| Abstract: | Retardation of growth and death of fetal rats were produced after uteroplacental ischaemia was induced by surgical ligation of the uterine arteries. Changes in maternal plasma levels of alpha-fetoprotein (AFP) were measured by radioimmunoassay. In rats in which the uterine blood supply was totally occluded, the resultant increase in maternal plasma AFP was due to resorption of fetal elements, because AFP levels in maternal rat plasma did not increase following hysterectomy in a control group. Maternal plasma AFP levels in rats with a partly occluded blood supply (and therefore some dead and some live fetuses) paralleled those of sham-operated rats, suggesting that increased placental transfer of AFP to maternal plasma may have offset the anticipated decline of AFP due to a decreased number of live fetuses. |
