Relações entre a espessura placentária medida pela ecografia antenatal e pela macroscopia após o nascimento, e resultados perinatais

Abstract

Introduction: The measurement of placental thickness can constitute an important clinical marker for newborns prediction affected by the restriction of uteroplacental blood flow. With a simple and inexpensive technique after birth, and with ultrasonographic findings obtained previously during pregnancy, it adds up an inexpensive and effective method in perinatal propaedeutics, adding greater security in the management of these high-pregnant women risk suffering from hypertension, diabetes mellitus and intrauterine growth restriction (IUGR). Objectives: To study the placental thickness in low-risk pregnant women and women with hypertensive syndromes of pregnancies, IUGR and diabetes mellitus; search for possible associations between placental thickness diagnosed by prenatal ultrasonography and immediately after birth; seek possible association between placental thickness and perinatal outcomes. Methodology: Cross-sectional, prospective, observational study of a group of pregnant women with hypertension, diabetes mellitus and intrauterine growth restriction to be compared to a control group. Such a study was carried out between the months of October 2013 and February 2015. The first group consisted of pregnant women with gestational diabetes mellitus, the second group consisted of pregnant women with hypertensive disorders of pregnancy, the third group consisted of pregnant women with IUGR and the fourth group, of low-risk pregnant women. During the hospitalization of the patient, six measures of placental thickness were performed by ultrasound examination. The placentas were examined macroscopically right after birth, to evaluated the placental thickness, performing five cuts transversely. With a total of six slices, the thickness measurement was performed with a digital equipment at the center point of each slice. Results: Total sample of this study consisted of 83 patients, 30 healthy patients with low-risk pregnancy, 20 women with hypertensive disorders of pregnancy, 17 with diabetes and 16 women with intrauterine growth restriction, and of these, eight had also pre-eclampsia associated with. Evaluating the correlation between measures of placental thickness of each slice, mesuared by ultrasound and macroscopic examination, there was a significant but weak correlation between the first (r = 0,26; p = 0,02) and sixth (r = 0,28; p<0,01) slices and a significant and moderate correlation between the third (r = 0,33; p = 0,02), fourth (r = 0,41; p<0,0001) and fifth (r = 0,38; p<0,0001) slices. As to the correlation between the average thickness at the macroscopic to the average thickness at ultrasound, separeted by groups, there was a significant correlation in the IUGR group (r = 0,60; p<0,05). Conclusions: measures of placental thickness evaluated by antepartum ultrasound and macroscopic examination of the placenta after birth, have a positive and significant correlation, regardless of the diseases of pregnant women prior or during pregnancy; there was no correlation between the average thickness of the placenta in postpartum measures with the average thickness of the antepartum ultrasound measures in groups of BXR, SHG and DM, but there was moderate correlation in the IUGR group; the division of the placenta into slices both ultrasound examination as at the macroscopic examination after delivery showed a low but significant correlation between the third slices and a positive and significant correlation between the first, third, fourth, fifth and sixth slices between the methods of measurement. There was no correlation between the measurements of placental thickness antenatal or postnatal with perinatal outcomes. By the findings of this study, it is recommended that the placental thickness measurement by ultrasound should be performed in the center of the placental disk, corresponding to the third or fourth slice.