Objective: The objective of this article is to evaluate the longitudinal changes in uterine artery Doppler pulsatility index (UtA-PI) in pregnancies complicated with early onset intrauterine growth restriction (IUGR).
Method: Case-control study comparing UtA-PI from 20 to 34 weeks gestation in pregnancies affected by IUGR at 20 to 28 weeks and confirmed at delivery (cases), matched with 1000 controls. Multivariable analyses were used to estimate the UtA-PI as a function of both gestational age and IUGR severity. Finally, bootstrapping technique was used to internally validate the models.
Results: We retrospectively retrieved 53 cases and 1000 controls. Regression line having log10 UtA-PI as dependent variable was a function of both gestational age and IUGR. UtA-PI decreased with gestational age in both groups. In IUGR group, UtA-PI was higher from 20 weeks onward and the difference with controls increased with gestational age. In fact, at 20 weeks, the UtA-PI ratio between cases and controls was 1.84, but at 30 weeks it rose to 2.05. Finally, the weight at delivery in the IUGR group was also inversely correlated with the UtA-PI values.
Conclusion: We presented a reliable multivariable statistical model to evaluate the temporal changes of UtA-PI values as a function of both gestational age and IUGR.
© 2014 John Wiley & Sons, Ltd.