Symptoms: If you develop symptoms, you'll see a chancre, which shows up about three weeks, or sometimes years, after you've been exposed to the infection. It appears where the bacteria entered your body.

The sore is round, firm and painless, so it often goes unnoticed, according to the Mayo Clinic. This first stage lasts 3-6 weeks. If untreated, syphilis may cause a rash all over the body, including the palms of your hands and bottoms of your feet.

Raised gray or white lesions may develop in the mouth, underarms or groin. The symptoms disappear with or without medication, but if syphilis isn't treated, it progresses.

STD risks to mother and child: The last stages of syphilis – which may appear 10-30 years after the initial infection appeared – damage your brain, nerves, eyes, heart, blood vessels, liver, bones and joints, possibly causing death, the CDC says. Syphilis also increases your risk of developing HIV.

A woman with syphilis can pass the disease to her unborn baby, who can be delivered prematurely or stillborn (dead). Babies with syphilis have low birth weight. That puts them at high risk of infections the first six days of life, and they may suffer the lifelong effects of delayed motor and social development and learning disabilities, according to the CDC. If not treated immediately, the baby may develop cataracts, deafness or seizures, and may die.

Treatment: Syphilis is easy to cure with antibiotics, such as penicillin, which kills the bacteria. But it won't repair the damage already done.

For more information and expert advice, visit Lifescript's Pregnancy ^[1] and HIV ^[2] health centers.