What Does Low Amniotic Fluid Really Mean?

Recently a client brought up low amniotic fluid concerns after a prenatal appointment. After a deep dive into this with them, we thought we'd circle back to our community here and chat low amniotic fluid (Otherwise known as: Oligohydramnios) and inductions. The standard practice in the U.S is to jump to induction if a full term mother experiencing an otherwise normal pregnancy is reported to have low amniotic fluid. You know we are all about the facts here, so let's dig in.

Is low amniotic fluid a valid reason for induction?

'A recent review of the literature (Rossi & Prefumo 2013) found that in term or post-term pregnancies oligohydramnios (with an otherwise healthy pregnancy/baby) was not associated with poor outcomes. However, it was associated with increased risk of obstetric interventions… probably because the diagnosis leads to intervention.' Check out the evidence on Low Amniotic Fluid and why inducing for this reason may not be the best answer when it’s used as a “blanket statement” solution. For example, "There is a lack of evidence supporting induction for oligohydramnios in ‘low risk’ pregnancies ie. when there is nothing else ‘abnormal’ going on with mother or baby (Quiñones et al 2012). Driggers et al. (2004) concluded that: “evidence is accumulating that in the presence of an appropriate-for-gestational age fetus, with reassuring fetal well-being and the absence of maternal disease, oligohydramnios is not associated with an increased incidence of adverse perinatal outcome.’’

So quick recap, even if you are one of the rare true cases of low amniotic fluid, (see below for how accurate fluid testing can be!)  there is no current evidence that low amniotic fluid at full term in an otherwise normal pregnancy shows poor outcomes for the mother or infant.  However, the use of inductions for low amniotic fluids alone does show an increased risk for a Cesarean section for the mother.  You need to make sure you are keeping the lines of communication open with your provider if you are diagnosed with low amniotic fluid in your prenatal care. 

( Also, here is a bit of information showing that inducing for due dates actually usually causes more harm than good if there is not a solid, medically founded reason for it. )

What can cause low amniotic fluids?

There are factors such as dehydration, broken waters, placental complications, past due pregnancies, medications, infant health conditions, the fetus swallows more of the fluid as the pregnancy progresses, etc. which can impact fluid levels. As well, you should remember that your fluid levels fluctuate throughout the day normally, so a report of low fluid levels can sometimes be addressed by increasing water intake.

How do they test your fluids?

You want to ensure they are using the "deepest vertical pocket" method to measure fluid, and not the outdated "amniotic fluid index," which is a 1-25 scale and what is typically used. ACOG no longer endorses the AFI, instead it endorses the DVP method because it reduces unnecessary intervention without additional risk to the baby. It is important to remember as well that testing used to measure your amniotic fluid catches only 10% of all cases of true low amniotic fluid accurately (Gilbert 2012). Low fluids can be a sign that something is wrong with the mother, the placenta or with the baby genetically, but it can also be dehydration or normal fluid fluctuation throughout the day. To increase the accuracy of your results, try to drink two liters of water before your appointment to keep your fluid levels up and lay on your left side during or before the testing to get the deepest measure.

The Final Word

You are responsible for you birth. You are responsible for planning and educating yourself. You are responsible for speaking up and using your voice. You are responsible for keeping the line of communication open with your provider when it counts.  Make sure you are making informed decisions about your care. 

You can do this. 

If you are concerned about having an unwanted c-section or being feared into decisions that are not based in evidence and science, let us help! Join The Birth Lounge to have an informed and confident birth experience, push for less than one hour, and avoid a c-section!

Post written by Kristin, TBH Team Member & Doula