Socio-economic, demographic and obstetric risk factors for late fetal death of unknown etiology in Lithuania: a case-referent study

Background. The purpose of this study was to evaluate the association betwe en third trimester unexplained prelabor fetal deaths and various socio-econ onmic, demographic and obstetric factors in Lithuania. Methods. A case-referent study on 58 women with third trimester fetal death and 116 women with live fetus at term was carried out. Inclusion criteria for women in the first group (cases) were: prelabor fetal death of unknown etiology, singleton pregnancy >26 weeks of gestation and intact fetal membr anes. For each case two referent women were recruited, admitted during the same period in active phase of labor at term (>37 weeks of gestation) with intact fetal membranes and fetus alive. Data were obtained by interview, an thropometry and by reviewing the medical records. Several potential socio-e conomic, demographic and obstetrical risk factors for unexplained fetal dea th were investigated. Results. Univariate analyses determined several factors that were associate d with fetal death of unknown etiology: low educational level, single marit al status, low income, etc. After secondary logistic regression analysis on ly three independent variables remained significantly associated with other wise unexplained stillbirth: small for gestational age fetus (OR 29.6; 95% CI 6.2-141.6), low income (OR 7.4; 95% CI 3.1-17.6), and maternal white blo od cell count more than 16,000/mm(3) (OR 5.4; 95% CI 1.4-21.6). Body mass i ndex, smoking, occupation of women and other evaluated parameters were not confirmed to be significant risk factors. Conclusion. Small for gestational age fetus, low income and elevated matern al white blood cell count are factors significantly associated with late pr elabor fetal death in Lithuania.