Secretion of prolactin and insulin-like growth factor I by decidual explant cultures from pregnancies complicated by intrauterine growth retardation.
OBJECTIVES: Prolactin and insulin-like growth factor I secretion elsewhere in the uterus have been shown to decrease when tissue-specific growth is limited. We investigated their secretion by decidual explant cultures from pregnancies complicated by fetal intrauterine growth retardation. STUDY DESIGN: Explant cultures from 13 pregnancies complicated by intrauterine growth retardation and 12 control pregnancies were established in minimal essential medium and media was harvested after 24 hours of culture. Prolactin and insulin-like growth factor I concentrations were determined by radioimmunoassay. Total protein in the media was also measured. Data were analyzed by analyses of variance and linear regression. RESULTS: Decidual prolactin secretion in the pregnancies with intrauterine growth retardation was reduced to 109 +/- 31 ng/100 mg tissue per 24 hours compared with 254 +/- 51 ng in the controls (p = 0.01). Insulin-like growth factor I secretion was reduced to 1.9 +/- 0.6 ng/100 mg tissue per 24 hours from 7.1 +/- 0.9 ng/100 mg in the controls (p < 0.0001). Total protein secretion did not differ between the two groups. Decidual prolactin and insulin-like growth factor I secretion had a highly significant positive correlation (r = 0.71, p = 0.0001). CONCLUSIONS: Our data show that two protein hormones secreted by the maternal decidua are dramatically reduced in intrauterine growth retardation and warrant further investigation into their roles in the intrauterine environment.