Transvaginal color Doppler study of blood flow in ectopic pregnancies

Objective To compare Doppler indices of blood flow in the uterine and spiral arteries and the corpus luteum (CL), in ectopic and intrauterine pregnancies (IUPs). Design A prospective study of women with an ectopic or singleton IUP at the corresponding stage of gestation. Setting The Gynaecological Ultrasound Clinic, King's College Hospital. Patients Fifty-two women, 19 with an ectopic pregnancy (EP) and 33 with an IUP. Interventions All women were examined by transvaginal ultrasonography with color Doppler immediately before surgery. Main Outcome Measures The resistance index from the left and right uterine arteries, the spiral arteries, and the CL. The peak blood velocity (cm/sec) from the uterine arteries. The length of gestation. Results Fetal heart activity was observed in all cases of IUP at 5 weeks' gestation. Three women had an EP with a live embryo, 5 had an embryo with no heart activity, 5 contained only a yolk sac, and 2 had an empty sac. A hematocele was seen in 3 women, and 1 had tubal thickening. The mean uterine and spiral arterial resistance index decreased with the gestational age of IUPs but remained constant during EPs. Peak blood velocity in the uterine arteries increased with the gestational age of IUPs, and the values were significantly higher than in EPs. A CL was seen in 88% of women with an IUP and in 100% of women with an EP. The resistance index was similar in CL associated with both types of pregnancy, and the values did not change with gestational age. Conclusion These data show that: (1) blood flow impedance in the uterine and spiral arteries, and CL, is similar in IUPs and EPs and (2) peak flow velocity in the uterine arteries reflects a decreased blood supply to EPs.