A Comparative Study of Prenatal Ultrasound Findings and Postmortem Examination in a Tertiary Referral Center

Abstract

Most women in the United Kingdom now have prenatal screening for fetal abnormalities. This retrospective study compared the findings on prenatal ultrasound study with postmortem findings in pregnancies in which a fetal abnormality resulted in fetal loss. A total of 153 pregnancies were screened in a 12-month period and found to have such abnormalities. Autopsy findings were available in 47 cases. There were 40 terminations, 5 intrauterine fetal deaths, and 2 early neonatal deaths. The mean gestational age at the time of autopsy was 21 weeks; 72% of pregnancies were at less than 24 weeks gestation. There was no major disagreement between the ultrasound and postmortem findings in 98% of cases. Agreement was considered to be complete in 22 of these cases and major in 24. A majority of cases with complete agreement involved neurologic abnormalities. In 11 cases, there were additional but minor findings at autopsy, and in 13 cases, there were significant additional findings that added to the final diagnosis. The most common additional findings were genitourinary anomalies and dysmorphic external features. Autopsy yielded a definitive diagnosis in 13% of cases. In only 1 instance was there complete disagreement between the ultrasound and autopsy findings. This was an infant with de Lange syndrome, severely restricted growth, facial dysmorphism, cleft palate, and other abnormalities. Ultrasound study at 27 weeks gestation had shown only symmetric growth restriction and anomalies of the hands. Greater agreement between prenatal ultrasound and autopsy findings was found in this series than in previous studies. In only 1 of 47 cases was there complete disagreement. Ultrasonography is very accurate when carried out in specialist centers, but autopsies remain important for refining the diagnosis or, in some instances, making a definitive diagnosis.