Roentgenologic Determination of Foetal Maturity

Abstract

Foetal length determination by roentgenologic measurement of the lumbar length is an unreliable method, with a large range of variation. It is important to be aware of this fact when the method is used for determining foetal maturity. It can be of some value, however, when no centres of ossification can be seen in the knee joint.

Foetal maturity can also be determined by non-roentgenologic methods. The biparietal diameter of the foetus can thus be measured with a relatively high degree of accuracy by the ultra sound technique which is simple and has no radiation effects on the mother or foetus. This method gives at a single examination about the same range of variation as the roentgenologic methods. It can, however, because of the lack of radiation hazards, be used in repeated examinations, whereby the rate of growth of the foetus can be estimated. We have therefore used this method during the last year, with satisfactory results.