Researchers from the Australian National University (Canberra, Australia) have discovered that pregnant women who smoke may be putting their daughters at increased risk of developing breast or ovarian cancer later in life. The results of the study were published recently in Human Reproduction.
The study utilized data on 1500 girls from the Australian Government study ‘Growing Up in Australia, the Longitudinal Study of Australian Children’. The study established that girls whose mothers smoked most days during pregnancy had an earlier first menstruation, or menarche.
Lead researcher of the study Alison Behie (Australian National University) explained that reaching menarche at a younger age increases the number of ovulation cycles a woman will go through in her life, and therefore puts these girls at increased risk of developing reproductive cancers, potentially due to greater exposure to hormones such as estrogen.
“We’re discovering more and more that major aspects of our biology, and even our behavior, are set before we are born,” commented Behie.
“We know the mother’s exposure to stress, such as smoking in this case, can influence the long-term health of the child. Understanding factors that lead to early menarche, especially preventable ones, are important given these long term health implications and increased cancer risk for women.”
Smoking during pregnancy has previously been linked to health risks for children including lower birth weight, reduced lung capacity, asthma and obesity; however, this study highlights a relatively uncommon link between smoking and the development of reproductive cancers later in life.
The findings of the study help to increase understanding of the factors that cause girls to begin menstruating early. Other studies point to the mother’s age at menarche, in addition to diet, weight and stress during childhood.