IVF since its inception 40 years ago, is not without its controversies, and they don’t come much bigger than the perennial debate of whether fresh or frozen is better, in terms of success and pregnancy outcomes. Depending on who you ask, everyone seems to have a different opinion and what to do. The amount of information out there is seriously confusing, yet it doesn’t seem any closer to being able to explain this reproductive enigma.
What happens in an IVF cycle?
Let’s first of all look at what happens in an IVF cycle. No matter whether you’re having a long, short, antagonist, agonist or natural cycle, the same principles apply. You are given drugs to stimulate the growth and production of several eggs until one or more are collected and then fertilised with sperm.
Fertilisation happens through in vitro fertilisation (IVF), or intracytoplasmic sperm injection (ICSI). The latter involves the individual injection of sperm into an egg, which is usually reserved for those with sperm abnormalities.
In a completely natural cycle, no stimulation is given and instead, growth of a single dominant follicle is closely monitored.
Should I go ahead with a fresh cycle or freeze the embryo?
What happens next is where the jury is out and where experts share many different points of view. Do you go ahead with the fresh transfer of an embryo that has developed over several days, or do you wait and freeze the embryo after culturing and defer transfer until a subsequent menstrual cycle?
Sometimes, there are strong factors which will heavily influence this decision. For example, practically all experts will agree that if you were to develop signs of ovarian hyperstimulation, associated with a profound response to the drugs used to encourage follicular growth, deferral of transfer until symptoms resolve is a necessity.