Gestational diabetes mellitus and neonatal hyperthyrotropinemia.
OBJECTIVE
To determine whether gestational diabetes mellitus (GDM) is associated with increased incidence of neonatal hyperthyrotropinemia.


METHODS
In a retrospective study, maternal characteristics, infant outcome and cord blood thyrotropin (TSH) concentration were compared between 469 diet-treated GDM pregnancies diagnosed by the World Health Organization 75 g oral glucose tolerance test (OGTT) with 474 non-diabetic pregnancies with normal OGTT results.


RESULTS
Hyperthyrotropinemia (TSH >16 mIU/l) was found in 7.2% of the GDM pregnancies and 2.1% of the controls (p < 0.001), but there was no difference in the birth weight or gestational age. The TSH concentration was correlated with the OGTT 2-hour glucose value (rho = 0.0948, p = 0.029) and Apgar score at the fifth minute (rho = -0.1197, p = 0.009). There was no difference in the TSH or free thyroxine concentrations between the hyperthyrotropinemic newborns of the GDM and control groups. In the GDM group, the hyperthyrotropinemic newborns had a higher incidence (p = 0.017) of neonatal jaundice.


CONCLUSIONS
Neonatal hyperthyrotropinemia is more frequently found in pregnancies with GDM, and this could have reflected increased fetal in-utero hypoxic stress in these pregnancies.
Lao
Terence T
TT
Department of Obstetrics and Gynaecology, The University of Hong Kong, Tsan Yuk Hospital, Hong Kong SAR, China. laotth@hkucc.hku.hk
Lee
Chin-Peng
CP
D000328:Adult; D001724:Birth Weight; D016640:Diabetes, Gestational / Q000150:complications*; D005260:Female; D005312:Fetal Blood / Q000378:metabolism; D005311:Fetal Hypoxia / Q000209:etiology; D006801:Humans; D007231:Infant, Newborn; D007567:Jaundice, Neonatal / Q000209:etiology*; D011247:Pregnancy; D011256:Pregnancy Outcome; D012189:Retrospective Studies; D013972:Thyrotropin / Q000097:blood*
D013972:Thyrotropin