THE EFFECT OF LEVOTHYROXINE TREATMENT ON MATERNAL AND PERINATAL OUTCOMES IN PREGNANT WOMEN WITH SUBCLINICAL HYPOTHYROIDISM: A 5-YEAR RETROSPECTIVE STUDY AT A TERTIARY CARE HOSPITAL IN TURKEY

Year 2023, Issue: 052, 297 - 310, 29.03.2023

Halil İbrahim Erbıyık , Rabia Merve Palalıoglu

https://doi.org/10.59313/jsr-a.1252381

Abstract

Subclinical hypothyroidism is characterized by elevated thyroid stimulating hormone (TSH) levels with normal free thyroxine (fT4) levels. The aim of this study was to compare obstetric and neonatal outcomes in pregnant women with and without treatment for subclinical hypothyroidism. In this study, maternal and perinatal outcomes were evaluated in a total of 270 pregnant women who were diagnosed with subclinical hypothyroidism as a result of screening performed in three trimesters of pregnancy between 2015 and 2020 and followed up in our clinic, 149 of whom received levothyroxine treatment and 121 of whom did not receive treatment. Further, different cutoff values for TSH were compared. The rates of neonatal intensive care unit (NICU) requirement were not different according to the levothyroxine use status of the patients (p=0.73, p>0.05). Miscarriage rates did not differ according to levothyroxine use (p=0,87, p>0,05). TSH, T4 and antithyroid peroxidase levels did not differ according to the maternal use of levothyroxine (p>0,05). Birth weight, gestational week at birth, 1- and 5-minute APGAR scores, neonatal TSH and T4 levels did not differ according to the maternal use of levothyroxine (p>0,05). Among the adverse maternal and perinatal outcomes, the need for NICU admission and the rates of placental abruption, fetal distress, preterm premature rupture of membranes, preeclampsia, preterm labor, and small for gestational age were not significantly different among the TSH cutoff groups (p>0,05). The rate of premature rupture of membranes was higher in the group with TSH levels ≥2.5 mIU/L (p=0.04). Choosing 2.5 mIU/L as the cutoff value for TSH levels allows early diagnosis of subclinical hypothyroidism with a higher rate in pregnant Turkish women and proactive therapeutic management. Our study provides limited evidence for the success of levothyroxine therapy for adverse obstetric and neonatal outcomes.

Keywords

Adverse pregnancy-fetal outcomes, Levothyroxine, Pregnancy, Screening, Subclinical hypothyroidism, Thyroid hormone replacement

Thanks

Financing has not been used. The authors declare that they have no conflict of interest. Patients signed informed consent for the publication of their data. All procedures comply with the ethical standards of the national research committee and the 1964 Declaration of Helsinki, its later amendments, or comparable ethical standards.

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