In the Emek Hospital in Afula they developed a new developmental curve with which to measure fetal head size which is more suited to the population in Israel. This growth curve is meant to minimize the great chance of error in calculating the size of the head of a fetus and prevent a lot of heartache from misdiagnoses.
The new study attacks the assumptions laid forth in measuring fetal head size and says those criteria aren’t quite accurate and often lead to needless checking and rechecking and a lot of other tests that can be dangerous and unnecessary like amniocentesis.
When checking for fetal development one of the things measured is head size. The size of various limbs and his torso are also measured but a small head size relative to the rest of the body quite often shows the chance of giving birth to a developmentally impaired child that may have poor mental or motor abilities. In some rare instances doctors may even recommend an abortion if they believe the baby will suffer immensely from a terrible disorder.
A woman “S” had a misread ultrasound telling her that her baby’s head was too small and that his would be a life of great suffering. It could be caused by any syndrome that the small head size predicts the fetus has. “S” said: “We were shocked from this prognosis and we kept taking more and more tests which didn’t show any change. After a 3rd ultrasound the doctor finally came in and said the baby’s head size is fine.”
Professor Eliezer Shelo the head of the maternity and women’s section of the Emek Hospital and dean of the medical faculty in the Technion together with Dr. Etti Spiegel a senior doctor in the hospital’s ultrasound unit and also a midwife both led the study. The study found that out of 17,705 pregnancies (from 12 to 42 weeks) that were checked out over 12 years one fifth were misdiagnosed with having a small head size.
According to Dr. Spiegel the current criteria for measuring fetal head size were established in the US in the 80’s and they don’t take the variable populations into account. “You would never consider using the measurements of one group to measure another”, Dr. Spiegel explains. If you take Scandinavian parameters to measure Chinese babies you would say they’re all going to be midgets! That’s why this whole method of measurement is undergoing an overhaul around the world. The new development curve developed from their research is suited to the population in Israel and we expect only 10% of ultrasounds to be misunderstood and be redone.
What do you do if you did find out your baby’s head size is too small? In such a case 30% of the women go to an ultrasound unit for closer monitoring. In this way doctors hope to minimize misdiagnosis but doctors still won’t make promises as to the health of a child so they don’t get sued for giving the parents false hope that their child was healthy.
“A doctor that is not familiar with the new developmental curve and misdiagnoses will send the woman for a genetic test and genetic counseling, amniocentesis and other tests when all he really needs to do is get familiar with the new developmental curve and spare the patient much unnecessary hardship,” concludes Dr. Spiegel.