Predição de parto prematuro pela biometria e dopplervelocimetria da glândula adrenal fetal em pacientes com sintomas de trabalho de parto prematuro

Abstract

Objectives: The purpose of this study is to evaluate the predicting capacity of the biometry of fetal adrenal gland in patients who are undergoing symptoms of premature labor and untouched membranes, and compare it with uterine collum measurement regarding such prediction. Methodology: A transverse kind of study was accomplished at the “Assis Chateubriand” Maternity School at the Federal University of Ceará from April 2014 to March 2015 on fifty-seven (57) patients consecutively hospitalized at the obstetrics section at pregnant age ranged from 24 to 36 weeks. Patients suffering from diabetes, hypertension, malformations or fetal-development restriction were excluded. Ultrasound was carried out on the first day of their hospitalization to measure the length of their uterine collum (transvaginal) as well as the biometry of their fetal adrenal gland. The main outcome variable was the time elapsed until the delivery itself, with a subclassification into two groups: the ones who had their delivery up to seven days or after the seventhy day. The significance level considered was p< 0,05. The Fisher – Exact test was used for nominal variables and the T-student or the Mann-Whitney Test for continuous variables. The ‘ROC’ curve was carried out to define cutoffs. Results: The prevalence of deliveries within seven days was 33,3% in the total population, and 32,6% in the subpopulation who had no previous history of premature delivery. When the general population was evaluated, no statistical difference concerning the fetal adrenal gland parameters was found. As for the subpopulation with no previous history of premature delivery (at low risk), there was a statistical difference regarding the depth, not only to its total and central component (fetal), but also to its relation (central/total). The cutoffs found measured 13,1mm, 7,7mm and 53,5mm, respectively. Sensibilities found (ranged from 71,4% to 76,9%) were to those presented by the uterine collum measurement; however, they were lower with regard to specificities (ranged from 55,2% and 69%) and accuracies (ranged from 60,5% to 72,1%). Conclusions: The depth of the adrenal gland is capable of predicting the delivery occurrence within seven days for patients with no history of premature delivery. Its predicting capacity was lower than the measurement of the uterine collum.