Symphysio-Fundal Height Nomogram In Ultrasound Dated Pregnancies

Abstract

Objective: Fundal height measurements in centimeters have always been an objective method of evaluating fetal growth in pregnancy. The accepted Mcdonald's rule refers primarily to Caucasians regrettably. Since fundal height may actually vary in an anthropological sense it was considered necessary to apply Mcdonald's rule to African subjects to see whether there is any significant difference. The aim of this study is to construct symphysio-fundal height nomogram for normal pregnant Nigerian women. Material & Methods:In a cross sectional mode, four hundred and five pregnant Nigerian women were studied to examine how their fundal height values compared with those in the literature. A regression equation was derived for the 10th and 90th centiles. Values outside the range of 10 -90th centiles are to be used for the prediction of small-for-dates and large-for-dates babies respectively. The prediction formulae for the various centiles derived from regression analysis and their usefulness in clinical anthropological practice using fundal height measurement are highlighted. Results:The study demonstrated a significant difference in fundal height values of Nigerian women especially in late pregnancy compared with other published values in the literature. A positive linear correlation between symphysio-fundal height and fetal gestational age was found in Nigerians with a correlation coefficient of R2 = 0.9962 (p<0.001). The relationship is best described by the second order polynomial regression equation y = -0.0024x2 + 1.1255x -1.8334 where y is the symphysio-fundal height in centimeters while x is the gestational age in weeks. Conclusion:Symphysio-fundal height chart is a valuable tool for assessing fetal growth in the antenatal clinic in as much as it is cautiously constructed for a given population and the same method of measurement is strictly adhered to by different observers in the same organization.

Fundal Height Growth Curve for Thai Women

“…These could be due to differences in ethnicity, socioeconomic, life style, nutritional status, study methodology, eligible criteria, gestational age definition, fundal height measurement, and statistical analysis. Our growth curve has a quadratic pattern similar to studies in Thailand [16, 17], Tanzania [13], and Nigeria [15] but was different from studies in Sweden [12] and Mozambique [14] which had cubic pattern curves. Thai women are relatively smaller and have relatively smaller pelvis compared to Caucasian women [22], causing an increase in a fundal height early in pregnancy (Figure 2).…”

“…A decline in fundal height around term was caused mainly by fetal engagement. Black women with African ethnicity with anthropoid typed pelvis (long anteroposterior diameter, short transverse diameter) [24] had similar fundal height pattern of growth curve to Thai women but did not decline around term due to unengagement [15]. An exception was observed in some African ethnic with gynecoid pelvis [25].…”

“…The sensitivity of fundal height measurement in detecting IUGR, SGA, and LGA varies from 17% to 86% [10, 11], due to differences in gestational age assessment and fundal height measurement techniques [3]. Many studies therefore recommend demographically specific fundal height growth curve rather than universally derived curve, as fundal height is influenced by ethnicity, socioeconomics, and nutritional status [12–15]. …”

Measurement of symphysis fundal height for gestational age estimation in low-to-middle-income countries: A systematic review and meta-analysis

“…One study from Panama displayed graphs with 10% and 90% values, however did not display values or report on the 50% or mean and thus was not included [ 9 ]. Eight studies had ultrasound confirmed dating as the GA gold standard ( Table 2 ) [ 44 , 47 , 50 , 53 , 54 , 56 , 61 , 65 ] and 11 used LMP dating (S3 Table in S1 Appendix ).…”

“…The Global Network developed a color-coded SFH tape measure to classify pregnancies in one of three GA categories: red zone (24-36 weeks), yellow zone (<24 weeks) or green zone (>36 weeks), with different thresholds for Africa vs. Asia [47]. Statistical models have also been developed by many groups and investigators to estimate GA from single or serial SFH measurements (S2 Table in S1 Appendix) [44,[48][49][50][51][52][53][54]. White et al developed an online calculator to estimate GA from SFH based on statistical modeling of serial SFH measures from a pregnancy cohort on the Thai-Myanmar border [54].…”