Is Time of Ruptured Membranes A Risk Factor for Low Apgar? A Case-Control Study of Apgar Score Less Than Seven At Five Minutes in Term Pregnancy Accessing Many Variables

Abstract PURPOSE To search for maternal, labor related and fetal variables associated with low Apgar in the fifth minute in term pregnancy. METHODS Retrospective case-control study with term births in a public teaching hospital from 2013 to 2020. Cases were term births with Apgar score less than seven in the fifth minute, and controls, the next one or two births following a case, with Apgar of seven or more. Were excluded non cephalic presentations, multiples and malformations. We accessed 100 cases and 190 controls. We considered significant values of p < 0.05. RESULTS Were accessed 27 variables which could be risk factors, from which 12 were associated with the outcome. We found a protective effect of prelabor cesarean for the outcome, odds ratio (OR) 0.37, p=0.011. Consequently, we conducted two sets of analyses: in the whole group and in the group of laboring women. The values OR were in general greater in the group of laboring women, compared with the whole group. We conducted multivariate analysis within the group of women in labor. The variables which fitted best in the model were nulliparity, male sex of the fetus, less than six prenatal visits and abnormal cardiotocography; all remained significant. It was found an association of rupture of membranes more than 360 minutes with the outcome, even after controlling for duration of labor; adjusted OR 2.45, p=0.023. CONCLUSION Twelve variables were associated with the outcome. Prelabor cesarean had a protective effect. Time of ruptured membranes was associated with low Apgar.