Objective: To assess the efficacy of 11-14 weeks ultrasound in the diagnosis of fetal abnormalities in high risk women.
Methods: Prospective study conducted at a teaching hospital in Karachi, Pakistan. One hundred ultrasound (mini-anomaly) scans were performed on 97 high-risk women, between 11-14 weeks of gestation.
Results: The most common indication for the ultrasound scan in the study, was previous history of structural or chromosomal abnormalities (40%) followed by advanced maternal age (22%). Out of 100 ultrasounds performed, two were found to have structural abnormalities at the time of mini-anomaly scan performed at 11-14 weeks. None of the ultrasound scans found to be normal at 11-14 weeks showed an abnormality on the subsequent scans.
Conclusion: Ultrasound scan performed between 11-14 weeks of pregnancy is effective in diagnosing major fetal abnormalities in the high-risk population. It can complement the anomaly scan performed in the second trimester, as some of the abnormalities become evident later in pregnancy.