Abstract To study the mechanism of alcohol-induced fetal damage, we determined the somatomedin C and growth hormone (GH) concentrations of umbilical cord blood samples in 56 infants of alcohol-abusing women and in 20 infants of alcohol-abstinent women. In addition, maternal serum somatomedin C concentrations were determined 1–7 days before delivery. Twenty-five infants born to alcohol-abusing mothers were growth-retarded and also had other signs of fetal alcohol effects, but the remaining 31 infants born to the drinkers and all infants of abstinent mothers were healthy. The somatomedin C levels of infants with fetal alcohol effects (mean ± SD 4.6 ± 1.5 nmol/L) were lower ( P < .005) than the levels of healthy infants of drinking (6.8 ± 4.0 nmol/L) or abstinent (7.1 ± 3.3 nmol/L) mothers, but the levels did not correlate with infant birth weight, placental weight, or fetal GH or maternal somatomedin C levels. Alcohol drinking was not associated with any changes in maternal somatomedin C levels. The GH levels of infants with fetal alcohol effects (25.4 ± 22.6 ng/mL) were elevated ( P < .01) when compared with those of infants of abstinent mothers (13.1 ± 5.3 ng/mL), but did not differ from those of healthy infants of drinking mothers (19.9 ± 15.1 ng/mL). Low somatomedin C levels and high GH levels in infants born to the drinkers suggest a disharmony in the regulation of the synthesis and/or release of these growth factors, which may be of importance in alcohol-induced fetal damage.