lotus



previous page: 1. What are the screens?
  
page up: Pregnancy Screening FAQ
  
next page: 2.b Why is the age of the fetus important?

2.a What is apha-fetoprotein?




Description

This article is from the Pregnancy Screening FAQ, by Lynn Gazis-Sax (gazissax@netcom.com) with numerous contributions by others.

2.a What is apha-fetoprotein?

2.a AFP is a protein produced by every fetus. The baby urinates it into the
amniotic fluid, and it makes its way from there into the mothers blood for
excretion. There is a normal range of AFP found in the mothers blood; this
is determined by the age of the fetus.

A baby with an open spinal defect often leaks larger quantities of AFP into
the amniotic fluid, and in turn, into the mothers bloodstream.

An elevated level of AFP *does NOT* diagnose a neural tube defect! Babies
with such defects tend to produce more AFP, which gets into the mother's
blood, but there are also other reasons for an elevated level. The most
common reason for elevated AFP is that the age of the fetus was estimated
incorrectly. Twin pregnancy would also tend to show elevated levels.
-----------------------------

Addition by Dr. Tim Reynolds:

This is a good reson why an ultrasound should be done first because it is
not possible to do Down's screens on multiple pregnancies: An amnio is
needed for confirmation of result and it is virtually impossible to be
certain that trisomy cells found in a twin pregnancy come from a particular
twin: This leads to the possibility of a selective abortion in which the
wrong twin is aborted: Ergo, Down's screening in twin pregnancies is very
inadvisable.
-----------------------------

 

Continue to:













TOP
previous page: 1. What are the screens?
  
page up: Pregnancy Screening FAQ
  
next page: 2.b Why is the age of the fetus important?