Old wives’ tales about gender, checked
Any guess about a baby’s sex is right about half the time, which is why these tales seem to work. Here’s what happens when they’re tested. They’re fun, but don’t paint the nursery yet.
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.
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.
What actually works
For a reliable answer, use a medical test: NIPT from about 10 weeks, or the anatomy scan. The nub theory is an educated guess from a scan, not a tale, and it can be fairly accurate at 12 to 13 weeks. Compare every option.
Questions people ask
Do any old wives’ tales predict the baby’s sex?
None has been shown to predict it for any one pregnancy. The closest is a small link between severe pregnancy sickness and having a girl, which is far too weak to predict anything.
Why do old wives’ tales seem to work?
Any guess about a baby’s sex is right about half the time, and people tend to remember the times it worked.
What actually tells you the baby’s sex?
NIPT from about 10 weeks and the anatomy scan at around 18 to 22 weeks are the usual reliable options. Diagnostic tests such as CVS and amniocentesis also show it, but are only done for medical reasons.
References
- Perry DF et al. Are women carrying “basketballs” really having boys? Birth, 1999
- McKenna DS et al. Gender-related differences in fetal heart rate during first trimester. Fetal Diagnosis and Therapy, 2006
- Papaioannou GI et al. Normal ranges of embryonic length and heart rate. Fetal Diagnosis and Therapy, 2010
- Askling J et al. Sickness in pregnancy and sex of child. The Lancet, 1999
- NHS: Severe vomiting in pregnancy
- Villamor E et al. Accuracy of the Chinese lunar calendar method. Paediatric and Perinatal Epidemiology, 2010
- Wilcox AJ et al. Timing of sexual intercourse in relation to ovulation. New England Journal of Medicine, 1995