Results
The prevalence of endometriosis in women attending the early pregnancy unit was 4.9% (95% CI 3.8 – 6.2); In 33/66 (50%, 95% CI 37.9 – 62.1) women with endometriosis, this was a new diagnosis made for the first time during their early pregnancy scan. The presence of endometriosis was strongly associated with congenital uterine anomalies (p < 0.001; OR 5.69, 95% CI 2.17 – 14.9) and uterine fibroids (p = 0.004; OR 2.37, 95% CI 1.31, 4.28).