A Guide to Oligohydramnios-Low Amniotic Fluid Levels

A Guide to Oligohydramnios-Low Amniotic Fluid Levels

If you’re pregnant, then you definitely need to know about Amniotic fluid and Oligohydramnios. Read on to learn all about them.

What is amniotic fluid?
When the baby is in the womb of its mother, it is surrounded by a fluid in which the baby floats. This is the amniotic fluid. Around 2 weeks after conception, a sac is formed around the fetus, called the amniotic sac. This amniotic sac produces a fluid called the amniotic fluid. The fluid is primarily made of water from the mother, which is then mixed with the urine from the fetus after around 20 weeks of intrauterine life.

Why is amniotic fluid important?
The baby’s life support is provided by the amniotic fluid. Primarily a protection for the baby as well as a shock absorber, amniotic fluid helps the development of limbs, digestive system, lungs, and muscles. The movement of the baby basically depends on this fluid. As the pregnancy progresses, the amniotic fluid is the medium where the baby breathes and swallows it. This helps in the development of the digestive system. Considering the functions that the amniotic fluid performs for the baby, the baby should be provided with optimum fluid for its growth. When the fluid level is less than normal, it is called oligohydramnios. Polyhydramnios is when the fluid level is more than average.

What is oligohydramnios?
The low fluid levels in the amniotic sac are known as oligohydramnios. There are ways to measure it. Sonologists use the amniotic fluid index (AFI), that uses deep pocket measurements. Oligohydramnios is when the fluid level is less than 5 cm, or if the volume is less than 500 ml, after around 35 weeks of gestation. The incidence of low amniotic fluid levels is around 8% of pregnant women. Though it can happen anytime during pregnancy, it is more profound during the last trimester. Usually, the fluid level decreases as the woman nears term. Post-dated pregnancies have the risk of low fluid levels. The incidence in post-dated pregnancies is around 12%.

What are the reasons for low amniotic fluid?
Birth defects – Developmental problems of the urinary system, kidneys and urinary tract that causes low urine production leads to low fluid levels in the amniotic sac.
Problems with the placenta – The anomalies of the placenta that might hinder with the circulation of the nutrients between mother and baby may lead to a failure in the recycling of the amniotic fluid.
Rupture of membranes or leaking – Sometimes there might be a slight rupture or tear in the membranes covering the baby, leading to the leakage of the fluid. When profound, it is referred to as premature rupture of membranes.
Post Dated Pregnancy – The fluid levels automatically decrease post term to enable labor. Post-dated pregnancies will have low amniotic fluids which are detrimental to the baby.
Complications in the mother – Any complications faced by the mother will have a direct effect on amniotic fluid levels, such as maternal hypertension, preeclampsia, eclampsia, diabetes, dehydration, low oxygen levels, etc.
What happens in a case of Oligohydramnios?
The risk depends on the trimester during which the fluid levels drop. In general, the development of the musculoskeletal system, digestive system, and limbs are severely affected. The development of the lungs and the breathing system depends on amniotic fluid and is thus also affected. Furthermore, the shock absorbing effect of the fluid is lost. leading to increased risk of injury to the baby. The complications become more serious, the earlier it develops.

The risks of low fluid levels during the first trimester and the first half of the second trimester include:
birth defects and compression of fetal organs
miscarriage or stillbirth

The risks of low fluid levels during the second half of the second trimester and third trimester include;

  • Intrauterine Growth Restriction (IUGR)
  • Preterm birth
  • Complications of labor
  • Cord compression
  • Meconium stained fluid
  • Cesarean delivery

What if I have low amniotic fluid levels?
First and foremost, consult an obstetrician. The physician will guide you regarding what you need to do. The management depends on the gestation age, and other maternal and fetal parameters.

  • Monitor fluid levels closely.
  • Monitor the activity of the baby through the non-stress test and contraction stress test.
  • Go for delivery of the baby if it is near term.
  • Use an intrauterine catheter during labor (amnio-infusion).
  • Amniocentesis by injecting fluid before delivery.
  • Rehydrate the mother using IV fluids or oral fluids.

By now, you would have understood that low amniotic fluid levels have a lot to do with nutrition and the health of the mother. Right from the day, you plan to have a baby, you need to maintain optimum nutrition . Make sure that there is no shortage of fluids in your body, to avoid dehydration. Furthermore, keep your physician informed about your health at all times.