Haemoglobin-F during pregnancy and delivery.

Abstract

It is possible to determine very small amounts of fetal haemoglobin (Hb-F) using the serological method described by Chernoff in 1953. In a study of the blood from 289 normal adults using this method Hb-F was found below 0.5 Yo in 95 per cent of cases; the upper limit was I per cent. In a series of normal pregnant women the concentration of Hb-F was determined every trimester, at the onset of labour, immediately after delivery and three months post partum. Some results of this investigation is shown in table I. The material has been divided into three groups: The first group with a Hb-F concentration less than 0.12 per cent, in the second between 0.12 and 0.5 per cent and in the third one the Hb-F concentrations was above 0.5 per cent. The first line of the table shows the distribution of a control series in the three groups. The last four lines refer to the series of pregnant women. During the first trimester the percentages of cases with a comparatively high amount of Hb-F are increased as compared to the normal series. Later in pregnancy the average Hb-F concentration decreases, and three months post partum the distribution is perfectly normal. The difference between the concentration of Hb-F in normal, nonpregnant women and pregnant in the first trimester and again between the Hb-F-concentration in the first and third trimester is statistically significant.