VARIATION IN EARLY FETAL GROWTH

Objective: To obtain more information on interindividual variation in early fetal growth by using early fetal ultrasound parameters. Design and subjects: Individual fetal growth was assessed prospectively in 10 9 pregnancies by serial ultrasound measurements of CRL and BPD. From t he resulting biometry data, individual CRL and BPD growth curves for e ach fetus were constructed and compared. Results: A high correlation w as found between growth rate and the start of growth of CRL and BPD, r = 0.79 and r = 0.84, respectively. Conclusion: The high correlation b etween growth rate and the start of growth of CRL and BPD might imply that a fetus with an impeded start of growth generally has a higher gr owth rate. This could be called an early pregnancy 'catch-up growth'. This interindividual variation of starting time and fetal growth rate may influence the assessment of gestational age in early pregnancy, if a CRL-curve obtained from cross-sectional measurements is used as a r eference. BPD seems to be a more constant parameter with less variatio n in growth rate.