Neonatal outcomes of pregnancies complicated by maternal Hyperthyroidism / Journal of the ASEAN Federation of Endocrine Societies

Objective@#This study aimed to determine the proportion, clinical characteristics, hormonal status, median time for normalization of serum thyroxine (FT4) and thyroid-stimulating hormone (TSH) and factors affecting time to thyroid function test (TFT) normalization of neonates born to mothers with maternal hyperthyroidism admitted in our institution.@*Methodology@#This was a retrospective cohort study that included 170 newborns admitted to the Neonatal Intensive Care Unit (NICU) of Hospital Universiti Sains Malaysia (HUSM) with a history of maternal hyperthyroidism from January 2013 until December 2018. We analyzed their baseline demographic and clinical characteristics, maternal thyroid status and antibody levels. Finally, we analyzed newborn thyroid function and thyroid antibodies.@*Results@#The proportion of neonates born to mothers with maternal hyperthyroidism was 0.8% (170 of 20,198 neonates within the study period). Seven (4.1%) developed overt hyperthyroidism, while four (2.4%) had thyroid storm. The median time for thyroid function test normalization was 30 days (95% CI: 27.1 to 32.8). The median time for TFT normalization was longer among neonates of mothers with positive thyroid antibodies [46.6 days (95% CI, 20.6 to 39.4)] and of mothers who received anti-thyroid treatment [31.7 days (95% CI, 23.5 to 39.9)].@*Conclusion@#Neonates born to mothers with hyperthyroidism is uncommon. These babies were observed to have a longer time for normalization of thyroid function tests if their mothers had thyroid antibodies or received anti-thyroid treatment.

Hijos de madres con enfermedad de Basedow Graves / Newborn of mothers with Graves' disease

Resumen: Introducción: La causa más frecuente de hipertiroidismo congénito es la enfermedad de Basedow Graves (EG) materna, en la que anticuerpos anti receptor de hormona tiroestimulante (TSH) (TRAb) atraviesan la placenta estimulando al receptor de TSH fetal y/o neonatal para producir hormonas ti roideas. La disfunción tiroidea en estos pacientes se confirma con el aumento de las concentraciones de tiroxina (T4) y triyodotironina (T3) acompañado de niveles de TSH suprimida. Objetivos: Carac terizar la evolución clínica y bioquímica de los recién nacidos (RN) hijos de madres con EG, y sugerir recomendaciones respecto al tratamiento y seguimiento. Material y Método: Se realizó una revisión de la literatura usando la base de datos MEDLINE, identificando artículos que incluyeran más de 30 RN de madres con EG y describieran su evolución. Se agregaron además revisiones del tema enfati zando la evaluación y manejo de los hijos de madres con EG. Resultados: Se incluyeron 9 estudios de cohorte que incorporaron 790 embarazadas. Hubo heterogeneidad entre los trabajos; un porcentaje variable de los hijos desarrolló tirotoxicosis neonatal, la que fue más frecuente cuando las madres presentaron concentraciones elevadas de TRAb. El tratamiento de los RN se inició según diferentes criterios. La literatura recomienda tratar los casos de hipertiroidismo clínico y considerarlo en casos de hipertiroidismo bioquímico. Conclusión: Los hijos de madres con EG y TRAb elevados deben ser evaluados por la probabilidad de desarrollar tirotoxicosis neonatal. Se sugiere controlar función tiroidea periódicamente durante el primer mes de vida y tratar los pacientes con hipertiroidismo clínico y bioquímico.

Abstract: Introduction: The most frequent cause of congenital hyperthyroidism is maternal Graves' disease (GD), in which thyroid stimulating hormone (TSH) receptor antibodies (TRAb) cross the placenta and stimulate the fetal and/or neonatal TSH receptor to produce thyroid hormones. Thyroid dys function in these patients is confirmed by increased thyroxine (T4) and triiodothyronine (T3) levels accompanied by suppressed TSH levels. Objective: To characterize the clinical and biochemical evo lution of newborns of mothers with GD and to suggest recommendations regarding treatment and follow-up. Material and Method: A literature review using the MEDLINE database was made, iden tifying scientific articles that included more than 30 neonates of mothers with GD and described their evolution. In addition, a review of the topic with an emphasis on the evaluation and management of these patients was included. Results: Nine cohort studies were included, with a total of 790 pregnant women. There was high heterogeneity among the studies. A variable percentage of newborns deve loped neonatal thyrotoxicosis, which was more frequent in those patients whose mothers had high levels of TRAb. The treatment of newborns was initiated according to different criteria. The literature recommends treating cases of clinical hyperthyroidism and considers it in cases of biochemical hy perthyroidism. Conclusion: Children of mothers with GD and high TRAb should be evaluated due to the likelihood of developing neonatal thyrotoxicosis. It is suggested to monitor thyroid function periodically during the first month of life and treat patients with clinical and biochemical hyper thyroidism.