CONTEXT: Polycystic ovary syndrome (PCOS) pregnancies are linked to metabolic disorders affecting maternal and fetal outcomes, with maternal metabolites differing from those in normal pregnancies. OBJECTIVE: To investigate the metabolic communication at the maternal-fetal interface in PCOS pregnancies. DESIGN: Placenta and umbilical cord serum were analyzed using gas chromatography-mass spectrometry. In-depth analysis was performed with clinical characteristics. SETTING: Placenta and umbilical cord serum were analyzed using gas chromatography-mass spectrometry, alongside clinical characteristics. PARTICIPANTS: Forty-five uncomplicated PCOS pregnancies and 50 normal pregnancies. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The metabolic characteristics at the maternal-fetal interface in PCOS pregnancies and the underlying mechanisms. RESULTS: A total of 79 metabolites in the placenta and 25 in umbilical cord serum showed significant differences between PCOS and normal pregnancies. The 10 most significant placental metabolites were identified through receiver operating characteristic analysis, 9 of which correlated significantly with maternal serum testosterone levels. Lasso regression analysis identified 4 key placental metabolite combinations: gamma-aminobutyric acid, proline, glycine, and isoleucine, achieving an area under the curve of 93.24%. In umbilical cord serum, 6 metabolites differed significantly between PCOS and normal pregnancies, with the highest area under the curve reaching 76.07%
5 of these metabolites showed significant correlations with maternal serum testosterone levels. Nine differential metabolites were shared between the placenta and umbilical cord serum, which also shared metabolic pathways, including ABC transporters and aminoacyl-tRNA biosynthesis, potentially influencing maternal-fetal interactions. CONCLUSION: This study identifies the metabolomic profile and key pathways in maternal-fetal communication during PCOS pregnancies.