Individualized risk assessment for adverse pregnancy outcome by uterine artery Doppler at 23 weeks

OBJECTIVE: To provide individualized risk prediction of severe adverse preg nancy outcome based on uterine artery Doppler screening at 23 weeks. METHODS: Color Doppler assessment of the uterine arteries was carried out i n 5121 women attending for routine care at 23 weeks in two inner-city obste tric units. The mean uterine artery pulsatility index (PI) was calculated, and the likelihood ratios in relation to PI were generated for severe adver se outcome. This was defined as fetal death, placental abruption, and deliv ery before 34 weeks associated with preeclampsia and birth weight less than the 10th centile. RESULTS: The likelihood of severe adverse pregnancy outcome increased quadr atically with mean uterine artery PI. This relationship was not affected by maternal age, ethnicity, or parity. At a mean PI of 1.45, the 95th centile for our population, the likelihood ratio for severe adverse pregnancy outc ome was 5. Cigarette smoking had an additional contribution to PI in predic ting severe adverse outcome, roughly doubling the risk for a given PI. CONCLUSION: The individualized risk of severe adverse pregnancy outcome can be determined by uterine artery Doppler screening at 23 weeks and knowledg e of cigarette smoking history. Such individualized risk would allow ultras ound resources and clinical follow-up to be tailored to the pregnant woman for the most appropriate use of antenatal care. (C) 2001 by the American Co llege of Obstetricians and Gynecologists.