Assesing the effect of thyroid dysfunction during pregnancy on maternal and neonatal outcomes with guidelines and population-based gestation-specific reference intervals

Onur Elbasan; Rana Turkal; Turan Cem Armağan; Serenay Aytan; Burcu Cakmak; Buşra Gozaydınoğlu; Takır Duygu Ceyda; Ozan Unlu; Gunel Bahramzada; Tekin Ahmet Faruk; Tulay Cevlik; Buyukbayrak Esra Esim; Onder Şirikci; Gozu Hulya Ilıksu; Goncagul Haklar

doi:10.1530/endoabs.90.P753

P753

Prev Next

Section Contents Cite

Endocrine Abstracts (2023) 90 P753 | DOI: 10.1530/endoabs.90.P753

ECE2023 Poster Presentations Thyroid (163 abstracts)

Assesing the effect of thyroid dysfunction during pregnancy on maternal and neonatal outcomes with guidelines and population-based gestation-specific reference intervals

Onur Elbasan ^1,2 , Rana Turkal ³ , Cem Armağan Turan ⁴ , Serenay Aytan ⁵ , Burcu Çakmak ⁵ , Büşra Gözaydınoğlu ⁵ , Duygu Ceyda Takır ⁵ , Ozan Unlu ³ , Gunel Bahramzada ³ , Ahmet Faruk Tekin ³ , Tülay Çevlik ³ , Esra Esim Büyükbayrak ⁶ , Önder Şirikçi ⁷ , Hülya Ilıksu Gözü ² & Goncagül Haklar ⁷

Err

Author affiliations

¹Sinop Ataturk State Hospital, Endocrinology and Metabolism, Sinop, Turkey; ²Marmara University School of Medicine, Endocrinology and Metabolism, Turkey; ³Marmara University Pendik Education and Research Hospital, Biochemistry, Turkey; ⁴Marmara University School of Medicine, Internal Medicine, Turkey; ⁵Marmara University School of Medicine, Turkey; ⁶Marmara University School of Medicine, Gynecology and Obstetrics, Turkey; ⁷Marmara University School of Medicine, Biochemistry, Turkey

Introduction: Adverse pregnancy outcomes have been associated with maternal thyroid dysfunction. However, optimizing the best threshold value to improve maternal and perinatal outcomes and alleviate complications by establishing population-based gestation-specific reference intervals (RIs) instead of using recommended universal cut-off values, especially for thyroid-stimulating hormone (TSH), is still an ongoing debate. The aim of this study was to compare the prevalence and risk of pregnancy outcomes based on established gestation- and laboratory-specific RIs and the recommended criteria.

Methods: We conducted a retrospective study on 2104 pregnant women in different trimesters and their infants. The national neonatal screening program was reached to obtain data on TSH measured in capillary blood. We considered TSH thresholds recommended by Endocrine Society clinical practice 2012 and revised American Thyroid Association (ATA) 2017 guidelines to classify thyroid dysfunction. In addition, trimester-specific and subgroup-specific RIs, which were based on our local population, and published previously by our group, were applied for comparison. Outcomes comprised fetal-maternal complications, including gestational hypertension, gestational diabetes mellitus (GDM), preeclampsia, preterm delivery, low birth weight (LBW≤ 2500 g), and elevated neonatal TSH (≥ 5.5mIU/l).

Results: Maternal hypothyroidism based on subgroup-specific classification was associated with a higher risk of GDM than was euthyroidism (2.8% vs. 7.5%; OR 2.78, 95%CI 1.01-7.62; P=0.047), while maternal hypothyroidism based on Endocrine Society 2012 criteria was associated with a higher risk of infants with elevated neonatal TSH (2.3% vs. 6.5%; OR 2.93, 95%CI 1.27-6.79; P=0.012) in the first trimester. Based on ATA 2017 guideline, trimester-specific and subgroup-specific RIs, lower median birthweight (P=0.032, P=0.031, P=0.01, respectively) was demonstrated in the hypothyroid women in early pregnancy compared to the euthyroid group. Among those tested in the third trimester, maternal hypothyroidism had significantly higher incidences of LBW (3.2% vs. 14.7%, P= 0.009; 3.5% vs. 27.3, P=0.008; 3.6 vs. 15.4, P=0.02; 3.7 vs. 14.8, P=0.025; based on four different criteria respectively). The incidence of preterm delivery was also higher in hypothyroid women than in euthyroid women in the third trimester (7.5% vs. 20.6, P=0.017; 7.7% vs 23.1, P=0.017; 7.6% vs 22.2%, P=0.02; based on Endocrine Society 2012 guideline, trimester-specific and subgroup-specific RIs, respectively).

Conclusions: Our data confirmed the adverse impact of maternal thyroid function and provided further evidence for an even stronger relationship between maternal hypothyroidism and pregnancy outcomes in the case of applying different thresholds for TSH in pregnant women.