Old Wives' Tales for Gender Prediction: The Complete List

The tale: Carrying high means a girl; carrying low means a boy.

The science: How high or low you carry is determined by your abdominal muscle tone, your body shape, the baby's position, and whether it is your first pregnancy — not by the baby's sex. First-time mothers often carry higher because their abdominal muscles are tighter; in subsequent pregnancies, those muscles have stretched and the baby sits lower (Healthline).

The baby's position — head-down, breech, transverse — also affects the shape of the bump. None of this is related to whether the baby has XX or XY chromosomes. This is one of the most widely believed tales, and it is one of the easiest to debunk: the same mother can carry differently in successive pregnancies of the same sex.

The tale: Severe morning sickness means a girl; mild or no morning sickness means a boy.

The science: This one has a kernel of truth, but it is not reliable enough to be a predictor. Some studies have found a weak statistical association between hyperemesis gravidarum (extreme, hospital-grade morning sickness) and carrying a girl, possibly because female pregnancies produce slightly higher hCG levels on average (Askling et al., 2006). But the effect is small and does not hold at the individual level — plenty of women with mild sickness have girls, and plenty with severe sickness have boys.

For the full breakdown, see our dedicated guide on morning sickness and gender.

The tale: Craving sweet things means a girl; craving salty or savoury things means a boy.

The science: There is no evidence that the type of food you crave is linked to your baby's sex. Pregnancy cravings are thought to be driven by hormonal changes, nutritional needs, cultural factors, and simple preference — not by whether the fetus is male or female.

Some versions add that craving dairy means a girl and craving meat means a boy, but again, there is no biological mechanism by which fetal sex would influence the mother's taste preferences. Cravings vary enormously from pregnancy to pregnancy in the same woman, regardless of the baby's sex.

The tale: A heart rate above 140 bpm means a girl; below 140 bpm means a boy.

The science: This has been repeatedly debunked. Studies have found no significant difference in fetal heart rate between male and female fetuses. The normal fetal heart rate range is 120–160 bpm regardless of sex, and the heart rate varies with gestational age and fetal activity — not with whether the baby is a boy or a girl. See our dedicated guide on fetal heart rate and gender.

The tale: Suspend your wedding ring on a thread over your belly. If it swings in a circle, it is a girl; if it swings back and forth in a line, it is a boy. (Some versions reverse the directions.)

The science: The ring test is a form of ideomotor effect — unconscious micro-movements of the hand holding the thread cause the ring to swing. The direction of the swing is determined by your own subtle muscle movements and expectations, not by the baby's sex. It performs at chance when tested.

Variations include using a needle on a thread, or a lock of hair. All versions work the same way and have the same (lack of) predictive value. It is a fun party game, nothing more.

There are many more old wives' tales, and they all share the same problem: no biological basis and chance-level accuracy.

• The baking soda test: mix urine with baking soda; if it fizzes, it is a boy; if it does not, it is a girl. The fizz depends on the urine's pH, which is not related to fetal sex.
• The Mayan math test: if the mother's age and the year of conception are both even or both odd, it is a girl; if one is even and one odd, it is a boy. This is numerology, not biology.
• The Drano test: mix urine with Drano and check the colour. Dangerous and meaningless — do not try this.
• Breast size: the claim that larger breasts in pregnancy mean a girl. Breast changes are driven by hormones and are not sex-specific.
• Linea nigra direction: the claim that if the dark line on your belly goes above the navel it is a boy. The linea nigra is caused by melanin production and is not sex-specific.
• Mood: the claim that moodiness means a girl and calmness means a boy. Pregnancy hormones affect mood regardless of fetal sex.

Every single one of these performs at about chance. They are traditions to enjoy, not predictions to rely on.

If you want a prediction with real evidence behind it, here are the methods that actually work:

Nub theory reads the genital tubercle angle on your 12-week scan — something genuinely related to the baby's sex. NubHub pairs AI with a human double-check, returning results in about 2 hours for under £40, with a money-back guarantee. See how our AI works or start with our complete guide to nub theory.