Obstetric Lie #90- Your Fluid Levels Are Low

GRRRR! Yes- it happened again. I heard about a first time mama who was told (conveniently after her due date) that her fluid levels were low. Induction must happen- ASAP!!! Induction goes though, mama is lucky quite frankly to have a vaginal birth, and delivers (after much fuss and turmoil) a baby hardly over five pounds.

Obstetrics score= One Million, and counting
Pregnant women score= Zero (but at least you have a baby!)

First, lets establish a few things.

Oligohydramos (or low amniotic fluid levels) is defined as,

"The volume of the amniotic fluid is evaluated by visually dividing the mother's abdomen into 4 quadrants. The largest vertical pocket of fluid is measured in centimeters. The total volume is calculated by multiplying this value by 4." via Medscape.

In addition,

"Oligohydramnios is sonographically defined as an AFI less than 7 cm or the absence of a fluid pocket 2-3 cm in depth." It is also stated that, "If the mother is in the third trimester and if the volume is less than 8 cm, suspect oligohydramnios. Levels less than 5 cm indicate significant oligohydramnios."

I mention the actual level that is considered dangerous because I get the distinct impression that women are routinely told that their fluid levels are low, without actually being told WHAT the fluid level is or what is actually considered low, dangerous or normal for full term. One of the first things that we need to know as women is what really is considered safe and unsafe when it comes to our health and our babies. If we have no idea what is normal, it is just too easy for us to be freaked out when we need not be.

Some more info and links regarding fluid levels:
Drinking water increases fluid levels. Here is an abstract from a study showing that drinking lots of water for a week can increase levels by a few points. So when your midwife/Dr/childbirth educator or whoever mentions that you should try to drink more water and stay hydrated to improve your fluid levels, they are not kidding. How we treat ourselves while pregnant can really have a big impact when we are trying to stay low risk.

A Cochrane Review found that,
"The accurate assessment of amniotic fluid volume by ultrasonography can be influenced by an inexperienced operator, fetal position, the probability of a transient change, and the different ultrasound diagnostic criteria of an abnormal volume." So, the reading that you get, if done via ultrasound, can vary depending on the skill of who is doing the ultrasound OR transient changes (such as, you didn't drink enough water that day).

Dr. Roger Harms on the Mayo Clinic website mentions that, " Amniotic fluid normally decreases in the last weeks of pregnancy." This is important because some decrease at the end of pregnancy is normal and is not dangerous.

Oligohydramnios occurs in 4% of pregnancies, according to Medscape. This is in fact, a fairly rare condition. However, it is one of the big reasons we hear so often for "necessary" induction. Why is something that is in fact fairly rare so common?

Rachel Reed, a midwife who writes the Midwife Thinking Blog mentions in this post that,

" The amniotic fluid is constantly being produced and renewed – Baby swallows the fluid; it is passed through the gut into the baby’s circulation; then sent out through the placenta. This process continues even if the amniotic membranes have broken. So, even when the waters have ‘gone’ there is still some fluid present ie. there is no such thing as a ‘dry labour’."

Another thing to keep in mind is that the test that often assesses fluid levels (the biophysical profile) is not without flaws itself. A doctor from Johns Hopkins mentions this here. He says:
"A gold standard test for diagnosing distressed babies may be overvalued. Doctors often use the amount of amniotic fluid around a baby to measure health in the womb. Low fluid levels late in pregnancy supposedly indicate a baby is endangered because it is not getting enough maternal blood. Johns Hopkins investigators compared outcomes of 131 babies with low levels of fluid with an equal number of babies in the normal range. Obstetrician Ernie Graham…

"Then we looked at the maternal demographics, we looked at the outcomes of the babies, and we found that the fluid measurements weren't very predictive of babies that later had problems.""

My, my- could it be that the wonders of modern technology, when applied to childbirth, are sometimes wrong?


Gloria Lemay wrote a beautiful post regarding the biophysical profile, its flaws, its misuse, and the beauty of good old fashioned, hands on midwifery care and fetal kick counts in assessing fetal normality. You can read it here. I have had four babies, two past 41 weeks, two with zero ultrasounds, none with full term biophysical profiles and they were all 100% healthy.

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Before moving on I want to mention that low fluid levels can in fact be very dangerous or indicative of a very serious problem. I am by no means recommending that women ignore the advice of their physician nor am I advocating that fluid levels don't matter. They do.

What is disturbing here is that women are pretty routinely told that their fluid levels are low and necessitate an induction when that may or may not be the case. This is a fairly easy scape goat for induction/c-section. If your care provider wants to find a 'medical' reason to induce you, they will probably be able to whip one up. This is why choice of care provider is so incredibly important. Let's not convince ourselves that because we did X Y or Z (hired a doula, took a class, picked a pretty hospital, etc) that we will have a charmed birth with whoever happens to show up. Tread softly when it comes to choosing your care provider and hospital.

Just a word for the medical community at large though: NEVER cry wolf. When you start telling women that they have a condition that they actually don't have or if you inflate minor risks or borderline test results into huge dangerous risks in order to make somebody birth at your convenience or on your schedule, women start to lose faith in you. Some will continue to believe everything you say. But many women will opt to stay away from hospitals, birth at home, birth unassisted, or opt out of tests simply out of fear that they will be lied to.

Women should never ever in a million years have to wonder if their care provider is telling them the truth when it comes to the health of them or their baby. A person whose job it is to care for pregnant women and their babies and who is sworn to first do no harm, should never over inflate risk in order to make a patient more compliant nor to better be able to schedule their life.

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So, in essence, a few things to remember:

~Fluid levels drop at the end of pregnancy.
~Drinking water can increase fluid levels.
~Truly low fluid levels are relatively rare (about 4%).
~Even when fluid levels are low, they only result in poor outcome a fairly small amount of the time.
~The test that determines fluid levels is in and of itself not foolproof.
~Amniotic fluid can replenish itself, it isn't a closed system that once lost is gone forever.
~How you care for yourself in pregnancy matters.
~Who you choose to care for you during your pregnancy matters.
~It is imperative that YOU know what is normal, borderline, and dangerous when it comes to diagnoses during your pregnancy.
~It is also imperative that you take responsibility for the real risks and benefits of whatever course of action you choose.