Bouw G M, Stolte L A, Baak J P, Oort J
Eur J Obstet Gynecol Reprod Biol. 1978 Feb;8(1):31-42. doi: 10.1016/0028-2243(78)90007-2.
The morphological changes in the placenta concomitant with the transition from maturity to postmaturity were investigated by stereology under early clamping of the umbilical cord. 37 placentas from nonpathological pregnancies delivered after a period of 224-303 days of amenorrhea were examined. It appeared that after 267-288 days of amenorrhea, 8 out of 9 placental components showed no further growth and even showed regression. Only the volume of the trophoblast continued to grow in postmaturity. It is suggested that during postmaturity the villous capacity to produce steroids is continuing at a normal rate (as judged by the increase of the volume of the trophoblast), whereas the capability to transfer is deteriorating (as testified by the decreasing surface of the trophoblast).
在脐带早期钳夹的情况下，通过体视学研究了胎盘从成熟到过熟转变过程中的形态学变化。对37例闭经224 - 303天的非病理性妊娠分娩的胎盘进行了检查。结果显示，闭经267 - 288天后，9个胎盘成分中的8个不再生长，甚至出现退化。仅滋养层体积在过熟期继续增长。提示在过熟期，绒毛产生类固醇的能力以正常速率持续（根据滋养层体积增加判断），而转运能力则在下降（根据滋养层表面减少证明）。
