Amniotic fluid is the fluid that surrounds your baby while he or she is in the uterus, and it contributes to the perfect environment needed for your baby to grow and develop. However, more is not always better, and the condition known as polydramnios — having too much amniotic fluid — can occasionally cause problems.
Polyhdramnios, which is seen in about 1 percent of all pregnancies, can be diagnosed a few different ways: by ultrasound (seeing too much fluid around the baby), physical exam (if a woman’s uterus measures larger than expected, it can be from having extra amniotic fluid), or at the time of delivery (when more fluid than normal is seen when a woman’s water breaks). Since ultrasounds are so common these days, they are often the method used to diagnose polyhydramnios.
Polyhydramnios can be the result of a few different issues. Some genetic disorders and malformations (when organs are not developed properly) can result in this condition. For example, amniotic fluid is continuously swallowed by the fetus and is then urinated out. Any issues along the way, such as an abnormally developed esophagus, can cause too much fluid to accumulate around the baby. Other causes of polyhydramnios include diabetes in the mother or twin pregnancies where one twin makes too much amniotic fluid and the other too little. Lastly, many times the cause is never found and the reason for the polyhydramnios remains unknown.
For some women, polyhydramnios is temporary. This means it may be seen on one ultrasound only to have been completely resolved on a follow-up ultrasound. In these cases, the cause for the polyhydramnios is often not known. These pregnancies usually have no ongoing issues and the babies continue to develop normally.
If a baby is found to have excessive amniotic fluid, a work-up is usually done that includes a detailed ultrasound to examine the baby’s anatomy. Diabetes in the mother will need to be ruled out, and in some cases genetic testing of the baby is recommended either by blood work or amniocentesis. If all is found to be normal, additional testing during the pregnancy may be done to monitor the baby. This may include extra ultrasounds and monitoring of the baby’s growth and heart rate.
If the fluid around the baby is so excessive that it causes symptoms in the mother such as contractions or shortness of breath — both the result of an over-stretched uterus — certain treatments may help bring relief and avoid a preterm delivery. This may include removal of amniotic fluid via a needle (just like in an amniocentesis) or medicine given to the mother to try to decrease the amount of fluid. However, both of these treatments have some risks associated with them, so it’s important to weigh the risks and benefits before proceeding.
Reviewed by Jennifer Lincoln, January 2019
- Polyhydramnios is the condition where too much amniotic fluid surrounds a baby in a uterus.
- This affects about 1 percent of pregnancies.
- Sometimes polyhydramnios resolves on its own.