Prevalence and risk factors of bacterial vaginosis during the first trimester of pregnancy in a large French population-based study D. Desseauve a,b,c, *, J. Chantrel c,e , A. Fruchart d,e , B. Khoshnood a,b,e , G. Brabant f,e , P.Y. Ancel a,b,e , D. Subtil a,b,c,e a INSERM, UMR S953, IFR 69, Unite ´ de Recherche Epide ´miologique en Sante ´ Pe ´rinatale et Sante ´ des Femmes et des Enfants, Hoˆpital Tenon, F-75020 Paris, France b UPMC Univ Paris 06, UMR S 953, F-75005 Paris, France c Ho ˆpital Jeanne de Flandre, Universite ´ Lille II, 1 rue Euge `ne Avine ´e, 59037 Lille Cedex, France d Laboratoire de Bacte ´riologie-Hygie `ne, Universite ´ Lille 2, 1 rue Euge `ne Avine ´e, 59037 Lille, France e Laboratoire de Bacte ´riologie, Centre Hospitalier, avenue Desandrouin, 59300 Valenciennes, France f Hoˆpital Saint Vincent, GHICL, 59046 Lille, France 1. Introduction Each year, 1 billion women have a urinary or lower genital tract infection, most frequently bacterial vaginosis (BV) [1], a modifica- tion of the vaginal flora that is associated with an increased risk of preterm delivery and spontaneous miscarriage during the first and second trimesters [2–4]. The nature of this association has not been clearly elucidated, but many authors suggest that preterm delivery results from bacteria ascending from the vagina to the membranes and amniotic fluid [5]. The earlier in pregnancy that this abnormal flora is discovered, the stronger the association between BV and preterm delivery appears to be [6]. Ascension of vaginal micro- organisms may thus occur as early as the first trimester. This implies that pregnant women should be tested for vaginosis as early as possible to prevent second trimester miscarriage or preterm delivery [7]. Recent investigations report a potential genetic susceptibility to lower genital tract infections [8]. The frequency of BV in low-risk pregnant women, i.e., those with no history of preterm delivery, aged between 25 and 29 years, is not well known. Studies in the US estimate the frequency of BV at 16–39% [9,3,10–14]. The reported frequency appears lower in Europe, ranging from 1.6% to 28% [15–28]. Most of these studies, however, were conducted in highly selected samples, e.g., patients undergoing in vitro fertilization or with threatened preterm delivery, or they used non-standard tests to diagnose BV, i.e., Amsel’s clinical criteria [9,24] or Pap smears [18]. European Journal of Obstetrics & Gynecology and Reproductive Biology xxx (2012) xxx–xxx * Corresponding author at: INSERM U953 Ba ˆtiment Recherche Ho ˆpital Tenon, 4, Rue de la Chine, 75020 Paris, France. Tel.: +33 01 42 34 55 70; fax: +33 01 43 26 89 79. E-mail address: desseauve.d@gmail.com (D. Desseauve). A R T I C L E I N F O Article history: Received 14 May 2011 Received in revised form 14 December 2011 Accepted 5 April 2012 Keywords: Population-based study Prevalence Risk factor Bacterial vaginosis A B S T R A C T Objectives: Bacterial vaginosis is a risk factor for preterm delivery. Its prevalence and risk factors in Europe are not well known. Our objective was to assess both in early pregnancy. Study design: As part of the PREMEVA randomized controlled trial, this population-based study included 14,193 women screened before 14 weeks’ gestation for bacterial vaginosis in the 160 laboratories of the Nord-Pas-de-Calais region in France. Bacterial vaginosis was defined by a Nugent score  7. Data were collected about maternal tobacco use, age, education, and history of preterm birth. We estimated the prevalence of bacterial vaginosis and used a multilevel logistic regression model to identify significant risk factors for it. Results: Among the 14,193 women assessed before 14 weeks’ gestation, the prevalence of bacterial vaginosis was 7.1% (95% CI: 6.6–7.5%). In the multivariate analysis, smoking during pregnancy tobacco (adjusted OR: 1.38; 95% CI: 1.19–1.60), maternal age 18–19 years (adjusted OR: 1.40; 95% CI: 1.01–1.93), and educational level (completed only primary school: adjusted OR: 1.77; 95% CI: 1.35–2.31; completed only secondary school: adjusted OR: 1.27; 95% CI: 1.10–1.48) were independent risk factors for bacterial vaginosis. History of preterm delivery was not an independent risk factor of bacterial vaginosis: adjusted OR: 1.15; 95% CI: 0.90–1.47. Conclusion: In a large sample of women in their first trimester of pregnancy in France, the prevalence of bacterial vaginosis was lower than rates reported in other countries, but risk factors were similar: young age, low level of education, and tobacco use during pregnancy. These results should be considered in future strategies to reduce preterm delivery. ß 2012 Elsevier Ireland Ltd. All rights reserved. G Model EURO-7689; No. of Pages 5 Please cite this article in press as: Desseauve D, et al. Prevalence and risk factors of bacterial vaginosis during the first trimester of pregnancy in a large French population-based study. Eur J Obstet Gynecol (2012), http://dx.doi.org/10.1016/j.ejogrb.2012.04.007 Contents lists available at SciVerse ScienceDirect European Journal of Obstetrics & Gynecology and Reproductive Biology jou r nal h o mep ag e: w ww .elsevier .co m /loc ate/ejo g rb 0301-2115/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ejogrb.2012.04.007