Yolk Sac Abnormalities – Is It a Reliable Indicatorof Abortions? – A Prospective Study in thePopulation Residing in Rural Setup of Mangaluru,Karnataka, India

Objective: This study was undertaken to determine if there were different abortion rates between normal and abnormal yolk sacs between 5-10 weeks of gestation, its association with pregnancy outcome and correlation with other parameters Materials and Methods: In this study, the yolk sac characteristics of 95 consecutive pregnant women, of 5-6.5 weeks gestation, with normal body mass index (BMI) were prospectively evaluated. All patients underwent two-dimensional transvaginal ultrasonography, which was performed by the same sonographer. We considered the following yolk sac characteristics as normal for classification: diameter: 2- 5 mm; round shape; absence of degenerative changes. Yolk sacs that had diameters smaller than 2 mm or larger than 5 mm; a shape that was not round (i.e., oval or distorted); the presence of degenerative changes. The outcome is statistically analyzed. Results: A total of 100 cases were evaluated. Five cases were excluded. 81(85.3%) continued beyond 20 weeks and the rest 14(14.7%) ended in abortions. About 95.7% of the pregnancies showed the presence of a yolk sac, while in 4.3% of them a yolk sac was absent. Pregnancies with large yolk sac diameter ended with abortions. The sensitivity of predicting normal outcome with regular yolk sac is as high as 94.2%, while specificity is 34.5%. Conclusions: Abnormalities of the yolk sac size or shape, and absence can be used as a reliable indicators of early pregnancy.