There are about 4 percent of pregnant women who experience little amniotic fluid before delivery. This condition is very dangerous, because amniotic fluid is needed to protect and support the development of the fetus in the womb.
Ideally, the volume of amniotic fluid at 12 weeks of gestation is about 60 milliliters (mL). Along with the development of the fetus, the volume of amniotic fluid will also continue to increase until the gestational age reaches 34-38 weeks. After that, the number will decrease.
Not all pregnant women have a normal volume of amniotic fluid during pregnancy. There are some pregnant women who have too little amniotic fluid, also known as oligohydramnios. This condition most often occurs in the last trimester of pregnancy, but does not rule out the possibility of a lack of amniotic fluid occurring at an earlier gestational age.
Causes of low amniotic fluid
Amniotic fluid contains nutrients, hormones, and immune system-forming cells produced by the mother. However, at 20 weeks of gestation, the composition of amniotic fluid will be dominated by fetal urine. Therefore, abnormalities in the fetal urinary system can also affect the volume of amniotic fluid.
The following are some of the factors that can cause the volume of amniotic fluid to be low:
1. Fetal urinary system is not fully developed
One of the causes of low amniotic fluid is the fetal urinary system is not fully developed. If the urinary system and kidneys fail to develop, the fetus will produce only a small amount of urine. In fact, urine is the main component of amniotic fluid when the gestational age enters the second trimester.
2. Placental disorders
Placental disorders, such as placental abruption, cause blood flow and nutrient intake to the fetus to be obstructed. This makes fetal urine production disrupted, so the amount of amniotic fluid becomes small.
3. Premature rupture of membranes
Small tears in the amniotic sac can cause amniotic fluid to seep out of the uterus. If the premature rupture of membranes is allowed, the volume of amniotic fluid will decrease or even run out altogether, causing disruption to the fetus.
4. Complications of twin pregnancy
Little amniotic fluid can also occur when a pregnant woman contains more than one fetus in her womb. Because, in identical twin pregnancies, pregnant women are at risk for complications twin-to-twin transfusion syndrome (TTTS). This complication causes the twins to share a placenta which allows one of them to receive a small amount of amniotic fluid.
5. Taking certain drugs
Pregnant women who are taking high blood pressure group angiotensin-converting enzyme inhibitor (ACE inhibitors) can also cause low amniotic fluid volume. Drugs that belong to the class of ACE inhibitors include ramipril, captopril, and lisinopril.
In addition to the factors above, certain diseases suffered by pregnant women, such as hypertension, diabetes, or lupus, can also increase the risk of pregnant women having a small amount of amniotic fluid.
Handling of little amniotic fluid
Handling low amniotic fluid (oligohydramnios) will usually be done according to gestational age. However, before giving treatment, the doctor will perform a series of examinations, including a pregnancy ultrasound, to determine the condition of the fetus in the womb.
If the amniotic fluid is low at the end of pregnancy, the doctor will usually recommend that the baby be delivered immediately. This is intended to prevent complications in the baby.
Meanwhile, if a little amniotic fluid occurs in mid-pregnancy, the doctor will suggest the following treatments:
- Amnio infusion, which adds fluid into the amniotic sac.
- Increase fluid intake during pregnancy.
- Complete rest (bed rest).
If not treated promptly, low amniotic fluid can lead to some serious complications, including premature birth, miscarriage, low birth weight baby, and Potter's syndrome.
To minimize the risk of low amniotic fluid during pregnancy, you need to increase fluid intake during pregnancy, maintain a healthy diet, and not smoke. In addition, you also need to have regular checkups with your obstetrician to monitor the condition of the womb and fetus.