Early screening tests during pregnancy

During pregnancy, women are often faced with more tests than at any other time in their lives. Women are tested for high blood sugar, high urine sugar, weight, baby development, sexually transmitted diseases and the possibility of chromosomal disorders in the baby.

Testing for disorders like Down Syndrome is a completely voluntary test and all mothers have the right to refuse the testing if they would rather not undergo the procedure. Most often, women who are pregnant and over the age of 35 choose prenatal testing due to the increased chance of chromosome disorders with pregnancies occurring late in life. 

Amniocentesis

One of the methods used to test for disorder and health problems with the fetus is amniocentesis. Amniocentesis requires the withdrawal of a small amount of amniotic fluid from the amniotic sac before the baby is born. In order to remove this amniotic fluid, a long needle is placed through the stomach, the uterus and into the sac of fluid surrounding the baby.

This fluid can be tested for a variety of illnesses or disorders and can even be used to determine if the baby is ready to breathe in a world of air. The amniotic fluid can predict how well the lungs are formed. This prediction can be very useful when babies need to be born early due to larger than normal size or complications in the pregnancy. The amniocentesis can be done around 15-18 weeks for genetic testing or later on in pregnancy for other tests including tests to check for pulmonary maturity (LS/PG test).

Possible complications after an amniocentesis

After the fluid is removed from the amniotic sac, the body will replace the fluid for the baby. However, in rare cases, the small hole used to withdraw the fluid will not reseal and the amniotic sac will slowly leak fluid. In these cases, the baby may need to be delivered earlier than term. Other reactions may include mild cramping.

Chorionic villus sampling (CVS)

Another way of testing baby is with chorionic villus sampling or CVS. The CVS test is usually done around 11-13 weeks or even later. When a doctor performs a CVS, a small section of the placenta is taken from inside the uterus. This small sample is taken via a needle or small tube inserted into the abdomen, or through a catheter inserted into the vagina and through the cervix.

Chorionic villus sampling can be used to test for the same chromosome disorders as the amniocentesis.

Possible complications after CVS

After the small section of the placenta is removed, the baby will be just fine. But mom may feel a small amount of cramping or see some spotting for a few hours after the procedure.

When will amniocentesis or CVS occur?

The first amniocentesis can occur any time after the 15^th week of pregnancy. CVS will most often be performed between the 10^th and 12^th weeks of pregnancy.

The choice to test the baby for possible disorders or birth defects will inevitably be up to mom and dad. The accuracy of amniocentesis and CVS testing is not 100% and in some cases, a red flag can trigger further testing only to find out the baby is fine.

Both amniocentesis and CVS tests carry a small chance of a miscarriage of the fetus.