Amniocentesis is an invasive procedure that requires removing the amniotic fluid to obtain fetal cells for chromosomal analysis. The procedure is usually performed between 15-18 weeks gestation and is done under ultrasound guidance.
Amniocentesis is most commonly done to diagnose the fetal chromosomal anomalies, after detecting fetal structural abnormalities on ultrasound that could be markers for chromosomal abnormalities, those with a previously affected child or with a family history of a genetic disorder, women over 35 and those with a serum screening positive for Down syndrome or trisomy 18. It can also be done to test fetal lung maturity, fetal infections and to evaluate the severity of fetal anaemia in cases of Rh sensitization.
Therapeutic uses for an amniocentesis may include the direct delivery of medications to the unborn fetus and to release intrauterine pressure in the presence of polyhydramnios.
Notify your doctor if you have:
You should rest at home and avoid strenuous activities for at least 24 hours and a ultrasound is repeated after 3 days for reassurance.
The mother and the fetus will be monitored after the procedure. The fetus heart rate and your vital signs will be reassessed. You should rest at home and avoid strenuous activities for at least 24 hours and a ultrasound is repeated after 3 days for reassurance. Amniotic fluid will be sent to specialty genetic lab for analysis and depending on test results, counseling with a genetics specialist may be recommended.
Miscarriage is the most common risk post amniocentesis. The risk also depends on the gestational age at the time of the procedure. Amniocentesis before 14 weeks has an increased risk for pregnancy loss and increased limb disruption defects. The risk of miscarriage is 0.6% if it is done at 15-18weeks. The other risks include leaking of the amniotic fluid either from the procedure site/vagina, bleeding, preterm labour, uterine infection.