Relative growth estimated from self-administered symphysis fundal measurements.

OBJECTIVE

To establish absolute- and relative-growth reference curves for the detection of intrauterine growth restriction from weekly self-administered symphysis-fundus (SF) measurements and to assess the influence of fetal sex, maternal obesity and parity.

DESIGN

Prospective longitudinal study.

SETTING

Pregnant women from six primary antenatal care centres.

POPULATION

Three hundred women with singleton ultrasound dated pregnancies.

METHODS

Weekly self-administered SF measurements from gestational week 25 until delivery were obtained. A linear mixed longitudinal model was used to estimate the absolute SF growth using the natural logarithm (lnSF). Relative lnSF growth was calculated as the lnSF measurement in one gestational week subtracted by the lnSF measurement in the previous gestational week. The influence of fetal sex, maternal obesity and parity was assessed in regression models and by a graphical display.

MAIN OUTCOME MEASURES

Absolute lnSF and relative lnSF growth curves and influence of fetal sex, maternal obesity and parity on these.

RESULTS

SF measurements from 191 women were used to establish an SF-growth reference. The absolute lnSF growth was influenced by maternal obesity, and for fetal sex and parity, borderline significance was recorded; while there was no evidence that the relative lnSF growth could depend on these variables.

CONCLUSIONS

Weekly self-administered SF measurements can be obtained and used to estimate SF growth. Relative growth of the lnSF height seems to be independent of fetal sex, maternal obesity and parity.