Fetal heart motion should be documented immediately after the procedure. Dark red or brown fluid indicates previous intra-amniotic bleeding and is associated with adverse pregnancy outcomes. Green fluid does not appear to be associated with adverse pregnancy outcomes. Needle injuries to the fetus are rare. Inability to obtain amniotic fluid, culture failure, and maternal cell contamination are unusual.
Amniotic fluid is aspirated from the first sac.
Fluid is then aspirated from the second sac at a location selected after the separating membrane is seen. Aspiration of clear fluid confirms that the second sac has been sampled. The same technique is used in pregnancies with more fetuses. Fetal sex can be determined before birth by constructing the karyotype from cultured fetal cells. When the mother has been identified as a carrier of an X-linked mutation and a specific test for the fetus is unavailable, fetal sex may be determined with the option to abort males, although half of them will be normal.