You won't know whether you're positive for Group B streptococcus until close to your due date, but knowing how Group B can affect you and your baby before, during and after birth starts now.

What exactly is Group B strep (GBS)?

GBS is bacteria women can harbor in their vaginas. It may not affect you, but there is a risk it could seriously affect your baby. According to the American Congress of Obstetricians and Gynecologists (ACOG):

GBS can cause infections of the blood (sepsis), lungs, brain, or spinal cord in newborns and is fatal in about 5 percent of babies who carry it. An estimated 10-30 percent of pregnant women are infected with GBS and up to 2 percent will transmit it to their newborns during delivery.

Scary stuff, but don't worry because there are things you can do to protect your baby.

How will you know if you have GBS?

ACOG recommends women get tested for GBS between 35-37 weeks. The test is done by swabbing your vagina front to back with what looks like a large Q-tip. The swab is cultured, then your doctor or midwife will let you know if you're positive or negative for GBS. If you test positive, your doctor or midwife will want to administer IV antibiotics when you're in labor.

How will GBS affect the rest of pregnancy?

Not much. If your water breaks before you're really in labor, your doctor or midwife may want you to come to the hospital sooner than you normally would so they can start the antibiotics. When your water breaks — even if you're GBS negative — the risk of infection increases, so combined with being positive with GBS, well, you get the picture!

How will GBS affect labor?

Giving IV antibiotics aims to prevent passing GBS to your baby when she travels through the birth canal. It also should eliminate having your baby go to the nursery for a battery of tests to make sure she's not infected. If you hate needles and are hoping not to have an IV during labor, talk to your healthcare provider if you're positive for GBS. You may be able to have the IV taken out in between doses of antibiotics. If you need continuous fetal monitoring — for instance, if you're induced — find out if a telemetry unit is available so you can still be mobile while being monitored. No further intervention for GBS is usually needed, so you can labor your way and bond with your baby as soon as he's born.

Read more about pregnancy and birth interventions

Are routine IVs necessary in labor?
How to write a birth plan
Understanding prenatal tests