THURSDAY, Aug. 30 (HealthDay News) -- Women who've had three or more abortions are at increased risk for premature and low birth-weight babies when they first give birth, a new study indicates.
Researchers looked at more than 300,000 Finnish mothers and found that 10.3 percent had had one induced abortion between 1996 and 2008, 1.5 percent had two abortions, and 0.3 percent had three or more abortions before a first birth.
Compared to mothers who had no abortions, those who had three or more abortions had a 225 percent increased risk of having a baby with a very low birth weight (less than 1,500 grams or 3.3 pounds), a 43 percent increased risk of low birth weight (less than 2,500 grams or 5.5 pounds), a 35 percent increased risk of preterm birth (before 37 weeks), and an increased risk of very preterm birth (before 28 weeks).
Women who'd had two abortions had only a slightly increased risk of very preterm birth, according to the study published online Aug. 30 in the journal Human Reproduction.
"To put these risks into perspective, for every 1,000 women, three who have had no abortion will have a baby born under 28 weeks. This rises to four women among those who have had one abortion, six women who have had two abortions, and 11 women who have had three or more," study leader Dr. Reija Klemetti, an associate professor and senior researcher in public health at the National Institute for Health and Welfare in Helsinki, said in a journal news release.
The researchers noted that they tried to take into account factors that could affect the outcomes for these births, such as smoking, and social and economic factors. "However, it is important to say that even though we adjusted for these factors, and also ectopic pregnancies and miscarriages, there might be some confounding for social class that we could not control for. Most probably, this may be related to women's (or some of these women's) way of life, life habits, and sexual and reproductive health," Klemetti explained.
"Our results suggest that induced abortions before the first birth, particularly three or more abortions, are associated with a marginally increased risk during the first birth. However, the increased risk is very small, particularly after only one or even two abortions, and women should not be alarmed by our findings," Klemetti added.
"Furthermore, this is an observational study and, however large and well-controlled, it only shows there is a link between abortion and some adverse birth outcomes -- it cannot prove that abortions are the cause," the study author stressed.
The researchers suggested that the potential for increased birth risks after a woman has had multiple abortions should be included in sex education. They also said health professionals should be aware of the potential risks of repeat abortions.
The U.S. National Institute of Child Health and Human Development has more about preterm labor and birth.
-- Robert Preidt
SOURCE: Human Reproduction, news release, Aug. 29, 2012
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