Pregnancy and breastfeeding reduce the risk of early menopause

Women who have been pregnant or who have breastfed have a lower risk of  early menopause . According to a new study, the cause can be found in the fact that ovulation is inhibited during pregnancy and suspended or slowed down during breastfeeding, thus allowing the ovarian reserve to be maintained for longer.

Approximately 10% of women experience early menopause, defined as the cessation of ovarian function before the age of 45 ( Pelosi et al., 2015 ). Early menopause is associated with an increased risk of cardiovascular disease, cognitive decline, osteoporosis, and premature mortality ( van Der Voort et al., 2003 ; Shuster et al., 2010; Gold, 2011 ; Wellons et al., 2012 ). Furthermore, early fertility decline has consequences for family planning as women increasingly delay pregnancy ( Burger et al., 2007 ; Broekmans et al., 2009).). Although genetic factors partly explain the increased risk of early menopause, there are some modifiable risk factors, such as lifestyle and reproductive choices.

Several studies have suggested that pregnancies might influence the timing of menopause, but many of these studies relied on the responses of women, who had to accurately remember when their menopause started. The onset of menopause is not always easy to pin down as menstrual cycles can be irregular in the months or years leading up to the end of fertility. Furthermore , menopause is confirmed only 12 months after the interruption of menstrual cycles.

Instead of asking for information many years after women have experienced menopause, Langton and her colleagues in their study published in the journal JAMA , looked at medical records in the Nurses’ Health Study II, a project that asked participants for detailed information about their health every two years since 1989.

The team of researchers led by Langton evaluated all pregnancy, breastfeeding and menopause events of 108,887 women over a 26-year period.

The team of researchers found that women who were pregnant for at least six months had a lower risk of experiencing an early menopause   than those who weren’t pregnant.

The study revealed a linear trend:

• women who had been pregnant had an 8% lower risk of early menopause,
• women who had two pregnancies had a 16% lower risk of early menopause
• women who had three pregnancies had a 22% lower risk of early menopause

The link is not explained by infertility, removing from the study the women who could not get pregnant, the data remained confirmed.

Breastfeeding reduced the risk of early menopause.

Women who breastfed for a total of 7-12 months during their lifetime and who had any number of newborns were 28% less likely to experience menopause before age 45 than those who had breastfed for less than a month.

Women who exclusively breastfed for a total of 7-12 months during their lifetime and who had three pregnancies had a 32% lower risk of early menopause.

The team has highlighted a correlation that appears evident from the data analyzed even if it cannot yet be stated with certainty that pregnancies or breastfeeding influence the timing of menopause.