There is so much you feel you need to know when you are pregnant, and nobody can blame any mother for doing her own research beyond what she hears at her antenatal classes and appointments. Unfortunately, there are a lot of myths, misconceptions, and outdated information that pregnant women hear all the time, and while some of it is harmless or just annoying, there are things that can put you or your baby at risk. So, let’s look at some popular myths, whether there is anything to them, and what you can do instead based on the most recent evidence.

Prenatal Myth #1: You Should Eat Twice as Much

Eating for two isn’t something a pregnant woman needs to do. In fact, in the first trimester, you do not need any extra calories at all. In the second trimester you only need 350 extra calories, and in the third trimester you only need 450 extra calories. These guidelines only apply if you began pregnancy with a BMI within the normal range; underweight and overweight pregnant women should seek individualised guidance from their doctor. When adding those extra calories, it is to your advantage (and that of your baby) that these be healthy and nutrient rich. You can get 350 calories from a snack, e.g., plain full-fat yoghurt with fruit, cheddar cheese with wholegrain crackers, or wholegrain rice cakes with peanut butter.

Some common advice shared among mothers is to “eat what your body tells you,” and while you should certainly have something whenever you feel hungry, it’s still important to prioritise balanced and nutritious food choices over cravings.

Prenatal Myth #2: Cocoa Butter/Caffeine Body Cream/Bio-Oil Prevents Stretch Marks

Your genes, age, and the amount of weight you gain govern whether you develop stretch marks in pregnancy and how significant they are. We lose skin elasticity with age, but that doesn’t mean a young mum who is genetically predisposed to stretch marks won’t see any. Similarly, even if you don’t gain much weight in pregnancy, your genetic makeup can mean you’ll see marks on your bump, thighs, breasts, or backside. About eighty percent of women will get them. The best thing we can do for one another is to support healthy choices in pregnancy and normalise the associated physical changes. Even models and beautiful celebrities get stretch marks. Actress Salma Hayek once generously revealed that her husband calls them her “tiger stripes” and means it as a compliment. Moisturising can keep your skin supple and comfortable in pregnancy, but you do not need to spend money on specific stretch mark-prevention products. There is some evidence that retinoin can improve their appearance, but you cannot use that while you are pregnant because of the Vitamin A content. You can laser-treat stretch marks to fade them after pregnancy, but this comes with risks, costs, and recovery time that should be carefully considered, especially if you want to have more children. Hyaluronic acid, almond oil, and Centella asiatica are ingredients that can improve their appearance. Unii feels the marketing claims on anti-stretch mark products ought to be more strictly regulated to protect women, who may feel more vulnerable about their appearance while pregnant.

Prenatal Myth #3: Flying in Pregnancy is Risky

This is somewhat true, but we feel it’s important that pregnancy not be treated like some sort of illness. It’s usually fine for a woman without pregnancy complications to fly as normal until she is 37 weeks, by which time she may not feel like going anywhere anyway. If you do want to fly after then, many airlines won’t allow it, while the ones that do will likely request a sign-off from your doctor. If you are pregnant with multiples or likely to deliver early for some other reason, the cut-off is 32 weeks, as long as your pregnancy is uncomplicated. Some women do give birth on planes, but it is unlikely that you, your doctor, or any flight crew or airline passenger wants this to happen! Dehydration and deep vein thrombosis are risk factors for pregnant women who fly, but you can usually mitigate them by sipping water and occasionally walking around when the “fasten seatbelt” sign is off. You should also avoid travelling by car or train for more than an hour without breaking for a quick walk. Airport scanners are safe for both mum and baby during pregnancy; they use radio waves, which are non-ionising radiation. That’s even less radiation than you get from your mobile phone. We recognise that some women do feel using mobile phones is unsafe in pregnancy because of the radiation, but there is no medical guidance that you shouldn’t from RCOG, ACOG, etc. However, we respect individual maternal choice in this.

Prenatal Myth #4: What You Eat in Pregnancy Shapes Your Baby’s Food Preferences

There is some evidence that weight gain and food choices in pregnancy have a long-term impact on your baby’s health, but not as much to show it impacts the kinds of food they like. Research shows that babies exposed to lots of inflammatory (junk) foods in pregnancy are more likely to have higher BMIs in childhood. This doesn’t mean they’ll be obese because you ate cake or crisps sometimes, but pursuing a balanced diet and avoiding fast weight gain are best for you and your baby during pregnancy. It’s also important to follow nutrition and food safety guidelines where you are, restrict your caffeine intake, take your prenatal vitamins (and any others that are recommended to you), and avoid alcohol completely. What you eat in pregnancy (and breastfeeding) can influence their palate to some extent, but your health and your baby’s health and development matter far more at this stage than whether they learn to prefer Italian or Chinese food in the womb.

Prenatal Myth #5: Caffeine in Pregnancy Can Cause Miscarriage or Preterm Birth

There are some studies that link high caffeine consumption in pregnancy to miscarriage, but there is no good evidence that it causes preterm labour. Another reason women are advised to restrict caffeine is because of its impact on the baby’s growth and development. There is some evidence that it can result in babies being born small for their gestational age. You shouldn’t have more than 200 mg of caffeine a day in pregnancy. It’s fine to get all of this from coffee, but please note that chocolate, some cakes and other deserts, tea, and soft drinks also contain caffeine.

Prenatal Myth #6: Pregnant Women Shouldn’t Run or Lift Weights

This is mostly untrue. We always recommend checking any form of exercise you want to do while pregnant with your doctor. Daily light-to-moderate exercise is recommended in pregnancy, and if gentle running lifting weights that aren’t too heavy is how you want to workout, it should be fine. One good rule of thumb is to avoid anything that significantly overheats you or gets your heart rate very high. So overextending yourself on the treadmill is not ideal. Similarly, weights that are incompatible with your fitness level should also be avoided.

Prenatal Myth #7: Medication-Free Pregnancy, Labours, and Births are Better for Your Baby.

This is likely to come up in any antenatal class in some form, and we feel it is designed to make any woman who has medication in pregnancy—whether it was in her birth plan or not—feel bad, which is disgraceful. If your doctor prescribes medication in pregnancy, whether it’s asthmatic inhalers, codeine, sleeping pills, antidepressants, or anything else, it will be because the benefits outweigh the risks to your pregnancy and therefore your baby. You shouldn’t take anything in pregnancy without checking with your doctor, even if you’ve done so safely in the past or bought it over-the-counter. Natural supplements and remedies count as medication you need to check. As for labour and birth, steroids can save a preterm baby’s life and reduce their risk of a variety of long-term health problems. Epidurals are not only the gold standard in labour pain relief but widely considered extremely safe for both mum and baby. Other forms of pain relief, such as opiates, can impact the baby’s heart rate and breathing, but this is temporary, and if you are given them, you and the baby will be carefully monitored for adverse reactions. Ultimately, medications are beneficial to both mum and baby in pregnancy, labour, and birth, and we are lucky to live anywhere that they can be accessed and administered safely.

For more advice on taking care of yourself in pregnancy, labour, and birth, check out Unii’s Antenatal Classes, with prenatal video episodes taught by senior NHS midwives, an award-winning obstetrician and gynaecologist, and six other leading healthcare experts. Only at unii.com.

Antenatal Class Questions: Prenatal Myths, Busted!