After egg retrieval and introducing the eggs to sperm, the next morning is a crucial moment for embryologists. They take a close look at the eggs to determine their fertilization status. Let’s break down what they typically observe.
Mature Unfertilized Egg
First up, we have a mature unfertilized egg. You’ll see a polar body (that’s the little circle in red) which shows that the egg was ready for fertilization. However, without any pronuclei and a second polar body, it’s clear that this egg didn’t get fertilized. You might notice a lone sperm (pointed out by the arrow) hanging out on the egg’s surface.
Normally Fertilized Egg
Next, here’s a normally fertilized egg. It has two pronuclei (marked in blue) and two polar bodies (in red). That’s what we want to see!
Abnormally Fertilized Egg with Three Pronuclei
Now, let’s look at an abnormally fertilized egg with three pronuclei (in blue). In this scenario, since there’s only one polar body (in red), it’s likely that two maternal pronuclei are present along with one paternal pronucleus.
Abnormal Case with One Pronucleus
We also have another abnormal case where the egg shows just one pronucleus (in blue) and one polar body (in red). This isn’t ideal either.
Egg with Four Pronuclei
Last but not least, here’s an egg with four pronuclei (highlighted in blue). Definitely not what we want!
If you’re curious about nutrition that supports fertility, check out our other blog about tasty and wholesome immunity-boosting smoothie bowls here. Plus, for those interested in at-home insemination, you can find a fantastic kit here. And for expecting parents, March of Dimes offers wonderful weekly pregnancy resources.
In summary, understanding the fertilization process is vital for anyone on a fertility journey. By knowing what embryologists look for, you can feel more informed as you navigate your options.