Oligohydramios & Polyhydramios
Amniotic fluid fills the sac surrounding your developing baby and plays several important roles:
- It cushions your baby to protect him from trauma (if you take a tumble, for instance).
- It prevents the umbilical cord from becoming compressed, which would reduce your baby’s oxygen supply.
- It helps maintain a constant temperature in the womb.
- It protects against infection.
- It allows your baby to move around so that his muscles and bones develop properly.
- It helps the digestive and respiratory systems develop as your baby swallows and excretes it and “inhales” and “exhales” it from his lungs.
Under normal circumstances, the amount of amniotic fluid you have increases until the beginning of your third trimester. At the peak of 34 to 36 weeks, you may carry about a quart of amniotic fluid. After that, it gradually decreases until you give birth.
When there’s too little fluid at any point in your pregnancy, it’s called oligohydramnios. When there’s too much, it’s called hydramnios or polyhydramnios.
Low levels of amniotic fluid can make complications during labor more likely. The main concern is that the fluid level will get so low that your baby’s movements or your contractions will compress the umbilical cord.
If you’re diagnosed with polyhydramnios, your practitioner will order a high-resolution ultrasound to check for abnormalities and possibly amniocentesis to test for a genetic defect and infections.
You’ll also need to have regular nonstress tests or ultrasounds for the rest of your pregnancy to monitor your baby’s development. And you’ll be watched closely for signs of preterm labor. If you haven’t yet been tested for gestational diabetes, you’ll be tested now.
You’ll be monitored carefully during labor as well. Because of the extra amniotic fluid, there’s a greater risk of an umbilical cord prolapse (when the cord falls through the cervical opening) or a placental abruption when your water breaks. Both require an immediate c-section.