Dual triggers Flashcards
What does LH surge do physiologically.
Induces final oocyte maturation.
Resting oocytes arrest in the diplotene stage of prophase 1.
Resumption in meoisis 1.
Disassembly of GV.
Chromosome condensation.
Spindle formation.
Extrusion of first polar body.
Enters metaphase 2 and arrests there until fertilisation.
Cumulus oophorous separates from the granulosa cell layer.
Rapid ascent in LH over 14hours, plateau for 14hours then descent over 20hours.
What does the FSH surge do physiologically prior to ovulation
Helps promote nuclear oocyte maturation
Favours cumulus oocyte complex
Stimulates cumulus expansion
Favours the release of proteolytic enzymes involved in ovulation
Potential physiological reasons for improved results with dual trigger?
Addition of endogenous FSH surge - synergistic effect of LH and hCG on LH receptor
FSH promotes formation of LH receptors in luteinizing GCs, nuclear maturation, cumulus expansion
Benefit of dual trigger:
Prolonged activation of HCG - restores endometrial recepetivity vs GnRHa alone
Seems to be supported by evidence suggesting benefit more in fresh ET rather than frozen with restoration of endometrial receptivity.
Evidence to support potential benefit
Haas 2020 Human Reproduction.
P - Normal responders, 18-41 years, BMI 18-35, AMH >1ng/ml = 7.14pmol/L,
Exclude: OHSS (E2 >15000 AFC >20), Mod-severe endo
I - GnRHa and hCG dual trigger
C - placebo trigger and hCG trigger
O - The clinical pregnancy rate (24.3% versus 46.1%, OR 2.65 (1.43-1.93), P = 0.009) and the live birth rate per transfer (22% versus 36.2%, OR= 1.98 (1.05-3.75), P = 0.03) were significantly higher in the dual trigger group compared to the hCG group
Meta-analysis in JBRA 2023
Conclusion dual drigger improved oocytes retrieved and live birth rate. Most included studies were in normal responders.
Less clear for poor responders.
Current use in our centre
To try and increase number of mature oocytes - usually recommended in those with previously high number of immature oocytes.
