Brazilian multicentre study on preterm birth (EMIP): prevalence and factors associated with spontaneous preterm birth.

Abstract

BACKGROUND:

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.

METHODS AND FINDINGS:

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.

CONCLUSIONS:

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.

• Authors: Renato Passini Jr, Jose G Cecatti, Giuliane J Lajos, Ricardo P Tedesco, Marcelo L Nomura, Tabata Z Dias, Samira M Haddad, Patricia M Rehder, Rodolfo C Pacagnella, Maria L Costa, Maria H Sousa, Brazilian Multicentre Study on Preterm Birth study group
• Journal: PloS one (PLoS One) Vol. 9 Issue 10 Pg. e109069 ( 2014) ISSN: 1932-6203 [Electronic] United States
• PMID: 25299699 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)

Topics

• Abortion, Induced (adverse effects)
• Adult
• Brazil (epidemiology)
• Cross-Sectional Studies
• Delivery, Obstetric (adverse effects)
• Female
• Humans
• Infant, Newborn
• Pregnancy
• Pregnancy Complications (physiopathology)
• Pregnancy, Multiple (physiology)
• Premature Birth (epidemiology, etiology)
• Prevalence
• Risk
• Risk Factors
• Weight Gain (physiology)
• Young Adult