7 things to avoid to help prevent birth defects

Most birth defects have no single cause anyone can point to. Genes, the environment and chance all play a part, and the WHO notes that in many cases no cause is ever found. That means a mother who did everything right can still have a baby with a congenital condition, and it is never something to blame yourself for.

A handful of risks are within your control, though. Most of them matter in the first eight weeks, when your baby's organs are forming and you may not yet know you are pregnant. So the ideal time to act on this list is before you conceive. Ideally, months before.

1. Too little folic acid

This is the clearest preventable cause. Folate helps your baby's neural tube, which becomes the brain and spinal cord, close properly in the first month. The CDC recommends 400 micrograms of folic acid every day for any woman who could become pregnant, starting at least a month before conception.

Folic acid is sold at any Malaysian pharmacy without a prescription, and your klinik kesihatan will give it to you once you register your pregnancy. If you have epilepsy, diabetes or a previous pregnancy affected by a neural tube defect, ask your doctor about a higher dose. Do not guess.

2. Alcohol

No safe amount of alcohol in pregnancy has been found. There is no safe trimester and no safe type of drink. Alcohol crosses the placenta and can cause fetal alcohol spectrum disorders, which affect growth, learning and facial development. Stop while you are trying to conceive. That removes the risk completely.

3. Cigarettes, vapes and secondhand smoke

Smoking in pregnancy is linked to cleft lip and palate, some heart defects, low birth weight and preterm birth. Vapes still deliver nicotine, which affects a developing baby. Secondhand smoke matters too, so ask whoever smokes at home to do it outside, well away from you.

Quitting is hard. You do not have to do it alone. Klinik kesihatan run quit-smoking services, and KKM's mQuit programme offers free support.

4. Medicines taken without a check

A few prescription drugs are known to harm a developing baby. Isotretinoin for severe acne and sodium valproate for epilepsy are two well-documented examples. Some blood pressure medicines also need changing before pregnancy.

The answer is a review with your doctor, not stopping everything. Stopping a medicine you need can be risky for you and the baby. Take your actual boxes to the appointment, including vitamins, traditional medicines, jamu and herbal tonics. They count as medicines too, and some contain ingredients that have not been checked for pregnancy.

5. Infections you can guard against

Rubella

Rubella in early pregnancy can cause deafness, cataracts and heart defects in the baby. Most Malaysian women were vaccinated as children, but immunity is worth confirming with a blood test before you try to conceive. The vaccine cannot be given in pregnancy, and doctors advise waiting a month after it before conceiving.

Zika and dengue

Zika infection in pregnancy can cause microcephaly and other serious brain problems, according to the CDC. Malaysia has recorded cases, and the same Aedes mosquitoes carry dengue, which is common here and dangerous for a pregnant mother. Use an insect repellent on exposed skin, wear long sleeves at dawn and dusk, and clear standing water from pot trays, drains and containers around the house. See a doctor quickly about any fever, especially with a rash, joint pain or red eyes.

CMV and toxoplasmosis

Cytomegalovirus spreads through the saliva and urine of young children, so wash your hands after diaper changes and avoid sharing cups and spoons with a toddler. Toxoplasmosis comes from cat litter, garden soil and undercooked meat. Wear gloves for gardening, let someone else empty the litter tray, and cook meat all the way through.

6. Raw and unpasteurised food

Some foods carry bacteria and parasites that can harm a baby. The NHS list translates easily to a Malaysian table.

• Raw or undercooked fish and shellfish, including sashimi, raw oysters and half-cooked cockles
• Raw or runny eggs, including half-boiled eggs unless the eggs are pasteurised
• Unpasteurised milk and soft, mould-ripened cheese
• Liver and high-dose vitamin A supplements
• Large predatory fish such as shark and swordfish, for their mercury content

Cook it through. Our fuller guide to foods to avoid during pregnancy covers the rest.

7. Health conditions left unplanned

Diabetes that is poorly controlled at the time of conception raises the risk of heart and neural tube defects. Good blood sugar control before pregnancy brings that risk down. The same planning helps with epilepsy, thyroid disease, lupus and high blood pressure.

Crash dieting during pregnancy is also worth avoiding. Your baby needs a steady supply of nutrients, so eat regular, varied meals and leave weight loss for after the birth.

What about stress, lifting and chemicals?

An earlier version of this article said that stress hormones stop a baby's nerves growing, that heavy lifting changes the baby's position, and that hundreds of toxins from body care products enter your body every day. We could not find good evidence for any of these, so we have taken them out.

Stress, anxiety and low mood in pregnancy still deserve care, for your own sake. Mention them at your antenatal visit, or call Talian Kasih on 15999 if you need someone to talk to. Heavy lifting can strain your back and pelvis, so ask for help, but it does not cause birth defects. For skincare, reading the label and choosing products formulated for pregnancy is a sensible habit. Our guide to ingredients to check in pregnancy goes through the ones worth knowing.

Where to get checked in Malaysia

Start at your nearest klinik kesihatan or with your GP. KKM's pre-pregnancy care service can check your rubella immunity, blood count, blood sugar and blood pressure, review your medicines and start you on folic acid. If you have an existing condition, ask for a referral to a hospital specialist before you conceive. That leaves time to adjust a prescription or finish a vaccine course.

Once you are pregnant, register early at a klinik kesihatan or with your private obstetrician. Your antenatal care carries on from there. Ask questions at every visit.