ABSTRACT
Myoglobin levels were measured in 70 maternal and 74 cord sera drawn immediately after
delivery. The mean cord myoglobin was 28 ng/ml. Myoglobin levels increased with birthweight,
and black infants tended to have slightly higher levels than white babies. Myoglobin
levels were not elevated in babies with fetal distress (evidenced by abnormal monitor
tracings or meconium staining) compared to babies with no distress. Maternal myoglobin
(18 ± 15.3 ng/ml) was about 10 ng/ml lower than cord levels and there was little correlation
between the two. Mothers differed among themselves only with respect to complications
of labor and delivery. Those with complications had significantly higher myoglobin
levels (29 ± 24.1 ng/ml) than mothers without difficulties (15 ± 10.0 ng/ml, P < 0.05).
The fetal myoglobin level was relatively independent of the mother's. While high or
potentially toxic myoglobin levels were not observed in this study, it appears that
the fetus may be protected by the placental barrier.
