Objective: To evaluate whether polycystic ovary syndrome (PCOS) affects pregnancy outcomes and complications in infertile women undergoing their first in vitro fertilization (IVF) treatment. Design: A retrospective cohort study. Setting: Private fertility center. Population: 7678 infertile women, including 666 women with PCOS and 7012 controls undergoing their first IVF treatment from 2010 to 2017. Methods: Maternal characteristics, pregnancy outcomes and complications were analyzed by independent t-test, Mann-Whitney U-test, or Chi-square test. A logistic regression analysis was performed to determine the impact of PCOS on pregnancy outcomes and complications. Main Outcome Measures: Risk of adverse pregnancy outcomes (miscarriage, preterm delivery, pregnancy-induced hypertension) and pregnancy outcomes (live birth rate, clinical pregnancy rate, implantation rate), adjusted for maternal characteristics. Results: After adjusting for differences in maternal age, BMI, infertility duration, total dose of gonadotropin, serum E2 and endometrial thickness on the day of hCG trigger, number of fertilized occytes, number of embryos transferred, embryo type (cleavage-stage embryo or blastocyst) and quality, women with PCOS had an increased risk of developing unfavorable pregnancy complications, including miscarriage (adjusted odds ratio [aOR] 1.629, 95% confidence interval [CI] 1.240-2.141), very preterm delivery (< 32 weeks) (aOR 2.135, 95% CI 1.170-3.895). For pregnancy outcomes, PCOS was associated with higher clinical pregnancy rate (aOR 1.248, 95% CI 1.038-1.501) and implantation rate (aOR 1.238, 95% CI 1.030-1.489) after adjusting for the above-mentioned confounders. Conclusions: Women with PCOS are at increased risk of adverse pregnancy outcomes. These women may need more frequent medical consultants and management during pregnancy and parturition.

Peripheral blood natural killer (pNK) cells can be recruited by the endometrium to participate in the decidualization and be in contact with the villus in the intervillous space during pregnancy. Moreover, pNK cells can exert cytotoxicity to cytotrophoblast, especially in abnormal pregnancy. However, it is still controversial about the association between pNK cytotoxicity and RM so far. In this study, we aim to compare the percentage, immunophenotype and function of pNK cells between patients with RM and fertile controls. The peripheral blood was collected from 49 patients with RM and 11 fertile women in their middle luteal phase of the menstrual cycle. pNK cells were co-cultured with K562 cells at three different cell ratios to measure the cytotoxicity. The percentage of CD3-CD56+ pNK was analyzed by flow cytometry and quantified to evaluate the expression of cytotoxic granules (granzyme B, granulysin, and perforin), and the cell surface receptors related to pNK cell cytotoxicity (NKG2D, NKp30, NKp46, CD158a, CD158b) were also detected. The general linear model analysis showed that pNK cell cytotoxicity in patients with RM was significantly lower than that in fertile controls. The RM group possessed a significantly lower level of granzyme B+ pNK cells and significantly higher level of CD158a+, CD158b+ pNK cells than that in the control group. However, there was no significant difference in the proportion of circulating CD3-CD56+ NK cells expressing the granzyme B, granulysin, perforin, NKG2D, NKp30, NKp46, CD158a, CD158b. Our results suggested that a lower pNK cytotoxicity might be associated with RM.