Transient hypothyroxinemia in severe hypertensive disorders of pregnancy.
OBJECTIVE
Assess whether and to what extent thyroid function is affected in pregnant women with early and severe hypertensive disorders and in their newborns.


METHODS
Patients were 80 women with preeclampsia, hemolysis, elevated liver enzymes, and low platelet count syndrome or gestational hypertension combined with fetal growth restriction in the 24th to 34th week of singleton pregnancies. Maternal thyroid hormone levels and thyroid peroxidase antibodies were determined at admission and 3 months postpartum. Neonatal levels were determined from cord blood at delivery. Maternal hypothyroxinemia was defined as free T(4) (fT(4)) value below 9 pM.


RESULTS
At admission 26 (33%) women in the study group had fT(4) levels below 9 pM, with spontaneous normalization during pregnancy. There were no statistically significant differences between thyroid hormone values in women in the study group and 10 normotensive pregnant women in their third trimester. Three months postpartum, 97.5% of patients had normal thyroid hormone levels. Thyroid peroxidase antibodies were elevated in 10% of women postpartum. Their infants, born at a median gestational age of 30 6/7 weeks, had lower cord blood fT(4) and thyroid-stimulating hormone values compared with preterm infants of the comparison group, appropriate for gestational age. Cord blood fT(4) had no correlation with gestational age or maternal fT(4), but there was a significant correlation of cord blood fT(4) with umbilical artery pH.


CONCLUSIONS
Women with severe hypertensive disorders of pregnancy may have transiently lower fT(4) levels, without evidence of a thyroid disorder. Their neonates have lower fT(4) levels at birth unrelated to maternal fT(4), but related to prenatal acidosis.


METHODS
II-2.
Buimer
Maarten
M
Department of Obstetrics and Gynecology, Academic Medical Center, 1100 DD Amsterdam, the Netherlands. m.buimer@amc.uwa.nl
van Wassenaer
Aleid G
AG
Ganzevoort
Wessel
W
Wolf
Hans
H
Bleker
Otto P
OP
Kok
Joke H
JH
D000328:Adult; D015551:Autoimmunity / Q000502:physiology; D015331:Cohort Studies; D005260:Female; D005312:Fetal Blood / Q000737:chemistry; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000097:blood* / Q000276:immunology; D007231:Infant, Newborn; D007453:Iodide Peroxidase / Q000097:blood; D049590:Postpartum Period / Q000097:blood; D011247:Pregnancy; D013961:Thyroid Gland / Q000503:physiopathology; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood*; D013975:Thyroxine-Binding Proteins / Q000378:metabolism; D014284:Triiodothyronine / Q000097:blood; D014285:Triiodothyronine, Reverse / Q000097:blood
D013975:Thyroxine-Binding Proteins; D014284:Triiodothyronine; D014285:Triiodothyronine, Reverse; D013972:Thyrotropin; D007453:Iodide Peroxidase; D013974:Thyroxine