Human chorionic gonadotropin (HCG) is used parenterally for treatment of threatened abortions and repeated spontaneous abortion in pregnant women. No controlled epidemiological studies of preterm birth and low birthweight newborns in pregnant women with HCG treatment have been published while the results of animal investigations were controversial. The data of 97 pregnant women with HCG treatment in the second and third months of pregnancy due to threatened abortion and/or previous spontaneous abortion(s) was compared with the data of other 38,054 pregnant women in the population-based large data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities. There was no difference in mean gestational age at delivery and birth weight, in addition the rate of preterm birth and low birthweight newborns. Parenteral HCG treatment in the early pregnancy due to threatened abortion did not associate with a higher risk for preterm births or low birthweight newborns. However, a higher occurrence of gestational diabetes was found in pregnant women with HCG treatment and there was a slight male excess among newborn infants (p=0.06).