Slightly elevated thyrotropin levels in pregnancy in our clinical practice

• Published in: Endocrinología, diabetes y nutrición. Vol. 66; no. 10; pp. 620 - 627
• Main Authors: Alcázar Lázaro, Victoria, López del Val, Teresa, García Lacalle, Concepción, Torres Moreno, Beatriz, Castillo Carvajal, Gabriela, Vergara Fernández, Lucrecia, Benfdil, Lina, Torre Carrera, Covadonga, Orizales Lago, María Carmen, Ramos Zuñiga, Leonardo
• Format: Journal Article
• Language: English
• Published: Elsevier España, S.L.U 01-12-2019
• Subjects: Gestación; Hipotiroidismo subclínico; Pregnancy; Prognosis; Pronóstico; Subclinical hypothyroidism; Tratamiento; Treatment; Pregnancy; Hipotiroidismo subclínico; Prognosis; Treatment; Pronóstico; Subclinical hypothyroidism; Gestación; Tratamiento
• ISSN: 2530-0180; 2530-0180
• DOI: 10.1016/j.endien.2019.11.009

The aim of this study was to assess the incidence of obstetric and neonatal complications in pregnant women with “normal” thyroid-stimulating hormone (TSH) levels in the first trimester (group A) and to compare them with those with “slightly elevated” TSH (SET) levels treated with levothyroxine (group B2) or not treated (group B1).
A total of 2375 women who had been performed laboratory tests in their first trimester of pregnancy were detected at our hospital between April 2015 and August 2017. Of these, 469 patients with SET were prospectively detected and randomized to groups B1 (227) and B2 (242). They were monitored prospectively until 6 months after delivery. Data of the control group (n=1906, group A) were retrospectively reviewed. A total of 1745 women were analyzed. Variables assessed included demographic and clinical characteristics and complications of pregnancy and delivery.
A, B1, and B2 had similar clinical characteristics. There were no statistically significant differences in complications between the three groups during pregnancy, except in that natural deliveries were more common in group A as compared to group B1 (76.8% vs. 68.7%, p 0.017) and group B2 (66.3%), p<0.002). There were more induced deliveries in groups B1 (35.8%), and B2 (36.2%) than in group A (18.4%), p<0.01. Although the recommended TSH level was achieved in the second and third trimesters, no benefit could be found of treatment of SET.
Although there were less natural deliveries and more induced deliveries in patients with SET, treatment with levothyroxine could not reverse this situation, despite achievement of levels considered appropriate in the second and third trimester.
El propósito de este estudio fue investigar la incidencia de complicaciones obstétricas y neonatales en mujeres embarazadas con una tirotropina (TSH) «normal» en el primer trimestre (grupo A) y compararlas con aquellas con una TSH «discretamente elevada» (SET) tratadas con levotiroxina (grupo B2) o no (grupo B1).
Dos mil trescientos setenta y cinco gestantes con analítica en el primer trimestre fueron detectadas en nuestro hospital entre abril de 2015 y agosto de 2017. Cuatrocientos sesenta y nueve pacientes con SET se detectaron prospectivamente y randomizaron a los grupos B1 (227) y B2 (242). Se siguieron prospectivamente hasta 6 meses posparto. Los datos del grupo control (n=1.906, grupo A) se revisaron retrospectivamente. Se analizaron 1.745 pacientes. Las variables incluyeron características demográficas, clínicas y complicaciones de la gestación y el parto.
A, B1 y B2 eran comparables en sus características clínicas. Los partos eutócicos fueron más frecuentes en el grupo A que en el B1 (76,8 vs. 68,7%, p0,017) y B2 (66,3%, p<0,002). Hubo más partos inducidos en los grupos B1 (35,8%) y B2 (36,2%) que en A (18,4%), p<0,01. Aunque se alcanzó el nivel de TSH recomendado en el segundo y tercer trimestres, no pudimos encontrar ningún beneficio en el tratamiento de SET.
Aunque hemos encontrado menos partos eutócicos y más partos inducidos en las gestantes con SET, el tratamiento con levotiroxina no pudo revertirlo, pese a alcanzar un valor considerado apropiado en el segundo y tercer trimestre.