Maternal hemodynamics and impaired fetal growth in pregnancy-induced hypertension.

Twenty-one subjects with pregnancy-induced hypertension were investigated with regard to the relationship between maternal hemodynamics and fetal growth. Five of the infants were small for gestational age (SGA) (less than tenth percentile) and 16 were appropriate for gestational age (AGA) (greater than tenth percentile). Mean arterial blood pressure, cardiac output, and stroke volume were significantly lower in the group of mothers with SGA infants than in the group with AGA infants (102 +/- 3 versus 115 +/- 3 mmHg, 5.8 +/- 0.2 versus 8.2 +/- 0.3 L/minute, and 76 +/- 7 versus 100 +/- 5 mL, respectively). The results of this investigation suggest that the hemodynamic background to the blood pressure increase in pregnancy-induced hypertension ranges from a low cardiac output, high vascular resistance condition to a high-output, low-normal resistance variant. The former subtype is often associated with the birth of an SGA infant.