Health Problems during Pregnancy

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:

1. Chromosomal factors
2. Congenital factors (renal agenesis, polycystic kidney)
3. Intrauterine growth restriction
4. Premature rupture of membranes

Placental causes:

1. Abruption
2. Twin-to-twin transfusion syndrome (monochorionic twins)

Maternal causes include:

1. Maternal dehydration
2. Uteroplacental deficiency
3. pre-existing Diabetes
4. gestational diabetes
5. Chronic hypoxia
6. Hypertension
7. Pre-eclampsia
8. Lupus

Drug-induced: indometacin and angiotensin-converting enzyme (ACE) inhibitors.

1. Unknown

Complications

1. Premature birth of baby (delivery of baby before 37 weeks)
2. Miscarriage
3. Death of baby inside the womb or shortly after birth
4. Increased risk of fetal infection
5. Pulmonary hypoplasia
6. Fetal compression syndrome
7. Amniotic band syndrome
8. 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

1. Providing oral or intravenous rehydration has been shown to increase the AFV by 30%. The hydration may include sodium chloride and aminoacids
2. Ringer's lactate solution or sodium chloride is infused under ultrasound guidance via a needle inserted through the uterine wall.

Management

Before term:

1. Ongoing antepartum surveillance (including assessment of fetal growth and follow-up monitoring of AFV) is necessary.
2. Continuous fetal heart rate monitoring during labour has been advocated for all pregnancies complicated by oligohydramnios.

During term:

1. Delivery is often the most suitable management.
2. 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.