Written by the wonderful Gloria Lemay.

Gloria Lemay Low Amniotic Fluid. . . I don’t think so

What will it take to stop the inductions for too little amniotic fluid? This is largely a wrong diagnosis based on ultrasound. Women are having their births wrecked by midwives and doctors who believe that Biophysical Profile is a valid testing method. We need to go back to clinical palpation skills and stop depending on sound wave fuzzy pictures to assess the amount of fluid at full term.

Here is where the problem begins:

Many North American women are being told at the very end of their pregnancies to go to an ultrasound clinic and have a biophysical profile done. Most are impressed by the thoroughness of their practitioner and have no idea what this test involves or what sort of harm could follow from consenting to this diagnostic procedure. They will probably not be told that there is no scientific basis for having faith in the test results and that no improvement in health has been proved from large numbers of fetuses being “profiled.” Certainly, no one will mention that the only benefits of the procedure are: 1) the ultrasound clinic will earn $275; and 2) the medical practitioner will be able to cover themselves legally in the very rare instance that a baby might die in utero.Until recently, physicians and midwives would tell women who were carrying their babies beyond 41 weeks gestational age to do “kick counts.” If the baby has 10 distinct movements between the hours of 9 a.m. and 3 p.m., it is widely accepted that the baby is thriving under the mother’s heart. In a culture that loves technology and with the push to expand the commercial use of ultrasound, it was inevitable that someone would come up with a more complex strategy to provide reassurance of the baby’s wellbeing in late pregnancy. Thus the biophysical profile (BPP) was born.

Here is the content of the testing, as it appears on the Family Practice Notebook Web site (www.fpnotebook.com/OB44.htm):

Cost: $275
Criteria (2 points for each)
Fetal Breathing
Thirty seconds sustained breathing in 30 minutes

Fetal Tone
Episode extremity extension and flexion

Body Movement
Three episodes body movement over 30 minutes

Amniotic Fluid Volume
More than 1 pocket amniotic fluid 2 cm in depth

Non-Stress Test
Reactive

Scoring
Give 2 points for each positive above

Interpretation

Biophysical Profile: 8-10
Low risk or Normal result
Repeat Biophysical Profile weekly
Indications to repeat Biophysical Profile biweekly
Gestational Diabetes
Gestational age 42 weeks

Biophysical Profile: 8
Delivery Indications: Oligohydramnios

Biophysical Profile: 6
Suspect asphyxia
Repeat Biophysical Profile in 24 hours
Delivery Indications
Repeat Biophysical Profile less than or equal to 6

Biophysical Profile: 4
Suspect asphyxia
Delivery Indications
Gestational age 36 weeks
Lung Maturity Tests positive (L/S Ratio 2)

Biophysical Profile: 0-2
Likely asphyxia
Continue monitoring for 2 hours
Delivery Indications
Biophysical Profile ‹ 4

“Breathing” above refers to movements in the lungs that show activity of the lungs in preparation for life outside the womb. The baby’s oxygen supply in utero comes via the placenta and umbilical cord while in the mother’s womb.

In the past year, I have had a number of letters and phone calls from doulas, midwives and childbirth educators about a flaw in this testing method. An unusually large number of diagnoses seem to be made that “there is not enough amniotic fluid.” This seems to be the factor in this outline that is most often used as an excuse for induction. It is important for parents to know that this is likely an inaccurate assessment. What the ultrasound technician is doing could be compared to viewing an adult in a see-through plexiglass bathtub from below the tub. In such a scenario, it would be difficult to assess how much water is in the tub above the body that is resting on the bottom of the tub. You might be able to get an idea of the water volume by measuring how much water was showing below the elbows and around the knees, but if the elbows were down at the bottom of the tub, too, you might think there was very little water. This is what the technician is trying to do in late pregnancy—find pockets of amniotic fluid in little spaces around the relatively large body of an 8 lb. baby who is stuffed tightly into an organ that is about the size of a watermelon (the uterus). If most of the amniotic fluid is near the side of the uterus closest to the woman’s spine, it can not be seen or measured. This diagnosis of low amniotic fluid frightens the parents-to-be into acquiescing to an induction of labour. Even though the official BPP guidelines do not require immediate induction for a finding of low amniotic fluid, in practise, the parents are pressured to induce. Stories abound of mothers who are induced for this indication and then report having abundant fluid when the membranes released in the birth process. The risks of induction, which can be catastrophic, and the resulting increase in the need for pain relief medication and cesarean section are usually not discussed with the parents prior to embarking on induction of the birth. Be warned that this latest suspect diagnosis using ultrasound is increasing in frequency and causing increased harm to mothers and unborn babies through aggressive use of induction.

After I published the above explanation in Midwifery Today Magazine in 2004, I received posts from women who had experienced being induced for this diagnosis. Here’s an example:

Thanks for writing this article, Gloria. It was the one that made me fully realize that my induction (at 41w1d - due to “low” amniotic fluid) & subsequent c/s due to failed induction were almost certainly unnecessary when I first read it in 2004. Everything you wrote happened to me. The BPP was perfect besides the fluid measurements. And then I did have “abundant fluid when the membranes released in the birth process”.

Cathleen in MA

——————

DS 5/03

DD 2/06 (HBAC!)

Here are some medical studies that confirm my alarm over using Amniotic Fluid Index as the reason to do an induction:



Low Levels of Amniotic Fluid No Risk To Normal Birth (2004)

Doctors may not have to deliver a baby early if it has low levels of amniotic fluid surrounding it, Johns Hopkins obstetricians report.

In a study to be presented Feb. 7 at the annual meeting of the Society for Maternal-Fetal Medicine in San Francisco, researchers show that babies born under such conditions fared similarly to those born to women whose wombs held normal amounts of amniotic fluid. No significant differences were found in the babies’ birth weights, levels of acid in the umbilical cord blood, or lengths of stay in the hospital.

Typically, doctors have been concerned about women with low levels of amniotic fluid during the third trimester - a condition called oligohydramnios - because too little fluid can be associated with incomplete development of the lungs, poor fetal growth and complications with delivery. Amniotic fluid is measured by depth in centimeters. Normal amounts range from 5 to 25 centimeters; any amount less than 5 centimeters is considered low.

“These study results are very surprising - they go against the conventional wisdom,” says Ernest M. Graham, M.D., senior author of the study and assistant professor of gynecology and obstetrics. “Amniotic fluid stems from the baby’s urine, and the urine results from good blood flow, so if we see low fluid we assume there probably is not good blood flow and the fetus is compromised. This study shows the fluid test is not as good as we thought, and there is most likely no reason to deliver the baby early if other tests are normal.”

The researchers studied 262 women (131 with oligohydramnios and 131 with normal amounts of amniotic fluid) who gave birth at The Johns Hopkins Hospital between November 1999 and July 2002, comparing the babies’ health at birth. Patients with oligohydramnios were delivered sooner, but were less likely to need Caesarian sections. Babies born to moms with isolated low amniotic fluid were normal size and were at no increased risk of respiratory problems, immature intestines or brain disorders.

Study co-authors were Rita Driggers, Karin Blakemore and Cynthia Holcroft.

Abstract # 318: Driggers, R. et al,

“Are Neonatal Outcomes Worse in Deliveries Prompted by Oligohydramnios?”

Related Web sites: Related Web sites:

Journal of Perinatology - Abstract of article: An Amniotic Fluid Index [le]5[thinsp]cm Within 7 Days of Delivery in the Third Trimester Is Not Associated with Decreasing Umbilical Arterial pH and Base Excess
Journal of Perinatology (2004) 24, 72–76. doi:10.1038/sj.jp.7211034 Published online 22 January 2004

An Amniotic Fluid Index 5 cm Within 7 Days of Delivery in the Third Trimester Is Not Associated with Decreasing Umbilical Arterial pH and Base Excess

Rita W Driggers MD1, Cynthia J Holcroft MD1, Karin J Blakemore MD1 and Ernest M Graham MD1
1Division of Maternal-Fetal Medicine, Department of Gyn-Ob, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Correspondence: Ernest M. Graham, MD, Johns Hopkins Hospital, Department of Gyn-Ob, Phipps 228, 600 N. Wolfe Street, Baltimore, MD 21287-1228, USA.