Glossary · Definition · v2026.3
What Is the Luteal Phase?
The luteal phase is the portion of the menstrual cycle that begins after ovulation and ends with the start of the next period or confirmation of pregnancy.
The Luteal Phase in IVF
After egg retrieval in IVF, the luteal phase is supported with progesterone supplementation because the natural hormonal signals may be disrupted by the stimulation medications. Adequate luteal support is necessary for the endometrial lining to remain receptive to implantation.
Why It Matters in IVF
Insufficient luteal phase support can lead to implantation failure even when a healthy embryo is transferred. Progesterone is continued until the placenta takes over hormone production, typically around 8 to 10 weeks of pregnancy.
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This content defines terminology for educational orientation. It does not constitute medical advice.
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