Clinical and pathologic correlates of stillbirths in a single institution

Background. To evaluate risk factors, placental and pathologic determinants of stillbirths. Methods. A retrospective analysis of stillbirths ≤ 25 weeks was performed. Clinical data was compared to a randomized control group. Statistical analysis included chi square test, student t test, and logistic regression. Results. One hundred and fifteen stillbirths and 193 controls were analyzed. Maternal age, nulliparity, tobacco use, previous induced abortions, anticardiolipid antibodies, elevated maternal serum alpha feto protein, twins, and amniocentesis, were significantly associated with stillbirth. Logistic regression analysis showed only maternal age, tobacco use, small for gestational age (SGA), previous induced abortions, decreasing gestational age as independent significant variables. The stillbirth baby was 6.8 times more likely to be SGA and 11.9 times more likely to be preterm. Primary pathologic diagnoses were placental factors (37%), cord complications (28%), and fetal causes (15%), 17% had maternal risk factors only and 3% had no known risk factors. Diagnosis was suggested by pathology in 40% of cases. Conclusions. Stillbirth delivery is associated with older, nulliparous patients with prenatal complications resulting in intrauterine growth retardation and prematurity. Perinatal histopathologic examination is important in diagnosis. Utilizing an extensive testing protocol will reduce the diagnosis of unexplained stillbirth.