Introduction
Polycystic ovary syndrome (PCOS), characterized by ovulatory dysfunction, biochemical or clinical hyperandrogenism, and polycystic ovaries, is one of the most common endocrine disorders, affecting 5.5–21% of women of reproductive age.1-5 To conceive, many women with PCOS failing to ovulate with clomiphene citrate and low-dose gonadotropin might require assisted reproductive technology (ART).6,7 It is estimated that in women attending infertility clinics, PCOS accounts for up to 70% of patients suffering from anovulatory infertility.7,8
In addition to the difficulty of conceiving, PCOS patients who are fortunate enough to become pregnant after either spontaneous or assisted conception, are still faced with the distressing issue of having increased risk for pregnancy loss. Previous studies indicate that PCOS patients are thought to have 30–50% rates of pregnancy loss which is three times higher than normal women.9,10 However, it is still unclear if the pathology of PCOS as such increase the risk of pregnancy loss following ART treatment or if maternal characteristics such as maternal age, body mass index (BMI) or multiple pregnancies play a crucial role in the higher rates.
Available data are limited in small size and most were unable to distinguish between early and late pregnancy loss. Current evidence on the associations among maternal characteristics, pre-existing health conditions, pregnancy plurality and pregnancy loss at different gestational ages is inadequate, which is important in counseling PCOS cases about their risks of loss throughout pregnancy.
We carried out a large cohort study of pregnant women after ART to access the risk of early and late pregnancy loss in women with PCOS. Furthermore, given that multiple pregnancies are common in IVF practice, the pregnancy loss was also calculated for each gestational sac separately.