Polycystic ovary syndrome (PCOS) affects approximately 6% to 20% of women of reproductive age globally and remains undiagnosed and poorly managed, especially during pregnancy, leading to significant healthcare costs. The economic burden of PCOS was estimated to be $8 billion annually in 2020, with $375 million attributed to pregnancy-related complications. The implementation of China’s universal two-child policy has led to an increase in the proportion of advanced-age pregnant women, a greater use of assisted reproductive technologies, and a rise in multiple pregnancy rates, further exacerbating the health risks faced by women with PCOS. However, limited large-scale studies have investigated the prevalence and maternal-fetal outcomes in pregnant women with PCOS. In addition, the impact of China's evolving fertility policies on this population remains largely unclear.
To address this gap, a research team from West China Second University Hospital, Sichuan University, analyzed data from the Chinese Maternal Near Miss Surveillance System covering the period 2012 to 2021. A total of 14,083,975 pregnant women from 438 hospitals in 30 provinces were included, with samples covering urban and rural areas, as well as eastern, central, and western regions of China, ensuring good national representativeness. Interrupted-time-series analysis was applied to explore trends during the Universal Two-Child Policy period. Poisson regression analyses were used to estimate the maternal and fetal risks associated with PCOS. Subgroup analyses were also performed to identify high-risk populations. Their findings were made available online on June 25, 2026, and published in Volume 139, Issue13 of the Chinese Medical Journal on July 05, 2026.
“Our study, which covers a decade of data and a large, nationally representative sample, provides epidemiological data and the impact of China's fertility policies on pregnant women with PCOS in China,” explains the corresponding researcher from West China Second University Hospital. “The universal two-child policy has brought significant changes to China’s reproductive landscape, and our findings highlight the need to pay more attention to the health of pregnant women with PCOS.”
The study showed that the prevalence of PCOS among pregnant women in China increased from 0.79 per 10,000 in 2012 to 19.0 per 10,000 in 2021. Pregnant women with PCOS had significantly increased risks of several adverse maternal outcomes, including diabetes (adjusted relative risk [aRRs] 2.10, 95% confidence interval [CI] 1.95–2.26), gestational hypertension (aRR 2.37, 95% CI 2.07–2.72), preeclampsia (aRR 2.29, 95% CI 2.04–2.57), superimposed preeclampsia (aRR 5.28, 95% CI 3.87–7.21), and HELLP syndrome (aRR 1.84, 95% CI 1.09–3.10). Additionally, women with PCOS had an increased risk of cesarean delivery (aRR 1.32, 95% CI 1.25–1.39). Regarding fetal outcomes, women with PCOS had elevated risks of abortion (aRR 1.66, 95% CI 1.20–2.30), preterm birth (aRR 1.81, 95% CI 1.63–1.99), full-term low birth weight babies (aRR 1.38, 95% CI 1.18–1.62), macrosomia (aRR 1.37, 95% CI 1.25–1.51), and neonatal asphyxia (aRR 1.72, 95% CI 1.32–2.24).
“PCOS is associated with a series of adverse maternal-fetal outcomes, especially among individuals with specific risk factors like advanced maternal age, inadequate antenatal care, nulliparity, and multiple pregnancy” notes a member of the research team. “These findings emphasize the need for targeted clinical intervention and offer valuable insights for improving healthcare strategies in this population.”
In conclusion, the prevalence of PCOS among pregnant women in China showed a significant upward trend from 2012 to 2021, with a long-term relative increase following the implementation of the universal two-child policy and significant regional variations. The study also confirmed that pregnant women with PCOS have significantly increased risks of adverse maternal and neonatal outcomes, emphasizing the necessity of targeted clinical interventions for high-risk groups. These findings provide important references for improving obstetric management strategies for pregnant women with PCOS in China.
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Reference
Title of original paper: Prevalence, trends, and maternal–fetal outcomes in pregnant women with polycystic ovary syndrome in Chinese mainland
Journal: Chinese Medical Journal
DOI: 10.1097/CM9.0000000000004132
About Rong Zhou and Juan Liang from West China Second University Hospital, Sichuan University
Dr. Zhou Rong, is the Chief Physician and Professor at West China Second University Hospital, Sichuan University, is a provincial academic leader and outstanding expert in obstetrics. She holds numerous key positions in national and provincial medical societies. With over 30 years of clinical and research experience, she has led more than 50 major projects (including NSFC grants), published 100+ papers in journals such as Hypertension and The Lancet , authored 20+ books, contributed to 10+ clinical guidelines, and holds 5 patents.
Dr. Liang Juan is a Researcher and Doctoral Supervisor at West China Second University Hospital, Sichuan University, affiliated with the National Office for Maternal and Child Health Surveillance / China National Center for Birth Defect Monitoring. She leads national hospital-based surveillance for maternal deaths and severe maternal morbidity. She has directed multiple projects from national ministries, CMB, and WHO. Her honors include a First Prize of the Sichuan Provincial Science and Technology Progress Award and a Second Prize of the Scientific and Technological Achievement Award from the Chinese Preventive Medicine Association.
Funding information
This study was supported by grants from the Natural Science Foundation of Sichuan Province of China (Grant No. 2024NSFSC1672) and the Clinical Research Fund of West China Second Hospital, Sichuan University (Grant No. KL123). Dr. Rong Zhou has received research support from the National Key R&D Program of China (Grants Nos. 2021YFC 2701600 and 2021YFC2701601) and the National Natural Science Foundation of China
(Grant No. 81871175).
Chinese Medical Journal
Observational study
People
Prevalence, trends, and maternal–fetal outcomes in pregnant women with polycystic ovary syndrome in Chinese mainland
25-Jun-2026