P-589 How Does Hypothyroidism Alter Perinatal Outcomes in Patients with Polycystic Ovary Syndrome? - An Evaluation of a Population Database
Authors: Hochberg A , Badeghiesh A , Baghlaf H , Dahan M 
Published: June 2023

Study question

Does concomitant hypothyroidism in polycystic ovary syndrome (PCOS) patients have an additive effect on the risk for adverse pregnancy, delivery and neonatal outcomes?

Summary answer

In patients with PCOS, hypothyroidism significantly increases the risk for preeclampsia, however risks of other adverse perinatal outcomes are unaltered.

What is known already

PCOS and hypothyroidism are common endocrinopathies during reproductive age, and each has been shown to be associated with pregnancy complications. While PCOS has been associated with gestational diabetes, gestational hypertension, and preeclampsia, overt hypothyroidism has been associated with pregnancy loss, intrauterine growth restriction, preeclampsia, and preterm birth. Furthermore, PCOS and thyroid abnormalities are known to be linked, with a higher prevalence of thyroid dysfunction in pregnant PCOS patients compared to controls. However, information on obstetric and neonatal outcomes in women with both PCOS and hypothyroidism is lacking.

Study design, size, duration

A retrospective population-based study utilizing data from the Healthcare Cost and Utilization Project—Nationwide Inpatient Sample (HCUP-NIS), was performed. A dataset of all deliveries between 2004 and 2014 inclusively, was created. This population-based cohort study included 14,882 women with an International Classification of Diseases (ICD)-9 diagnosis of PCOS in the United States. IN 2015 data was converted to ICD-10 codes which are not comparable to ICD-9 codes.

Participants/materials, setting, methods

All pregnancy admissions that resulted in delivery or maternal death were included so that patients were counted only once per pregnancy. We compared PCOS women with a concurrent diagnosis of hypothyroidism to those without. Women with hyperthyroidism were excluded. Pregnancy, delivery, and neonatal outcomes were compared between the two groups. Multivariate logistic regression analysis was used to adjust for confounding effects.

Main results and the role of chance

Overall, 14,882 women met the inclusion criteria. Amongst them, 1,882 (12.65%) had a concomitant diagnosis of hypothyroidism, and 13,000 (87.35%) did not. Women with concomitant hypothyroidism, compared to those without, were characterized by increased maternal age (25.5% ≥35 years vs. 18%, p &lt; 0.001, respectively), and had a higher rate of multiple gestations (7.1% vs. 5.7%, p = 0.023). Interestingly, pregnancy, delivery, and neonatal outcomes were comparable between the groups, except for a higher rate of small-for-gestational-age (SGA) neonates in the group with hypothyroidism (4.1% vs. 3.2%, p = 0.033), when not accounting for confounding effects. In a multivariate logistic regression adjusting for potential confounders, hypothyroidism was no longer found to be associated with SGA (adjusted odds ratio [aOR] 1.32, 95% confidence interval [CI] 0.99-1.75, p = 0.057), but was found to increase the odds for preeclampsia (aOR 1.30, 95% CI 1.06-1.59, p = 0.012). Of note when controlling for confounding effects, all other pregnancy, delivery, and neonatal outcomes were comparable between the groups, including pregnancy-induced hypertension; eclampsia; gestational diabetes mellitus; preterm premature rupture of membranes; preterm delivery; placental abruption; cesarean delivery; hysterectomy; post-partum hemorrhage; wound complications; maternal death; blood transfusions; maternal infection; venous thromboembolism; disseminated intravascular coagulation; SGA; intrauterine fetal death; and congenital anomalies.

Limitations, reasons for caution

Due to our study’s retrospective nature, some data is missing such as TSH levels, TPO antibody status, the time period in which hypothyroidism was diagnosed (pre-gestationally or during the 1st, 2nd or 3rd trimesters), and Levothyroxine treatment dose and compliance.

Wider implications of the findings

Patients with PCOS and hypothyroidism during pregnancy should be managed with consideration of instituting both preventive measures for preeclampsia development and heightened blood pressure, proteinuria, and symptom monitoring. Interestingly, hypothyroidism did little to affect the already increased rates of pregnancy complications in PCOS. This should be further studied.

Trial registration number

not applicable