T. Steingromsdottir et al., SYMPHYSIS-FUNDUS HEIGHT - CONSTRUCTION OF A NEW SWEDISH REFERENCE CURVE, BASED ON ULTRASONICALLY DATED PREGNANCIES, Acta obstetricia et gynecologica Scandinavica, 74(5), 1995, pp. 346-351
Repeated measurements of the symphysis-fundus (SF) distance is general
ly regarded as an acceptable screening instrument for antenatal detect
ion of intrauterine growth retardation (IUGR). In the present investig
ation an SF curve is constructed, based on measurements from 1650 Swed
ish women with ultrasound dated pregnancies. The SF measurements were
included in a cross-sectional stratified manner; only one measurement
from each woman was used and the same number of measurements (n=75) wa
s used for each gestational week from 20 through 41. A regression anal
ysis by a polynomial equation of third degree was applied on the means
and standard deviations of the SF measurements in each week respectiv
ely to construct a graph of fundal height. This SF curve was compared
with the SF curve in common use in Sweden (constructed by Westin); in
the new curve the mean measurement was about one cm higher up to 37 ge
stational weeks, after which time the curves almost coincided. Neither
did the mean SF height differ between smokers and non-smokers nor bet
ween nulliparous and parous women. The mean SF difference between the
heaviest women (greater than or equal to 79 kg) and the lightest (grea
ter than or equal to 53 kg) was about two cm throughout pregnancy. The
validity of the constructed SF curve as a screening instrument for IU
GR needs to be investigated in a different study.