An evaluation of routine midtrimester ultrasonic scanning

Area of Science:

• Obstetrics and Gynecology
• Medical Imaging
• Fetal Medicine

Background:

• Accurate gestational age assessment is crucial for optimal pregnancy management.
• Traditional menstrual dating can be unreliable.
• Ultrasonography offers a non-invasive method for fetal assessment.

Purpose of the Study:

• To evaluate the accuracy of combined ultrasonic A and B scans in determining gestational age.
• To assess the diagnostic capabilities of ultrasound for multiple gestations and fetal anomalies.
• To investigate the relationship between placental location and pregnancy complications.

Main Methods:

• A retrospective analysis of 1,987 patients undergoing combined ultrasonic A and B scans between 16 and 30 weeks' gestation.
• Gestational age determined by ultrasound parameters was compared with menstrual history.
• Ultrasound findings for twin gestations, fetal anomalies, and placental location were recorded.

Main Results:

• Ultrasonic assessment of gestational age was more accurate than menstrual history in 19.5% of patients.
• All 31 twin pregnancies were correctly diagnosed at the initial scan, with a 3.2% perinatal mortality rate.
• Ultrasound identified four anencephalic fetuses and two molar pregnancies, leading to timely interventions. A significant association was found between low-lying placenta and threatened abortion.

Conclusions:

• Combined ultrasonic A and B scans provide accurate gestational age assessment, surpassing menstrual dating in a notable percentage of cases.
• Ultrasound is highly effective in early diagnosis of twin pregnancies and detection of major fetal anomalies.
• Placental location identified via ultrasound has implications for managing pregnancy complications like threatened abortion.