Approaching pregnancy with a healthy body is common sense, but a new study published in the British Medical Journal has quantified the risks of maternal obesity, finding that children born to obese mothers are more likely to die prematurely in their later adult years.
The authors of the BMJ study say that in the US, about 64% of women in the child-bearing age bracket are overweight and 35% are obese, creating "a major public health concern" for high-risk groups of people who should be assessed for their cardiovascular risk.
Researchers in Scotland who led the study used birth and death records beginning in 1950 and continuing to the present day. In total, they analyzed 28,540 women's files, which included a body mass index (BMI) reading from the first antenatal visit. The researchers also studied the resulting 37,709 offspring aged between 34 and 61 at the time of follow-up visits.
The researchers classified the women by four groups:
- Underweight - BMI of 18.5 or under
- Normal weight - BMI between 18.5 and 24.9
- Overweight - BMI between 25 and 29.9
- Obese - BMI of 30 or more.
Of the women in the study, 21% were overweight and 4% were obese, which is a decidedly lower rate than today's numbers in the US cited by the researchers, of 65% and 35%, respectively.
Still, the results showed that the risk of premature death for the adult offspring of obese women, compared with offspring of normal weight mothers, was 35% higher.
Children of obese pregnant women had a higher risk of early death as adults
Additionally, there was a 42% higher risk for being admitted to the hospital due to a "cardiovascular event" in the adult offspring of obese mothers.
The findings show that the main cause of death from the entire offspring population was cardiovascular disease (24% of male deaths and 13% of female deaths) and cancer (26% of male deaths and 42% of female deaths).
The results adjusted for factors such as the mother's age at delivery, previous pregnancies, parental social class, as well as the infant's sex, weight and gestation at birth, say the researchers.
In an editorial response to the study, Pam Factor-Litvak from Columbia University notes that maternal obesity has already been associated with risks for the mother, including increased mortality, pre-eclampsia and diabetes.
However, she also says this recent study is the first to link maternal obesity and risk of cardiovascular death in mid-life.
She notes that there may be some implications after the findings of the recent study:
"The US Institute of Medicine guidelines, adopted in 2009, recommend weight gains of 15 lbs. to 25 lbs., and 11-20 lbs. for overweight and obese pregnant women, respectively, with no more than 0.6-0.5 lb weight gain per week in the second and third trimesters."
Because these recommendations were made to balance risks involving fetal growth and other complications, Pam Factor-Litvak notes that appropriate diet and exercise should be discussed during pregnancy.
The authors of the study conclude by noting:
"Our findings highlight the urgent need for strategies to prevent obesity in women of childbearing age and the need to assess the offspring of obese mothers for their cardiovascular risk."