Does past abortion or miscarriage affect a woman’s risk of developing breast cancer?

A prior abortion or miscarriage was not linked with an increased risk of developing pre- or postmenopausal breast cancer in a study published in Acta Obstetricia et Gynecologica Scandinavica.

In the nationwide Finnish registry-based study, investigators analyzed data on 31,687 women with breast cancer diagnosed in 1972–2021 and 158,433 women without breast cancer.

The risk of breast cancer was the similar among women with a history of induced abortion and women with no history of abortion, both before and after 50 years of age. Risks were also similar among women with and without a past miscarriage.

In addition, breast cancer risks did not vary significantly by the number of abortions or miscarriages, nor by the time of first abortion or miscarriage.

“Miscarriage or induced abortion as potential risk factors for breast cancer has continued to raise concerns and has led to the spread of misinformation. In this study using high-quality Finnish registry data, we can reliably eliminate these concerns,” said corresponding author Oskari Heikinheimo, MD, PhD, of the University of Helsinki and Helsinki University Hospital. “Induced abortion or miscarriage are not risk factors for breast cancer, even if there are several of them. This information is important and reassuring for millions of women around the world.”

Reference:

Sushmita Katuwal, Jaana Männistö, Maarit Niinimäki, Eero Pukkala, Oskari Heikinheimo, Induced abortion, miscarriage, and the risk of breast cancer—A registry-based study from Finland, Acta Obstetricia Et Gynecologica Scandinavica, https://doi.org/10.1111/aogs.70154Digital Object Identifier (DOI)