[Prospective study at 1 week of life of thyroid function in 97 consecutive pre-term newborns under 32 weeks of gestation]. / Étude prospective à une semaine de vie de la fonction thyroïdienne chez 97 prématurés consécutifs de terme inférieur à 32 semaines d'aménorrhée.

UNLABELLED: Hypothyroxinemia of prematurity (HTOP) is associated with neurodevelopmental impairment in pre-term newborns born at less than 32 weeks of gestation (WG). HTOP is not clearly defined in the literature and there is no consensus on whether or not treatment of HTOP is beneficial. OBJECTIVE: To describe the epidemiologic characteristics of HTOP and to determine the population at risk of HTOP. POPULATION AND METHODS: Ninety-seven pre-term newborns under 32 WG were prospectively included in this study. FT4 and thyroid-stimulating hormone (TSH) serum levels were assessed between day of life 5 and 7. HTOP was defined as serum level of FT4 0.80 ng/dl or less and TSH less than 20 mUI/l. RESULTS: The HTOP incidence was 29% in pre-term newborns under 32 WG and 64% in pre-term newborns 28 WG or less. FT4 levels were correlated with gestational age (P<0.001). The incidence of hypotension (61% vs 33%; P<0.05), patent ductus arteriosus (50% vs 17%; P<0.05), dopamine treatment (39% vs 16%; P<0.05), and hydrocortisone treatment (25% vs 6%; p<0.05) was higher in the HTOP group. Similarly, severe intracerebral hemorrhage (14% vs 0%; P<0.01) and hypothermic events under 36 °C (1.8 ± 1.7 vs 0.0 ± 0.4; P<0.05) were higher in the HTOP group. CONCLUSION: Incidence of HTOP is high in pre-term newborns born at less than 28 WG. Morbidity during the first week of life is higher in cases of HTOP. Whether or not treatment of all pre-term with l-thyroxin is beneficial is unknown. However, treatment of the subgroup of pre-term newborns under 28 WG with HTOP should be considered.

Persistent pulmonary hypertension of the newborn with transposition of the great arteries: successful treatment with bosentan.

Persistent pulmonary hypertension of the newborn (PPHN) occurs in 1-4% of neonates with transposition of the great arteries with intact ventricular septum (TGA/IVS). This association is often lethal. To our knowledge, only eight survivors have been described in the literature, two of whom benefited from extracorporeal membrane oxygenation (ECMO). We report two cases of PPHN complicating a TGA/IVS that were refractory to multiple therapies and resolved 48 hours after initiation of bosentan therapy. Bosentan, an oral dual endothelin-1 receptor antagonist, is a new treatment for pulmonary arterial hypertension that was both effective and safe in these two cases of TGA/IVS with PPHN. To our knowledge, it is the first use of bosentan in newborns.