Comparison of Abdominal and Vaginal Sonography in Normal and Abnormal Early Pregnancy

It is clinically important to confirm early normal and abnormal pregnancy, of which diagnostic accuracy has been raised recently by the technical advance in the field of sonography and radioimmunoassay of human chorionic gonadotropin.

The author reviewed 123 cases with 5-13 gestational weeks of abdominal and vaginal sonograms which were confirmed as 87 cases of early intrauterine pregnancy. 20 cases of non viable pregnancy and 16 cases of ectopic pregnancy

The results were as follows :

1) Vaginal sonograms showed intrauterine gestational sac in 100% of cases at the 5 gestational weeks, fetal echo in 100% of cases at the 6 gestational weeks, and fetal heart activity in 79% of cases at the 7 gestational weeks, compared with abdominal sonograms showing intrauterine gestational sac in 100% of the case at the 6 gestational weeks, fetal echo in 79% of cases at 7 gestational weeks and fetal heart activity in the 73% of cases at the 8 gestational weeks, so vaginal sonogram confirmed the intrauteine gestational structures 1 weeks earlier than abdominal sonogram.

2) Intrauterine gestational sac was shown in the 100% of cases at the serum level more than 6.000 mlU/ml on the vaginal sonograms compared in the 100% of cases at the serum level more than 8.000 mlU/ml on the abdominal sonograms. Fetal echo was shown in the 100% of cases on the vaginal sonograms. compared in the 50% of cases on the abdominal sonograms at the serum hCG levels of 10,000 mlU/ml. Fetal heart activity as identified in the 80% of cases on the vaginal sonograms. compared in the 28% of cases on the abdominal sonograms at the serum hCG levels between 10,000-60,000 mlU/ml.

3) There was no difference in finding of blighted ovum or missed abortion between abdominal and vaginal sonogrms. but vaginal sonograms showed more detailed abnormal gestational structures than abdominal sonograms.

4) In ectopic pregnancy, vaginal and abdominal sonograms showed absence of intrauterine gestational sac in 100% of cases, fluid collection in cul de sac in 80% of cases and adnexal mass in 81 % of cases respectively. Extrauterine gestational sac were identified in 38% of cases on the vaginal sonograms. compared in 26% of cases on the abdominal sonograms.

With the above findings, intrauterine pregnancy can be confirmed 1 week earlier by vaginal sonogram than abdominal sonograms and we suggest that diagnostic accuracy can be raised by the combined use of abddominal and vaginal sonography compared with single use of abdominal or vaginal sonography in the cases of non-viable or ectopic pregnancy.