Prenatal Genetic Screening Chooser

A screening test estimates the chance that a pregnancy has a condition — it can only ever say 'higher chance' or 'lower chance,' never yes or no. Cell-free DNA (NIPT), the first-trimester combined screen, and the quad screen are all screens, done on your blood and ultrasound with no risk to the pregnancy. A diagnostic test — CVS at 10–13 weeks or amniocentesis at 15–20 weeks — analyzes the baby's actual chromosomes from placental tissue or amniotic fluid and gives a definitive answer for the conditions tested, with a small procedure risk. ACOG recommends every pregnant person be offered both paths; you can screen first, go straight to diagnosis, or decline everything.

NIPT is a blood draw, possible any time from 10 weeks, that reads fragments of placental DNA circulating in your blood. It's the most sensitive screen for Down syndrome (trisomy 21) and also screens for trisomies 18 and 13 — and, if you want, the sex chromosomes. What it can't do: give a yes/no answer (it's a screen, and its accuracy in your case depends on your age and the condition's rarity), detect most genetic conditions, or replace the anatomy ultrasound. It can also occasionally return no result. A positive NIPT is always offered confirmation with CVS or amniocentesis before any decision.

No — a screen positive is not a diagnosis. What it means depends on the positive predictive value (PPV): the chance that a positive screen is a true positive. PPV varies enormously with how common the condition is at your age — for rarer conditions, or for younger people, a large share of positive screens turn out to be false alarms, even on a very accurate test like NIPT. That's exactly why ACOG advises confirming any positive screen with a diagnostic test (CVS or amniocentesis) and talking it through with a genetic counselor before drawing any conclusions. Take a breath: a positive screen starts a conversation, it doesn't end one.

No. That old cutoff is gone: ACOG's Practice Bulletin 226 recommends that all pregnant people, regardless of age, be offered both aneuploidy screening and diagnostic testing, and that the choice between them — or the choice to test at all — is personal. Age still matters to the math: the baseline chance of chromosomal conditions rises with age, which also makes a positive screen more likely to be a true positive in older parents and more likely to be a false alarm in younger ones. But age never decides your options — your values, history, and how you'd use the information do.

Carrier screening tests you — and ideally your partner — for silent, recessive gene variants for conditions like cystic fibrosis, spinal muscular atrophy, and hemoglobin disorders. Carriers are healthy; the question is whether both partners carry variants for the same condition, which would give each pregnancy a chance of being affected. The ideal time is before pregnancy, when every option is still open, but it can be done at any point during one. Your own results never change, so it's typically done once per lifetime, not once per pregnancy. ACOG recommends carrier screening be offered to everyone who is pregnant or planning to be.

Yes. This tool runs entirely in your browser. Your answers are used on your own device and are never sent to a server, saved, or shared — close the tab and they're gone. In a post-Dobbs world we treat reproductive and genetic information as sensitive by default. The result is general education based on ACOG guidance: it maps which conversations fit your situation, it never recommends a test, and it isn't medical advice — your prenatal clinician or a genetic counselor personalizes it from here.