Estradiol to progesterone ratio is not a predictor of oocyte maturity at time of ovulation trigger
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Updated: Sep 20, 2025

Human Egg Maturity Assessment and Its Clinical Application
Published on: August 19, 2019
Marisa Berger1, Hency Patel2, Richard Buyalos3
1Obstetrics and Gynecology, University of California Los Angeles, Los Angeles, CA, USA. mberger@mednet.ucla.edu.
Purpose:
To evaluate the relationship between progesterone and oocyte maturity rate via estradiol to progesterone ratio (E/P) at the time of ovulatory trigger.
Methods:
This is a retrospective cohort study of first autologous IVF cycles from January to December 2018 from a private practice fertility center. Serum estradiol and progesterone levels were measured on the day of ovulatory trigger. E/P was calculated to control for degree of response. Embryos were cultured to the blastocyst stage for trophectoderm biopsy. Preimplantation genetic testing for aneuploidy (PGT-A) was performed using next-generation sequencing (NGS). Oocyte retrieval rate (oocytes retrieved/follicles ≥ 13 mm), maturity rate (MII/oocytes retrieved), and euploid rate (euploid/total biopsied embryos) were calculated. Clinical pregnancy, ongoing pregnancy (> 10 weeks), and live births following frozen embryo transfer (FET) were examined in relation to E/P. Regression analyses were performed to analyze E/P as a categorical value (defined by quartile) on oocyte maturity.
Results:
Two hundred eleven women underwent controlled ovarian hyperstimulation and had steroid levels at trigger available. Mean E at trigger was 3449 ± 2040 pg/mL while mean P was 1.13 ± 0.58 ng/mL, with mean E/P of 3.36 + 2.04. There were no differences between quartiles of E/P with respect to retrieval, maturity rate, or euploid rate. Two hundred eleven IVF cycles resulted in 138 euploid frozen embryo transfers. There were no differences between quartiles of E/P with respect to clinical pregnancy, ongoing pregnancy, or live birth rate.
Conclusion:
E/P ratio at the time of trigger does not impact oocyte retrieval rate, maturity rate, or euploid rate. Pregnancy and live birth outcomes were also not impacted.
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