The Relationship Between the Height of the Uterus and Pregnancy in Normal Pregnant Women at Maharat Nakhon Ratchasima Hospital

Abstract

A prospective study was undertaken in 993 pregnant women attending the antenatal clinic at Maharat Nakhon Ratchasima Hospital to assess the correlation of symphysis-fundal height and gestational age. A total of 1221 symphysis-fundal height measurements were arranged on the basis of 10^th, 50^th and 90^th percentile. The symphysis-fundal height was well correlated with the gestational age by the correlation coefficient (r=0.98) and the correlation of determination (r²=0.96) the type of correlation was positive curvilinear relation and was best fit to the exponential equation of In (y) = 2.3601435 + 0.0375715x as well the parabola equation of

y = 10.6216769 + 0.3202591x + 0.01400374x²

            (where x = gestaional age, and y = symphysis-fundal height)

During the 17^th and 36^th week of gestation, the correlation of symphysis-fundal height and gestational age was well correlated in linear relationship and was fit to the equation

            y = 2.6698488 + 1.0198841x

            During these weeks, the increment of symphysis-fundal height was 1 cm. weekly and the gestational age can be simply calculated by adding 3 to the symphysis-fundal height measured. This is a simple, reliable and inexpensive method, eventhough it is not a precise diagnostic tool but it does provide an improvement on abdominal palpation in the prediction of abnormal fetal growth. An attempt to develop a normogram of symphysis-fundal height for our population was made.