Quantitative assessment of right and left ventricular growth in the human fetal heart: a pathoanatomic study.

We quantitated the growth patterns of the normal fetal heart and the right and left ventricles from postmortem hearts obtained from 55 spontaneously aborted human fetuses from the completion of cardiogenesis to term. Fetal gestational age was assessed by menstrual history of the mother, crown-rump length, head circumference, and body weight and ranged from 8 to 40 weeks. Each heart was perfused and fixed at constant pressure and dissected to obtain right and left ventricular free wall, left ventricular, and total heart weights. Right and left ventricular free wall thicknesses were measured and the respective surface areas were calculated. The changes in each of these parameters with gestational age were examined by regression analysis. Total heart and right and left ventricular wall weights increased linearly with body weight, but exponentially with head circumference, crown-rump length, and menstrual history. Right and left ventricular free wall weights were similar throughout gestation and the percent that each contributed to total heart weight were constant at 29 +/- 2% and 30 +/- 2%, respectively. Right and left ventricular wall thicknesses did not differ significantly, increasing linearly with menstrual age, crown-rump length, head circumference, and body weight from 8 to 40 weeks. The surface areas of the right and left ventricular free walls that we used as an index of changing ventricular architecture were indistinguishable throughout the period of gestation studied.(ABSTRACT TRUNCATED AT 250 WORDS)