The Resource Mothers Study of Maternal Phenylketonuria: preliminary findings

Abstract

Women with phenylketonuria (PKU) must follow a strict low-phenylalanine diet during pregnancy in order to protect the fetus from the deleterious effects of high maternal blood phenylalanine. The Resource Mothers Study of Maternal PKU was undertaken to determine whether a home visitation programme was effective in helping women with PKU attain blood phenylalanine control earlier during pregnancy. Resource Mothers were trained to provide social support and practical assistance to women with PKU during pregnancy. Eight metabolic clinics in the United States participated in the study. Women with PKU who were planning pregnancy or already pregnant were enrolled in the study and were treated with a low-phenylalanine diet aimed at controlling blood phenylalanine to 120-360 micromol/L. They were randomly assigned to receive the services of a Resource Mother (RM group) or to a control group. Fifty women were enrolled, and accounted for 44 pregnancies which resulted in 28 live births, and 6 spontaneous abortions. Ten women are currently pregnant and another 6 have not become pregnant. Fifty-six percent of enrolled women began the diet prior to becoming pregnant. Fifty-three percent of women in the Resource Mother group were in metabolic control by 10 weeks gestation as compared to 39% in the control group. In addition, women who began diet after pregnancy and had a Resource Mother attained metabolic control earlier (mean gestational age of 22.4 weeks in the RM group vs 29.8 weeks in the control group). There was no difference in birth measurement z -scores of offspring born to women in the RM group compared to controls. All but 4 women rated themselves as feeling worse about the diet at the end of pregnancy than at the beginning, and few women in either group remained on diet after delivery.