Prediction of early pregnancy loss by ultrasound markers

Background: The purpose of the present study is to determine the performance of ultrasound markers in transvaginal scan (TVS) for the diagnosis of early pregnancy loss (EPL). Materials and methods: This was a prospective observational study of 365 women undergoing initial TVS at between 6 weeks and 10 weeks of gestation. Demographic data were collected. Ultrasound parameters like gestational sac diameter (GSD), yolk sac diameter (YSD), crown rump length (CRL), and embryonic heart rate (HR) were studied at the booking visit, and patients with an inconclusive scan report were asked for follow up after a week or 10 days. Outcome: The measured outcome was first trimester (up to 14 weeks) pregnancy loss. Univariate analysis was done to compare both groups. Receiver-operating curve (ROC) was derived to find out the best cutoff value for studied parameters. Results: Among 365 recruited patients, outcome was known for 91.7% (n = 335). Of 335 analyzed subjects, 272 had ongoing pregnancy (group I) and 63 had miscarriage (group II). Univariate analysis showed significant association of age, symptoms like bleeding per vagina, suprapubic pain, and low GSD, CRL, HR, and difference of GSD CRL with EPL (p < 0.05). Detection of EPL was highest for HR below 5th centile (57%). Best cutoff values were derived for all parameters in ROC and it was found that GSD value of less than 20 mm had sensitivity of 60% with 77% specificity; for CRL of less than 7.5 mm, it was 61% and 75%; and for HR less than 85 bpm, it was 85% and 99%, respectively. The GSD CRL difference of less than 8.5 mm was found highly sensitive (91%) for prediction of EPL on ROC cutoff. Conclusion: We conclude that calculating GSD, YSD, CRL, and HR at 6th-10th gestational weeks was significant in predicting gestational prognosis. Low embryonic HR (<85 bpm) was found to be an excellent performer in prediction of EPL through ROC. This study emphasizes further on the importance of performing obstetric ultrasound scan with precision and mindfulness.