When it comes to causes of infertility and their treatments, there are a host of situations that may occur and I won’t pretend to be an expert. It’s incredibly complex. I can, however, shed some light on the basics of In Vitro Fertilization (IVF) for those who may be unfamiliar, based on my own experience before I dive in deeper later.
At the start of someone’s menstrual cycle, they’ll likely get a baseline blood test to make sure their body is ready for medications. The first injectable medications are used as ovarian stimulants. The goal is to increase egg growth, so instead of only a single mature egg during that cycle, hopefully a significant amount more will grow (anywhere from just a couple to 40 or more!). During this 2-3 week period on medications, there is consistent monitoring of egg follicle growth and blood levels.
At a certain point, the bloodwork will indicate that ovulation will happen soon so another medication is administered daily to prevent ovulation while the eggs continue to grow. Once a majority of the eggs reach 18-22mm (ish), it becomes time to take the trigger injections. These injections prepare the body for the egg retrieval and are incredibly time-sensitive (usually given 36 hours before the scheduled retrieval). The day after trigger injections, the last blood monitoring occurs to make sure the meds worked properly and if so, then it’s go-time!
The egg retrieval itself involves going under anesthesia for a quick 15-20 minute procedure. They remove all the egg follicles, regardless of size, and check each egg within to determine if they’re mature. Only the mature eggs can then go onto the fertilization step.
Typically, one egg and 50,000 or more sperm are placed in a laboratory dish where hopefully one sperm attaches to the outside of the egg and fertilization begins. Depending on the situation, there is a more precise ICSI procedure where one sperm is injected directly into the egg. The fertilized egg then grows over the course of 5-6 days and if it reaches the blastocyst stage, it is ready for a fresh embryo transfer or cryopreservation for later use. Not all will fertilize and/or grow to the necessary stage to be used, so there are no guarantees. Lastly, there is the opportunity to take a biopsy sample of the blastocyst for chromosomal testing. This can only be done with a frozen embryo transfer because it takes a few weeks, and thus delays the process.
In the end, someone can choose to do a fresh embryo transfer soon after the egg retrieval or do a frozen embryo transfer at another time. Each option has their pros and cons and with all the variables throughout the process, every person’s journey will look different.