Reference
Prenatal Tests Guide
Doula-perspective explainers on every prenatal test — what it is, when it happens, what results mean, and questions worth asking. Sources: ACOG, NICE, SOGC, Cochrane, Evidence-Based Birth.
Tests are tools — they give you information, and information creates choices. Every page demystifies the test, names what you can expect, and surfaces questions worth asking your provider.
First Trimester
Confirming pregnancy, baseline labs, first screenings, optional genetic testing.
- UniversalFirst Prenatal Blood Panelweeks 8–12 (first prenatal visit)The first prenatal blood panel is a routine collection of blood tests done early in pregnancy to provide essential information about your health and help guide your care.
- OptionalNIPT — Cell-Free DNA Screeningfrom 10 weeks (typically 10–14)NIPT, or cell-free DNA screening, is an optional blood test available from 10 weeks of pregnancy that screens for certain chromosomal conditions and can determine fetal sex.
- OptionalNuchal Translucency (NT) Scanweeks 11–13+6 daysThe Nuchal Translucency (NT) scan is an optional first-trimester ultrasound that, combined with blood tests, estimates the risk of certain chromosomal conditions and structural concerns.
- RecommendedDating Ultrasoundweeks 6–12 (typically 8–10)The dating ultrasound, often your first glimpse of your baby, is a routine scan typically done between 6 and 12 weeks to confirm pregnancy and establish a clear timeline.
- OptionalCVS — Chorionic Villus Samplingweeks 10–13Chorionic Villus Sampling (CVS) is an optional diagnostic test performed between weeks 10 and 13 to provide definitive information about your baby's chromosomes by sampling placental tissue.
- RecommendedFlu Vaccination in Pregnancyany trimester during flu seasonThe flu shot during pregnancy is a recommended vaccination to protect both you and your baby from influenza, offered at any point in pregnancy during flu season.
- RecommendedCOVID-19 Vaccination in Pregnancyany trimesterThe COVID-19 vaccination in pregnancy is a recommended way to protect both you and your baby from severe illness caused by the virus.
- UniversalPreeclampsia Screening (PE Risk Assessment)first trimester (risk) + ongoing BP monitoringPreeclampsia risk evaluation is a routine part of your prenatal care, combining blood pressure and urine checks with early assessments to identify potential risks.
- OptionalGenetic Carrier Screeningideally pre-conception or first trimesterGenetic carrier screening is an optional test, ideally done pre-conception or in your first trimester, to see if you carry gene mutations that could be passed to your baby.
Second Trimester
Anatomy scan, glucose screening, diagnostic options after positive screens.
- OptionalQuad Screen / Triple Screenweeks 15–22 (optimal 16–18)The Quad Screen, also known as the Triple Screen, is an optional second-trimester blood test that helps estimate the risk for certain chromosomal conditions and neural tube defects.
- UniversalAnatomy Scanweeks 18–22The anatomy scan, also known as the 20-week ultrasound, is a routine mid-pregnancy scan typically performed between weeks 18 and 22 to examine your baby's development.
- OptionalAmniocentesisweeks 15–20 (sometimes later)Amniocentesis is an optional diagnostic test performed in the second trimester to provide definitive information about your baby's chromosomes, neural tube development, and potential infections.
- UniversalGlucose Challenge Test (1-hour)weeks 24–28The 1-hour glucose challenge test is a common screening in the second trimester to check for gestational diabetes, typically done between weeks 24 and 28.
- RecommendedGlucose Tolerance Test (3-hour)weeks 24–32 (after failed 1-hour)The 3-hour Glucose Tolerance Test (OGTT) is a diagnostic test performed after a positive 1-hour screen to confirm or rule out gestational diabetes during pregnancy.
- RecommendedRhoGAM (Anti-D Immunoglobulin)week 28 (routine) + after delivery if baby is Rh+RhoGAM (Anti-D Immunoglobulin) is an injection given to Rh-negative pregnant people to prevent complications from Rh incompatibility, protecting both current and future pregnancies.
- High-risk onlyCervical Length Ultrasoundweeks 18–24A cervical length ultrasound, also known as a cervix measurement scan, uses transvaginal ultrasound in the second trimester to assess your risk for preterm birth.
- OptionalContinuous Glucose Monitoring (CGM) in Pregnancyafter GD diagnosisContinuous Glucose Monitoring (CGM) is an optional wearable sensor used in late pregnancy, particularly after a gestational diabetes diagnosis, to provide real-time glucose readings.
- High-risk onlyFetal Echocardiogramweeks 18–24A fetal echocardiogram, or fetal heart ultrasound, is a detailed diagnostic scan of your baby's heart, typically performed between weeks 18 and 24, when specific risk factors are present.
Third Trimester
GBS, fetal wellbeing monitoring for high-risk, late vaccinations.
- UniversalGroup B Strep Testweeks 36–37The Group B Strep (GBS) test is a routine third-trimester screening that checks for a common bacteria, helping you make informed decisions for labor.
- High-risk onlyNon-Stress Test (NST)weeks 28+ (typically 32+)The Non-Stress Test (NST) is a late-pregnancy assessment that monitors your baby's heart rate in response to their movements, offering insights into their well-being.
- High-risk onlyBiophysical Profile (BPP)weeks 28+The Biophysical Profile (BPP) is a late-pregnancy ultrasound and Non-Stress Test that assesses fetal wellbeing, often recommended for high-risk pregnancies.
- High-risk onlyUmbilical Artery Dopplerweeks 28+ (when IUGR suspected)The Umbilical Artery Doppler, or cord blood flow ultrasound, is a specialized late-pregnancy scan used to assess blood flow through your baby's umbilical cord, especially when growth concerns arise.
- RecommendedTdap Vaccination (Pertussis Booster)weeks 27–36 (ideally 27–28)The Tdap vaccination, often called the whooping cough vaccine, is a recommended booster during your third trimester to help protect your newborn from pertussis.
This is general wellness information drawn from ACOG, NICE, SOGC, RANZCOG, USPSTF, Cochrane, and Evidence-Based Birth — not medical advice. Discuss test choices with your obstetric provider. 23 prenatal tests indexed.