Effect of psychic factors on onset of parturition and its mechanism

Objective To study the effect of psychic factors on parturition of primiparae and its possible mechanism. Methods Primiparae admitted to our hospital were divided into late pregnancy group and premature labor group（n=37 each）.Their psychic factors were evaluated with a SCL-90 scale.Three ml of venous blood was collected 1h（phase1） after parturient and 24h（phase 2） after parturition,respectively,for the measurement of plasma corticotrophin releasing hormone（CRH） and COX-2 levels by radioimmunoaasay and ELISA. Results No significant difference was found in psychic factors between the late pregnancy group and the preterm group（P＞0.05）.The levels of plasma CRH（258±45μg/L and 250±39μg/L） and COX-2（6.5±3.8ng/ml and 6.0±3.8 ng/ml） were significantly higher than their fundamental levels（P＜0.05）.Anxiety and phobia emotion were significantly related with the plasma level of CRH and COX-2 in the third trimester of pregnancy（r=-0.403 and-0.399,r=-0.357 and-0.423,P＜0.05）. Conclusion Anxiety and phobia emotion can increase the CRH level in placenta,leading to elevation of plasma COX-2 level which participates in onset of parturition.