A Study on Risk Factors of Preterm Delivery

Park, Sang Hwa; Kim, Eung Ik; Kim, Myung Hee; Park, Joong Shin; Jun, Jong Kwan; Kim, Seok Hyun

Abstract

In order to investigate the risk factors of preterm delivery, we reviewed 1,676 birth cases excluding still-birth and multiple birth delivered at Seoul National University Hospital in 1995. The logistic regression analysis was used to examine the relationship between preterm birth and risk factors. The distribution of birth weight showed 9.7 % in low birth weight(< 2.5 kg), and 4.8 % in macrosomia(>or= 4.0 kg). The rate of preterm delivery was 9.2 %(155/1,676). The incidence of preterm delivery in maternal ages under 25(15.6 %) and above 35(14.3 %) was higher than that in 25~34 years old(7.9 %). There was a significant association between preterm birth and previous history of preterm birth, spontaneous abortion and induced abortion. There was no association between preterm birth and fetal sex or birth order. The risk for preterm birth was higher in nulliparous women aged 35 or older(OR : 2.521, 95% CI : 1.387-4.584, p < 0.001). There was a significant increase in preterm birth in women with following risk factors : previous history of preterm birth(OR : 3.616, CI : 2.138 - 6.118, p < 0.0001), history of spontaneous abortion(OR : 1.861, CI : 1.296-2.671, p < 0.0001), irregular menstrual cycle (OR : 2.174, CI : 1.469 - 3.215, p < 0.0001), and previous history of pregnancy complications(OR : 5.296, CI : 3.709 - 7.561, p < 0.0001). There was no significant increase in preterm birth in women with history of induced abortion(OR : 1.250, CI : 0.830 - 1.881, p = 0.2846).