Longest diameter of fetal skull is :

Ans. is d i.e. Submentoveical Let's first see the transverse diameters of the skull. Mnemonic ? Miss Tina So Pretty (In ascending order) Miss - Bimastoid diameter 7.5 cms Tina Bitemporal diameter 8 cms So Super subparietal diameter ? 8.5 cms Pretty Biparietal diameter 9.5 cms Therefore. from above options - between bitemporal and biparietal, it is biparietal diameter which is longer. Coming on to - Antero posterior diameters of Skull. Diameter Value Subocupito bregmatic 9.5 cms Sub mento bregmatic Suboccipito frontal 10 cms Occipito frontal Sub mento veical Therefore, Sub mento veical diameter is 11.5 cms and is longer than biparietal diameter. Remember : Smallest diameter Longest diameter = Bimastoid diameter 1'1 = Mento veical Ilnd = Bitemporal diameter IInd = Submento veical/occipito frontal