Ted (G.J.) Kloosterman: On Intrauterine Growth. The Significance of Prenatal Care. Studies on Birth Weight, Placental Weight and Placental Index

In the last century, there was a heated debate on whether fetal growth retardation is caused by a small placenta or whether a placenta is small because the baby is small. One of the active participants in this debate was Kloosterman who studied 80,000 birth weights, and 30,000 placental weights, in relation to gestational age at birth, fetal sex, maternal parity, and perinatal mortality. He found that pregnancies related to heavier placentas last longer. He also found that, from about 32 weeks of gestation onwards, children from primiparous women as compared to those from multiparous women, like twin children as compared to singleton children, are relatively growth retarded, most likely related to prior relatively poor placental growth. He concluded that poor fetal growth is not the cause, but the result of poor placental growth.