[Effect of socioeconomic factors on twin pregnancy].

A material of 336 mothers of twins was divided into four groups on the basis of socioeconomic background. On average, mothers belonging to the first social class delivered at 38.2 +/- 1.6 week of pregnancy and their newborn weighed more than those in other social classes. Careful follow-up at outpatient maternity clinics is warranted in the case of expectant mothers of twins belonging to the third or fourth social class.