Obstetricians' attitudes towards ‘isolated’ oligohydramnios at term

Abstract

Oligohydramnios at term in the absence of maternal and fetal complications poses a dilemma in management. It is one of the major indications for antenatal surveillance and induction of labour. There is a growing body of evidence that oligohydramnios in the absence of maternal or fetal risk factors ('isolated' oligohydramnios) is not associated with an adverse perinatal outcome. In this study, we surveyed the management of isolated oligohydramnios at term in a tertiary referral maternity unit. Out of 92 women who were scanned at term, 22 (24%) women had isolated oligohydramnios. A greater tendency to intervene in such cases was noted with 10 (45%) women having labour induced, while one (4.5%) had an elective caesarean section. Emergency caesarean section rates were also higher in the oligohydramnios group (13.5%) than in a low risk group (6%). There was no increased perinatal morbidity when compared with pregnancies managed expectantly.

Oligohydramnios and Fetal Outcome: A Review

“…Higher rate of isolated oligohydramnios (24%) was detected in a study in term 8 and this is double incidence as compared to other studies. [5][6][7] The AFV of 135 women was evaluated between 70 women (52%) in the upper greater group that was established by AFI and 65 women (48%) in the lower greater AFI group.…”

“…IUGR, spontaneous rupture of membrane, diabetes, pre-eclampsia or severe maternal systemic diseases. 8 In a study by Chhabra, Dargan and Bawaskar; the overall labour induction during the study period of the retrospective cases was 18.2% but in oligohydramnios, it was 66.1%. The C/S rate in the retrospective cases with spontaneous labor was 42.4% and with induced labor it was 38.5%.…”

“…8 The incidence is high in laboring women, largely due to rupture of fetal membranes during or just before labor. 9 A prospective study conducted at University of Texas Southwestern Medical Center showed the incidence of oligohydramnios to be 2.3%.…”

Management of severe oligohydramnios with antepartum transabdominal amnioinfusion

“…Fetuses in these cases tend to be appropriately sized at the diagnosis of isolated oligohydramnios and their perinatal outcomes are similar to those of pregnancies with a normal AFV 69 . The occurrence of such isolated oligohydramnios is more frequent at term 49,68,99 , which can be an additive factor toward a better outcome. .…”

“…On the other hand, the association between oligohydramnios and neonatal acidosis has not been sufficiently demonstrated; the observed adverse perinatal outcome results can be explained by the unnecessarily aggressive obstetrical management in the case of a reduced AF 59,62 . Other authors have found oligohydramnios to be a significant risk factor for an adverse perinatal outcome only in the presence of intrauterine growth retardation (IUGR) 66,67 , while isolated oligohydramnios in the third trimester does not seem to involve a risk of perinatal morbidity 68,69 .…”