Oligohydramnios

Oligohydramnios

• Oligohydramnios is defined as decreased amniotic fluid volume (AFV) for gestational age.

• Isolated oligohydrominos is the presence of decreased liquor of an appropriate for gestational age , non compromised fetus with no maternal disease
• Causes :

In general  Oligohydramnios is caused by a reduction in production of fetal urine due to placental insufficiency, fetal renal anomalies or obstruction of urine flow; or because the urine that is produced, drains away due to ruptured amniotic membranes

• Maternal

- Medical conditions that cause utero-placental insufficiency (e.g., preeclampsia, chronic hypertension, collagen vascular disease, nephropathy, thrombophilia)

- Medication: as  ACE inhibitors

àFetal

o Chromosomal abnormalities

o Congenital abnormalities (renal agenesis )

o Growth restriction

o Fetal demise

o Post term pregnancy

o Ruptured fetal membranes

o Placental thrombosis

o Twin to twin transfusion

• Early oligohydrominous complications :

pulmonary hypoplasia , limb contrtactures , abnormal chest wall and lethal infection .

• Late oligohydrominous (in 3^rd trimester )complications

Fetal risks : stillbirth , neonatal death , fetal distress , low apgar score and neonatal complications

Maternal risks: failure of VBAC or ECV and increase risk of urgent cesarean section, and post partum sepsis

-Investigations :

Ultrasound to check on the fetal kidneys and urinary bladder and fetal measurments,  with umbilical artery Doppler to check for IUGR and placental flow

• Time of delivery :

-At gestational age >= 37 weeks Induction of labour should be considered. If not acceptable by the patient, after counselling, organise scans every week for liquor volume and Umbilical artery Dopplers, and twice weekly CTG.

- Steroid should be considered if cesarean delivery is planned at less than 39 weeks.

-   patient should report any change in fetal movements.

Dr Najeeb Layyous  F.R.C.O.G

Consultant Obstetrician, Gynecologist and Infertility Specialist