Central separation of placenta is otherwise called:

Appeared in: BTSC 3 August 2025

Explanation

The Schultze mechanism describes the process where the placenta separates from the uterine wall starting from the center.
This central separation leads to the formation of a retroplacental hematoma, which is a collection of blood behind the placenta.
The weight of this hematoma aids in the complete detachment of the placenta.
The placenta is then delivered with its shiny fetal surface presenting first, which is why it's often remembered by the mnemonic 'Shiny Schultze'.

Option A: The Shirodkar procedure is a type of cervical cerclage, a surgical stitch placed around the cervix to prevent premature dilation and miscarriage or preterm birth.
Option B: The Mathews-Duncan mechanism describes a marginal or peripheral separation of the placenta, not central. In this method, the rough maternal surface presents first ('Dirty Duncan').
Option C: The McDonald procedure is another common type of cervical cerclage, similar to the Shirodkar procedure, used to manage cervical incompetence.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Mechanisms of placental separation in the third stage of labor as background academic context rather than a clinical decision trigger.
Observing the mechanism of placental separation is clinically important for the nurse and obstetrician as it provides clues about the completeness of separation and potential for postpartum hemorrhage (PPH).
In the Schultze mechanism, bleeding is initially concealed behind the placenta, and a sudden gush of blood often accompanies the delivery of the placenta. This can sometimes lead to an underestimation of initial blood loss.
The Mathews-Duncan mechanism is associated with a higher incidence of retained placental fragments, which is a significant risk factor for secondary PPH and uterine infection.

How to Approach the Question

First, identify the key phrase in the question: 'Central separation of placenta'.
Recall the two primary mechanisms of placental separation: one starts centrally, and the other starts at the margins.
Analyze the options. Recognize that 'Shirodkar' and 'McDonald' are names of surgical procedures (cervical cerclage) and are unrelated to placental delivery. This eliminates two options.
Differentiate between the remaining two options. Remember the mnemonic 'Shiny Schultze' for the central separation where the shiny fetal side appears first, and 'Dirty Duncan' for the marginal separation where the rough maternal side appears first.
Since the question asks for 'central separation', select the option corresponding to the Schultze mechanism.

Concept Tested & Keywords

QIuaCXgQwI8u9nYmABaFmx

E6 Obstetrics Williams p. 4-11

Practise the full BTSC 3 August 2025

Attempt every question from this paper in a timed mock, then review the full solution for each one.