When you find out you're pregnant, there are many things your doctor will discuss with you in regards to having a healthy pregnancy and labor and delivery. In addition to regular prenatal care and maintaining a healthy lifestyle, you'll also be advised to undergo some routine testing during your pregnancy, to identify and treat any potential problems. One of these tests includes a screening for Group B Strep between your 35th and 37th week of pregnancy. Here's everything you need to know about Group B Strep and how it affects your pregnancy and newborn.

What Is Group B Strep?

Group B Strep, or Group B Streptococcus (GBS), is a bacteria that lives in the body. It is not a sexually transmitted disease, and it is different than the strain of bacteria that causes strep throat. In women, it's found in the vagina or rectum, and can be passed from mother to baby during labor. Although Group B Strep does not usually cause serious illness in carriers, it can be potentially dangerous if passed to a baby during labor and delivery.

How can I find out if I have Group B Strep infection?

Group B Strep screenings are recommended by the CDC for all pregnant women, between their 35th and 37th week of pregnancy. Your doctor will take a swab of your vagina and rectum, and the culture will be analyzed for the presence of the Group B Strep bacteria. Results are usually back within 24-48 hours.

How does someone get group B strep?

Contrary to what you might have heard, Group B Strep is not a sexually transmitted disease. It's also a different strain from the bacteria that causes strep throat. Group B Strep, or GBS, is a bacteria that normally lives in the intestines, vagina, and rectum. In most carriers, there are no symptoms and Group B Strep doesn't cause any illness. Approximately 25% of healthy women are GBS carriers.

What if I test positive for Group B Strep?

If your Group B Strep test comes back positive, there's no reason to panic. That simply means that you are a carrier of the bacteria. It doesn't mean that GBS will automatically pass to your baby during labor. But as a precaution, your doctor will most likely administer antibiotics intravenously during your labor. Approximately 1 in 200 babies born to a Group B Strep carrier who wasn't treated with antibiotics will contract the bacteria during labor, whereas 1 in 4000 babies born to a mother who was treated with antibiotics test positive at birth.

If your membranes rupture before 37 weeks, or you go more than 18 hours between membranes rupturing and delivery, or if you have a fever during labor, your doctor will most likely insist on antibiotics, as those can increase the risk of transmitting GBS to your baby.

How does Group B Strep affect a newborn baby?

Doctors recommend routine Group B Strep screening for all pregnant women, because although it's fairly rare for a newborn to contract GBS, it is very serious if that does happen. A baby exposed to Group B Strep will either have early-onset or late-onset disease. In early-onset disease, symptoms appear within 12-48 hours after birth, but can appear up to seven days later. Complications can include pneumonia, sepsis, and meningitis. Early-onset disease is more common than late-onset disease, and both mother and baby are treated immediately with intravenous antibiotics.

Late-onset disease can be evident between a week to a few months after birth. In cases of late-onset disease, the baby may have contracted the bacteria from the mother during delivery, or could have been infected by exposure to a different carrier. It is also very serious, and can lead to meningitis. Symptoms of late-onset Group B Strep include irritability, lack of energy, high fever, and poor feeding.

READ NEXT: New Mom Ensured People Got Vaccinated Before Meeting Her Newborn