Predictors of miscarriage: a matched case-control study / 한국역학회지

OBJECTIVES: The risk factors for miscarriage vary across communities and countries. This study was conducted to investigate the predictors of miscarriage in the west of Iran. METHODS: This matched case-control study was conducted in Hamadan Province from April 2013 to March 2014. Cases were selected from women who had a recent spontaneous abortion and controls were selected from women who had a recent live birth. Two controls were selected for every case and matched for date of pregnancy and area of residence. Multivariate conditional logistic regression analysis was performed and odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: Five hundred fifty cases were compared with 1,091 controls. The OR of miscarriage was 1.58 (95% CI=1.30-1.92) for every five-year increase in age, 0.20 (95% CI=0.14-0.28) for every live birth, and 3.43 (95% CI=2.03-5.79) for a history of previous spontaneous abortion. Compared to nulliparous women, primiparous or multiparous women had an OR of 17.85 (95% CI=6.65-47.91) for miscarriage. There was a strong association between miscarriage and abnormal amniotic status (OR, 2.46; 95% CI, 0.46-13.09) and also abnormal placenta status (OR, 10.44; 95% CI, 0.95-114.92); however, these associations were not statistically significant. No significant associations were observed between miscarriage and body mass index, previous history of stillbirth, low birth weight, congenital anomaly, ectopic pregnancy, impaired thyroid function, or high blood pressure. CONCLUSIONS: Our study suggests that miscarriage is a multifactorial outcome associated with several modifiable and non-modifiable risk factors that may vary among different communities.

Risk factors for maternal mortality in the west of Iran: a nested case-control study / 한국역학회지

OBJECTIVES: With a gradual decline in maternal mortality in recent years in Iran, this study was conducted to identify the remaining risk factors for maternal death. METHODS: This 8-year nested case-control study was conducted in Hamadan Province, in the west of Iran, from April 2006 to March 2014. It included 185 women (37 cases and 148 controls). All maternal deaths that occurred during the study period were considered cases. For every case, four women with a live birth were selected as controls from the same area and date. Conditional logistic regression analysis was performed and the odds ratio (OR) and its 95% confidence interval (CI) were obtained for each risk factor. RESULTS: The majority of cases were aged 20-34 years, died in hospital, and lived in urban areas. The most common causes of death were bleeding, systemic disease, infection, and pre-eclampsia. The OR estimate of maternal death was 8.48 (95% CI=1.26-56.99) for advanced maternal age (> or =35 years); 2.10 (95% CI=0.07-65.43) for underweight and 10.99 (95% CI=1.65-73.22) for overweight or obese women compared to those with normal weight; 1.56 (95% CI=1.08-2.25) for every unit increase in gravidity compared to those with one gravidity; 1.73 (95% CI=0.34-8.88) for preterm labors compared to term labors; and 17.54 (95% CI= 2.71-113.42) for women with systemic diseases. CONCLUSIONS: According to our results, advanced maternal age, abnormal body mass index, multiple gravidity, preterm labor, and systemic disease were the main risk factors for maternal death. However, more evidence based on large cohort studies in different settings is required to confirm our results.