Pregnancy disorders that lead to delivery before the 28th week of gestation: and epidemiologic approach to classification

T F McElrath, J L Hecht, O Dammann, K Boggess, A Onderdonk, G Markenson, M Harper, E Delpapa, E N Allred, A Leviton, ELGAN Study Investigators

Am J Epidemiol 2008;168:980-9

PubMed Link

We enrolled 1,006 women who delivered a liveborn singleton ELGAN infants. Each delivery classified by presentation: preterm labor (40%), prelabor premature rupture of membranes (23%), preeclampsia (18%), placental abruption (11%), cervical incompetence (5%), and fetal indication/intrauterine growth restriction (3%). Using factor analysis, the authors found 2 broad patterns. One pattern, characterized by histo chorioamnionitis and placental microbe recovery, was associated with preterm labor, prelabor PROM, placental abruption, and cervical insufficiency. The other, had paucity of orgs and inflammation but presence of histo features of abnl placentation, & ass’ed w/PET and IUGR. Preterm delivery disorders may be separated into two groups: those with intrauterine inflammation and those associated with aberrations of placentation.