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| Oligohydramnios |
Oligohydromnios in Pregnancy
Amniotic fluid is a fluid which surrounds the baby in the uterus. Oligohydramnios is defined as decreased
amniotic fluid . Oligohydramnios is a frequent finding in pregnancies
involving intrauterine growth restriction and is most likely secondary to
decreased fetal blood volume, renal blood flow and subsequently fetal urine
output
Causes
Fetal causes:
- Chromosomal factors
- Congenital factors (renal agenesis, polycystic kidney)
- Intrauterine growth restriction
- Premature rupture of membranes
- Abruption
- Twin-to-twin transfusion syndrome (monochorionic twins)
Maternal causes include:
- Maternal dehydration
- Uteroplacental deficiency
- pre-existing Diabetes
- gestational diabetes
- Chronic hypoxia
- Hypertension
- Pre-eclampsia
- Lupus
Drug-induced: indometacin and angiotensin-converting enzyme (ACE) inhibitors.
- Unknown
- Premature birth of baby (delivery of baby before 37 weeks)
- Miscarriage
- Death of baby inside the womb or shortly after birth
- Increased risk of fetal infection
- Pulmonary hypoplasia
- Fetal compression syndrome
- Amniotic band syndrome
- Caesarian delivery
Prognosis
Fetal
mortality rates reported as high as 80-90%
Investigations
Oligo
hydramnios is confirmed by Targeted Imaging for Fetal Anomalies (TIFFA) Scan
and Ultrasound scan
Treatment
- Providing oral or intravenous rehydration has been shown to increase the AFV by 30%. The hydration may include sodium chloride and aminoacids
- Ringer's lactate solution or sodium chloride is infused under ultrasound guidance via a needle inserted through the uterine wall.
Management
Before term:
- Ongoing antepartum surveillance (including assessment of fetal growth and follow-up monitoring of AFV) is necessary.
- Continuous fetal heart rate monitoring during labour has been advocated for all pregnancies complicated by oligohydramnios.
During term:
- Delivery is often the most suitable management.
- With encouraging fetal testing, delivery may be safely delayed on the base of the parity, the gestational age, the inducibility of the mother's cervix and the severity of the oligohydramnios.
