Group B Streptococci Clinical Trial
Official title:
Respiratory Distress of the Newborn and Its Relationship to Group B Streptococcal Colonization
This study will evaluate whether babies are more at risk of developing breathing problems if
their mothers carry group B streptococci (GBS) in vagina/rectum, and whether the breathing
problem is due to phospholipids released by the GBS. About one in five pregnant women carry
GBS in their vagina/rectum. Mothers who carry these bacteria are given antibiotics during
labor to prevent infection in the baby. However, recently it has been suspected that even
without blood stream infection, the chemicals released by GBS, called phospholipids, might
lead to breathing problems.
Women at 32 or more weeks of pregnancy who deliver at Ben Taub Hospital and St. Luke s
Episcopal Hospital in Houston, Texas, and Alta Bates Summit Medical Center in Oakland,
California, may be eligible for this study.
Mothers undergo the following procedures:
- Vaginal/rectal GBS culture. A sample is collected from the lower vagina and rectum using
a cotton swab upon admission to labor and delivery.
- Blood collection to test for phospholipids. A blood sample is obtained from the mothers
at the time of routine blood drawing during labor, and a blood sample is obtained from
the umbilical cord (after delivery).
- Collection of health information from the medical record.
Newborns undergo the following procedures:
- GBS culture. Samples are collected from cotton swabs of the ears, navel, anus and throat
to test for GBS bacteria.
- A small amount of blood from newborns is obtained for phospholipids test when the
newborns have blood drawn for other tests.
- Collection of health information from the medical record.
Phospholipids from the group B streptococcal (GBS) cell wall cause pulmonary hypertension in
experimental animals. We hypothesize that newborns colonized with GBS receive bacterial
phospholipids leading to pulmonary hypertension and respiratory distress. When exposed to
penicillin (beta-lactam), Streptococcus mutans releases phospholipids immediately. An
analysis of 1610 colonized newborns from the NICHD GBS study conducted in six academic
centers from 1995 to 1999 showed that 8.8% of GBS colonized newborns greater than or equal to
32 weeks gestation had signs of respiratory distress as compared to 1-3% observed in general
newborn populations, and that beta-lactam use during labor was associated with 2.62 fold
increase in respiratory distress in the colonized newborns. These findings support the
association of neonatal respiratory distress with GBS colonization and with penicillin use
during labor. These data however require confirmation.
We now plan to conduct a prospective study to relate the levels of serum bacterial
phospholipids to the occurrence of respiratory distress in newborns of mother colonized GBS.
This study will also evaluate the effect of beta-lactam use during labor on the release of
phospholipids and therefore the occurrence of respiratory distress in newborns of mothers
colonized with GBS. The study will be conducted at the Baylor College of Medicine and Oakland
Children s Hospital and Research Center. Serum phospholipid levels will be measured in
newborns with respiratory distress, newborns of mothers colonized by GBS, treated or
untreated with beta-lactam during labor.
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