Which of the following is a mandatory prerequisite before proceeding with a forceps-assisted vaginal delivery?

The supplied material lists full cervical dilatation, ruptured membranes, an engaged head, and estimated fetal weight below 4 kg among the forceps prerequisites. It also requires a known fetal position, no cephalopelvic disproportion, an empty bladder, adequate analgesia, neonatal resuscitation facilities, and operator skill. A cervix dilated to 6 cm is not fully dilated.\n\n**Key takeaway:** Forceps should only be used after all relevant prerequisites have been assessed.\n\n**Glossary:** **Cephalopelvic disproportion (CPD)**: A mismatch between fetal head size and maternal pelvic capacity; **dilatation**: Opening of the cervix.