr. Naveed Sattar, professor of metabolic medicine at the Institute of Cardiovascular and Medical Sciences, University of Glasgow, Scotland, provided an independent comment on the findings. He said the data “strongly reiterate that the BMI with which you enter pregnancy gives you not only pregnancy complications but means that you are much more likely to be obese later on.”
Dr. Sattar added: “The interesting thing that it showed beautifully was that weight gain in pregnancy is inversely associated with the BMI at the beginning of pregnancy, so women who actually gain the least weight in pregnancy are the most obese. That suggests to me that the IOM criteria are very crude and perhaps not that useful.”
The IOM criteria may need reevaluation, he suggested. “The most important fact is that your weight when entering pregnancy is much more important than any weight gain during pregnancy,” he noted.
Dr. Moll had no conflicts of interest to disclose. Dr. Sattar had no disclosures relevant to his comments.