Breastfeeding and childbearing tied to lower odds of early menopause

Women who have babies and breastfeed may be less likely to go through menopause early than those who don’t have children or nurse their infants, a US study suggests.
 

Researchers tracked 108,887 women, ages 25 to 42, who had not yet gone through menopause. Just over half had experienced at least one pregnancy lasting at least six months and more than half of these mothers exclusively breastfed their babies for at least one month.
 

During follow-up for up to 25 years, women who had one pregnancy were 13 per cent less likely to experience menopause before age 45, and the risk declined with subsequent pregnancies, the study found. Breastfeeding appeared to explain at least some of the reduced risk; after accounting for that factor, a single pregnancy was still associated with an 8 per cent lower risk of early menopause.
 

“While most women may not be thinking about menopause timing when deciding how many children they plan to have, we feel our breastfeeding findings add new insight into ways to prevent early menopause,” said lead study author Christine Langton of the University of Massachusetts Amherst. “And they align nicely with recommendations of both the American Academy of Pediatrics and World Health Organization that US women exclusively feed their infants breast milk for at least six months and continue breastfeeding for up to one year.”
 

Women go through menopause when they stop menstruating, which typically happens between ages 45 and 55. As the ovaries curb production of the hormones estrogen and progesterone, women can experience symptoms ranging from vaginal dryness to mood swings, joint pain and insomnia.
 

About 10 per cent of US women go through menopause before age 45, the authors note, and this has been linked to an increased risk of heart disease, osteoporosis, diabetes, cognitive decline and sleep problems, previous research has found.
 

Both pregnancy and breastfeeding might delay menopause by temporarily halting monthly ovulation cycles to release eggs, Langton said by email. Women are born with a set number of eggs, and depletion of this egg supply contributes to the end of menstruation and the start of menopause.
 

For the current study, researchers examined data from an ongoing long-term study of US nurses, which began collecting data in 1989.
 

Overall, 59,388 women, or about 54 per cent, had at least one pregnancy lasting at least six months and more than half of these mothers exclusively breastfed their babies for at least one month.
 

A total of 2,571 women, or 2.5 per cent, went through menopause before age 45.
 

Women who had one pregnancy and only exclusively breastfed for less than one month still had a lower risk of early menopause than women who didn’t get pregnant. The risk of early menopause also declined more with subsequent pregnancies and longer periods of exclusive breastfeeding, researchers report in JAMA Network Open.
 

With two pregnancies, women were 16 per cent less likely to go through early menopause, after researchers accounted for the duration of exclusive breastfeeding, while the risk was 19 percent lower with four or more pregnancies.