Fetal volume and crown-rump length from 7 to 10 weeks of gestational age in singletons and twins Martins WP et al. - Twins and singletons had similar fetal volume and crown-rump length between the 7th and 10th week of gestational age. Additionally, fetal volume assessed by VOCAL was better than crown-rump length to estimate the gestational age at the evaluated period. However, the improvement was small and probably without clinical significance. [more...]