The facts about a Strep-B positive diagnosis

OB/GYN Lauren Hyman, MD, explains what Strep-B is during pregnancy and how a positive diagnosis affects a pregnant woman and her baby
The Facts About a Strep-B Positive Diagnosis
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The facts about a Strep-B positive diagnosis

Group B strep is bacteria that are similar to but not the same as the bacteria that causes strep throat that’s Group a strep. Group B strep is a bacterium that colonizes the vagina in one out of every four women. So 25% of the pregnant women will be colonized by the group b strep at any given time. It’s not a sexually transmitted disease. It lives in the intestines and the vagina and one can be colonized and then not colonized and then colonized again. Well it’s very uncommon for a full term baby to be infected with group B strep. The consequence can be absolutely devastating of neonatal Group B strep infection. So every woman who is pregnant between 35 and 37 weeks gets a swab of their vagina and their rectum send to see if they in fact colonized. If they are and again, one in four women is, it’s nothing to be panicked about; it’s just something to be aware of. And when these women are in the hospital delivering, we give them antibiotics generally IV penicillin, if they are not allergic and we like to get in at least two doses 4 hours apart. This is prophylactic treatment for the baby, it’s not meant to treat the women’s vagina, it’s meant to treat prophylactic the baby to try to reduce the risk of neonatal infection. If a woman who is positive for group B strep delivers the chance that her baby will have the infection is 1 in 200 but if she receives antibiotics, it’s 1 in 4,000. If one is in a high risk group for group B strep, for instance the bag of water has been ruptured for over 18 hours, the baby is premature, less than 37 weeks, the mother has a fever or sign of infection during labor, there is a previous baby born in the family who had group B strep infection or the mother had a urinary culture that showed group b strep, that women will be given antibiotics as well to try to help prevent neonatal infection. Again all these things are done to help try to reduce neonatal group b strep infection and thankfully since the swabbing has taken place, since the protocol for IV antibiotics is gone into effect, we have been able to markedly reduce the number of babies who have group b strep infection and sepsis.

OB/GYN Lauren Hyman, MD, explains what Strep-B is during pregnancy and how a positive diagnosis affects a pregnant woman and her baby


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Lauren D. Hyman, MD

Obstetrician Gynecologist

Dr. Lauren Hyman is a board-certified obstetrician gynecologist. After receiving her ScB from Brown University and her medical degree from Yale University, Dr. Hyman returned to Southern California where she has been in private practice in the West Hills area for fifteen years. She can be seen weekly on Hallmark Channelʼs Home and Family Pregnancy Series and is a contributing writer on She lives with her husband and two children in Los Angeles.

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