Amniotic fluid is a fundamental element in pregnancy. It is a slightly yellowish liquid that begins to fill the amniotic sac two weeks after fertilization and surrounds the baby during its development inside the mother's womb.
It contains proteins, carbohydrates, lipids and phospholipids, urea and electrolytes, all of which help the development of the fetus. In addition, it contains fetal cells, thanks to which possible malformations can be diagnosed.
How is amniotic fluid produced?
During the first trimester, the amniotic fluid is produced by the mother. It is an ultrafiltrate of the maternal plasma that passes from its circulatory system to the amniotic sac.
In Babies and more Amniotic fluid losses in pregnancy: what you should knowFrom the second trimester, the baby begins to swallow that liquid and produces urine. This is done several times a day, so 90% of the amniotic fluid is made up of fetal urine.
What is the normal amount of amniotic fluid in pregnancy?
The amount of fluid increases as the pregnancy progresses reaching its maximum volume of between 800 milliliters and 1 liter around 32-36 weeks of gestation. From that moment, the liquid begins to decrease slightly until the moment of birth. Approximately 600 milliliters surround the full-term baby at 40 weeks.
The baby controls the volume of the liquid by compensating the speed of production (urinating) with the speed of elimination (swallowing).
When an imbalance occurs between the amount of amniotic fluid that is produced and eliminated, an anomaly arises, or by excess (polyhydramnios) as per deficit (oligohydramnios).
How is the amount of amniotic fluid measured?
Towards the end of pregnancy, the amount of amniotic fluid present is monitored by ultrasound.
There are two ways to measure the liquid: amniotic fluid index (ILA or AFI), and maximum vertical pocket (BVM or MPV, for its acronym in English).
The ILA controls how deep amniotic fluid is in four areas of the uterus. Those amounts add up. If your AFI index is less than 5 centimeters, it has oligohydramnios. If it is more than 24 centimeters, it has polyhydramnios.
The BVM measures the deepest area of the uterus to verify the level of amniotic fluid. If your maximum vertical pocket is less than 2 centimeters, it has oligohydramnios. If it is more than 8 centimeters, it has polyhydramnios.
Polyhydramnios: excess amniotic fluid in pregnancy
The pregnant woman may feel some symptoms due to increased fluid inside the uterus such as difficulty breathing, back pain, abdominal discomfort, and excessive swelling of the feet and legs. Some feel no sign at all, that's why prenatal checkups are so important.
The causes of this excess fluid can be varied. Among the most common are maternal diabetes, multiple pregnancy, genetic abnormalities, malformations or fetal infections, Rh incompatibility and fetal transfusion syndrome.
In Babies and more, how do I know if I have broken waters?A mild polyhydramnia usually resolves on its own towards the end of pregnancy, if not, or is severe, the doctor will look for the cause that causes it to solve the excess liquid. You may have a high resolution ultrasound and suggest an amniocentesis to rule out possible birth defects.
They will make you strict controls during the rest of the pregnancy to monitor the development of the baby.
Having an excess of amniotic fluid increases the risk of premature delivery, premature rupture of membranes, placental abruption, umbilical cord prolapse, fetal death or postpartum hemorrhage.
Oligohydramnios: low amount of amniotic fluid in pregnancy
Having less amniotic fluid than necessary is also a complication. The most common signals are the losses of amniotic fluid, a size of the uterus too small for gestational age or a decrease in fetal movements.
Oligohydramnios can be caused by diabetes or preeclampsia of the mother, premature rupture of the bag that is causing a loss, problems in the functioning of the placenta, multiple pregnancy or fetal abnormalities.
If it happens during the first half of pregnancy, it is associated with an increased risk of abortion, premature delivery, and birth defects. Towards the end of pregnancy, the consequences that it can bring is that the baby does not grow properly as well as problems during childbirth such as umbilical cord compression. The doctor will rigorously monitor the growth of the baby and ask you to control his movements inside the belly.
In the event that the mother has a disease or a risk is detected for the baby or the mother, the doctor will evaluate the delivery.
Photos | genue.luben and Daquella maneraen Flickr CC On Babies and more | What is amniotic fluid
