Analyze the biometric parameters and the size (area) of abdominal wall defect (AWD) in fetuses with gastroschisis and omphaloceles and correlate them with the herniated internal organs. We studied 22 fetuses (11 with AWDs and 11 without anomalies). In all fetuses we evaluated the xiphopubic distance (XPD) and iliac crest distance (ICD). In fetuses with AWDs we dissected the abdominal wall and measured the width and length of the defect for calculating its area and studying the correlation between the size of the defect with the organs that were herniated. For statistical analysis, the Anova and Tukey post-test were used (p < 0.05). The XPD in the control group had mean of 4.2 mm (2.3-5.9; SD ± 1.11), while in the AWDs it was 4.2 mm (2.9-5.5; SD ± 0.98) (p = 0.4366). The ICD had mean values of 2.5 mm (1.6-3.4; SD ± 0.58) in the control group, and 2.3 mm (1.2-3.0; SD ± 0.56) in AWDs fetuses (p = 0.6963). The number of herniate organs do not have significant correlation with the area of the defect (r2 = 0.2504, p = 0.5068). There is no correlation between the size (area) of abdominal wall defects and the number of the internal organs that herniated. Therefore, the hole size is not a predictor of the severity of the gastroschisis or omphalocele.