Sexual intercourse association with asymptomatic bacterial vaginosis and Trichomonas vaginalis treatment in relationship to preterm birth.
OBJECTIVE
The purpose of this study was to determine whether sexual intercourse was associated with the treatment efficacy or the incidence of preterm birth in two large randomized trials in which metronidazole treatment of bacterial vaginosis or Trichomonas vaginalis did not reduce preterm birth.


METHODS
Secondary analysis of two multicenter, double-blind, placebo-controlled trials in which women with asymptomatic bacterial vaginosis on Gram stain or asymptomatic T vaginalis on culture were randomized at 16 to 23 weeks of gestation to metronidazole or placebo. In both studies, women took 2 g of metronidazole or placebo in the presence of a nurse (first dose) and were given a second dose to take 48 hours later. This regimen was repeated (third and fourth doses) at 24 to 29 weeks. At the time of the third dose, bacterial vaginosis and T vaginalis specimens were collected again. Patients who were randomly selected to receive metronidazole were analyzed for bacterial vaginosis and T vaginalis at 24 to 29 weeks and for preterm birth of <37 weeks of gestation, according to intercourse between first and second doses and between the second and third doses. Continuous variables were compared with the use of the Wilcoxon rank-sum test; categoric variables were compared with the use of the chi(2 ) test, Fisher exact test, or the Mantel-Haenzel test of trend.


RESULTS
Sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of bacterial vaginosis (18% vs 24%; relative risk, 0.7; 95% CI, 0.5-1.1; and 23% vs 20%; relative risk, 1.2; 95% CI, 0.9-1.6, respectively) or T vaginalis (4% vs 8%; relative risk, 0.5; 95% CI, 0.1-3.6; and 5% vs 10%; relative risk, 0.5; 95% CI, 0.2-1.1; respectively) at 24 to 29 weeks of gestation compared with no intercourse. In the T vaginalis trial, sexual intercourse between the first and second doses or between the second and third doses did not influence the incidence of preterm birth (13% vs 17%; relative risk, 0.8; 95% CI, 0.3-2.1; and 16% vs 17%; relative risk, 1.0; 95% CI, 0.6-1.6; respectively) compared with no intercourse. In the bacterial vaginosis trial, although sexual intercourse between the first and second doses did not influence the incidence of preterm birth (11% vs 12%; relative risk, 0.9; 95 % CI, 0.6-1.5), sexual intercourse between the second and third doses was associated with a reduction in the incidence of preterm birth (10% vs 16%; relative risk, 0.6; 95% CI, 0.4-0.9) compared with no intercourse.


CONCLUSIONS
Sexual intercourse was associated with neither the efficacy of metronidazole treatment of bacterial vaginosis or T vaginalis nor with the incidence of preterm birth. In the bacterial vaginosis study, intercourse between the second and third doses had a negative association with preterm birth.
Berghella
Vincenzo
V
Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA, USA.
Klebanoff
Mark
M
McPherson
Cora
C
Carey
J Christopher
JC
Hauth
John C
JC
Ernest
J M
JM
Heine
R Phillip
RP
Wapner
Ronald J
RJ
Trout
Wayne
W
Moawad
Atef
A
Leveno
Kenneth J
KJ
Miodovnik
Menachem
M
Sibai
Baha M
BM
Van Dorsten
J Peter
JP
Dombrowski
Mitchell P
MP
O'Sullivan
Mary J
MJ
Varner
Michael
M
Langer
Oded
O
D001741:Black or African American / Q000706:statistics & numerical data; D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use; D003075:Coitus; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use; D015337:Multicenter Studies as Topic; D007752:Obstetric Labor, Premature / Q000208:ethnology / Q000382:microbiology* / Q000469:parasitology*; D011247:Pregnancy; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D014245:Trichomonas Infections / Q000150:complications* / Q000208:ethnology / Q000209:etiology; D014246:Trichomonas vaginalis; D016585:Vaginosis, Bacterial / Q000150:complications* / Q000188:drug therapy / Q000208:ethnology / Q000209:etiology; D044465:White People / Q000706:statistics & numerical data
D000890:Anti-Infective Agents; D008795:Metronidazole