Influence of previous reproductive history on low birth weight infants

Abstract

Objective To explore the influence of previous reproductive history on low birth weight (LBW) infants. Methods From February 2009 to December 2010, a total of 375 hospitalized LBW infants were included in the study as LBW group(n=375). Meanwhile 5 157 normal birth weight infants in the same hospital were chosen as control group (n=5 157). The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Gansu Provincial Maternity and Child-care Hospital.Informed consent was obtained from each participants' parents.The effects of the pregnancy previous reproductive history were compared between two groups. Results ①The gravidity(gravidity≥1, OR=1.46, 95%CI: 1.18-1.81; gravidity≥2, OR=1.80, 95%CI: 1.40-2.32), parity(parity=1, OR=1.65, 95%CI: 1.29-2.11; parity≥2, OR=2.68, 95%CI: 1.71-4.20), multiple spontaneous abortion history (OR=2.70 95%CI: 1.67-4.35), previous delivery history of preterm infants (OR=6.31, 95%CI: 2.86-13.97) and LBW infants(OR=4.62, 95%CI: 1.48-14.40), adverse pregnancy history(OR=3.26, 95%CI: 2.07-5.14) were risk factors of LBW. The multiple spontaneous abortion history (aOR=1.08, 95%CI: 0.49-2.39), previous delivery history of preterm infants (aOR=1.00, 95%CI: 0.31-3.19) and adverse pregnancy history(aOR=1.5; 95%CI: 0.64-3.55) were the independent risk factors of LBW. ②The gravidity, parity, spontaneous abortion history, previous delivery history of preterm infants and adverse pregnancy history were the risk factors of preterm infants with LBW (OR=1.72, 95%CI: 1.34-2.20; OR=1.99, 95%CI: 1.54-2.58; OR=1.80, 95%CI: 1.30-2.50; OR=8.32, 95%CI: 3.75-18.43; OR=3.57, 95%CI: 2.18-5.85). The independent risk factors of term infants with LBW was previous delivery history of LBW infants(aOR=7.93, 95%CI: 1.72-36.46). Conclusions The occurrence of LBW infants had strong relationship with the previous reproductive history of their mother, such as gravidity, parity, mutiple spontaneous abortion history, previous delivery history of LBW infants, and had little relationship with spontaneous abortion history, previous delivery history of preterm infants, adverse pregnancy.The woman who had risk factors of LBW is pregnant again, should do well in pregnancy, prenatal care services, in order to effectively reduce the occurrence of LBW. Key words: Low birth weight infant; Reproductive history; Case-control studies; Logistic regression