Evaluation of Yolk Sac Diameter on Abdominal Scan and Its Fetal Outcome

Authors: Manchanda Prabhjot (DNB),   D. Nirmala (DNB),   Tolia Dhvanit (DNB)


Prospective observational clinical study of 100 cases has been carried out in Hindustan Aeronautics Ltd Hospital Bangalore, Karnataka, to investigate the role of yolk sac diameter in between 9-10 weeks of gestation by TAS in prediction of pregnancy in an unselected population,. The study of 100 singleton pregnancies has been conducted at HAL hospital, Bangalore. Women attending routine ANC clinics were offered an early TAS of 3.4-5 MHz transducer between 9-10 weeks of gestation. 100 patients were screened for yolk sac diameter by subjecting them to TAS at 9-10 weeks at HAL hospital, Bangalore & followed up till delivery. All the 73 cases with yolk sac diameter 2-6mm had successful pregnancy outcome. Cases out of 22 cases with yolk sac diameter >6mm, 19 had missed abortion leaving 100% sensitivity of abnormal yolk sac diameter with poor pregnancy outcome and a p value of significant <0.001.  Yolk sac diameter at 9-10 weeks of gestation between 2-6 mm is significant to conclude successful pregnancy outcome. Yolk sac diameter >6mm is a good predictor of poor pregnancy outcome with sensitivity 100%, specificity 96.3%, PPV 86.36%, NPV 100%, accuracy 97%.


Yolk sac diameter, Spontaneous abortions, Missed abortions, Transabdominal Ultrasound, Gestational age

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Evaluation of Yolk Sac Diameter on Abdominal Scan and Its Fetal Outcome