Pregnancy Outcomes in Women with Thyroid Diseases

Tomomi Kotani; Kenji Imai; Takafumi Ushida; Yoshinori Moriyama; Tomoko Nakano-Kobayashi; Satoko Osuka; Hiroyuki Tsuda; Seiji Sumigama; Eiko Yamamoto; Fumie Kinoshita; Akihiro Hirakawa; Akira Iwase; Fumitaka Kikkawa; Hiroaki Kajiyama

doi:10.31662/jmaj.2021-0191

Pregnancy Outcomes in Women with Thyroid Diseases

JMA J. 2022 Apr 15;5(2):216-223. doi: 10.31662/jmaj.2021-0191. Epub 2022 Feb 28.

Authors

Affiliations

¹ Department of Obstetrics and Gynecology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
² Centre for Maternal-Neonatal Care, Nagoya University Hospital, Nagoya, Japan.
³ Department of Obstetrics and Gynecology, Fujita Health University School of Medicine, Toyoake, Japan.
⁴ Department of Obstetrics and Gynecology, Japanese Red Cross Nagoya Daiichi Hospital, Nagoya, Japan.
⁵ Office of International Affairs/International Medical Education, Nagoya University Graduate School of Medicine, Nagoya, Japan.
⁶ Department of Healthcare Administration Nagoya University Graduate School of Medicine, Nagoya, Japan.
⁷ Data Science Division, Data Coordinating Center, Department of Advanced Medicine, Nagoya University Hospital, Nagoya, Japan.
⁸ Department of Biostatistics and Bioinformatics, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
⁹ Department of Obstetrics and Gynecology, Gunma University Graduate School of Medicine, Maebashi, Japan.

Abstract

Introduction: Overt hyperthyroidism and hypothyroidism are associated with pregnancy complications; however, most women with these conditions are diagnosed before conception and are under treatment during pregnancy, especially in high-income countries. The purpose of this study was to investigate pregnancy complications among these women.

Methods: A retrospective cohort study was conducted, and data on pregnant women who gave birth to a singleton at Nagoya University Hospital in Japan in 2005-2014 was collected. The pregnancy outcomes were divided and compared among three groups: the control group (n = 3531), the hyperthyroidism group (n = 48), and the hypothyroidism group (n = 61). Additionally, risk factors for placental abruption were evaluated by multivariable logistic regression analysis. Moreover, in hyperthyroidism, thyroid function at the placentation period was compared between placental-related diseases and nonplacental-related disease groups, and the latter group included placental abruption and preeclampsia.

Results: The incidence of placental abruption was higher in hyperthyroidism than in control and hypothyroidism groups. Hyperthyroidism was independently associated with an increased risk of placental abruption (adjusted odds ratio, aOR = 8.21, 95% confidence interval, CI: 1.76-38.34), as well as preeclampsia (aOR = 4.10, 95% CI: 1.13-14.76) and preterm labor (aOR = 3.38, 95% CI: 1.19-9.64). Additionally, thyroid-stimulating hormone (TSH) at the placentation period was significantly lower in the placental-related disease group than in the nonplacental-related disease group (p < 0.05).

Conclusions: Pregnancy outcomes in women with hyperthyroidism and hypothyroidism would be comparable with those without thyroid disease. Hyperthyroidism was an independent risk factor for placental abruption as well as preterm labor and preeclampsia. However, its frequency was extremely low, and further research is required to validate our findings.

Keywords: hyperthyroidism; hypothyroidism; placental abruption; preeclampsia.