For Problem Pregnancies, An Early Detection Test
Circulatory problems, malnutrition, or diseases such as AIDS can impair the flow of blood and glucose through the placenta to the developing fetus. Although this doesn't permanently harm all fetuses, it can cause low birth weight, learning disabilities, retardation, or even death. Current tests for placental problems are reliable only after 18 to 20 weeks of pregnancy. Now, researchers in Israel have found a technique that would spot trouble four to six weeks after conception--when the fetal brain is first forming.
Current procedures rely on ultrasound to measure blood flow from the placenta to the fetus and from fetal heart to brain. The new test measures the ratio of two hormones in the mother's blood and urine, says neurochemist Ephraim Yavin of the Weizmann Institute of Science in Tel Aviv. The hormone ratio varies in response to disturbances in the flow of oxygen. So far, the new technique has been used only in animal studies, and as yet there is no treatment for such problems.