The management of isolated oligohydramnios (IO) in post/term pregnancies is controversial.
The aim of this paper was to review outcomes of term and post-term pregnancies with
IO versus normal amniotic fluid (AF) at labor assessment.
A search in PubMed, Medline, EMBASE, and reference lists was performed. Inclusion
criteria for articles selection: singleton pregnancy, definition of olgohydramnios
as AFI <5 cm, AF assessment at 37–42 gestational weeks. Exclusion criteria: fetal malformations,
preterm delivery, premature rupture of membranes, intrauterine growth restriction.
Perinatal outcomes were: obstetric intervention for non-reassuring fetal heart rate
(cesarean section, operative delivery), meconium-stained AF, Apgar score <7 at 5 min, umbilical artery pH <7.0, small for gestational age infants (SGA), admission
to neonatal intensive care unit (NICU) and perinatal death. Meta-analysis compared
outcomes of pregnancies with IO vs normal AF. Inter-studies heterogeneity was tested.
Pooled odds ratio (OR) and 95% confidence interval (95% CI) were calculated. Differences
between the two groups were considered significant if 95% CI did not encompass 1.
MOOSE guidelines were followed.
Four articles provided 679 (17.2%) cases with IO and 3264 (82.8%) with normal AF.
Obstetric interventions occurred more frequently in the IO than normal AF group (IO:
89/679, 13% vs normal; AF: 166/3354, 5%; OR: 2.30; 95% CI: 1.00–5.29). Meta-analysis
did not show differences with regard to meconium, Apgar, pH, SGA, NICU and perinatal
In term or post-term pregnancies, IO is associated with increased risk of obstetric
interventions but outcomes are similar to those of pregnancies with normal AF.