WASHINGTON — It’s been known for some time that smoking while pregnant can cause a number of health problems for a baby, including low birth weight, asthma, birth defects and sudden infant death syndrome. But a new study adds an additional consequence to the list of risks: Prenatal smoke exposure may cause a lifetime of reproductive health issues in girls.
A study recently published in Human Reproduction and conducted by a team of Australian researchers found that girls whose mothers smoked while they were pregnant started puberty at an earlier age.
Dr. Veronica Gomez-Lobo, director of Pediatric and Adolescent Ob/Gyn
at MedStar Washington Hospital Center and director of Pediatric and Adolescent Gynecology at Children’s National Health System, explains that early menstruation can lead to a number of health troubles.
“If girls have earlier periods, then they are also at risk for cancers later in life,” Gomez-Lobo says. Those cancers include uterine, endometrial and breast cancer.
Early puberty is also linked to higher rates of obesity and psychological issues, she says. “It hasn’t been very well studied, but some girls who mature earlier may be taken advantage of, or they may become sexually active earlier.”
For the study, researchers followed about 1,500 girls from birth to the age of 12 to 13 and reviewed several factors that influenced the timing of their first period. Having a mother who smoked “most days” during pregnancy was a significant factor, the researchers concluded. The daughters of mothers who smoked while pregnant were 40 percent more likely to start menstruation at an early age than those who were not exposed to smoke in utero, Reuters Health reports.
Despite the known risks of smoking while pregnant, the Substance Abuse and Mental Health Services Administration found that one in five white women (or 21.8 percent) admit to smoking cigarettes while pregnant. About 14 percent of black women and 6.5 percent of Hispanic women smoke during pregnancy.
Gomez-Lobo points out the researchers had to make some statistical adjustments to the Australian study, and that further research is needed, but that the findings shouldn’t be discounted.
“I want to be cautious, because this is a study where they didn’t have all of the data, but I think it’s very compelling evidence, and it would be consistent with the other studies that show that small-for-gestational-age babies also have earlier puberty,” she says. “Smoking causes the babies to be smaller, and then we know that smaller babies mature earlier.”
The next step, she says, is to learn more about the exposures that affect babies, including the window in which they affect development. She also says it’s important to know what happens when a mother quits smoking during pregnancy, but then resumes after birth, thereby exposing a newborn to secondhand smoke. According to the Centers for Disease Control and Prevention, about 40 percent of mothers who quit during pregnancy relapse within six months of delivery.
“I think this is one more piece of evidence that smoking is not good during pregnancy and that it has long-term effects. It’s not just while you’re pregnant, but it can have lifelong effects,” Gomez-Lobo says.
