Applicability of fetal renal artery Doppler values in determining pregnancy outcome and type of delivery in idiopathic oligohydramnios and polyhydramnios pregnancies

Abstract

Aims: To investigate the relationship between fetal renal artery Doppler results and pregnancy outcomes in patients with idiopathic abnormal amniotic fluid indices. Material and method: A total of 110 patients without signs of fetal distress were included in the study: 31 idiopathic oligohydramnios and 29 idiopathic polyhydramnios pregnancies (study group) and 50 normal pregnancies (controls). Doppler investigation of the umbilical artery (UA), middle cerebral artery (MCA), fetal descendant thoracic aorta (DTA) and fetal renal artery (RA) was performed in all patients. Fetal RA resistive index (RI) and pulsatile index (PI) values were measured. Values pertaining to type of birth, newborn weight and APGAR scores were compared. Results: Average patient age, gravidity and week of pregnancy were 25±4, 1.6, and 37.4±1, respectively. There were no statistically significant differences between the groups as far as UA S/D, MCA S/D, DTA S/D, DTA RI, DTA PI, and RA S/D measurements were concerned. However, in the oligohydramnios group RA RI and RA PI values were significantly higher than the other two groups. Birth weight in the polyhydramnios group and cesarean section rate due to fetal distress in the oligohydramnios group were significantly higher. Conclusions: In the oligohydramnios group, without affecting fetal distress parameters, Doppler USG evaluation identified an increase in the RA resistance. Also in that group, cesarean rate due to fetal distress during labor was significantly higher than in the remaining two groups. Due to the predictive potential of values of fetal renal artery Doppler of fetal outcome further large sample-sized studies on the subject ought to be carried out.