Adverse perinatal outcomes are strongly associated with degree of abnormality in uterine artery Doppler pulsatility index

S Dockree; C Aye; C Ioannou; A Cavallaro; R Black; L Impey; Oxford Growth Restriction Identification Programme Group (OxGRIP)

doi:10.1002/uog.27668

Adverse perinatal outcomes are strongly associated with degree of abnormality in uterine artery Doppler pulsatility index

Ultrasound Obstet Gynecol. 2024 Apr 26. doi: 10.1002/uog.27668. Online ahead of print.

Authors

S Dockree¹, C Aye^{1

2}, C Ioannou^{1

2}, A Cavallaro¹, R Black^{1

2}, L Impey^{1

2}; Oxford Growth Restriction Identification Programme Group (OxGRIP)

Affiliations

¹ Oxford University Hospitals NHS Foundation Trust, Oxford, UK.
² University of Oxford, Oxford, UK.

PMID: 38669595
DOI: 10.1002/uog.27668

Abstract

Objectives: To investigate the association between varying degrees of abnormality in the uterine artery Doppler pulsatility index (UtA-PI) and adverse perinatal outcomes.

Methods: Prospective study of 33,364 women who gave birth to singleton, non-anomalous babies in Oxford, following universal measurement of UtA-PI in mid-pregnancy. Relative risk ratios for the primary outcomes of extended perinatal mortality and live birth with severe small-for-gestational-age (SGA) were calculated by multinomial logistic regression, for early preterm birth (<34⁺⁰) and late preterm/term birth (≥34⁺⁰). The risks were also investigated for iatrogenic preterm birth or a composite adverse outcome before 34⁺⁰ weeks.

Results: Compared with women with normal UtA-PI, the risk of extended perinatal mortality before 34⁺⁰ weeks was higher in women with UtA-PI >90^th centile (RRR 4.7, 95% CI 2.7-8.0, p<0.001), but this was not demonstrated in later births. The risk of severe SGA birth was strongly associated with abnormal UtA-PI for both early births (RRR 26.0, 95% CI 11.6-58.2, p<0.001), and later births (RRR 2.3, 95% CI 1.8-2.9, p<0.001). Women with a raised UtA-PI were more likely to undergo early iatrogenic birth (RRR 7.8, 95% CI 5.5-11.2, p<0.001). For each of the outcomes and the composite outcome, the risk increased significantly in association with the degree of abnormality, through the 90^th, 90-94^th, 95-99^th and >99^th centiles (p_trend<0.001).

Conclusions: An elevated UtA-PI is a key predictor of iatrogenic preterm birth, severe SGA and perinatal loss up to 34⁺⁰ weeks. It is the 90^th centile that should be used, and management should be further tailored to the degree of abnormality, as pregnancies with very raised UtA-PI measurements constitute a group at extreme risk. This article is protected by copyright. All rights reserved.

Keywords: fetal growth; pregnancy outcomes; ultrasound; uterine artery.