Preventing Neonatal Infection

Preventing Neonatal Infection

Will I Have Antibiotics During Labor?

If you have a Group B Streptococcus (GBS) infection when you go into labor, there is a risk of the infection being transmitted to your baby at birth. GBS infection in newborn babies can lead to serious problems.

Preventing GBS Infections in Newborns

If you are given antibiotics during pregnancy, the chance of your baby contracting a GBS infection decreases significantly. The typical antibiotics used are penicillin (PenVK) or ampicillin (Principen). For women who are allergic to penicillin, either clindamycin (Cleocin) or erythromycin (Ery-Tab, PCE) can be used.

The preferred approach to GBS screening is based on universal cultures.

  • Culture-based approach -All women who are expected to deliver prematurely (before the 37th week of pregnancy) are given antibiotics during labor. All other patients will have a routine GBS culture between their 35th and 37th weeks of pregnancy. A culture involves having a specimen from the lower portion of your vagina and the outside of the rectum sent to a laboratory, grown, and analyzed. Those with positive cultures are given intravenous antibiotics during labor, usually for at least four hours prior to delivery.

If I Am Given Antibiotics, Will My Baby Need to Take Antibiotics?

If you receive antibiotics at least four hours before delivery, your baby probably won't need antibiotics. However, if you were given antibiotics less than four hours before delivery or if your doctor or nurse suspects an infection, your baby may need to stay in the hospital for observation and blood tests. These may include lab tests to measure the number of white blood cells in your baby's blood, a blood culture, and a chest x-ray. Your baby may receive antibiotics until results from all of these tests are available, as a preventive measure.

Why Don't All Women Receive Antibiotics to Prevent GBS Infection?

Unfortunately, any antibiotic can cause side effects or adverse reactions-including penicillin and ampicillin. In general, when these side effects arise, they are mild and do not cause significant harm. But in a few cases, a person can have a severe or even life-threatening reaction to antibiotic medications.

Experts are also concerned that giving antibiotics to a large number of pregnant women could result in an increased chance for serious infections of newborn babies from bacteria other than GBS due to a process called selection pressure.

About "Selection Pressure"

A woman's body normally contains a great number of bacteria on the skin, mouth, ears, nose and throat, intestines, and vagina. The majority of bacteria in the body are not harmful. These are called non-pathogenic bacteria. However, in addition to non-pathogenic bacteria, a small number of other bacteria also reside in the body. If these pathogenic bacteria multiply to great enough numbers, a person will get ill. These different types of bacteria compete for nutrients and space to grow, and there is normally a healthy balance, with large numbers of non-pathogenic bacteria and only small numbers of pathogenic bacteria present.

When an antibiotic (such as ampicillin or penicillin) enters the body, it may upset this balance. The antibiotic may actually kill non-pathogenic bacteria but not harm the pathogenic bacteria. This is called selection pressure because the antibiotics unintentionally impair the growth of (or kill) the non-pathogenic bacteria, allowing the pathogenic bacteria to increase. The infections caused by selection pressure can be difficult to treat. Some patients require extremely powerful antibiotics since the pathogenic bacteria are resistant to (not affected by) standard antibiotic drugs.

When deciding whether or not to administer antibiotics, your doctor will consider:

  • which antibiotic is likely to eliminate the harmful bacteria without harming the patient. There are hundreds of types of bacteria that can cause infections in humans, and no one antibiotic will work against every type. A specific antibiotic may work against some types of bacteria, but not on other types;
  • the possibility of serious side effects. All antibiotic drugs cause side effects. Mild side effects, such as a skin rash, occur in about one out of every 10 people given penicillin or ampicillin. Some side effects can be serious, even life-threatening. One of the most serious side effects associated with penicillin and ampicillin is anaphylaxis, or anaphylactic shock. This severe allergic reaction causes a patient's throat and airway to swell and fluid to accumulate in the lungs, making it difficult for the person to breathe. Left untreated, anaphylaxis can be fatal within a few minutes. Anaphylaxis occurs in approximately one out of every 10,000 people given penicillin or ampicillin; and
  • the most selective, least toxic, and least expensive antibiotic possible to achieve the desired result. The more an antibiotic is used, the less effective it becomes. Many decades ago, when penicillin was first discovered, most types of bacteria that caused infections in humans were killed by it. Now, after widespread use of penicillin over the past several decades, most types of bacteria that cause infections in humans are resistant to penicillin.

You can see why health care providers must be careful in selecting an antibiotic drug and use it only when it is likely to help the patient and unlikely to harm the patient. Experts currently recommend that only women who have been shown to be colonized with GBS or have a significant risk factor for their infant developing GBS infection receive antibiotics during labor.

Why Shouldn't I be Treated for GBS Before I Go into Labor?

Taking antibiotic drugs is only effective in reducing GBS infection in the newborn if they are administered at the time of delivery. Since there is a four to five week time span when most pregnant women go into labor (between the 37th and 42nd weeks of pregnancy), trying to take antibiotics before labor to prevent GBS infections may require the regular use of antibiotics for up to five weeks. Taking an antibiotic drug for several weeks is likely to cause serious side effects. The only time that antibiotics are typically prescribed to treat GBS prior to labor is in women with bladder infections. Treatment of women with GBS present in urine cultures may help prevent premature labor or rupture of the membrane (bag of waters) before the onset of labor.

Will My Labor Be Conducted Any Differently if I Have GBS?

There is no evidence that your labor should be any different in the presence of GBS. This includes the stripping or membranes or the use of internal scalp electrodes in labor. Methods of labor induction should be unaffected by GBS status.

Will Antibiotics Given During Labor Prevent All Cases of Newborn GBS Disease?

Administering antibiotics to all women in labor who are at risk of having an infant with GBS disease will reduce the chances of infection, but it does not completely eliminate newborn GBS disease. This is because:

Administering antibiotics to all women in labor who are at risk of having an infant with GBS disease will reduce the chances of infection, but it does not completely eliminate newborn GBS disease. This is because:

  • antibiotics are not 100% effective in preventing newborn GBS infections. It is estimated that giving antibiotics to laboring women who are colonized with GBS will reduce the chance of her baby having a serious infection by over 95%. Babies delivered to women in labor with a high fever due to an infection of the womb are particularly at risk for developing newborn GBS disease, even when antibiotics are used during labor;
  • there is a slight chance that a woman colonized with GBS during labor will have had a negative culture, even if the culture was done several days or weeks before delivery; and
  • some women have short labors and deliver shortly after arriving at the hospital or birth center, which may not allow time to administer antibiotic medication.

Is There a Vaccine for GBS?

There is no vaccine for GBS at this time, though, researchers are currently working on it. Use of a vaccine will likely be preferable to giving antibiotics during labor for prevention of GBS disease, since a vaccine is likely to have fewer side effects and offer greater protection for most babies.

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