Testing for Birth Defects – Part II

Second Trimester Continued…

This is also the stage of pregnancy at which an amniocentesis may be offered  if necessary. It cannot be performed until a woman is at least 16 weeks along and is only  offered to those that are at high risk for birth defects. The cells collected are analyzed and doctors can provide a diagnosis of possible defects. Women are offered the option of this test depending on their risk of a genetic/chromosomal problem as per the results of the first and second trimester tests.

This is also the time for an ultrasound which can also pick up some defects.   Most women will choose this test as it is a great chance to see their child and assess the sex of the baby if desired!

 Third Trimester

In the third trimester of pregnancy, mothers-to-be may receive a glucose tolerance test, to show if they have gestational diabetes. This test is more for the health of the moms, and can lead your physician to provide many healthy options to maintain a perfectly healthy pregnancy.

Group B Streptococcus is another third trimester test that may be performed. While it does occur in 10 to 30 percent of all pregnant women, it is generally harmless. You physician will only need to give you a few extra pointers when it comes to labor and delivery, but in most cases it is not life threatening for you or the baby.


The process of testing for birth defects in moms-to-be can be scary and unnerving, but there is no path to the reassurance the tests provide without some anxiety. It is  useful to know what to prepare for when the time to give birth draws nearer in cases with defects. Conversations with a pediatrician and mental preparation is key to solid medical care decisions that can make a difference in the life of a newborn baby facing uphill medical challenges.

At AOA, we are here with you every step of the way, from the first test to the last, and everything in between. While many of these tests are routine, it can still be a stressful time for moms and dads, so take care in knowing that our highly trained physicians have the experience and compassion to get everyone through it together.