Psychological changes in pregnant women induce communications towards the fetus. Maternal vocal behavior induces fetal reactions. Prenatal communication takes fetuses and newborns to perform auditory discriminations. Fetuses in risk pregnancies present difficulties in these matters. To study possible changes in vocal activity during healthy and risk pregnancies, SMPNC was organized with 28 items related with maternal vocal communication. SMPNC was submitted to pregnant women waiting for sonograms at the third trimester. Adequate indexes (KMO = .888; BTS, χ 2 = 2792.795, df = 378, p = .000) allowed the performance of several factorial analysis. Analysis with Equamax rotation identified five factors: Verbal Communication With the Baby, Engaging the Partner in the Communication Towards the Baby, Contents Shared in the Communication Towards the Baby, Perception About the Baby's Auditory Competence and Availability for the Communication Towards the Baby. Together the items of these factors constitute a Total Scale. Subscales and Total Scale were correlated with sociodemographic and clinical variables. Some subscales of SMPNC present negative correlations with variables related with reproductive status. These results suggest that maternal motivation for prenatal communication is especially high during the first gestation and decreases as mothers must divide their maternal attention for several sons.