When you’re going through in vitro fertilization (IVF), timing truly matters — especially when it comes to the trigger shot, the hormone injection that signals your eggs are ready to be retrieved. Getting the timing just right can make a big difference in how many mature eggs are collected and, ultimately, your chance of success.

A new study published in Reproductive Biology and Endocrinology explores how fertility specialists can better predict the optimal timing for egg retrieval — offering new insights that may help improve IVF outcomes.

What the Study Looked At

During controlled ovarian stimulation (COS), fertility medications are used to help the ovaries grow multiple eggs in one cycle. The “trigger shot” is then given to help those eggs complete their maturation before retrieval. But knowing the perfect moment to trigger is both an art and a science.

The study looked at how certain clinical and lab factors might predict when eggs are mature enough for retrieval. The goal was to identify measurable signs that help doctors decide the best time to administer the trigger — and ultimately increase the number of mature oocytes (eggs) collected.

Key Findings

Researchers found several predictors that can help pinpoint the optimal window for triggering egg maturation. When these predictors are used effectively, fertility specialists may be able to:

✅ Retrieve a higher number of mature eggs
✅ Improve fertilization and embryo development rates
✅ Make IVF cycles more efficient by reducing unnecessary medication use and clinic visits

In other words, small changes in timing can lead to meaningful improvements in treatment outcomes.

Why Egg Maturity Matters

When eggs are retrieved too early, they may not be fully mature, which lowers fertilization rates. Waiting too long can also reduce egg quality. That’s why IVF timing is such a critical part of the process.

Collecting more mature eggs increases the chances of creating healthy embryos. This gives patients more opportunities for a successful transfer and pregnancy.

This study adds to a growing body of evidence showing that careful monitoring and individualized timing are key to optimizing success in fertility treatment.

What This Means for Patients

For patients, this research reinforces that your fertility team’s focus on timing isn’t just about scheduling — it’s about maximizing your chance of success. Every ultrasound, blood test, and lab check helps your doctor determine the precise moment your eggs are ready.

By using evidence-based prediction tools, clinics can further personalize treatment, improving both the efficiency and effectiveness of IVF.

Questions to Ask Your Fertility Specialist

If you’re preparing for IVF, here are a few good questions to discuss with your doctor:

• How do you decide when to give the trigger shot during my cycle?
• What factors help you predict the best time for egg retrieval?
• How does egg maturity affect my chances of creating healthy embryos?
• How does your clinic personalize the timing of IVF treatments?

Having this conversation can help you feel informed and confident about your care plan.

The Takeaway

This new research highlights an important truth: in IVF, timing is everything. Advances in how fertility specialists determine the right time to retrieve eggs can help improve outcomes, reduce the stress of uncertainty, and make every cycle count.

At Genesis Fertility, we use the latest evidence-based approaches and follow ASRM guidelines to personalize each patient’s treatment — ensuring every step, including trigger timing, is carefully tailored for the best possible results.

This information has been medically reviewed by Alexander M. Kotlyar, MD, FACOG, Director of Resident Education at Genesis Fertility