Profile of pregnancy in young spontaneously hypertensive rats.

The uterine contents and ovaries of pregnant spontaneously hypertensive rats (SHR) were compared to those of control Wistar-Kyoto rats (WKY). Although there were no strain differences in the number of released oocytes as indicated by corpora lutea, there were fewer viable fetuses in the SHR litters compared to WKY. Since there was no difference in post-implantation intrauterine loss, the lower SHR fetal number was most likely due to fewer successful implantations in the SHR. Maternal blood pressures declined significantly in both strains on day 18 of gestation.