* 3 hour Glucose Tolerance Test performed if 1 hour glucose>130 mg%
**Anemia studies and Glucose Tolerance are done at any time during pregnancy as indicated
In 2013, Laboratory Services and other Laboratories have introduced new antenatal blood tests
, NIPS or Non-invasive Prenatal Screening (commercially branded as MaterniT21Plus, Harmony, Panorama
, etc.) that can screen for Trisomy 21 (Down’s syndrome), Trisomy 13, and Trisomy 18 starting around 11 weeks of pregnancy
. Further these tests can reveal the sex of your baby. Your blood is drawn (maternal blood) and the laboratory checks your blood for the baby’s blood hemoglobin
that has crossed into your circulation. This blood test can be done as early as the 10th week of pregnancy. Because this test can make an extremely early diagnosis of some chromosomal defects, parents can be made aware of the baby’s condition and decide earlier in the pregnancy on the various options and treatments that are available to them.One important caveat: if there is less than 3.5% of fetal hemoglobin in the patient’s blood sample, these tests may not be able to produce any results. Further, if you weigh over 160 lbs. this type of testing may return showing “not enough fetal Hemoglobin extraction for testing. The testing may have to be postponed until the time window between 16 to 20 weeks.
These tests may take up to 2 weeks before a report is available. Accordingly, other screening tests and anatomy ultrasounds will continue to have a place in the antenatal diagnosis of fetal abnormalities.
During these times of rapid technological advances OB’s will continue to perform “Anatomy Ultrasounds” for physical defects that are not genetically related.
Multiple Marker screening on maternal blood is performed at 18 to 20 weeks to help diagnose chromosomal abnormalities. Also, during this window of time in pregnancy ultrasound can screen for physical defects as well as the sex of the baby. If an abnormality is found on these latter two tests (ultrasound and Multiple Markers) then maternal blood sampling for Fetal DNA (NIPS testing) can be performed to make a more clear diagnosis. Most OB’s are moving away from the more invasive testing, i.e., amniocentesis and CVS, particularly if the targeted ultrasound study is normal. Obviously, invasive testing carries increased risks to the pregnancy such as rupture of the amniotic sac, infection, bleeding, etc. Very rarely, the pregnancy can be lost due to complications of these more invasive procedures (1:350 approximately).