Associations Between Polycystic Ovary Syndrome and Adverse Obstetric and Neonatal Outcomes

A Population Study of 9.1 Million Births

Ginevra Mills; Ahmad Badeghiesh; Eva Suarthana; Haitham Baghlaf; Michael H. Dahan


Hum Reprod. 2020;35(8):1914-1921. 

In This Article

Abstract and Introduction


Study Question: Does polycystic ovary syndrome (PCOS) confer an independent risk for adverse delivery and neonatal outcomes, based on analysis of the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (HCUP-NIS) database?

Summary Answer: After controlling for all potential confounding effects, women with PCOS are at an increased risk of experiencing preterm pre-labour rupture of membranes (PPROM), pre-term delivery (PTD), placental abruption, caesarean section (C/S) delivery, chorioamnionitis and post-partum maternal infections.

What Is Known Already: PCOS may be associated with an increased risk of adverse perinatal outcomes. However, there remain significant gaps in understanding the correlation between PCOS and important delivery and neonatal complications.

Study Design, Size, Duration: This is a retrospective population-based cohort study utilising data from the HCUP-NIS over 11 years from 2004 to 2014. A cohort of all deliveries between 2004 and 2014 inclusively was created. Within this group, all deliveries to women with PCOS were identified as part of the study group (n = 14 882), and the remaining deliveries were categorised as non-PCOS births and comprised the reference group (n = 9 081 906).

Participants/Materials, Setting, Methods: The HCUP-NIS is the largest inpatient sample database in the USA and it is comprised of hospital inpatient stays throughout the entire country. It provides information relating to 7 million inpatient stays per year, includes ~20% of admissions, and represents over 96% of the American population.

Main Results and the Role of Chance: After adjustment for all potential confounders, women with PCOS were more likely to experience PPROM (aOR 1.48, 95% CI 1.20–1.83), PTD (aOR 1.37 95% CI 1.24–1.53) and placental abruption (aOR 1.63, 95% CI 1.30–2.05) and were more likely to deliver by C/S (aOR 1.50, 95% CI 1.40–1.61 (all P < 0.001). Women with PCOS more often developed chorioamnionitis (aOR 1.58, 95% CI 1.34–1.86, P < 0.001) and maternal infections (aOR 1.58, 95% CI 1.36–1.84 (both P < 0.001)). With the exception of multiple gestations (aOR 1.27, 95% CI 1.01–1.62, P = 0.04), there was no difference in the number of women who gave birth to small for gestational age (SGA) infants (aOR 0.97, 95% CI 0.82–1.15, P = 0.72) between the women with PCOS and the reference group. Intrauterine foetal deaths (IUFDs) were also comparable between the two groups (aOR 1.03, 95% CI 0.68–1.59, P = 0.88). However, congenital anomalies were more likely to occur in the offspring of women with PCOS (aOR 1.89, 95% CI 1.51–2.38, P < 0.001).

Limitations, Reasons for Caution: This is a retrospective analysis utilising an administrative database which relies on the accuracy and consistency of the individuals coding the data. There are known limitations in how accurately hospital coding is able to capture perinatal conditions and complications, making it difficult to know with certainty that such events are accurate.

Wider Implications of the Findings: Women with PCOS are more likely to experience adverse delivery and neonatal outcomes. It is important to additionally consider the risk of all other co-existing conditions frequently encountered in PCOS women, as these risks are additive and place women with PCOS at significantly increased risk of adverse pregnancy outcomes.

Study Funding/Competing Interest(S): No specific funding was obtained for this study. The authors have no conflicts of interest to disclose.


Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age, with a worldwide prevalence of up to 10% (Azziz, 2006; Lizneva et al., 2016). This syndrome is characterised by a combination of ovulatory dysfunction, hyperandrogenism and polycystic ovarian morphology on ultrasound (Rotterdam ESHRE/ASRM-Sponsored PCOS consensus workshop group, 2004; Azziz, 2005). Up to 80% of women with PCOS are also known to have intrinsic insulin resistance (IR) and when combined with obesity, IR may put them at increased risk of complications during pregnancy and the perinatal period (Palm et al., 2018). PCOS is suspected to be an independent risk factor for increased rates of gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP) and preeclampsia (PEC), all of which individually could contribute to an increased risk of adverse delivery and neonatal outcomes (Boomsma et al., 2006; Kjerulff et al., 2011; Qin et al., 2013; Gilbert et al., 2018; Khomami et al., 2019). Women with PCOS have been shown in some studies to be at increased risk of requiring caesarean section (C/S), experiencing pre-term delivery (PTD), having small-for-gestational age infants and undergoing induction of labour (IOL) (Qin et al., 2013; Palomba et al., 2015; Khomami et al., 2019). Unfortunately, data on these complications are not indisputable, as some groups have failed to establish an increased risk of C/S (Kjerulff et al., 2011; Qin et al., 2013), preterm delivery (Qin et al., 2013) or small for gestational age (SGA) (Boomsma et al., 2006; Yu et al., 2016) among women with PCOS.

Women with PCOS are also suspected to be at increased risk of non-reproductive health risks, including obesity, impaired glucose tolerance, IR and hypertensive disorders the metabolic syndrome (Christ et al., 2018; Palm et al., 2018). These metabolic conditions, as well as pregnancy-associated metabolic conditions such as GDM, HDP and PEC, are known to increase the risk of adverse delivery and neonatal outcomes, independent of PCOS (Khomami et al., 2018). Nevertheless, it remains controversial as to whether PCOS alone is an independent risk factor for delivery and neonatal outcomes (Christ et al., 2018). There have been numerous meta-analyses that have attempted to determine the independent risk of PCOS on outcomes such as C/S, PTD, SGA and rates of induction (Boomsma et al., 2006; Kjerulff et al., 2011; Qin et al., 2013; Yu et al., 2016; Khomami et al., 2019). However, the data remain limited given the significant gaps in understanding of the pathophysiological associations between PCOS and pregnancy and delivery outcomes (Khomami et al., 2018). This lack of knowledge is likely secondary to the range of potential confounders. Finally, to our knowledge, there are no studies to date that assess the risk of PCOS on the development of delivery-related infections, including chorioamnionitis and post-delivery infections. The objective of this study, therefore, was to assess the prevalence of adverse delivery-associated maternal and neonatal outcomes, including infections, in women with and without PCOS, while accounting for potential confounders through the use of the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (HCUP-NIS) database of over 7 million yearly hospital admissions.