Oligohydramnios: Low amniotic fluids in pregnancy

Maxwell Adeyemi

AMNIOTIC FLUID is a protective water-like fluid that surrounds the foetus (baby) in the uterus (womb) throughout pregnancy and is contained within a casing called the amniotic membrane or sac. It is an essential component of pregnancy and foetal development. Amniotic fluid is mostly water in the early stages of pregnancy. However, as the pregnancy progresses, the amniotic fluid changes composition and serves new functions.

The foetus begins to inhale and swallow amniotic fluid, which aids in the development of the lungs and digestive system. When amniotic fluid is swallowed, it is digested by the developing gastrointestinal system of the foetus, and the byproducts are excreted in the foetal urine on a regular basis. The amniotic fluid contains less water and more foetal urine around week 20 of gestational age.

Amniotic fluid that women normally carry ranges in volume from 500 to 1,000 ml. The level may change depending on the mother, foetal weight, and gestational stage. However, throughout the pregnancy, the amount of amniotic fluid should remain above a set minimum. It guards against infection, prevents umbilical cord compression, helps the foetus develop its muscles and limbs, and cushions their movements while inside the uterus. It also maintains the foetus’s temperature.

However, too little (oligohydramnios) or too much amniotic fluid (polyhydramnios) in the uterus is linked to abnormalities in foetal development and may lead to pregnancy complications.

Oligohydramnios

Oligohydramnios is a pregnancy condition where there is insufficient amniotic fluid surrounding the foetus. Low amniotic fluid may indicate an underlying condition or contribute to foetal health issues. These conditions may impair a baby’s growth or cause complications during labour and delivery.

Causes of oligohydramnios

* Placental abnormalities: When the placenta is unable to supply the foetus with enough blood and nutrients, the foetus stops recycling fluid, which may result in a decrease in the amount of amniotic fluid.

* Leaking or rupture of foetal membranes: This may be a gush of fluid or a slow constant trickle of fluid in the foetal membranes due to tear or uterine rupture which may result in low amniotic fluid levels.

* Maternal health condition: A crucial component of the amniotic fluid is maternal water. Low amniotic fluid may be caused by the mother’s health.

- Dehydration may lead to nutritional deficiencies and poor tissue perfusion, which may be harmful to the developing foetus and the pregnant woman’s health.

- Pre-eclampsia is a hypertensive condition that develops during pregnancy. Due to the placenta’s and foetus’s constrained blood supply, these conditions lead to a reduction in placental perfusion. This could cause the foetus to receive less oxygen and nutrients, which could lead to oligohydramnios.

- Maternal diabetes can cause the kidneys to work extra hard to filter and absorb the extra glucose that accumulates in the blood. Dehydration may result from the excess glucose and bodily fluids that are excreted in the urine when the kidneys are unable to keep up.

* Birth defects: Low levels of amniotic fluid may be caused by congenital anomalies that may have an impact on the foetus’s kidney or urinary tract development and cause little urine production.

* Post-term pregnancy: Low levels of amniotic fluid may occur in post-term (pregnancies lasting over 42 weeks), which may be caused by deteriorating placental function.

* Twin-to-twin transfusion syndrome: Identical twins and higher-order multiples who share a placenta may develop this serious disorder. This happens when the placentas of the babies are connected at the blood vessels.

Signs and symptoms

of oligohydramnios

The following are common signs and symptoms of oligohydramnios. However, each woman may have a unique set of symptoms which may include:

* Amniotic fluid leakage when the cause is an amniotic sac rupture

* Decreased amount of amniotic fluid than expected on ultrasound scan

* Measurement of the uterus is smaller than expected for the gestational age

* Smaller abdominal size for the gestational age

* Slow heartbeat of the foetus

* The doctor can easily feel the foetus when abdomen of the mother is touched

* Less frequent foetal movements than usual

* Lower maternal weight than normal for the gestational age.

Complications of

oligohydramnios

Amniotic fluid is very important for healthy foetal growth and development so abnormally low fluid levels may be harmful no matter when it occurs. However, the particular risks and potential complications from oligohydramnios vary depending on the trimester in pregnancy when the condition occurs.

These complications could consist of:

* Developmental birth defects caused by pressure compression of the foetus’s organs as they develop inside the womb.

* Deformities: Due to the foetus’s inability to move and stretch due to a very low amniotic fluid level, it may develop contractures or tightness in the joints.

* Respiratory issues or underdeveloped lungs: The amniotic fluid is crucial for lung development because it forces the air sacs to open and encourages them to expand.

* Intrauterine growth restriction and umbilical cord constriction.

* Increased risk of infection.

Treatment

The gestational age of the foetus determines the course of treatment for oligohydramnios. When the foetus is nearly at full term, the clinician may decide that inducing labour early is best for the baby’s safety.

If not up to term the clinician may conduct more frequent prenatal visits. However, there are few steps or guidelines that can be effected in managing the condition:

* Biophysical profile: This procedure monitors the foetus’s movement, muscle tone, heart rate, breathing, and the amount of amniotic fluid surrounding the foetus in the uterus.

* A foetal non-stress test: During this test, the foetus’s heart rate and movements are monitored both when it is active and when it is not.

* Monitoring: The clinician may schedule a frequent prenatal visit. This may include weekly ultrasounds to check the amount of amniotic fluid.

* Amnioinfusion: A special fluid (saline solution) is injected into the amniotic sac to replenish any lost or depleted amniotic fluid. When a woman’s membranes have ruptured during labour, amnioinfusion may be administered. Umbilical cord compression may be prevented by the fluid’s ability to relieve pressure on the cord.

* Labour induction or caesarean delivery: The foetus may need to be delivered in cases where the foetal circulation may be compromised or if the foetal heart rate becomes abnormal in order to prevent birth injuries.

* Medications: Antibiotics may be administered to treat oligohydramnios, which are caused by premature membrane rupture, as well as medications like steroids that may help the foetal lungs develop if the placenta is not functioning properly.

* Amniocentesis: This process is used to collect an amniotic fluid sample from the womb. Cells in the fluid can be examined for birth defects and other issues.

Contact Dr Maxwell on 3631807 or 7575411