Intrauterine growth retardation: clinical and experimental.

Intrauterine growth retardation is a common and potentially hazardous problem for the fetus. Despite this, the obstetric factors associated with growth retardation have changed little in the last twenty years. Some of the other factors, the so-called behavioural factors should be amenable to correction through education or changing social circumstances. Experimental studies presented here support the clinical observations that the growth retarded fetus is often malnourished and/or hypoxaemic. Restriction of placental growth results in fetal growth failure and these fetuses are chronically hypoxaemic and hypoglycaemic. Furthermore the apparent margin of safety between the delivery to and consumption by the fetus is less for the small fetuses. We suggest that this reduction in supply results in the endocrine changes and that these in turn, modulate the pattern of fetal growth.