Endometriosis linked to lower live births prior to diagnosis

Endometriosis is linked to a reduction in fertility in the years preceding a definitive surgical diagnosis of the condition, according to new research published recently.

The researchers in Finland found that the number of first live births in the period before diagnosis was half that of women without the painful condition. This was the case regardless of what form of endometriosis the women had: ovarian, peritoneal, deep endometriosis or other types. In addition, the researchers found evidence that the number of babies women had before endometriosis was diagnosed was significantly reduced, compared to women who did not have endometriosis.

The team looked at 18,324 women in Finland, aged between 15 and 49 years, who had surgical verification of endometriosis between 1998 and 2012. They matched them with 35,793 women of similar age who did not have an endometriosis diagnosis.

A total of 7,363 women (40%) with endometriosis and 23,718 women (66%) without endometriosis delivered a live-born baby during the follow-up period. The incidence rate of first live births among women with endometriosis was half that of women without the condition (0.51%). When analyzed according to women’s birth decade from 1940s to 1970s, the birth rate decreased in both groups of women. Importantly, over the decades, an increasingly lower first-live birth rate was seen in women with endometriosis, compared to women without. In those women born in 1940-1949, the difference in live birth rates between the two groups was 28% before surgically diagnosed endometriosis, but this difference increased steadily to 87% by 1970-1979.

Reference: First live births before surgical verification of endometriosis – a nationwide register study of 18 324 women, Human Reproduction, DOI 10.1093/humrep/dead120