Objective: To study the funic thyroid hormone levels in cases were fetal distress during labor resulted in acidemia at birth.
Material and methods: Arterial and venous levels of TSH, total T4, free T4 and total T3 obtained from cord blood at birth of twelve acidemic fetuses were compared with normal controls.
Results: Acidemic fetuses had a significanly higher TSH levels than controls (16.5+/-2. 1 microI/dl vs. 9.6+/-1.4 microI/dl, P=0.01). Total T3 levels were significantly lower in acidemic fetuses (49.2+/-2.9 ng/dl vs. 63+/-5. 5 ng/dl, P=0.04). Total and free T4 levels were similar and there was no difference between arterial and venous levels of the hormones.
Conclusions: Birth acidemia from fetal distress during labor is associated with higher TSH levels and lower T3 levels.