High Levels Of Amniotic Fluid
All About the Amniotic Sac and Amniotic Fluid
About 12 days after conception takes place, a sac forms in which the developing fetus will live and grow until the time of birth. During the first trimester of pregnancy this sac fills with fluid from the mother's circulatory system and provides a safe environment for the baby. In the second trimester, the baby begins swallowing the fluid and it then passes through the kidneys and is excreted. The process begins again with swallowing and excreting until, by the time the fetus is 20 weeks, he's drinking and swimming in his own urine, recycling it every few hours. The baby, therefore, plays an important role in the management of the levels of amniotic fluid in the sac. There are times when the system doesn't work resulting in too much or too little fluid in the sac. Either situation is problematic for the baby.
The Ups and Downs of Amniotic Fluid
Normal levels of fluid vary in the womb, increasing regularly until the last trimester when they level off. Sometimes, when they level, they are too low. This situation is called oligohydramnios. If the measurements are too high, the condition is called polyhydramnios. Approximately one to two percent of pregnant women have high levels of amniotic fluid, although most of these cases are quite mild with only slightly elevated levels.
What Causes Polyhydramnios?
The causes of polyhydramnios include congenital defects in the baby. The higher the level of fluid, the greater the likelihood of a congenital defect. These congenital defects may create a problem swallowing which stops the ingesting of amniotic fluid. The result is a build-up of fluid in the womb. Intestinal tract blockages or neurological problems are also a possible contributor. Rh factor had, at one time, a marked effect on polyhydramnios. However, with the increase in screening over recent years, the effects of Rh factor implications have been reduced significantly.
There is a connection between diabetes in the mother and too much amniotic fluid. If the pregnancy is a multiple (twins), there is a condition known as twin-to-twin transfusion syndrome which is a complication that can affect a pregnancy with identical twins. Blood flow is very great in one baby and insufficient in the other as a result of blood vessel connections in the placenta. About 65 percent of cases of polyhydramnios are attributed to unknown causes.
The Effects Of High Levels Of Amniotic Fluid
While most cases of polyhydramnios are mild, those that are not may experience the risk of premature rupture of the membranes or placental abruption. Preterm labor and delivery occurs in about 26 percent of cases. Intrauterine growth restriction accounts for skeletal malformation of babies. The rate of stillbirths increases with polyhydramnios as does caesarean deliveries. There is also an increased risk of postpartum hemorrhage for the mother who has polyhydramnios.
Many times this condition can be treated without complications as long as it is monitored well. Medication that reduces the fluid production has been shown to be 90 percent effective, although it is not used after 32 weeks because of possible problems. The draining of fluid through amniocentesis can release excess fluid, but there is a risk of infection as well as the fact that fluid may build up again soon. The delivery of the baby deals with polyhydramnios immediately.