Pregnancy after 35 brings with it a range of medical considerations, one of the most significant being prenatal genetic and screening tests. For many women, the landscape of available tests can feel overwhelming — there are multiple options, different timelines, and decisions that carry real emotional weight.
This article offers an overview of the main prenatal tests typically discussed or offered for pregnancies after 35, what current evidence says about each, and how to approach conversations with your healthcare provider. The goal is not to create anxiety but to provide the kind of information that supports informed, confident decision-making alongside your medical team.
For broader context on pregnancy after 35, including what changes and what stays the same, our article on pregnancy after 35: a complete guide may be a useful companion read.
Why Prenatal Testing Is Discussed More After 35
According to the American College of Obstetricians and Gynecologists (ACOG), the chance of chromosomal abnormalities in a pregnancy increases with maternal age. The most commonly discussed is trisomy 21 (Down syndrome), but other chromosomal variations also become somewhat more common. At age 35, the risk of a chromosomal abnormality at birth is approximately 1 in 178; by age 40, that rises to approximately 1 in 63.
It’s worth keeping this in perspective: the absolute risk is still relatively low at these ages, and many pregnancies after 35 — and after 40 — result in healthy babies. However, because the relative risk is meaningfully higher than in younger age groups, ACOG recommends offering genetic counseling and testing to all pregnant women, particularly those 35 and older, so they can make informed decisions.
First-Trimester Screening Options
Several screening and diagnostic options are available in the first trimester, typically between weeks 10 and 13.
Cell-Free DNA (cfDNA) Screening / NIPT
Non-invasive prenatal testing (NIPT) analyzes fragments of placental DNA circulating in maternal blood and can screen for common chromosomal conditions including trisomies 21, 18, and 13, as well as sex chromosome variations. Research suggests NIPT has high sensitivity and specificity for Down syndrome (often cited at 99% sensitivity), though it is a screening test, not a diagnostic one — a positive result warrants follow-up with diagnostic testing. NIPT can typically be performed from week 10 onward.
First-Trimester Combined Screening
This approach combines a nuchal translucency ultrasound (measuring fluid at the back of the baby’s neck) with blood tests measuring pregnancy-associated plasma protein-A (PAPP-A) and hCG. Together, these provide a risk estimate for certain chromosomal conditions. Detection rates are lower than NIPT, but this test has been widely used and provides additional information about pregnancy anatomy and viability.
Second-Trimester Options
For women who prefer to wait or who need additional information, second-trimester screening and diagnostic options are also available.
Quad Screen (Multiple Marker Screening)
Typically performed between weeks 15 and 20, the quad screen measures four substances in maternal blood (AFP, hCG, estriol, and inhibin A) to estimate the risk of Down syndrome, trisomy 18, and neural tube defects. It’s a screening test with lower sensitivity than NIPT, but it can be used when NIPT wasn’t performed or when additional information is needed.
Anatomy Ultrasound
The mid-pregnancy anatomy scan, typically performed around weeks 18–22, evaluates fetal development in detail. It can identify structural differences in the brain, heart, spine, kidneys, and limbs, among other areas. For women with higher-risk pregnancies, this scan may be supplemented by a fetal echocardiogram or other targeted imaging.
Diagnostic Testing: Amniocentesis and CVS
Unlike screening tests, which estimate risk, diagnostic tests can confirm or rule out chromosomal conditions with much greater certainty. The two main options are chorionic villus sampling (CVS), performed between weeks 10 and 13, and amniocentesis, typically offered between weeks 15 and 20.
Both procedures carry a small risk of pregnancy loss — current estimates for trained providers are approximately 0.1–0.3% for amniocentesis and slightly higher for CVS, though complication rates vary by facility and provider experience. Many women find genetic counseling helpful in weighing these options. The decision to pursue diagnostic testing is deeply personal and depends on individual circumstances, values, and what a family would do with the information.
Genetic Counseling: A Valuable Resource
Genetic counselors are trained to explain testing options, interpret results, and support families through the decision-making process. ACOG recommends genetic counseling for all women who are offered or considering diagnostic prenatal testing. A counseling session can help clarify what tests mean (and don’t mean), what false positive and false negative rates look like in practice, and what options are available depending on results. Many maternal-fetal medicine specialists also provide this guidance as part of routine care for higher-risk pregnancies. Our article on preparing for pregnancy after 35 also touches on when to involve a specialist.
Frequently Asked Questions
Do I have to have prenatal testing if I’m over 35?
No. Prenatal testing — whether screening or diagnostic — is offered to you as an informed choice, not a requirement. ACOG recommends that all pregnant women receive information about available testing, but the decision to proceed is entirely yours. Many women choose to decline some or all testing based on personal values and circumstances, and that is a valid choice to discuss with your provider.
What does a positive NIPT result actually mean?
A positive NIPT result indicates an elevated risk of a chromosomal condition, not a definitive diagnosis. False positives do occur, particularly for some rarer conditions. A positive screen result is typically followed up with diagnostic testing (amniocentesis or CVS) for confirmation before any decisions are made. Your provider or genetic counselor can walk you through what a positive result means in your specific context.
When should I have the anatomy ultrasound?
The standard anatomy scan is typically offered between weeks 18 and 22 of pregnancy. Your OB/GYN or midwife will advise on the best timing based on your specific pregnancy and any additional monitoring that may be recommended.
Is prenatal testing covered by insurance?
Coverage varies by insurance plan and location. NIPT, in particular, was initially offered primarily to high-risk pregnancies but has become more broadly available. It’s worth checking with your insurer ahead of time about what’s covered, as out-of-pocket costs for some tests can be significant. Many genetic counselors and hospital billing departments can help navigate this.
Key Takeaways
- Prenatal genetic screening and testing options expand meaningfully for women over 35 due to increased risk of chromosomal variations, though absolute risk at age 35–40 remains relatively low.
- NIPT (non-invasive prenatal testing) is considered highly sensitive for common chromosomal conditions but is a screening test — not a diagnostic one.
- Diagnostic tests like amniocentesis and CVS provide definitive answers but carry a small procedural risk; genetic counseling can help weigh the decision.
- All prenatal testing is offered as an informed choice — not a requirement. The right approach depends on individual values, circumstances, and what you’d want to know.
Medical Disclaimer
This content is for informational purposes only and does not constitute medical advice. Individual health situations vary significantly. Always consult a qualified healthcare provider before making decisions related to your health, fertility, or pregnancy.
About the Author
Emily Carter is a women’s health writer focused on fertility, pregnancy after 35, and sleep changes in midlife. She writes research-informed, non-alarmist content to help women navigate reproductive and hormonal transitions with clarity and confidence.