Key Prenatal Tests and Screenings: What They Are and Why They Matter

The moment you see those two lines on a pregnancy test, your world begins to change. Alongside joy and anticipation come a series of decisions and checkups designed to keep you and your baby safe. Among them? Prenatal tests and screenings—some of the most important tools in modern obstetric care.

But what exactly do these tests look for? Are they all necessary? And how do they support a healthy pregnancy?

Whether you’re newly pregnant or preparing for your first prenatal appointment, understanding the purpose and timing of key prenatal tests can help you feel informed, empowered, and more at ease during your journey.

Prenatal testing is not just about identifying problems—it’s about gathering information. These tests help:

Many tests are routine and low-risk. Some are optional, and your provider will guide you through the options based on your health history, preferences, and individual risk factors.

Prenatal testing typically falls into two main categories:

These tests estimate the likelihood that your baby has certain conditions. They do not provide a definitive diagnosis but can indicate whether further testing is needed.

These tests confirm or rule out specific conditions. They are typically more accurate but may carry a slightly higher risk, especially if they involve invasive procedures.

Early on, your provider will take blood samples to check:

These tests establish your baseline health and identify any conditions that may need monitoring during pregnancy.

Often done between 6 and 9 weeks, this early ultrasound:

A simple blood test that analyzes tiny fragments of your baby’s DNA found in your bloodstream. NIPT screens for:

This test is highly accurate and has no risk to the baby.

Includes:

Used together, these can estimate the risk of chromosomal abnormalities. While safe, these are screening—not diagnostic—tools.

This blood test measures four substances related to pregnancy and screens for:

Not all providers offer this if you’ve already done NIPT or first-trimester screening.

Typically done between 18–22 weeks, this detailed ultrasound checks:

This is one of the most exciting and informative scans—it’s often when you can see your baby in detail and sometimes find out the sex.

Some parents opt for or are offered diagnostic testing based on screening results, age, or family history.

Performed between 10–13 weeks, CVS involves taking a small sample of placental tissue to test for genetic and chromosomal conditions.

Usually done between 15–20 weeks, this test involves collecting amniotic fluid to diagnose:

While highly accurate, it also carries a small risk of complications.

These tests are optional, and decisions about them should be made in collaboration with your healthcare provider, based on your values and risk tolerance.

This test checks for gestational diabetes, a temporary condition that can affect your baby’s growth and delivery.

If the initial glucose screening shows elevated levels, a second glucose tolerance test may follow for a clearer diagnosis.

A swab of the vagina and rectum tests for Group B Streptococcus, a common bacteria that can be passed to the baby during birth. If positive, antibiotics are given during labor to reduce the risk of newborn infection.

If you have risk factors (e.g., high blood pressure, diabetes, or decreased fetal movement), your provider may recommend:

Testing can bring peace of mind, but it can also spark worry or uncertainty, especially if you’re awaiting results or facing complex choices.

It’s okay to feel nervous. Prenatal testing is not just medical, it’s emotional and deeply personal. Talk openly with your provider, ask questions, and don’t hesitate to involve a genetic counselor if you need extra support.

Remember: information is power, not pressure. The goal is always to help you make informed choices that feel right for you and your family.

Prenatal testing is an essential part of modern pregnancy care, offering insight into your baby’s development and giving you the chance to plan ahead—both medically and emotionally.

While the number of tests can feel overwhelming at times, each one serves a specific purpose and is offered with your and your baby’s well-being in mind. Many are optional, and none should be approached with fear.

With a trusted healthcare provider by your side, you’ll have the guidance you need to navigate each step with clarity and calm. Your pregnancy is unique, and so is your path through it.