Pregnancy myths vs facts
Old wives’ tales, internet theories and half-truths, each one checked against published research. Some are surprisingly true. See the boy or girl tales together.
Does carrying high mean a girl and carrying low mean a boy?
No. The shape and height of a bump depend on your muscles, body shape, how many pregnancies you’ve had and the baby’s position, not the baby’s sex.
MythDoes a heart rate over 140 mean it’s a girl?
No. Studies comparing early heart rates in boys and girls found no meaningful difference. Heart rate depends mostly on gestational age.
Partly trueDoes bad morning sickness mean you’re having a girl?
There’s a small statistical link between severe sickness and girls, but it can’t predict the sex of any one baby.
MythDo sweet cravings mean a girl and salty cravings a boy?
No. There’s no evidence cravings relate to the baby’s sex. They are shaped by hormones, culture, habit and changes in taste and smell.
MythIs the Chinese gender calendar accurate?
No. When tested on real birth records, it performed no better than guessing.
MythCan the ring (pendulum) test predict the baby’s gender?
No. A ring swinging on a string over your belly or wrist moves because of tiny, unconscious hand movements.
MythDoes the baking soda gender test work?
No. Whether urine fizzes with baking soda depends on its acidity, which changes with food, fluids and time of day, not the baby’s sex.
MythIs the Ramzi theory accurate for predicting gender?
Not reliably. The Ramzi theory guesses the sex from which side the placenta is on at about 6 weeks, and we found no peer-reviewed study that confirms it works.
MythIs the skull theory accurate for predicting gender?
Not reliably. The skull theory guesses the sex from the shape of the baby’s skull on a 12-week scan, and we found no peer-reviewed study that confirms it works.
Partly trueIs the nub theory accurate at 12 or 13 weeks?
It can be fairly accurate at 12–13 weeks in experienced hands, but it is an educated guess, not a diagnosis.
MythDoes the mother determine the baby’s sex?
No. The egg always carries an X chromosome. The sperm carries either an X (girl) or a Y (boy), and that decides the chromosomal sex.
MythCan timing sex around ovulation choose a boy or girl?
No. Methods like Shettles (sex close to ovulation for a boy, earlier for a girl) weren’t supported when tested.
MythDoes pregnancy acne or looking “tired” mean a girl?
No. “Girls steal their mother’s beauty” is folklore. Skin changes come from pregnancy hormones, whatever the baby’s sex.
MythDoes morning sickness only happen in the morning?
No. For most people, pregnancy nausea can strike at any time of day, and for some it lasts all day.
MythDoes having no pregnancy symptoms mean something is wrong?
No. Many people have healthy pregnancies with few or no symptoms, especially early on.
Partly trueIs the “pregnancy glow” real?
Partly. Around 40–50% more blood volume and more active oil glands can make skin look flushed and dewy. Not everyone gets it.
MythCan raising your arms above your head wrap the cord around the baby’s neck?
No. Your arm movements have no effect on the umbilical cord. Cords around the neck (nuchal cords) are common and happen from the baby’s own movements.
Partly trueIs it dangerous to sleep on your back while pregnant?
In the third trimester (from 28 weeks), going to sleep on your side is recommended. Earlier in pregnancy, back sleeping is fine.
MythDo twins skip a generation?
No. Non-identical twins can run in families, but there’s no evidence they skip a generation. Most identical twins aren’t caused by genetics.
MythDo you need to eat for two when pregnant?
No. The NHS says there’s no need to “eat for 2”. US guidance suggests no extra calories in the first trimester, about 340 extra a day in the second, and about 450 in the third.
MythDo you have to give up coffee completely during pregnancy?
Not necessarily. Most guidelines say up to 200 mg of caffeine a day, about one or two cups of coffee, is acceptable.
MythShould you avoid fish when pregnant?
No. 2–3 servings a week of low-mercury fish are recommended. Just avoid the high-mercury ones.
MythIs exercise dangerous during pregnancy?
No. For uncomplicated pregnancies, about 150 minutes a week of moderate activity is recommended.
MythIs it unsafe to dye your hair while pregnant?
Probably not unsafe. Very little dye is absorbed through healthy skin, and used as directed it isn’t expected to greatly increase the chance of birth defects. Some people prefer to wait until after the first trimester.
MythDo you need to get rid of your cat when you’re pregnant?
No. Have someone else change the litter tray if you can, or wear gloves and change it daily, to lower the risk of toxoplasmosis.
MythIs flying unsafe during pregnancy?
For most uncomplicated pregnancies, flying is safe up to around 36 weeks. Airlines have their own cut-offs, often earlier for international flights or twins.
Partly trueCan you take a hot bath while pregnant?
Warm baths are fine. Avoid hot tubs, saunas and very hot baths that raise your core temperature, especially in the first trimester.
Partly trueDoes heartburn mean the baby will have lots of hair?
Surprisingly, there’s some evidence for it. One small study found a link, possibly because the same hormones relax the stomach valve and affect fetal hair growth.
TrueCan babies hear in the womb?
Yes. In one study, babies first responded to a sound at 19 weeks, and most responded by 27 weeks. Newborns recognise their mother’s voice.
MythDo babies move less at the end of pregnancy?
No. Movements may feel different as space gets tight, but the baby should keep moving as much as before, right up to and during labour.
Partly trueIs pregnancy really 9 months?
Roughly. It is 40 weeks (280 days) from the first day of your last period, which is about 9 months and 1 week. From conception it is about 38 weeks.
MythWill my baby be born on the due date?
Unlikely. Only about 4% of babies arrive on their exact due date. Most are born within about two weeks either side.
MythCan spicy food or pineapple bring on labour?
There’s no good evidence that spicy food or pineapple starts labour. Some small studies suggest eating dates late in pregnancy may help the cervix ripen.
MythDoes a full moon bring on labour?
No. Large studies of hundreds of thousands of births found no link between the lunar cycle and when babies are born.