Posts Tagged ‘fertilisation’

IVF – the hurdles

Friday, October 2nd, 2009

So you’ve read the IVF manual and are all ready to start a cycle. What are some of the “wish I’d known that” snippets that veteran IVFers can share with you to help fill the knowledge gaps about what to expect? Well, one that comes up a lot is having a clear understanding of the not-so-straightforward hurdles involved in an IVF cycle. Here’s a typical comment from an IVFer …

When you start this journey you read the “ivf manual” and all sounds so easy – take some drugs, grow some eggs, have them collected, fertilised and put back in and voila! a baby. Ha!! They don’t tell you about the things that go wrong. Or the things that don’t work the way they should.

So, what are the main hurdles you face in an IVF cycle?

  1. Downregulation or precycle suppression might take longer – some gals do their downregulation blood tests after several days on Buserelin and find they need to keep downregulating for several more days before starting stims. If you’re on no precycle suppression or something very mild, you may find that you have a dominant follicle or a cyst at the beginning of your cycle and it may not be a good idea to proceed with stims.
  2. Assuming you get out of the starting blocks, your first hurdle is whether your ovaries will respond to the stims. This is assessed with blood tests (for estrogen, or E2) and an ultrasound. If you grow too few follicles or your E2 is too low or the follies don’t grow fast enough or your E2 doesn’t rise enough, the clinic is likely to cancel your cycle for poor response. The good news is that you may do better on another protocol – see an earlier post on IVF protocols for more information …
  3. Some women have the exact opposite problem to poor response – they overrespond. They grow too many follicles and their estrogen shoots dangerously high. In this case the clinic will either drop your dose of stims or stop stims altogether (this is called ‘coasting’). The blood tests continue, and if your E2 drops to a safe level they will let you trigger and go ahead with your egg collection; if the levels stay too high for too long, you may be cancelled for your own safety because you are at high risk of OHSS (ovarian hyperstimulation syndrome). Even if you make it to egg collection, you may be told it’ll be a freeze-all cycle – research shows that women at risk of OHSS are at higher risk if they do a fresh transfer and get pregnant.
  4. You make it as far as egg collection (a.k.a. ‘retrieval’) and have 10 follicles. That’ll be 10 eggs, right? Unfortunately not. Not all follicles yield an egg, and some women have major problems at this hurdle, getting only eggs from only 50% of their follicles, or sometimes fewer. [See Empty Follicle Syndrome] Others have a 100% strike rate just about every time. So, it’s just the luck of the draw. In any case, you shouldn’t expect to get an egg from any follicle that was smaller than about 15-16mm at trigger, and you shouldn’t expect all your mature (large) follicles to yield eggs.
  5. Yay, we got six eggs!! That’ll be six embryos, right? If you’re lucky, yes, but there are more hurdles here too. First, it’s possible not all of your eggs were mature. Only the mature ones can potentially fertilise. And not all of them do. Some couples get 100% fertilisation just about every time, and others get a very low %. Some also get abnormal fertilisation, such as when two sperm enter one egg. ICSI can improve fertilisation rates if there are sperm issues or if the eggs have hard ‘zona’ (eggshells).
  6. The day after egg collection, the embryologist will usually call you to let you know how many of your eggs were mature and how many have fertilised normally. From there, you are in a waiting game to find out how many of those embryos will make it to Day 3, and how well they divide. Some may ‘arrest’ (stop growing) along the way, some will divide more slowly (or quickly) than is optimal. The best possible result is to have 4-cell embryos on Day 2 and 8-cell embryos on Day 3. The survival rate from fertilisation to Day 3 is not usually too bad.
  7. If you’re taking your fresh or leftover embryos from Day 3 to blastocyst stage, there is a VERY high die-off rate at this point. Before deciding to do this, I strongly recommend you read the post on this issue (2-day, 3-day or blast transfer?), discuss it with your doctor, nurse and embryologist, and make your wishes crystal clear.
  8. Once the embryos are transferred back to the uterus, you are in the dreaded 2ww (2-week wait). Arrrghh! Enjoy the first week because you are going to drive yourself insane in the second week obsessing about every twinge. 🙂

Well, those are the main hurdles for an IVF cycle. The bad news is that if you DO get a BFP there’s a whole other set of even more hair-raising hurdles to clear! But we’ll save that for another post …