We've all heard about "old wives' tales (OWT)." Definitions abound - from "a superstitious belief or story belonging to traditional folklore" to "a traditional belief, often founded in superstition, typically stated in the form of a maxim or proverb."

We've all heard about "old wives' tales (OWT)." Definitions abound - from "a superstitious belief or story belonging to traditional folklore" to "a traditional belief, often founded in superstition, typically stated in the form of a maxim or proverb."

But how did they become part of our lexicon? And how many of them really are true?

The beginning
Many of the tales began centuries ago, such as the old wives' tale that if a black cat crosses your path you will have bad luck. Why? A Norse legend tells of the chariot of the goddess Freya that was pulled by black cats that changed into black horses. They were so exceedingly swift that they were thought to be possessed by the Devil. After serving Freya for seven years, the cats were rewarded by being turned into witches, disguised as black cats. This may have led to the belief in the Middle Ages that black cats were associated with witches, and often became witches themselves.

Some OWTs concern jewelry which was thought to prevent evil spirits from entering the body while earrings and painted lips were talismans to keep devils away. In medieval times, pearls were believed to be solidified tears and thus unlucky, as were emeralds because there were used as the eyes in religious figures and were usually stolen. And lastly, diamonds were believed to bring good luck - possessing the power to drive off witches.

Staying power
"Throw some salt over your shoulder for luck" is one of the most common myths, and it is still practiced every day by talk-show host and celebrity chef Rachael Ray. Really. Just watch the show and see for yourself! While salt played an important part over the centuries as a preservative and method of payment, it is still closely associated with luck. Some people believed that an evil spirit waits over your left shoulder - which started the custom of throwing salt over your left shoulder (and into their eyes).

In many parts of the world salt is given to newborns for luck and some people have even been known to carry salt in a small bag on their person for the same reason.

Pregnancy OWTs
Speaking of newborns, old wives' tales about pregnancy, including determining the sex of the baby, far outnumber any other topic. And the myths have been around as long as child-bearing. The advent of the ultrasound may have taken some of the fun out of guessing the baby's gender, yet the tales are still told.

Heart rate
If the baby's heart rate is above 140 beats per minute (bpm), the baby is a girl. If it is under 140 bpm, then it's a boy. "The heart rate is not a prediction of sex," said Stuart Jones, M.D., chair of the Department of Obstetrics and Gynecology at Riverside Methodist Hospitals. "Fetal heart rates average 160 bpm in the first 20 weeks of a pregnancy with little variation and can be as low as 120 bpm at the end, with variations during episodes of movement. The bpm may be less when sleeping, so if it's true, we would have a lot of girls at the beginning of pregnancy and boys at the end."

Shape of belly
It's been said if you are carrying high with a big, round belly, you are having a girl. If you are carrying low with a smaller belly that sticks straight out, it's a boy. "The way a person carries a baby is based on a mother's abdomen - short-waisted versus long-waisted,"Jones said, "and [also] which pregnancy it is and what position the baby is in. Remember, the baby is within the uterus, which is a muscular structure that will not change due to sex of the baby."

Shape of Mom's face
If your face gets fuller and rounder when pregnant, it means you're going to have a girl, say some legends. If your face is long and narrow, it's a boy. "The face changes are secondary to water retention which is normal but can be changed by foods and diseases of pregnancy," Jones explained. "Also, changes in the face are caused by weight gain. Someone that gains more weight will show a rounder face."

Some people believe that if you crave salty foods while pregnant, you can count on having a boy. If you crave sweets, fruit and orange juice, you are having a girl. "There are no metabolic differences from boys and girls that will change cravings," Jones said. "These cravings [usually] change with each pregnancy, [and] often [moms are] craving things that they would never want when not pregnant."

Eating spicy foods will induce labor
While Jones has "heard everything from spicy foods to Pizza Hut pizza" will induce labor, this too is a myth. "Nothing truly has proven to start labor and it's more likely to give you heartburn than anything else," he said.

Since medical advice is far safer than OWTs, for a healthy pregnancy Jones shared some tips - like thinking ahead. "Three months of folic acid before pregnancy will decrease risk of spina bifida in the baby," he said. "And if you are on medications, check those out with your obstetrician. Some meds can be dangerous to the fetus."

And don't smoke. "Stop smoking before attempting to get pregnant," Jones said. "Smoking adds a big risk to the pregnancy and increases risk to the baby of asthma after birth."

He also debunks the OWT of "I'm eating for two." Along with eating healthy and exercising, Jones suggested establishing the amount of food that kept your weight stable before. "And you can actually start exercising after you become pregnant, just ask your doctor for guidelines," he said.

"Always ask questions," Jones said. "Patients always say, 'I have a stupid question.' I always tell them no question is stupid if you don't know the answer. Write down your questions and bring them with you."

Marguerite Marsh is a freelance writer and winner of the Ohio Public Images 2008 Print Journalism Award of Excellence for her Columbus Parent article "Motherhood Redefined and Transformed by Treacher Collins Syndrome."