Effect of early oral clindamycin on late miscarriage and preterm delivery in asymptomatic women with abnormal vaginal flora and bacterial vaginosis: a randomised controlled trial.
BACKGROUND
Abnormal vaginal flora and bacterial vaginosis are associated with amplified risks of late miscarriage and spontaneous preterm delivery. We aimed to establish whether antibiotic treatment early in the second trimester might reduce these risks in a general obstetric population.


METHODS
We screened 6120 pregnant women attending hospital for their first antenatal visit--who were at 12-22 weeks' gestation (mean 15.6 weeks)--for bacterial vaginosis or abnormal vaginal flora. We used gram-stained slides of vaginal smears to diagnose abnormal vaginal flora or bacterial vaginosis, in accordance with Nugent's criteria. We randomly allocated 494 women with one of these signs to receive either clindamycin 300 mg or placebo orally twice daily for 5 days. Primary endpoints were spontaneous preterm delivery (birth > or =24 but <37 weeks) and late miscarriage (pregnancy loss > or =13 but <24 weeks). Analysis was intention to treat.


RESULTS
Nine women were lost to follow-up or had elective termination. Thus, we analysed 485 women with complete outcome data. Women receiving clindamycin had significantly fewer miscarriages or preterm deliveries (13/244) than did those in the placebo group (38/241; percentage difference 10.4%, 95% CI 5.0-15.8, p=0.0003). Clindamycin also reduced adverse outcomes across the range of abnormal Nugent scores, with maximum effect in women with the highest Nugent score of 10.


CONCLUSIONS
Treatment of asymptomatic abnormal vaginal flora and bacterial vaginosis with oral clindamycin early in the second trimester significantly reduces the rate of late miscarriage and spontaneous preterm birth in a general obstetric population.
Ugwumadu
Austin
A
Department of Obstetrics and Gynaecology, St George's Hospital, Blackshaw Road, SW17 0QT, London, UK. augwumad@sghms.ac.uk
Manyonda
Isaac
I
Reid
Fiona
F
Hay
Phillip
P
D000022:Abortion, Spontaneous / Q000209:etiology / Q000517:prevention & control*; D000284:Administration, Oral; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002981:Clindamycin / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007752:Obstetric Labor, Premature / Q000209:etiology / Q000517:prevention & control*; D011247:Pregnancy; D011256:Pregnancy Outcome; D014626:Vaginal Smears; D016585:Vaginosis, Bacterial / Q000150:complications / Q000188:drug therapy
D000900:Anti-Bacterial Agents; D002981:Clindamycin