The engaging diameter in a face presentation is

Correct Answer: A

Rationale: The engaging diameter in a face presentation is the sub-mento vertical diameter. This is the correct answer because it represents the distance from the tip of the chin (mentum) to the highest point on the skull (vertex), which is the most critical diameter for the face to descend through the pelvis during childbirth. Choice B (Sub-mento bregmatic diameter) is incorrect because it represents the distance from the tip of the chin to the anterior fontanelle, not the highest point on the skull. Choice C (Mento vertical diameter) is incorrect because it refers to the distance from the chin to the base of the skull, not the highest point on the skull. Choice D (Sub-occipito bregmatic diameter) is incorrect because it represents the distance from the base of the skull to the anterior fontanelle, not involving the chin.

Correct Answer: C

Rationale: Rationale: Face to pubis delivery occurs when the fetal face presents towards the mother's pubic bone during birth. Choice C is correct because a 45˚ anterior rotation of the occiput is needed for this positioning. This allows the fetal face to be directed towards the mother's pubis for a successful face to pubis delivery. Choices A and D are incorrect as they mention incorrect angles of rotation. Choice B is incorrect as a persistent occipito posterior position would result in a face to sacrum delivery, not face to pubis.

Correct Answer: D

Rationale: The correct answer is D because in deep transverse arrest, the sagittal suture of the fetal head is typically aligned with the oblique diameter of the pelvis, causing an obstruction in the descent of the baby. This alignment leads to a difficult labor scenario where the baby's head cannot pass through the pelvis due to the mismatch in diameters. Choices A, B, and C are incorrect because they do not accurately describe the specific anatomical alignment that characterizes deep transverse arrest. Choice A refers to occipito-frontal diameter, choice B refers to sub-occipito-bregmatic diameter, and choice C mentions a face to pubis delivery, which are not the defining features of deep transverse arrest.

Correct Answer: B

Rationale: The correct answer is B: Oligohydramnios. Oligohydramnios leads to reduced volume of amniotic fluid, which can result in poor fetal movements and inadequate cushioning for the fetus. This can increase the likelihood of abnormal fetal positions like shoulder presentation. Other choices are incorrect because: A: A sub-septate uterus is a structural uterine abnormality and not directly related to shoulder presentation. C: Prematurity may lead to preterm labor but is not specifically associated with shoulder presentation. D: Multiple pregnancy can increase the risk of malpresentation but is not a direct maternal cause of shoulder presentation.

Correct Answer: C

Rationale: Rationale for choice C: 1. Excessive molding or abnormal stretching of the fetal head can indicate neonatal intracranial injury due to the trauma during birth. 2. This feature suggests possible compression or trauma to the baby's head during delivery. 3. It may lead to intracranial hemorrhage or other injuries, requiring close monitoring and medical intervention. Summary of other choices: A. An oedematous swelling resolving in 48 hours is likely a normal finding (cephalohematoma) and not specific to intracranial injury. B. Notable bleeding between the epicranial aponeurosis & periosteum may indicate cephalohematoma or caput succedaneum, not necessarily intracranial injury. D. Peripheral cyanosis is related to oxygenation and circulation, not specific to intracranial injury.