Prenatal Screening/Maternal Screening

Causes & Risk Factors

Prenatal screening is offered broadly during pregnancy, but certain factors increase the relevance of thorough risk assessment:

•  Advanced maternal age — chromosomal abnormality risk, particularly trisomy 21, increases with maternal age, especially from age 35 onward.

•  Previous pregnancy affected by a chromosomal condition — increases the relevance of screening in a subsequent pregnancy.

•  Family history of a chromosomal or genetic condition.

•  Abnormal findings on routine ultrasound during the current pregnancy.

•  Personal preference — many women choose screening regardless of specific risk factors, as part of routine antenatal care.

Symptoms & When to Test

Prenatal screening is not driven by symptoms — it is offered proactively at defined points in pregnancy, based on gestational age rather than clinical signs.

•  First-trimester screening (dual test) — performed during approximately 11 to 13+6 weeks of pregnancy

•  NIPT — can be performed from the validated gestational age specified by the test, generally from around 10 weeks onward

•  Second-trimester maternal serum screening — performed during a later, defined pregnancy window

When Should You Consider Testing?

Prenatal screening timing is determined by gestational age rather than symptoms. Your obstetrician will advise the appropriate screening window based on how far along your pregnancy is at your first antenatal visit.

Why Tests Are Combined

First-trimester (dual test) screening combines maternal age, nuchal translucency (NT) measured by ultrasound, and two biochemical markers — PAPP-A and free β-hCG — because no single marker alone provides sufficiently accurate risk estimation; combining them substantially improves detection compared to any one component.

NIPT, based on cell-free fetal DNA in maternal blood, offers higher accuracy for common trisomies than the dual test, but it remains a screening test — a high-risk NIPT result still requires genetic counselling and consideration of confirmatory diagnostic testing rather than being treated as a final answer.

Some women undergo both dual test and NIPT — using the dual test's ultrasound component (including NT) for broader structural assessment alongside NIPT's higher chromosomal detection accuracy, guided by their obstetrician's recommendation.

Tests Available at NPL

Most reproductive hormone and genetic tests do not require fasting. However, some tests have specific timing requirements (such as a particular day of the menstrual cycle), and if other tests are ordered at the same time, fasting may be required for those investigations. Please follow the preparation and timing instructions provided by your doctor or NPL.

Home Sample Collection

NPL offers convenient home sample collection for Prenatal Screening blood tests, so you don't need to visit a lab in person.

→ Book your test online, via the NPL app, or by calling +977 1 5970147 and select a convenient time slot for home sample collection.

→ A certified and experienced NPL phlebotomist visits your home at the scheduled time, following strict hygiene and safety protocols.

→ Your sample is transported under controlled, monitored conditions to NPL's NABL ACCREDITED UNDER ISO 15189:2022 laboratory for processing.

→ Your digital report is delivered securely to your phone or email, along with access to download and share it as needed.

When to See a Doctor

•  High-risk result on first-trimester screening or NIPT — arrange prompt genetic counselling

•  Abnormal findings on routine ultrasound

•  Uncertainty about which screening test is appropriate for your gestational age

•  Family history of a chromosomal condition not yet discussed with your obstetrician