PLACENTAL HEAT-SHOCK PROTEINS - NO IMMUNOHISTOCHEMICAL EVIDENCE FOR ADIFFERENTIAL STRESS-RESPONSE IN PRETERM LABOR

The aetiology of idiopathic preterm labour remains obscure. The hypoth esis that a stress response induced by low-grade bacterial infection i n utero-placental tissues was investigated. Distribution of cognate an d inducible isoforms of heat shock proteins (HSP) 70 kD, HSP 60 kD and HSP 90 kD were investigated in an immunohistochemical study of placen tal and decidual tissues before and after labour at varying gestations . Subjects were pregnant women undergoing singleton delivery after idi opathic preterm labour at less than 34 weeks' gestation (n = 23); spon taneous term labour at 37-42 weeks' gestation (n = 24); preterm caesar ean sections at less than 34 weeks' gestation for preeclampsia or intr auterine growth retardation (n = 14); elective caesarean section at 37 -42 weeks' gestation for cephalopelvic disproportion (n = 6). HSP expr ession was constant throughout the third trimester of pregnancy and di d not change following the onset of labour, regardless of gestational age. A stress response in decidual tissues as determined by immunohist ochemical analysis is apparently not associated with preterm labour.