Shortest diameter of fetal skull is
(B) (Submentobregmatic) (85-Dutta 7th)FETAL SKULL AND MATERNAL PELVISDimetersMeasurement in cm (inches)Attitude of the headPresentation1. Suboccipito- bregmatic- extends from the nape of the neck to the center of the bregma9.5 cm 3 3/4 ")Complete flexionVertex2. Suboccipito-frontal- extends from the nape of the neck to the anterior of the anterior fontancll or center of the sinciput10 cm (4")Incomplete flexionVertex3. Occipito-frontal- extends from the occipital eminence to the root of the nose (Glabella).11.5 cm (4 1/2 ")Marked deflexionVertex4. Mento-vertical- extends from the mid point of the chin to the highest point on the sagittal suture.14 cm (5 1/2 ")Partial extensionBrow5. Submcnto-vcrtical-extends from junction of floor of the mouth and neck to the highest point on the sagittal suture11.5 cm 4 1/2 ")IncompleteextensionFace6. Submento- bregmatic- extends from junction of floor of the mouth and neck to the centre of the bregma9.5 cm (3 3/4 ")Complete extensionFace* Transverse diameters- Biparietal diameter - 9.5 cm (3 3/4 ")- Super- subparietal - 8.5 cm (3 1/2 ")- Bitemporal dimeter - 8.cm (3 11/4")- Bimastoid diameter - 7.5 cm (3")A. Diameters of pelvic inlet1. Antero-posterior (True conjugate/Anatomical conjugate 11cm2. Obstetric conjugate 10 cm3. Diagonal conjugate 12 cm4. Transverse diameter 13 cm5. Oblique diameter 12 cm6. Sacroclyloid (smallest) 9.5 cmB. Diameter of pelvic outlet1. Obstetrical* Anteroposterior; from inferior border of symphysis pubis to tip of sacram 11 cm* Transverse (bispinous) interspinous distance between two ischial spines 10.5 cm2. Anatomical outlet* From lower borders of symphysis pubic to tip of coccyx 13 cm* Transverse diameter (inter tuberous diamcter/distance between inner borders of ischial tuberosities 11cm* Diagnal conjugate measured clinically **
Mentovertical
Submentobregmatic
Mentobregmatic
Occipitofrontal
Miscellaneous (Gynae)