Obesity in pregnancy linked to early puberty for girls

[May 05, 2018]  By Lisa Rapaport

(Reuters Health) - Mothers who are overweight or obese during pregnancy are more likely to have daughters go through early puberty than pregnant women who are a normal weight, a U.S. study suggests.

Researchers examined medical records for nearly 15,300 mother-daughter pairs. Compared to daughters whose mothers were a normal weight during pregnancy, girls whose mothers were obese were 39 percent more likely to develop breasts early, the study found - typically, seven months sooner.

Some girls, particularly white and Asian girls, also developed pubic hair earlier when their mothers were obese during pregnancy, though this wasn't true for Hispanic daughters, and African-American girls actually had later pubic hair development under these circumstances.

"It has been known that obesity during pregnancy or excess gestational weight gain can lead to complications of pregnancy as well as (negative) birth outcomes and childhood obesity," said lead study author Dr. Ali Kubo of the Kaiser Permanente Northern California Division of Research in Oakland. "Our study extends the previous knowledge showing that obesity and (high blood sugar) may also influence pubertal timing."

"Young age at puberty in girls is associated with numerous adverse emotional and behavioral outcomes, including higher risk for anxiety, depression, body dissatisfaction, early sexual initiation and pregnancy during adolescence, and later in life, risks of cardiac problems, all-cause mortality, and breast and reproductive cancers," Kubo said by email.

Children who go through early puberty may be shorter than average adults because their bones may stop growing at a younger age, and they are also at increased risk of obesity as adults. During adolescence, they may face an increased risk of social and emotional problems and earlier sexual experiences.

Some recent research points to earlier puberty onset in the general population, especially in girls in developed countries. Environmental factors like diet, obesity and chemicals that mimic human hormones have all been suspected of playing a role.

In the current study, which was drawn from data collected between 2003 and 2017, researchers also found that when mothers were overweight but not obese during pregnancy, daughters were 21 percent more likely to experience early breast development than girls with normal weight pregnant mothers.

In addition, women who had high blood sugar during pregnancy were more likely to have daughters go through early breast development, researchers report in the American Journal of Epidemiology.

The study wasn't a controlled experiment designed to prove whether or how women's weight during pregnancy directly influences puberty timing in their daughters.

Still, the results underscore a need for women . . . to focus on healthy habits and achieving a healthy weight before they consider a pregnancy, said Dr. Amos Grunebaum, a researcher at Weill Cornell Medicine in New York City who wasn't involved in the study.

"Obesity changes the whole body and is part of the `metabolic syndrome,' a cluster of conditions that occur together, and also increases the risk of heart disease, stroke, and diabetes,"Grunebaum said by email. "With obesity, a woman's hormones are abnormal, and . . . as this study shows it can affect the developing fetus with long term consequences."

SOURCE: http://bit.ly/2HQzsvN American Journal of Epidemiology, online April 16, 2018.

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