First trimester is crucial, since 80% of pregnancy losses occur spontaneously during this period. Contributing factors are diverse, so there is difficulty in reliably predicting the outcome of pregnancy. There is a need for accurate method to assess the early pregnancies that allows early indication of unwanted outcomes. This can guide a tailored and pre-emptive management strategy, and aids in a much needed psychologic preparation of the expecting mother. Numerous ultrasound signs have been proposed as predictive of poor pregnancy outcome, including an excessively large, excessively small, or irregular gestational sac, a large or irregular yolk sac, weak decidual reaction and a slow embryonic heart rate. Yolk sac plays a pivotal role in exchange of essential substrates between mother and embryo before the placental circulation establishes. It reaches the highest level of functional activity during the fourth to seventh week and undergoes degeneration after the twelfth week. With transabdominal sonography (TAS), the yolk sac is mostly evident by seven weeks of gestational age, when its diameter reaches a mean of 20 mm. TAS is the routine practice at our set up, whereas transvaginal sonography (TVS) is preferred when difficulty in visualization and assessment of early pregnancies.