WEEK 8 — Parturition & Preterm Birth - ANHB3316

List the 3 coordinated steps required for successful delivery.

Myometrial contractions, membrane rupture, cervical dilation.

What are the three main phases of labour (0–2)?

0 initiation, 1 conditioning, 2 active labour.

Describe uterine changes in Phase 1 of labour.

Increased coupling, ion channels, receptor expression; reduced NO and progesterone receptor expression.

How is preterm labour pathophysiologically different from term labour?

Early, uncoordinated inflammatory activation often with exaggerated inflammation.

What are the main sources of inflammatory triggers in parturition?

Maternal (stretch, oxidative stress), foetal (lung mediators, glucocorticoids), placental (SASP/DAMPs).

What is the role of progesterone receptor B in labour?

Maintains uterine quiescence and inhibits CAP expression and NF-κB signalling.

Which transcription factor is the master regulator of inflammatory signalling?

NF-κB.

What is the most common microorganism associated with intrauterine infection leading to PTB?

Ureaplasma spp.

How does oxidative stress contribute to parturition?

Induces DNA/protein damage, apoptosis, inflammation—promoting pro-labour signals.

What percentage of twins are born preterm due to uterine stretch?

50–60%.