Objective: To determine to what extent the placental quotient (PQ: placental volume/crown-rump length) is able to detect
adverse perinatal outcomes and to compare the value of first trimester placental volume and second trimester uterine artery
Doppler velocimetry for predicting adverse perinatal outcomes.
Methods: This was a prospective study comprising of 263 women with singleton pregnancies attending our hospital for
nuchal translucency screening at 10-13 weeks of gestation. Three dimensional ultrasound was used to obtain images for
measurement of placenta volume at 10-13 weeks of gestation. In addition, Doppler assessment of both uterine arteries was
carried out for measurement of the pulsatility index (PI) in the second trimester and the mean PI of the two vessels was
calculated. The variables of adverse perinatal outcomes were preeclampsia, preterm delivery, small for gestational age
(SGA), 5-minute APGAR score, and admission to the neonatal intensive care unit.
Results: Of the initial 263 pregnancies originally participating, 219 women who delivered at our institution were included in
the final analysis. Pregnancy complications occurred in 27 (12.3%) of the 219 pregnancies. Comparison between crownrump
length and placental volume proved a significant correlation (r=0.474, p<0.001). There were no correlation between PQ
and uterine artery Doppler velocimetry PI. PQ was significantly lower in SGA group and neonatal intensive care unit
admission group (p=0.049, p=0.019, respectively). Uterine artery Doppler velocimetry PI was significantly higher in SGA
group (p=0.024). PQ in the first trimester and uterine artery Doppler velocimetry in the second trimester had similar
sensitivities for predicting SGA.
Conclusions: PQ in the first trimester and uterine artery Doppler velocimetry PI in the second trimester have significant
difference in SGA group compared to appropriate for gestational age, and have similar sensitivities for predicting SGA.
While both methods seem to be insufficient for screening, the PQ method has the potential advantage of being performed in
the first trimester