Importância da estimativa ultrassonográfica de peso fetal para macrossomia na Maternidade Escola da Universidade Federal do Rio de Janeiro

Abstract

Purpose: Verify the role of ultrasonography (US) in the diagnosis of fetal macrosomia. Methods: Cross-sectional and retrospective study realized in Maternity School of Rio de Janeiro Federal University in the period from January 1, 2011 to September 30, 2012. Women undergoing cesarean section for macrosomia fetal indication, which made the US in the institution up to seven days before delivery, were all included. Patients with multiple pregnancies, fetuses with changes in the morphology and stillbirths were all excluded. The variables studied were: maternal diabetes, parity, gestational age at delivery, estimated fetal weight (EFW) in the US, the presence of oligohydramnios, indications of cesarean delivery, birthweight. The test was considered concordant when the margin of error was plus or minus 10%. Data were stored in Microsoft Excel and analyzed using STATA version 8.0. To analyze the association between qualitative variables, we used the Fisher exact test and statistical significance was assumed when p <0.05. Results: The final sample was composed of 139 cases. Gestational mean age was 40 weeks and 2 days. Sixtysix (34.7%) patients were primiparous and 124 (65.3%) multigravidae. There was agreement between EFW obtained by US and birth weight in 106 cases (76.25%). In the other 33 exams (23.75%) the variation was greater than 10% (non-concordant tests). Among the non-concordant tests (n=33) it was observed that, despite the variation in weight estimated by US and birth weight was greater than 10% in 10 cases, newborns were actually macrosomic. The others 23 were newborns weighing less than 4000g for which overestimate weight. Of this group, 15 cases had the indication of cesarean exclusively by suspected fetal macrosomia and in 8 cases other indications for surgery. Of the total sample, 13 (9.35%) patients had a diagnosis of diabetes (of any type). Reported the presence of oligodramia in 4 (12.1%) of 33 cases of non-concordant tests. There was no significant association between diabetes (p = 0.49), gestational age greater than or equal to 41 weeks (p = 0.91) and presence of oligohydramnios (p = 0.47) and examinations concordant or non-concordant. Conclusions: The agreement between the US and the EFW fetal weight at birth was 76.25%. There was no significant association between diabetes, gestational age greater than or equal to 41 weeks and oligohydramnios and examinations consistent/not consistent. Of the tests considered accurate (n=106) only 48 (45.28%) infants had weight greater than or equal to 4000g. That is, there was indication of caesarean mistaken for fetal macrosomia in 58 of these cases (54.72%).