Prenatal Tests In 2nd Trimester
You’ll visit your obgyn monthly for the first and second trimesters. These visits will be shorter than the first one, where you had a battery of tests done all at once. Your doctor will advise you about recommended tests as well as the risks and benefits of each. Note down your questions before the visits and don’t forget to take notes while you’re there!
Between the 18th to 20th week, your doctor will take an ultrasound scan and give you that long-awaited grainy photo. This will confirm how far along you are and allow him to check that baby’s spine, heart, brain and other parts are developing well. The scan will also check for multiple foetuses and investigate complications such as a low-lying placenta or slow foetal growth.
This is a routine test done at 24 to 28 weeks for pregnancy-induced diabetes although it may be done earlier if you have gestational diabetes in this or a previous pregnancy.
The Triple Test
This non-invasive blood screening is performed between the 15th and 20th week. The blood taken is tested for three proteins – AFP (Alpha-fetoprotein), hCG (Human Chorionic Gonadotropin) and UE3 (Unconjugated Estriol), which are present in all pregnant women. Varying levels of each, in combination with other factors, can point to certain troubling conditions such as brain or spinal defects. The test does not make a diagnosis but predicts the likelihood of certain problems occurring and indicates whether further tests are needed. The test is not compulsory.
If the triple test indicates that further tests need to be done to determine if your child has a genetic disorder, you may be offered an amniocentesis test, particularly if you are over 35 years of age as the risks are higher than for younger women. A small amount of amniotic fluid is removed from the sac surrounding the foetus for testing, under ultrasound guidance. This pre-diagnostic test is usually performed between 15 and 18 weeks of pregnancy and is more than 99% accurate in diagnosing - and ruling out (which is more common) – Down Syndrome.