Trial Complete



prospective practical evaluation of intrapartum screening for maternal GBS carriage


Principal Investigator – Dr. Maeve Eogan


Women, men and children of all ages can be colonized with Group B streptococcus (GBS) bacteria without having any symptoms. GBS is particularly found in the gastrointestinal tract (‘gut’), vagina and urethra (‘water passage’). GBS occurs in both developed and developing countries. Between 1 in every 5-10 pregnant women carry this bacterium and, unfortunately, a small number of their babies will become unwell. Between 0.5 and 3 newborn babies in every 1000 develop GBS bacterial infections, usually evident as respiratory disease, general sepsis, or meningitis within the first week.

This can have devastating effects on the baby, including cerebral palsy and death so anything we can do to reduce this incidence must be explored. Because the baby contracts the infection from the mother during labour, giving the mother an antibiotic directly into a vein during labour causes bacterial counts to fall rapidly and reduces the incidence of severe disease in the baby. The crux of the issue, however, is who should receive these antibiotics, and this pilot study aims to tease that out further, with a view to changing how we decide which women need antibiotics in labour.

  • It is not appropriate to routinely give antibiotics to all pregnant women at the start of labour.
  • Therefore, many countries screen all pregnant women for GBS late in pregnancy, the problem with this is that GBS carriage can be transient or intermittent – so a woman can screen positive at 37 weeks but be negative at delivery or vice versa.
  • In other countries (including Ireland and UK) therefore, a risk based approach is adopted. Women who have risk factors for GBS disease are treated with antibiotics during labour – risk factors include the following: mothers who have previously had a baby with GBS infection, mothers who have GBS detected on a urine or vaginal swab sample, mothers with high temperature in labour, mothers who’s waters have broken for more than 18 hours. This strategy does not however prevent all GBS infections as some affected babies will be born to mothers without any of these risk factors.

Very few of the women in labour who are GBS positive give birth to babies who are infected with GBS, and antibiotics can have harmful effects such as severe maternal allergic reactions, increase in drug-resistant organisms and exposure of newborn infants to resistant bacteria, and postnatal maternal and neonatal yeast infections.

Therefore, here at the Rotunda we are undertaking a study assessing whether it is feasible and effective use a rapid test to screen all women for GBS at onset of labour and whether such a strategy would better inform who should receive antibiotics and thus improve maternal and fetal outcomes.