My infertile friends can probably skip this post.
And also anyone else who doesn't want to read a bunch of dull science-type crap. Actually you folks should just probably skip the whole blog because really, it's pretty much ALL going to be science-type crap.
How it's supposed to work:
First off, let's review some basic biology of the reproductive system. Each month a woman's pituitary gland secretes a hormone called FSH (follicle stimulating hormone). FSH stimulates the ovaries to produce follicles in which eggs can grow. The ovaries start off producing lots of follicles but soon the largest one will become dominate. The growing follicles produce estrogen which operates as a biofeedback mechanism to slow the production of FSH in the pituitary gland. Reduced FSH stops the growth of the lesser follicles and the ovaries ends up producing only one (or sometimes two) eggs.
The egg is released into the abdominal cavity and is picked up by the fallopian tube. Sperm fertilizes the egg and if the embryo is viable it will grow for several days in the tube as it makes it's journey to the uterus. In most cases the embryo would emerge into the uterus at the blastocyst stage (about 5 or 6 days old). If conditions are right, the blast will implant into the uterine lining and start growing into a baby.
After the egg is released, the follicle on the ovary becomes a corpeus luteum and produces progesterone which is necessary to maintain a pregnancy until the placenta is mature enough to produce this hormone on it own.
How Infertility (IF) works:
The human reproductive system is super complicated and there are a gazillion things that can go wrong which will prevent a couple from conceiving. Here's a few examples.
- Sperm can't reach egg: This can be due to structural issues like blocked tubes (in the girl or the guy) or chemical issues like hostile cervical mucus, or the man may have low sperm volume or poor quality.
- Poor egg quality: This issue is more common in woman over 35 but it can effect ladies in their 20's.
- No ovulation: Some women don't ovulate due to hormone imbalances (like PCOS) or for other reasons.
- Embryo can't implant: Due to poor quality lining, overactive immune system which attacks the embryo or other reasons.
- Recurrent miscarriages: The embryos might have genetic abnormalities which cause the pregnancy to fail or the mom may have some condition or hormone imbalance which makes it difficult for the body to sustain a pregnancy.
When IVF was developed 30 odd years ago, it was a miracle treatment for condition #1. It also helps #2 and #5 because the RE can identify the best quality embryos to be transferred back into the uterus.
How Invitro Fertilization IVF works:
There are a number of different protocols but I'm going to give a brief description of the most common one.
Step 1 Suppression: With IVF, the ovaries are artificially stimulated to produce multiple eggs instead of just one. Prior do this, the woman takes a suppression drug to stop the pituitary gland from producing FSH so the body's natural hormones and biofeedback mechanism don't interfere with this goal.
Step 2 Stimulation: The woman takes daily injections of FSH (and sometimes LH) to stimulate the ovaries to produce multiple follicles (ideally between 10 and 20). The RE monitors the follicles by ultrasound until they are large enough. Assuming this phase is successful and there are a sufficient number of follicles, the woman takes an "trigger" injection to mature the eggs.
Step 3 Retrieval: The woman undergoes a minor surgical procedure to extract the eggs from the ovaries.
Step 4 Fertilization and culture: The eggs are fertilized in the lab and the embryos are grown in a petri dish for up to five days. (Note: despite the term "Test Tube Babies" no actual test tubes are used in this procedure.)
Not all eggs will fertilize and there is a natural attrition among the embryos as the genetically abnormal ones stop growing. This is a very clinical description that doesn't do justice to how excruciating that week is. I woke up every morning at 4am unable to sleep and sat by the phone waiting to for the embryologist to call and tell me how many of my embryos made it through the night. Are your hopes (and a great deal of money) are invested in something that's completely beyond your control. It's not uncommon for none of the embryos survive the culture period.
Step 5 Embryo transfer: The embryologist selects one or two of the best quality embryos and the RE transfers them into the uterus. If there are any good quality embryos remaining, they are cryogenically preserved (ie frozen) to be transferred again at a later date. In some cases, the clinic will transfer more than 2 but this isn't common because it increases the risk of triplets or other higher order multiples. The woman takes a progesterone supplement because since she didn't ovulate, her body isn't producing this hormone naturally.
Step 6 Beta: About two weeks later you take pregnancy blood test called a beta. A positive beta test does not guarantee a viable pregnancy. About 1/3 of pregnancies end in miscarriage. Most fertile women don't even know they were pregnant when they have one of these early miscarriages. So IVF patients have a 2nd blood test to ensure that the HCG levels are increasing and then an ultrasound at around 8 weeks. If the embryo has a heart-beat at that ultrasound, its counted as a pregnancy in the clinic's stats.
At my clinic, the pregnancy rate when for patients that transfer 2 embryos is about 60% . This excludes the couples who didn't make it to transfer because none of their embryos were viable, or those couples whose cycles were cancelled before retrieval because they weren't producing enough follicles. On average, if you start an IVF cycle, the chances of getting pregnant are about 35 to 40%. It may take several cycles for a couple to become pregnant and some couples will never become pregnant because IVF isn't enough to help them overcome the medical condition which causes their infertility.
An average IVF cycle in Canada costs between $8,000 to $15,000 (including meds) which is not covered by public health care except in Quebec (and in some circumstances in Ontario). More complex cycles can cost even more. Is it worth the cost? Yes, absolutely! We had tried for almost 5 years before we tried IVF and getting pregnant with the twins felt like a miracle for us. A true blessing.
Our IVF Cycle:
We had a very successful initial IVF cycle. It started out slow; we only retrieved 6 mature eggs which is considered a low response. However, the fertilization and culture went very well. At day 5, we still had 5 good quality embryos (we transferred 2 and froze the rest).
Wow, this post turned out to be much longer and detailed than I indended. Hopefully somebody cares...well I care at least and that's the important thing.
In case you're curious...
Kate Goselin (from Jon and Kate Plus Eight) did not use IVF to conceive her famous sextuplets. She used a much cheaper treatment called IUI. She took medication that caused her to produce multiple eggs but instead of having them removed and cultured in a lab, she ovulated and had a sample of Jon's little swimmers injected into her uterus. This procedure is popular because it's cheaper but the success rate is lower than IVF and it has a higher risk of multiples.
Octomom: Nutcase Nadia Suleman did do IVF but conceived her record 8 babies because her equally nutty doctor transferred 12 embryos into her uterus when the industry standard is 2 to 3. My RE privately referred to it as criminal negligence. Nadia's doctor later lost his medical license (quite rightly).
