Low Amniotic Fluid

Oligohydramnios and what it means for your pregnancy

Amniotic fluid is an important part of pregnancy, and if you have less amniotic fluid than you should have at any given point, you may be diagnosed with a condition known as oligohydramnios. A low level of amniotic fluid may leave your baby vulnerable to a life-threatening situation like cord compression, lung immaturity or insufficient oxygen. Of the 4 percent of women who are diagnosed with oligohydramnios, most occur in the third trimester and the condition tends to cause more complications in pregnancies that go longer than 41 weeks. But whether a low level of fluid is detected in the first or third trimester, there are steps to take that will preserve a healthy uterine environment and avoid fetal distress.

Leaking Amniotic Fluid and Late Pregnancies

If your membranes rupture prior to labor, you may experience a gush of fluid or a continuous trickle. This condition, known as premature rupture of membranes or PROM, won't necessarily interrupt your baby's comfort and wellbeing: there's a good chance that your baby is preparing to head down the birth canal, and will still receive oxygen through the placenta and umbilical cord. However, if your doctor or midwife detects a low level of amniotic fluid before any signs of labor present themselves, you may have a problem.

Complications like preeclampsia, gestational diabetes or problems with your placenta can cause oligohydramnios, so it's likely that moms-to-be who suffer from any of these conditions will be checked more frequently, and perhaps more closely, towards the end of pregnancy. And since amniotic fluid levels naturally begin to decrease after the baby reaches full-term, pregnancies that go past week 40 are at greater risk for low amniotic fluid levels. In fact, fluid levels can decrease by nearly half their original volume at 42 weeks, so your doctor or midwife will want to keep a close eye on the pockets of fluid in any post-term pregnancy.

The Amniotic Fluid Index and Treatment

The best way for your practitioner to evaluate your amniotic fluid is to use the amniotic fluid index, or AFI. Your doctor or ultrasound technician will measure the pockets of fluid in four areas of your uterus and add the measurements together to determine your final score on the index. The normal range is quite large: anything between 5 cm and 25 cm indicates that your baby has enough amniotic fluid to support his health. A total measurement of 5cm or less is cause for concern, and some precautions will need to be taken for the remainder of your pregnancy.

In the last weeks of the third trimester, close monitoring of your baby's heart and muscle movement may be all you need to continue along in your healthy pregnancy. On the other hand, if your baby's growth is a concern, your doctor might decide that it's safer to induce labor than to allow your baby to stay in you womb. If it's not yet the right time to induce labor, a doctor may choose to inject fluid via amniocentesis or hydrate mom with oral or IV fluids to carry on the pregnancy a bit longer.