# Detecting partial premature ovulation during follicular aspiration compromises the quantity, but not the quality, of the oocytes retrieved in stimulated in vitro fertilization (IVF) cycles

## TL;DR

This study finds that partial premature ovulation during egg retrieval in IVF reduces the number of eggs and embryos available, but not their quality.

## Contribution

The novel contribution is identifying that partial premature ovulation affects oocyte quantity but not quality in IVF cycles.

## Key findings

- PPO cycles had significantly fewer oocytes, mature oocytes, fertilized oocytes, and top-quality blastocysts compared to non-PPO cycles.
- Oocyte and embryo quality metrics like maturation and fertilization rates were comparable between PPO and non-PPO groups.
- Pregnancy rates were similar in PPO and non-PPO cycles despite fewer embryos available in PPO cases.

## Abstract

To analyze if partial premature ovulation (PPO) detection during oocyte
pick-up (OPU) impairs the quality of the retrieved oocyte cohort.

The PPO concept refers to the situation when premature ovulation happens only
in some of the follicles and it is detected during OPU. This study
constitutes a retrospective analysis performed in an infertility clinic
(Spain) during 2016-2021 with patients undergoing OPU after controlled
ovarian hyperstimulation for an in vitro fertilization
(IVF) treatment. Study code: 2110-VLC-091-VG, registered on December 9 2021.
Data from women with PPO (n=111) were compared to a matched control sample
of cycles without PPO (n=333) at a proportion of 1:3.

Cycles were matched for age, body mass index (BMI), treatment year, embryo
genetic analysis and stimulation protocol type. The mean numbers of oocytes
(6.1 vs. 11.2), mature oocytes (4.7 vs.
8.8), correctly fertilized oocytes (3.6 vs. 6.6) and top-quality blastocysts
(0.9 vs. 1.8) were significantly lower in the PPO group
than the nonPPO group (p<0.05). However, maturation,
fertilization, top-quality blastocyst and pregnancy rates were statistically
comparable among groups (p>0.05).

Cycles with PPO have fewer available oocytes and, thus, fewer available
embryos for transfer, al though their quality is intact, and still offer
chances of pregnancy in these cases. Hence cycle cancellation may not be
worth associated money, time and morale losses once PPO is detected.