Yaffe H, Hay-Am E, Sadovsky E
Obstet Gynecol. 1981 Apr;57(4):490-2.
The danger to the newborn inherent in a postmature pregnancy has gained recognition. However, the diagnosis of postmaturity remains a difficult problem. The thromboplastic activity of amniotic fluid (TAAF) increases with the gestational age. Based on this phenomenon, the TAAF of 45 women in the 41st to 43rd weeks of gestation was established, using their amniotic fluid as a source of thromboplastin. It was found that in all cases in which the TAAF value was less than 42 seconds, the newborns exhibited clinical evidence of postmaturity.
过期妊娠对新生儿的潜在危险已得到公认。然而，过期妊娠的诊断仍然是一个难题。羊水的促凝血活性（TAAF）随孕周增加而升高。基于这一现象，以45例孕41至43周孕妇的羊水作为凝血活酶源，测定其TAAF。结果发现，所有TAAF值小于42秒的病例中，新生儿均有过期妊娠的临床证据。
