Endocrine Abstracts

Introduction: Many studies have examined maternal and fetal complication rates in treated and untreated overt and subclinical hypothyroidism. Maternal hypothyroidism may adversely affect the development of the fetal pituitary–thyroid axis. It has also been reported to be closely related to adverse pregnancy outcome.

Aim: To study the prevalence and outcome of hypothyroidism in pregnancy during the last decade in a high volume obstetric center in Jerusalem.

Methods: A retrospective study of the obstetric database between August 2005 and December 2015 in Shaare Zedek Medical Center, Jerusalem.

Results: During the study period there were 142,277 deliveries of singleton or twin pregnancies (1.9% twin deliveries). The medical files of 4042 (2.8%) deliveries (group A) included a diagnosis of maternal hypothyroidism. Women giving birth with the diagnosis of hypothyroidism were older (31.1±6 years 28.8±5.6 y. P<0.0001). Gestational diabetes was more prevalent (7.3% vs 3.3%, P<0.0001) in group A as were hypertensive disorders (3.7% vs 2.3%, P<0.0001). Higher rate of assisted reproduction techniques were used in group A (8.5% vs 3.7%, P<0.0001). Although not previously reported, the incidence of twin pregnancies was higher in group A (3.8% vs 1.8% P<0.0001) and this association remained significant in a multivariate analysis with IVF as a co-variate (OR 1.43 95%CI[1.20–1.71], P<0.001). Obstetric complications including preterm deliveries (7.8% vs 5.2%, P>0.0001), cesarean sections (20.6% vs 11.4%, P>0.0001), any obstetric hemorrhage and prolonged hospitalization were more frequent in group A. The incidence of adverse neonatal outcome including low birth weight (7.3% vs 5.4%, P>0.0001) and NICU admission (5.1% vs 3.6%, P>0.0001) was higher in group A but there was no difference in fetal macrosomia and apgar scores.

Conclusions: In this large database, hypothyroidism is associated with adverse obstetric outcome. This is the first study to describe a higher incidence of hypothyroidism in twin pregnancies. TSH screening should be considered in twin pregnancies.