Are MRSA Carrier Moms a Risk to Their Babies?

Study participants were tested for the presence of MRSA bacteria in their nose to see if they were a carrier.

I just ran across this MRSA study from Vanderbilt University Medical Center that examined pregnant moms. They wanted to see for mothers who were carriers of MRSA (an antibiotic resistant form of Staph aureus bacteria), would they pass MRSA bacteria along to their baby during birth, and would their baby then become infected?

Their study showed good news for babies. They found the risk of getting a MRSA infection was lower than they thought, however more women and babies were carriers than they expected.

Here’s what the researchers did. They swabbed the nose and vagina of 500 pregnant women at regular intervals before birth and at time of delivery (a typical test for MRSA). The babies were swabbed in their nose at birth and 8 and 16 weeks of age. The swab was then tested for the presence of MRSA bacteria. This test was performed in conjunction with looking for Group B strep bacteria, which also poses a risk for newborn babies.

Results: mom’s don’t pass MRSA during birth, but later on

The researchers found that 20% of pregnant women were MRSA carriers (this doesn’t mean the mom was infected) and that 20% of babies were positive for the bacteria at 8 weeks of age. However, it didn’t appear the bacteria were transferred at birth, but by the time babies were 2 months old, they closely matched the carrier status of their mother (if the mom was a carrier, then the baby was likely to be a carrier too).

Importantly, even though some newborns were carriers at 2 months of age, the babies rarely became infected with the bacteria. According to study author Buddy Creech M.D., “We don’t want to overreact to carriage when incidence of disease is low. A lot of babies are colonized. Twenty percent at 2 months of age is the highest rate we’ve ever seen, but in our study only two babies got disease.”

What should be done about MRSA colonization in pregnant women? According to the study author, “the best action may be no action at all”. The researchers plan to do further studies to see if newborns carrying the bacteria may have greater protection against getting infected with MRSA later in life.

Additional thoughts

Because the babies closely match their mothers in carrier status in this study, this shows the dynamic of how MRSA carriers can pass the bacteria to other family members. While it didn’t happen at birth, it did happen over time.

Carriers can transfer bacteria to others by touch or through airborne exposure to the bacteria. And of course there will be (and should be) very close contact between a mother and her child and this study shouldn’t be a reason to not have close contact with your child if you are a carrier.

The study author didn’t believe treatment was necessary. I would agree as far as not using antibiotics. I also believe it’s important to realize that when using antibiotics, they also kill off your baby’s good gut and skin bacteria which provides huge health benefits to your baby.

These good bacteria form during the first months of a baby’s life and research shows it may be difficult to normalize gut flora after exposure to antibiotics. Find out more here and at the links below: Newborns with MRSA.