Timeline of Testing During Pregnancy

As a surrogate, there will be a number of prenatal tests you will be required to undergo during your pregnancy. These are to check the health and growth of the baby as it grows. Since the Intended Parents are likely not to be present for these tests, it is critical that you update both the IPs and the agency of any and all testing dates and results since you will be the primary point of contact for healthcare professionals. After all, you are the one who is pregnant. The following is a timeline of the required testing during pregnancy. This testing is mandatory and if you do not follow the doctor’s instructions or skip any of these tests, you will be in breach of contract and your surrogacy payments could potentially be placed on hold until the testing is complete or the issue is resolved (depending on your gestational carrier agreement/contract).


Timeline of Testing During Pregnancy

NIPT Testing (Non-Invasive Prenatal Testing)

The NIPT is a blood test which tests small fragments of the fetus’s DNA circulating in a pregnant woman’s blood and determines the risk that the fetus will be born with genetic abnormalities. The NIPT tests for chromosomal abnormalities such as Down Syndrome, Trisomy 18, Trisomy 13 and others. It is generally performed during the first trimester, although it is possible to test early on in the second trimester.

NT (Nuchal Translucency) Screening

The nuchal translucency scan must be performed in the first trimester and is usually scheduled between weeks 11 and 13 of pregnancy. This is an ultrasound scan which measures the size of the clear tissue at the back of the baby’s neck. Too much clear tissue could indicate Down Syndrome, Edwards Syndrome and other chromosomal abnormalities. Because the nucha translucency usually disappears by week 15 of pregnancy, most clinics will not perform the scan any later than 13 weeks 6 days of pregnancy.


AFP (Alpha Fetoprotein) Test

AFP is a protein produced by the fetal liver, which passes into the amniotic fluid, through the placenta, and into the pregnant woman’s bloodstream. Sometimes, this test will be performed as part of routine bloodwork during a regular OB visit, so your doctor may or may not explicitly tell you they’re performing this test. If your IPs require it, you may ask your doctor to perform this test and most will oblige since the baby you’re carrying is a result of IVF. An abnormal AFP result can indicate various issues, including:

  • Defects in the fetal abdominal wall
  • Chromosomal abnormalities
  • Open neural tube defects such as Spina Bifida
  • Miscalculated due date
  • Twins

This test is usually performed between weeks 15-20 of pregnancy.

Anatomy Scan

One of the most important tests you will undergo as a gestational carrier is the fetal anatomy scan. This scan is preferably performed at weeks 18-20 of pregnancy, although it can be done as late as 24 weeks. The anatomy scan is an in-depth ultrasound, which measures the baby’s structures and checks the fetal anatomy for any abnormalities. They will also confirm your due date, although it is unlikely to change much. At the anatomy scan, they will determine the baby’s sex; although it’s likely you will already know beforehand since the doctor knows which embryo they’re transferring! The anatomy scan is critical in finding out if the fetus has any serious issues.

Glucose Test

The glucose test is a screening for gestational diabetes. You are normally required to fast for 12 hours before the appointment and may only drink water; you must not eat or drink anything else or the result of the test will be abnormal. Your fasting blood will be drawn, and you will then be given a special glucose formula to drink (this is like a very sweet soda). You must finish the entire bottle and wait for 1 hour, at which point your blood will be drawn again. If your blood glucose level comes back abnormal, you will be required to take either a 2-hour or 3-hour glucose test, during which your blood will be drawn fasting and every hour for up to 3 hours. If this test also comes back abnormal, you will be diagnosed with gestational diabetes.


GBS (Group B Streptococcus) SWAB

GBS is a type of bacteria that can be found in the vagina and rectum. While it normally doesn’t cause any issues, GBS can cause major problems for pregnant women and the fetus. GBS infection can lead to preterm labor; but more importantly, it can also cause major issues for the baby at birth, such as meningitis and pneumonia. A vaginal-rectal swab will be performed at 35-37 weeks of pregnancy. If you test GBS positive you don’t need to worry, it is fairly common. You will be given antibiotics intravenously during labor to treat the infection so that there will be no risk to the baby.



Amniocentesis is a test that analyzes cells in the amniotic fluid which have been shed by the fetus during the pregnancy. Since these cells contain genetic information, they can be used to test for many genetic and chromosomal abnormalities. An amniocentesis test involves the doctor inserting a hollow needle through the abdomen into the womb to extract a sample of amniotic fluid. The test is not usually very painful, although you may experience some cramping during or after the procedure. Amniocentesis, if needed, is usually performed between weeks 15 and 20 of pregnancy.

CVS (Chorionic Villus Sampling)

CVS is a test similar to amniocentesis, except that instead of testing cells from the amniotic fluid, a small sample of placental cells is taken. Since the placenta contains the same genetic material as the fetus, the placental cells can be used to test for a wide array of genetic abnormalities. CVS may be performed trans-abdominally which an ultrasound-guided needle, or alternatively the doctor may perform a transvaginal CVS whereby they insert a small catheter through the cervix guided by ultrasound, position the catheter next to the placenta and extract a small amount of tissue using a syringe on the other side of the catheter. CVS is usually performed between weeks 10 and 13 of pregnancy, but it only usually needed if the intended parents know they are carriers for genetic issues.


The amount of testing required during pregnancy can seem daunting, and you may feel concerned about forgetting or missing any testing that you should be receiving. Your doctor will guide you through everything you need to know, and your agency will also give you periodic reminders to schedule any necessary tests in plenty of time. From all of us at GSHC, we wish you a healthy, safe and enjoyable pregnancy!


If you are ready to begin your surrogacy journey with GSHC Surrogacy Agency, please complete our Surrogate Intake Form.