The key factors regulating the phases of parturition

[Medicoman]

1. PHASE 1(QUIESCENCE)

• progesterone
• prostacyclin
• relaxin
• PDGH
• nitric oxide
• hCG
• CRH

2. PHASE 2(ACTIVATION)

• estrogen
• progesterone (non classic withdrawal)
• uterine stretch
• gap junction receptors
• relaxin
• hyaluronan
• changes in proteoglycan composition
• fetal signals(CRH, SPA)
• prostaglandin
• cortisol

3. PHASE 3(STIMULATION)

• prostaglandin
• oxytocin
• relaxin
• CRH
• inflammatory cell activation

4. PHASE 4(INVOLUTION)

• oxytocin
• inflammatory cell activation