Belly Up

* bellies * birth * babies * breastfeeding *

Tuesday, September 13, 2011

Group B Strep - Its Not About Your Throat

Not that kind of Strep!
We can probably all remember at some point having the sore throat and fever of strep throat.  However Group B Strep is not a sore throat in one's vagina (and thank goodness for that).  Group B Strep, otherwise known as GBS, is a generally harmless bacteria that makes its home in the intestinal track of our bodies.  It is generally intermittent and it is thought that roughly 1/3 of the population has this bacteria hanging out deep in their intestines at any given time.

While GBS is not a big deal for most adults, during their little trip through the birth canal some babies pick up GBS and a small number of those babies will become sick.  Babies that are born prior to 37 weeks of pregnancy, those whose membranes were broken for an extended period or whose mothers ran a fever during labor are at greater risk of infection.  Typically in the US a women is not told much about GBS and may not even know what they are being tested for when they are given a routine vaginal swab late in their pregnancy.  However, there is math behind GBS and here is how it breaks down:*

- An expecting woman has a 1 in 3 chance of carrying GBS
- If she has it and does nothing, there is a 1 in 200 (0.5%) chance that her baby will get GBS
- If the baby gets GBS, there is a 6% chance that he will develop severe complications/die
- 3 out of 10,000 (0.03%) of babies born to GBS positive mothers NOT treated will die
- 1 out of 10,000 (0.01%) of babies born to GBS positive mothers who ARE treated will die

Obviously without or without treatment, the odds are highly favorable that a baby born to a GBS mom will be healthy, but anytime you start talking about dead babies that is downright scary.  In order to mitigate the small but real risk, maternity providers seek to push the risk closer to the 0.01%  level rather than the 0.03% level.   The current standard of care is that a woman who tests positive by vaginal swab in her 3rd trimester (or anytime in her urine) will receive IV antibiotics during labor.  However there are a number of options out there and antibiotics carry their own risks, so in the spirit of informed consent lets look at the issue.

Antibiotic use is prevalent in our country and currently 1/3 of laboring moms can expect to receive antibiotics for GBS during labor  However studies done by the CDC show that antibiotics fail to prevent up to 1/3 of GBS deaths each year.  While it is clear that use of antibiotics does reduce the GBS infection rates,  there is now mounting evidence that reduction in GBS must be weighted against the increase in death and illness from the subsequent infections created by drug resistant "super bugs" that have arisen from the overuse of antibiotics.  In fact ampicillin and amoxicillian are no longer useful in treating GBS due to their overuse and much stronger drugs are currently used.  Another risk of antibiotics includes the risk of yeast infection in moms and babies, but even more troubling is that statistically as many infants may have allergies to the antibiotics given during labor as the number of babies who will be infected by GBS and these allergic reactions can also be life threatening.

Another factor to consider is that while maternity providers have sought to reduce deaths from GBS infection, they also can create the situations where the risk factors of GBS exist.  One risk is prolonged rupture of membranes.  The membranes may naturally rupture at any point during labor, but care providers often artificially rupture membranes when a woman is still in early labor thus putting her at risk for having prolonged rupture of membranes. Inductions (and scheduled surgical births) have increased the number of late preterm babies, ie babies that due to miscalculation in the due dates are born just before 37 weeks of pregnancy which is another known risk factor for GBS infection.  As the artificial rupture of membranes tends to go hand and hand with induction, a reduction in inductions will also reduce the incidents of increased risk due to prolonged rupture of membranes.

Women do have choices about how they want to handle the GBS issue.  First of all any testing in a health care setting is optional.  A woman can choose to not get tested and many make this choice.  Others choose to be tested but do their own vaginal swab, usually when they provide a urine sample so as to avoid the uncomfortable process of having someone else do it.  Women can take measures to reduce their risk of even having GBS using a variety of regimens that can boost the immune system and clear any GBS hanging out in intestines.(taking garlic and echinechia is a common route).  There are also other ways to treat besides taking antibiotics.  In Europe where IVs (and thus IV antibiotics) are not standard during labor, a vaginal wash called chlorhexadine is commonly used and has documented high effectiveness.  Chlorhexadine is easily bought here in the US so it certainly represents a choice that is readily available.

Basically these are the choices:
1. Choose to follow dietary, herbal or homeopathic methods to decrease the risk of carrying GBS
2. Choose testing and treat with antibiotics
3. Choose testing and treat with chlorhexadine during labor
4. Choose not be be tested, educate yourself about the early symptoms of GBS infection in infants

I want to close by saying that if a GBS positive mom decides the best option is to treat with antibiotics this does not mean that she must be hooked up to an IV her whole labor.  It takes 20-40 mins for the IV bag to empty and mom will receive a bag only once every 4 hours.  After the bag is empty, the IV may be made into a heplock leaving mom free to move as desired.  The IV can be timed to be given during a period when the careprovider also monitors the baby, that way both are done concurrently and mom can then be left alone for a while.  Choosing to be treated with IV antibiotics also doesn't take away the option of an out of hospital birth as most midwives are able to give moms an IV at home or in a birth center.  If getting antibiotics, mom should also purchase some good probiotics and watch for yeast in herself and baby.

*A big huge thank you to Ann Crowell, CPM, LM at Gentle Beginnings for having a handout with this math already done.  I am so thankful I didn't have to mess with a calculator myself.  Ann is a fabulous MW in the DFW area if  you are looking!