Polycystic ovary syndrome (PCOS) is a common endocrine metabolic dysfunction closely associated with insulin resistance and obesity, which predisposes to pregnancy complications and prenatal programming of the offspring. The aim of this review is to report our experience in PCOS patients who became pregnant and were followed during the whole pregnancy. Firstly, we analyzed the effect of pregnancy on PCOS pathophysiology and secondly the role of PCOS in pregnancy outcomes. Regarding the firstpoint, during normal pregnancy a progressive insulin resistance, serum lipid changes and an increase in androgen levels is observed, which is exacerbated in the PCOS condition. This adverse intrauterine environment could have a prenatal programming effect with detrimental consequences for female or male fetuses. Regarding the second point, PCOS is associated with an increased risk for maternal complications such as gestational diabetes (GDM) and pregnancy-induced hypertension. Moreover, these adverse pregnancy outcomes are more frequently associated with an increase in low birth weight and high birth weight newborns. According to our clinical experience, PCOS patients who became pregnant and were not treated with metformin during the whole pregnancy, showed a higher prevalence of gestational diabetes and SGA newborns, which was improved with metformin treatment. In summary, pregnancy may constitute a period in which an abnormal condition is established or aggravated in the fetus of a PCOS mother. Moreover, PCOS enhanced adverse obstetric and neonatal outcomes.