Which of the following is the most favorable presentation/position for vaginal birth?

Correct option is A

Sol. In vertex presentation, the fetal head is fully flexed, and the occiput leads the way through the birth canal. This position allows the smallest diameter of the fetal head (suboccipitobregmatic) to pass through the maternal pelvis. It facilitates smooth and safe vaginal delivery and is associated with the least number of complications. Most spontaneous vaginal deliveries occur in this presentation. It is considered the most natural and optimal fetal position for childbirth.
Explanation of each option:
· (a) Vertex presentation – Correct. It is the most common and favorable presentation for vaginal delivery, reducing labor complications and minimizing maternal and fetal risk.
· (b) Transverse lie – The fetal long axis lies perpendicular to the mother's; vaginal delivery is not possible unless the fetus rotates, usually requiring cesarean section due to risks of cord prolapse and uterine rupture.
· (c) Frank breech presentation – In this position, the fetal buttocks present first with legs extended upward. It increases risks like cord prolapse, birth injury, and often necessitates C-section for safe delivery.
· (d) Posterior position of the fetal head – In occiput posterior, the fetal head faces the mother's spine, which causes prolonged, painful labor and may require instrumental delivery or cesarean in some cases.