Amniotic Fluid Increase (Polyhydramnios)

Definition:
It is the increase in the fluid surrounding the fetus.
It is usually harmless but may cause some complications in some cases.

In some cases, it can occur early in week 16 of pregnancy but usually it occurs later.

Severity Measurement of Polyhydramnios:
There is a measurement called AFI (Amniotic Fluid Index).
Normal: 5 to 25 cm.

Causes:
Often, the cause behind the increase is not known.

1. Fetal genetic disorder
2. Fetal nervous system abnormalities
3. Maternal diabetes
4. Fetal anemia due to mismatched blood type (Rh factor) between the mother and the fetus
5. Fetal gastrointestinal obstruction: results in decrease in fetal swallowing
6. Increase in fetal urine production due to renal hyperperfusion
7. Multiple pregnancy
8. Infection during pregnancy (rare)

Symptoms:
Mild cases can show no symptoms.

Moderate to severe Polyhydramnios:
They are a result of the pressure on the other organs due to increased uterus size.
1. Shortness in breath.
2. Extremities swelling.
3. Decreased urination.
4. Constipation.
5. Feeling tightness in abdomen.

If Polyhydramnios is diagnosed, other tests will be done such as:
1. Blood tests for some infectious diseases that might be related to Polyhydramnios, and for glucose level.
2. A sample from the amniotic fluid to test any chromosomal abnormalities with the fetus.

Follow up tests:
After Polyhydramnios is diagnosed, nonstress test (NST) and biophysical profile (BPP) are performed.

A. In mild and moderate cases:
Done every 1 to 2 weeks until week 37 of pregnancy.
Then, done weekly from week 37 of pregnancy to delivery.

B. In severe cases:
Done every week until delivery.

Polyhydramnios complications:
Possibility of:
1. Preterm labor
2. Stillbirth
3. Premature rupture of membranes
4. Umbilical cord prolapse
5. Placental abruption
6. C-section delivery
7. Heavy bleeding
8. Abnormal fetal position

Treatment:
Mild cases do not need treatment and it can go away in their own.

Treating diabetes can help.

For moderate and severe cases:
In the hospital:
1. Medication with indomethacin to stop the production of the amniotic fluid.
It can not be done after week 31 of pregnancy.
Amniotic fluid will be monitored weekly.

2. Amnioreduction: amniocentesis is performed to reduce amniotic fluid volume.
Done for severe cases.
Done between 32 and 34 weeks of gestation.
After the procedure, amniotic fluid volume will be monitored every 1 – 3 weeks.
Holds some risks of:
a. Preterm labor
b. Premature rupture of the membranes
c. Placental abruption

Delivery:
1. In mild and moderate cases, labor will be induced around week 39 of pregnancy.
2. In severe cases, labor will be induced at week 37 of pregnancy to reduce the risk of umbilical cord prolapse, abruption or rupture of membranes.