Low Amniotic Fluid No Risk To Normal Birth
Typically, doctors have been concerned about women with low 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, MD, 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.