POLYMORPHISM OF THE BETA(3)-ADRENERGIC-RECEPTOR GENE ASSOCIATED WITH MATERNAL BODY-WEIGHT GAIN AND FETAL BODY-WEIGHT

Objective: To investigate whether the polymorphism of the beta(3)-adre nergic-receptor (beta(3)-AR) gene was associated with the maternal and fetal conditions during pregnancy. Method: The association between th e genotypes of beta(3)-AR and clinical phenotypes during pregnancy was analyzed in 92 women (a total of 126 pregnancies). Result: The overal l frequency of the Trp64Arg beta(3)-AR allele in 92 pregnant Japanese women was 20.7%. In 125 pregnancies, excluding one homozygote (51 hete rozygote group and 74 wild-type group), a significant difference in th e maternal body weight gain during pregnancy was observed between the heterozygote group and wild-type group. The heterozygote group had sig nificantly higher neonatal body weights, neonatal body weight index va lues and placental weights compared with the wild-type group. Conclusi on: The Trp64Arg heterozygous mutation in the beta(3)-AR gene is assoc iated with not only the increase in the body weight of pregnant Japane se women hut also the increase in the weights of their neonate and pla centas. (C) 1998 International Federation of Gynecology and Obstetrics .