The impact of pre-evacuation ultrasound examination in histologically confirmed hydatidiform mole in missed abortion.

BACKGROUND

Early detecting hydatidiform mole in missed abortion is challenge. In this retrospective observational study, we analysed the sensitivity of detecting hydatidiform mole by pre-evacuation ultrasound examination or naked eye after surgical uterine evacuation in missed abortion.

METHODS

Data on 577 cases with histologically confirmed hydatidiform mole were collected over a 10-year period and analysed. Data included serum β-hCG level before surgical evacuation, the ultrasound examination findings, histology findings and naked eye findings. In addition, serum β-hCG level on 2398 cases without hydatidiform mole was also collected.

RESULTS

The median maternal age was 29 (range, 17-53) years and the range of gestational age was 6 to 12 weeks. The sensitivity of detecting hydatidiform mole by ultrasound examination or by naked eye was 25% or 60% respectively. This sensitivity was not increased by the combination of ultrasound and naked eye. There was no difference in the sensitivity of detecting subtypes of hydatidiform mole. The higher β-hCG level was seen in cases with hydatidiform mole, compared to cases without hydatidiform mole. However, there was a lot of overlap in the distributions of β-hCG between the two groups.

CONCLUSIONS

In this study, we found lower sensitivity of detecting hydatidiform mole by ultrasound in missed abortion. β-hCG level was higher in hydatidiform mole than in non- hydatidiform mole in missed abortion. Although higher sensitivity of detecting hydatidiform mole is seen by naked eye (60%), in order to minimise missed opportunity of detecting hydatidiform mole, our study suggests that routine histopathological examination is necessary in missed abortion.