Amniotic fluid is fluid present inside the amniotic sac. Amniotic fluid is extremely important for the fetus for its overall protection and development. It acts as a cushion and protects the baby from trauma. It prevents compression of umbilical cord and allows the baby to move freely inside the sac thus aids in development of muscles, limbs and lungs.
The amniotic fluid is produced soon after amniotic sac is developed within 10 to 12 days of conceiving. In the beginning the fluid consists of water but after 20 weeks it majorly consists of urine released by the fetal kidneys.The baby swallows the fluid and excretes it again thus maintaining the exact recycling and balance of fluid in the amniotic sac.
But sometimes this perfect balance is disrupted resulting in too low or too high amount of fluid, both of which can be harmful for the developing fetus. Low amniotic fluid in medical parlance is called oligohydramnios.
How To Know If You Have Low Amniotic Fluid?
You may know leakage of fluid if the undergarment is soiled with fluid. Tell your doctor immediately if you suspect fluid leakage or if you do not feel the movement of the fetus.The health care provider also looks for other signs such as if you have not gained weight or if the fetus is not growing fast. He may also inquire if there was previous history of growth restriction. He may also look out for hypertension, diabetes or other medical problems such as lupus.
To find what is going on exactly he will recommend for an ultrasound of uterus. The sinologist can measure and evaluate the amount of fluid through a method called amniotic fluid index (AFI). He measures the amniotic fluid in four different sections of uterus and adds them together. Normally AFI is 5 to 25 cm. If the total is less than 5 cm, it is considered low amniotic fluid. If the amount of fluid is less than 500 ml at 32 to 35 weeks, it is suspected to be low.
At least 4 out of hundred pregnant women have oligohydramnios. The condition can occur anytime during pregnancy but it most common in last trimester.
Dangers Of Low Amniotic Fluid In Pregnancy
Low amniotic fluid can occur during any stage of pregnancy but if it develops during the 6 months it can cause serious problem for the baby. The problems can be:
- Birth defect.
- Miscarriage as the fetus does not live in the womb more than 20 weeks.
- Premature birth of the fetus.
- Still birth where the fetus does not survive after 20 weeks.
Low amniotic fluid in third trimester can result is following abnormalities:
- Slow development of fetus.
- Umbilical cord compression during birth and labor.
- Risk of cesarean section increases.
Causes Of Low Amniotic Fluid During Pregnancy
There are several causes of low level of amniotic fluid.
- Defect in kidney or development of urinary tract can cause less production of urine which can lead to low level of amniotic fluid.
- Tear or rupture of membrane can cause mild to moderate leakage of amniotic fluid. The fluid may come out gushing or it may trickle slowly depending the on amount of tear. Sometimes a minor tear may heal itself and leakage may stop spontaneously.
- Placenta is the main life line for providing oxygen and nutrients to the fetus derived from mother. Tear or abruption of placenta from the inner wall of uterus where it is attached can reduce blood and oxygen supply to the fetus. It will affect the production of urine in the fetus and thus may have less recycling of amniotic fluid.
- Medical conditions of the pregnant women such as diabetes, high blood pressure and lupus can lead to low amniotic fluid.
- Post term pregnancy meaning pregnancy has continued more than 2 weeks of expected due date.
- The risk of low amniotic fluid is more if the pregnant woman is carrying twins or multiple fetuses.
Treatment For Low Amniotic Fluid In Pregnancy
If the pregnant woman has low level of amniotic fluid the first thing that her doctor will advise her is frequent monitoring. If the pregnant woman is near her term there may be induction of labor. Sometimes the baby may have to be delivered earlier than the expected due date especially when the woman is also suffering from high blood pressure or if the baby is has growth retardation in the womb.
In all the cases the baby will be monitored frequently for her health through various techniques and imaging such as ultrasound etc. The woman is also advised to take rest and drink enough amount of water. This may help to increase amniotic fluid. In some cases amniofusion may be necessary to prevent problems related to cord as there is risk of it being squeezed if there is low amniotic fluid.