MONDAY, May 11, 2026 (HealthDay News) -- Endometriosis is associated with an increased risk for congenital anomalies, according to a study published online May 11 in CMAJ, the journal of the Canadian Medical Association.Bailey Milne, M.P.H., from Queen's University in Kingston, Ontario, Canada, and colleagues conducted a population-based study of births in Ontario from April 7, 2006, to March 31, 2021, to identify infants born at 20 weeks of gestation or later to women aged 15 to 50 years to examine the associations of endometriosis before conception with congenital anomalies in the infant. The proportion of these associations mediated by subfertility, ovulation induction or intrauterine insemination, and in vitro fertilization or intracytoplasmic sperm injection was assessed.Data were included for 1,460,564 eligible births; 2.3 percent had endometriosis. The researchers found that congenital anomalies occurred in 6.3 and 5.4 percent of infants of women with and without endometriosis, respectively. There was an independent association seen for endometriosis with a higher risk for any congenital anomaly (adjusted relative risk, 1.16). The highest associated risks were seen for specific anomalies, including unspecified cleft palate, hypospadias, and pulmonary artery stenosis (adjusted relative risks, 1.52, 1.47, and 1.41, respectively). Endometriosis was an independent risk factor for any congenital anomaly; in vitro fertilization or intracytoplasmic injection mediated 11.0 percent of the associated risk, while subfertility, ovulation induction, and intrauterine insemination did not mediate the association."Although we observed modest relative increases in risk, the absolute risk of congenital anomalies for infants born to patients with endometriosis remained low, because congenital anomalies are uncommon," Milne said in a statement.Abstract/Full TextEditorial.Sign up for our weekly HealthDay newsletter