Brazilian multicentre study on preterm birth (EMIP) : prevalence and factors associated with spontaneous preterm birth
Passini, R.; Cecatti, J.G.; Lajos, G.J.; Tedesco, R.P.; Nomura, M.L.; Dias, T.Z.; Haddad, S.M.; Rehder, P.M.; Pacagnella, R.C.; Costa, M.L.; Sousa, M.H.; Cecatti, J.G.; Marba, S.T.; Zotareli, V.; Gurgel, L.T.; Feitosa, F.E.; Chaves, G.N.; Porto, A.M.; Coutinho, I.C.; Barbosa Lima, A.C.; Melo, E.F.; Leite, D.éb.F.; Amorim, M.M.; Melo, A.S.O.; Melo, F.O.; Martins, M.íl.G.; Nunes, M.V.; Paiva, C.áu.S.; Lima, M.D.; Freire, D.M.; Tristão, E.G.; Nascimento, D.J.; Souza, R.T.; Menezes, C.A.; Aquino
PLOS one 9(10): E109069
2014
ISSN/ISBN: 1932-6203 PMID: 25299699 DOI: 10.1371/journal.pone.0109069Document Number: 636719
Preterm birth rate is increasing and is currently a worldwide concern. The purpose of this study was to estimate the prevalence of preterm birth in a sample of health facilities in Brazil and to identify the main risk factors associated with spontaneous preterm births. This was a multicentre cross sectional study on preterm births in 20 referral obstetric hospitals with a case-control component to identify factors associated with spontaneous preterm birth. Surveillance was implemented at all centres to identify preterm births. For eligible consenting women, data were collected through a post-delivery questionnaire completed with information from all mother-newborn medical records until death or discharge or at a maximum of 60 days post-delivery, whichever came first. The risk of spontaneous preterm birth was estimated with OR and 95%CI for several predictors. A non-conditional logistic regression analysis was then performed to identify independently associated factors. The overall prevalence of preterm birth was 12.3%. Among them, 64.6% were spontaneous and 35.4% therapeutic. In the case-control component, 2,682 spontaneous preterm births were compared to a sample of 1,146 term births. Multivariate analyses identified the following as risk factors for spontaneous preterm birth among women with at least one previous birth: a previous preterm birth (ORadj = 3.19, 2.30-4.43), multiple pregnancy (ORadj = 29.06, 8.43-100.2), cervical insufficiency (ORadj = 2.93, 1.07-8.05), foetal malformation (ORadj = 2.63, 1.43-4.85), polyhydramnios (ORadj = 2.30, 1.17-4.54), vaginal bleeding (ORadj = 2.16, 1.50-3.11), and previous abortion (ORadj = 1.39, 1.08-1.78). High BMI (ORadj = 0.94, 0.91-0.97) and weight gain during gestation (ORadj = 0.92, 0.89-0.95) were found to be protective factors. The preterm birth rate in these health facilities in Brazil is high and spontaneous preterm births account for two thirds of them. A better understanding of the factors associated with spontaneous preterm birth is of utmost importance for planning effective measures to reduce the burden of its increasing rates.