To investigate plasma antimüllerian hormone (AMH) concentration and its relation to steroid hormone levels in pregnant women with polycystic ovary syndrome (PCOS) and controls at term. Case-control study. University-affiliated hospital. A total of 74 pregnant women at term: 25 women with PCOS (aged 31.6 ± 3.9 years [mean ± standard deviation], body mass index 24.0 ± 3.9 kg/m2, mean gestational length 279 ± 9 days) and 49 controls (aged 31.7 ± 3.3 years, body mass index 24.0 ± 3.3 kg/m2, mean gestational length 281 ± 9 days). None. Plasma AMH and steroid hormone levels. Antimüllerian hormone, T, and androstenedione levels were higher in women with PCOS at term compared with controls, whereas estrogen and P levels were similar. The differences were pronounced in women carrying a female fetus. Testosterone and AMH levels correlated positively in both groups, but E2 levels only in women with PCOS. Pregnant women with PCOS present with elevated AMH and androgen levels even at term, suggesting a hormonal imbalance during PCOS pregnancy. Differences were detected especially in pregnancies with a female fetus, raising the question of whether female pregnancies are more susceptible to AMH and steroid hormone actions.