Multivariate analysis of risk factors for stillbirth in Leon, Mexico.

BACKGROUND: To identify sociodemographic and clinical risk factors for antenatal fetal death in a developing country setting. METHODS: A case-control study was carried out, including 753 women: 251 had a stillbirth (cases) and 502 had a healthy live birth (controls). Stillbirths were considered as antenatal fetal death after 21 weeks of gestation. Seventeen sociodemographic and clinical risk factors for stillbirth were analyzed. Statistical analysis. Student's t-test or the Mann-Whitney U-test for continuous data and the chi2-test or Fisher's exact test for categorical variables were used. Logistic regression analysis was used to find significant predictors for stillbirth. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. RESULTS: Three risk factors were significant in the logistic regression model: maternal age (OR 1.04, 95% CI 1.00-1.08), antenatal care (OR 0.1, 95% CI 0.0-0.2) and umbilical cord complication (OR 5.8, 95% CI 3.2-10.2). The whole model had a determination coefficient of 0.280, with a chi2-value of 246.2 (p < 0.001). CONCLUSIONS: In our setting antenatal care should be considered as the cornerstone in the prevention of stillbirth. With adequate antenatal care both women with advanced maternal age and umbilical cord complication could be identified. This finding could be useful for developing as well as developed country settings to avoid the occurrence of stillbirth.

[Risk factors for stillbirth]. / Factores de riesgo y muerte fetal anteparto.

BACKGROUND: Antenatal fetal death is one of the most devastating complications of pregnancy. OBJECTIVE: To identify socio-demographic and clinical risk factors for antenatal fetal death. MATERIAL AND METHODS: A case-control study was carried out. Five hundred women were included: Two hundred fifty patients had a stillbirth (cases) and 250 women had a healthy live birth (controls). Stillbirths were considered as antenatal fetal death after 20 weeks of gestation. Seventeen socio-demographic and clinical risk factors for stillbirth were analyzed. Statistical analysis included: Student t test or Mann-Whitney U test for continuous data, and Chi-square or Fisher exact test for categorical variables. Multiple logistic regression analysis (backward stepwise procedure) was used to find significant predictors for stillbirth. Odds ratio (OR) with 95% confidence intervals (95% CI) were calculated. It was set an Alfa level of 0.05. RESULTS: Six risk factors were significant in the final logistic regression model: Age (OR 1.07, 95% CI 1.03-1.1), smoking habits (OR 9.1, 95% CI 1.07-78.0), placental abruption (OR 51.9, 95% CI 6.8-393.9), cord entanglement (OR 5.0, 95% CI 2.5-9.7), nulliparity (OR 1.3, 95% CI 1.1-1.5) and antenatal care (OR 0.1, 95% CI 0.08-0.4). The whole model had a determination coefficient R2 = 0.234 (p < 0.001). CONCLUSIONS: We developed a predictive model for antepartum fetal death appropriate at our population. The six significant risk factors for stillbirth could be diagnosed early during pregnancy. The antenatal care could be considered the cornerstone for the prevention of antenatal fetal death.