Often, old wives’ tales are just that: tales. But sometimes, certain beliefs persist generation after generation. With sophisticated tools to examine these beliefs, some have been found to be surprisingly scientifically sound, like the examples discussed below.

Go Bananas for Boys

If you are trying to conceive boys, midwives of the past would have you eating bananas. Turns out, this old wives' tale has scientific basis. Bananas contain high levels of potassium, which researchers recently linked to increased percentage in women giving birth to males. Along with a reasonable intake of calcium and sodium, a healthy amount of potassium in your diet (in all, leading to a higher calorie intake than without potassium rich foods) could load the genetic dice in favor of boys. This makes perfect sense from an evolutionary perspective: When food is abundant, mothers have better chances of producing physically stronger offspring that in turn could father more offspring in the future to preserve the species.

Always consult with your doctor, however, before altering your diet for 'selective breeding' as changing the mineral content of what you eat could have other health implications for you and your baby.

Husbands Should Avoid Hot Baths If They Want to Conceive

If you are trying to conceive, avoid hot baths altogether, at least until after your wife has become pregnant. The testicles, where sperm are produced, are held in the scrotum for a reason: to be away from the heat of the body. Thus, if you dip into any hot bath, expect that your sperm count will take a dive. Findings published in the Harvard Medical Journal indicate that even a two degree Fahrenheit increase in water temperature can be enough to negatively affect sperm and testosterone production.

Heartburn During Pregnancy Suggests a Hairy Baby

Before the Johns Hopkins study about the correlation between heartburn and a hairy baby came along, doctors routinely dismiss the pregnancy-related digestive discomfort and hairy baby connection as non-sense. But after studying a group of pregnant women and took into account the seriousness of their heartburn and the baby's amount of hair, there was a clear connection between the two. The reason is that a lot of estrogen and other hormones appear to relax the sphincter at the bottom of the esophagus (which prevents acid and stomach contents from sloshing back into the esophagus) and the same hormones appear to positively affect fetal hair growth.

Pregnant Mothers Who Love Veggies Make Veggie-Loving Babies

It's challenging for moms even of generations past to make kids fall in love with their vegetables because the most nutritious are often bitter-tasting. To establish healthy eating habits well before the baby is born, eat a lot of vegetables, bitter-tasting and all, when trying to get pregnant, while pregnant, and while nursing. This is because the foods and drinks that pregnant women ingest flavor the amniotic fluid that a fetus swallows in the second trimester. The baby's exposure to vegetables - or any other food for that matter - in utero sets the stage for the baby’s preference when they start eating solid foods.

The flavor of the mother's diet also transmits to her breast milk. Nursing mothers who eat vegetables while breastfeeding infants between 4 to 8 months are more likely to make their toddlers readily accept vegetables than those who have not introduced vegetables to an infant’s diet via milk. So if you want your kids to gobble up bitter gourds without protest, start including those veggies in your own diet well before they are born.