Ten-Year Follow-up of Children Born at <30 Weeks’ Gestational Age Supplemented With Thyroxine in the Neonatal Period in a Randomized, Controlled Trial

Abstract

ABSTRACT. Background. Thyroid hormones are essential for brain development. We conducted a randomized, controlled trial with thyroxine (T4) supplementation in infants <30 weeks' gestation and with the last neurodevelopmental follow-up moment at the age of 5.5 years. T4 supplementation was associated with improved outcome of infants <28 weeks' gestation and worse outcome of infants of 29 weeks' gestation. We studied gestational age-dependent effects of T4 supplementation at the mean age of 10.5 years in children participating in our randomized, controlled trial.Methods. Questionnaires regarding school outcome, behavior, quality of life, motor problems, and parental stress were sent to the parents and children and their teachers at the same time point for all surviving children (9 -12 years of age).Results. Seventy-two percent of the families responded to our questionnaires. Nonrespondents had more sociodemographic risk factors and worse development until 5.5 years. At the mean age of 10.5 years, T4 supplementation was associated with better school outcome in those who were <27 weeks' gestation and better motor outcome in those who were <28 weeks' gestation, whereas the reverse was true for those who were born at 29 weeks' gestation. No other gestational age-dependent outcomes were found.Conclusions. Gestation-dependent effects of T4 supplementation remain stable over time. These effects do not prove beneficial effects of T4 in infants <28 weeks but should be the background for a new randomized, controlled trial with thyroid hormone in this age group.

Wrodzona niedoczynność tarczycy — polskie rekomendacje dotyczące leczenia, monitorowania terapii i badania przesiewowego w specjalnych kategoriach noworodków z wysokim ryzykiem niedoczynności tarczycy

“…TSH levels have no significant diagnostic value, since in the foetus and in preterm newborns the pituitary-thyroid axis is not always efficient. In preterm newborns and SGA babies, with low and very low body weight (VLBW) of 1500-1000 g and extremely low body weight (ELBW) below 1000 g, the maintenance of normal levels of fT4 and fT3 is very important [33][34][35][36].…”

“…After 4-6 weeks of life, a preterm newborn with fT4 deficiency is not going to have an appropriate number of dendrites and synapses [13,36].…”

“…Stężenia TSH nie mają tu istotnej wartości diagnostycznej, gdyż u płodu i wcześniaka oś przysadkowo--tarczycowa nie zawsze działa sprawnie. U wcześniaka, dziecka z niską masą urodzeniową w stosunku do wieku ciążowego (SGA), z niską i bardzo niską masą urodzeniową (VLBW, very low body wieght -1500-1000g i ELBW, extremely low body wieght -poniżej 1000 g) najważniejsze jest utrzymanie prawidłowych stężeń fT4 i fT3 [33][34][35][36]. Przyczyną pierwotnej niedoczynności tarczycy u wcześ niaków mogą być: -agenezja lub dysgenezja tarczycy; -ektopia tarczycy; -defekty enzymatyczne syntezy hormonów tarczycy; -obwodowa oporność na hormony tarczycy; -znaczny niedobór jodu w środowisku; -nadmierna podaż jodu (stosowanie leków zawierających jod, np.…”

“…Nawet jeżeli przyczyny te ustępują i wtórna niedoczynność tarczycy ma charakter przejściowy, to upływa optymalny czas rozwoju komórek nerwowych. Po 4.-6. tygodniu życia u wcześniaka z niedoborem fT4 nie wytworzy się odpowiednia liczba dendrytów i synaps [13,36].…”

Thyroid Stimulating Hormone and Thyroxine Screening in the Preterm Newborn: Reference Values

“…Per tali motivi alcuni AA. hanno prospettato la necessità di somministrare ormoni tiroidei fin dai primi giorni di vita nel neonato di età gestazionale estremamente bassa (ELGAN) [10][11][12][13][14][15][16][17][18][19][20]. Tuttavia non sono presenti in letteratura lavori che abbiano valutato in 2°-3° giornata di vita, momento in cui i fenomeni di adattamento neonatale sono ormai completati, i livelli di TSH e tT4 in un numero sufficientemente ampio di soggetti ELGAN, suddivisi in varie fasce di età gestazionale (EG).…”