Colonization with genital mycoplasmas in pregnant women and their neonates and birth weight.

The colonization by genital mycoplasmas of mothers and their newborn infants was examined in 114 pregnant women and their 84 neonates. Urine and cervical swabs were taken from the pregnant women in the last trimester, and urine from the neonates within six days after birth. Ureaplasma urealyticum was found in 73.7% of the pregnant women and in 17.9% of the neonates. Mycoplasma hominis was isolated in 8.8% of the material from the pregnant women and in 1.2% of that from the neonates. The isolation rate of U. urealyticum from newborn girls was significantly higher than that from newborn boys (p less than 0.01). There was no correlation between the germ density in the urine of the pregnant women and that of the neonates. The urine of the neonates harboured as many U. urealyticum as that of the adults. The frequency of colonization by mycoplasmas in the pregnant women or the neonates was not related to the duration of gestation or the babies' birth weight.