Uterine artery Doppler, birth weight and timing of onset of pre-eclampsia: providing insights into the dual etiology of late-onset pre-eclampsia.
OBJECTIVE
To investigate the relationship between uterine artery Doppler ultrasound indices and birth weight in women with early-, intermediate- and late-onset pre-eclampsia as compared with women with uneventful pregnancy outcome.


METHODS
In a retrospective, observational cohort study, uterine artery Doppler assessment was carried out at 18+0 to 23+6 weeks' gestation in 26,893 women attending for routine antenatal care in a tertiary care center. The mean resistance index (RI) and its relationship to the outcome of pregnancy and birth-weight centiles were evaluated.


RESULTS
Uterine artery RI showed a significant, negative correlation with birth weight (r= -0.20, P<0.0001). Patients with early-onset pre-eclampsia had an increased prevalence of high uterine artery mean RI, above the 90(th) centile, corresponding to an increased proportion of small-for-gestational age (SGA) neonates with a birth weight below the 10(th) centile. In late-onset pre-eclampsia, however, there was an unexpectedly higher proportion of large-for-gestational-age (LGA) neonates with a birth weight above the 90(th) centile without a concurrent increase in the prevalence of low uterine artery mean RI below the 10(th) centile.


CONCLUSIONS
The finding of a bimodal skewed distribution of birth weight, with neonates exhibiting a higher prevalence of both LGA and SGA with late-onset pre-eclampsia, indicates that there are two types of late-onset pre-eclampsia. These findings explain the poor performance of mid-trimester uterine artery Doppler in predicting pre-eclampsia at term and provide insights into the placental origins of the early and late forms of pre-eclampsia.
['Verlohren|S|S|', 'Melchiorre|K|K|', 'Khalil|A|A|', 'Thilaganathan|B|B|']
D000328:Adult D001724:Birth Weight D005260:Female D006801:Humans D007231:Infant, Newborn D021041:Placental Circulation D010927:Placental Insufficiency D011225:Pre-Eclampsia D011237:Predictive Value of Tests D011247:Pregnancy D011256:Pregnancy Outcome D011673:Pulsatile Flow D012189:Retrospective Studies D012680:Sensitivity and Specificity D013997:Time Factors D018617:Ultrasonography, Doppler, Pulsed D016216:Ultrasonography, Prenatal D006113:United Kingdom D055988:Uterine Artery
uterine artery Doppler pre-eclampsia resistance index small-for-gestational age large-for-gestational-age