SingaporeMotherhood | Pregnancy

March 2026

Navigating Prenatal Tests and Scans: A Singapore Mum’s Guide

By Balvinder Sandhu

You’ve taken that first test to find out if you are pregnant, and got a Big Fat Positive. Congratulations! Now it’s time to think about the prenatal tests and scans that you may choose to take throughout your pregnancy. If you are in good health, there may not be a need to undergo all of them. However, many women in Singapore opt to do all the prenatal tests and scans, just to ensure that their pregnancies are progressing well, especially if they are over 35 years of age.

At KK Women’s and Children’s Hospital (KKH), prenatal risk assessment in the first trimester also includes screening for preeclampsia (a pregnancy condition involving high blood pressure and its complications), Dr Samantha Yeo, consultant at KKH’s Department of Obstetrics and Gynaecology, tells us.

“In addition, we also test for rubella antibodies, an indication of the patient’s immunity to rubella infection and response to past MMR (measles, mumps, and rubella) vaccination, together with routine antenatal blood tests.

“Some of the more recent significant developments in prenatal tests include non-invasive antenatal testing (NIPT) as a first-line option for Down syndrome screening, together with advanced 3D and 4D ultrasound techniques in special situations,” she adds.

(See also: True Story: “I Had Pre-eclampsia with Two Pregnancies”)

Prenatal Tests and Scans by Trimester

Dr Yeo goes on to summarise the antenatal scans, tests, and vaccinations that KKH recommends for pregnant patients.

First Trimester

• Dating scan to determine the estimated delivery date (EDD)
• Blood tests to screen for anaemia, thalassaemia, blood group, Rhesus D (RhD) status and red-cell antibodies, hepatitis B, syphilis and HIV infection, and German measles (rubella) immune status
• Down syndrome screening tests
• The flu vaccine, which is the most effective method of protection against influenza. It can be safely given at any point in pregnancy. Flu is a serious illness that can lead to complications for mothers and babies and is more dangerous if contracted during pregnancy.

Second Trimester

• 20-week ultrasound scan to screen for foetal anomalies and low-lying placenta
• Blood tests to screen for anaemia and gestational diabetes
• Whooping cough (pertussis) vaccine at 16 weeks to 32 weeks into pregnancy. Whooping cough is a serious respiratory illness that can cause death in newborns.

Third Trimester

• Growth scan to screen for foetal growth restriction, and to monitor baby’s size and wellbeing
• If the patient has a Rhesus negative blood group, she will receive a RhoGAM injection at week 28.
• Vaginal swab to screen for Group B Streptococcus infection at week 35

(See also: Pregnancy in Singapore: A Week-by-Week Guide for Expecting Mums)

Blood Tests at Your First Prenatal Checkup

First things first. At your first prenatal checkup, the nurse will draw your blood to test for various conditions.

Full blood count – To measure haemoglobin levels and help detect anaemia (low levels of red blood cells that carry oxygen in your body). Your blood will also be screened for thalassaemia, a blood disorder that can be transmitted to your baby.

Blood typing – To show which blood group you belong to (A, B, O or AB) and determine your Rhesus D status. If you are RhD negative, a RhoGAM injection at week 28 helps prevent the production of antibodies that may harm your baby.

Hepatitis B – Hepatitis B may affect your liver function and can be transmitted to the baby during birth. If you have it, your doctor will start you on an immunisation regimen to prevent transmission. It will also minimise the chance of your baby developing liver dysfunction and liver cancer later in life.

Syphilis – This sexually-transmitted disease is now rare. However, doctors will offer the test as a precaution. Early treatment with antibiotics can help prevent stillbirth and foetal deformities.

HIV – The HIV (human immunodeficiency virus) causes AIDS (acquired immunodeficiency syndrome). An HIV-positive mother can transmit the virus to her baby during birth and through breastfeeding. With medication, a Caesarean section, and avoidance of breastfeeding, the risk of transmission goes down.

Others – Blood tests can also screen for infections like Toxoplasmosis and Cytomegalovirus (TORCHES), as well as genetic disorders like cystic fibrosis, sickle cell disease, and Tay-Sachs disease.

According to Dr Quek Swee Chong, consultant obstetrician and gynaecologist at ASC Clinic for Women at Gleneagles Medical Centre, whether these tests are necessary often depends on the mother’s ethnic background and medical history.

(See also: I Dream of Gynae – How to Choose Dr Right when You’re Pregnant)

More about Prenatal Tests and Scans

Now let’s dig a little deeper. Read on for a more in-depth look at various prenatal tests and scans that you can do during pregnancy.

Viability and Dating Ultrasound Scans

First trimester

This early ultrasound scan (from 6 to 8 weeks gestation) confirms that the pregnancy is developing normally. It also checks that it is in the right location (not ectopic), and identify the foetal heartbeat. “From 8 to 10 weeks of gestation, the scan can give you the most accurate EDD,” adds Dr Quek.

NIPT (Non-Invasive Prenatal Testing)

From week 9

These detect foetal DNA from the mother’s blood and screen for common chromosomal disorders. They can also determine gender. While the tests cannot detect every genetic disorder, they are highly accurate for Down syndrome. “However,” explains Dr Quek, “because this DNA comes from the placenta and not from the foetus, there is a small chance that the results are not 100 per cent accurate.”

OSCAR (One-Stop Clinic for Assessment of Risk for foetal anomalies)

Weeks 11 to 14

This tests for Down syndrome (Trisomy 21) and other chromosomal problems. The risk is calculated using an ultrasound scan to assess the thickness of the skin in the neck of the foetus (Nuchal Translucency), and a blood test from you. This test is about 90 per cent accurate and results are usually available within the day.

Even though the NIPT and OSCAR tests are not compulsory, Dr Quek advises that all pregnant women — regardless of age — have the option to do them. In Singapore, companies that offer the tests include EasyDNA, Harmony, iGene, MaterniT21 Plus, and Panorama. Each has slightly different screening panels for various genetic disorders such as Down syndrome, Edwards syndrome, Patau syndrome, Turner syndrome, and Jacobs syndrome.

(See also: Bad OSCAR Test Results? Here’s What you Should Do Next)

Chorionic Villus Sampling (CVS)

Weeks 11 to 12

This also helps to determine chromosomal or genetic disorders in the foetus. A biopsy needle is inserted through the abdomen (under ultrasound guidance) and into the placenta to withdraw a small amount of placental tissue. The procedure takes a few minutes and is relatively painless. Results take two to three weeks to be ready

Amniocentesis

Weeks 16 to 20

Under ultrasound, a hollow bore needle is guided through the abdomen and into the amniotic fluid surrounding the foetus. A small amount of amniotic fluid is removed for testing. Results are available after two to three weeks.

Both CVS and amniocentesis are invasive tests and carry a small risk of miscarriage (CVS 0.5–1%; amniocentesis 0.25–0.5%). Hence doctors usually recommend them only for women whose previous children have a chromosomal/genetic disorder. Women who have a high-risk result from the OSCAR or NIPT tests may also choose to take the tests.

Detailed Ultrasound Scan

Weeks 19 to 22

This scan helps to detect structural anomalies in the foetus. In particular, it looks for abnormal heart structures, facial clefts, head, abdomen and limb size, placental position, Doppler blood flow, cervical length, and the amount of amniotic fluid present.

Oral Glucose Tolerance Test (Screening for Gestational Diabetes)

Second trimester

“Women with gestational diabetes are at higher risk of developing Type 2 diabetes later in life,” says Dr Quek. For this test, the mum-to-be has to fast overnight before giving a blood sample the next morning. She then drinks a 75g glucose drink. Two hours later another blood test is taken. The results are usually available within one to three days.

(See also: Gestational Diabetes 101 – Are You at Risk?)

Ultrasound Growth and Doppler Scans

Late in second trimester/going into third trimester

Some women may need to undergo repeat ultrasound scans to monitor the growth of the foetus. These usually include Doppler flow studies of the vessels supplying blood to the foetus.

Group B Streptococcus (GBS)

Week 35

This group of bacteria is found in the genital area of around 30 per cent of women and is detected via a vaginal swab. If you are positive for GBS, your doctor will prescribe antibiotics. “Generally, the condition does not cause any problems,” says Dr Quek. “However, it can affect the baby as they pass through the birth canal during delivery.”

Beyond Prenatal Tests and Scans

Apart from prenatal tests and scans, Dr Yeo also recommends vaccinations for mums-to-be to contribute to the health and wellbeing of mother and baby.

Antenatal tests and scans help identify potential health issues in the foetus, allowing for early intervention and management. The results of these investigations can better inform decision-making and allow healthcare professionals to provide support and counselling where necessary.

“Meanwhile, vaccinations in pregnancy protect against potentially serious yet highly preventable illnesses,” she says.

So together, these lead to better outcomes for both mother and baby.

Prenatal Tests and Scans – Nothing to Fear!

It may be stressful to think about doing all these tests and scans when you’re pregnant. Didn’t we already take enough tests in school? Still, we suggest taking these prenatal tests and scans as helpful guides and assurance that your pregnancy is going well, or to find solutions and options otherwise. That way, you can ensure that you are doing what you can for yourself and your little one. All the best for a healthy pregnancy and smooth delivery!

(See also: Baby Coming Soon? Here’s How to Get Ready for D-Day (Delivery Day))

All images: Depositphotos

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