Fetal growth retardation: a limit for the further reduction of preterm births.

Fetal growth retardation is at present the major obstacle for further reduction in preterm births. After 25 years of continuous decline in the preterm birth rate in France from 6.9% in 1972 to 4.4% in 1981 and 3.8% in 1989, there has been an increase to 4.5% in 1995. The major new fact is the progressive increase of medically induced preterm births, mostly related to fetal growth retardation. Spontaneous preterm births have continued to decrease throughout all these years.