The relationship between changing values of pregnancy-associated plasma protein-A in late pregnancy and the onset of labour.
The pattern of change of PAPP-A was established in three separate groups of patients. Day-to-day change from the 38th week was measured in six healthy patients whose pregnancies ended in spontaneous labour. The slow fluctuations of PAPP-A suggest that values found in labour are a consequence of events prior to the onset of labour. Increases of PAPP-A during the last few days of pregnancy and into labour were compared in patients going into labour spontaneously and patients who were induced. The induced patients showed a sharper increase in PAPP-A during this interval than the spontaneous onset group. A comparison at an earlier stage of pregnancy of PAPP-A increase was made between normal pregnancies going into labour on or before 280 days and those who went into labour later. Between 31 +/- 1 and 35 +/- 1 weeks, those who delivered in the earlier group showed a sharper rise in PAPP-A. It seems likely that the behaviour of PAPP-A in late pregnancy is the consequence of uterine activity and it seems unlikely that an increasing level of PAPP-A in itself has anything to do with the initiation of spontaneous labour.
D005260:Female; D006801:Humans; D007700:Kinetics; D007745:Labor Onset; D007751:Labor, Induced; D007743:Labor, Obstetric; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000378:metabolism*; D011263:Pregnancy Trimester, Third; D011266:Pregnancy-Associated Plasma Protein-A / Q000378:metabolism*
D011257:Pregnancy Proteins; D011266:Pregnancy-Associated Plasma Protein-A