Parenting Australia

In Vitro Fertilisation

In Vitro Fertilisation sounds technical but it’s really just ‘assisted contraception’. IVF can increase the chance of pregnancy by increasing the number of eggs available for fertilization and also by increasing the number of sperm that get to where the egg is.

In general, fertility starts to decline after the age of 35 and pregnancy rates are extremely low by the mid forties, but women and men also turn to IVF for other reasons - ovulation disorders, endometriosis, blocked fallopian tubes, uterine anomalies and polyps and fibroids as well as sperm issues also affect fertility.

So how does IVF actually work?

When you begin IVF, a follicle-stimulating hormone (FSH) is used daily by injection to recruit as many follicles as possible in one cycle. The ovaries’ response is monitored by several ultrasounds, to measure the growth of the follicles. Usually it takes 11 to 14 days for the follicles to reach a size of 18mm to reliably produce fertilizable eggs.

In order to grow the follicles, normal ovulation needs to be suppressed, and this is done with a second drug either started before the stimulation begins (agonist cycle) or introduced in the middle of the cycle (antagonist cycle). When the follicles are ready, a trigger injection of Human chorionic gonadotropin (hCG) is given to set into motion everything that will make ovulation happen, causing the egg in the mature follicle to be fertilizable and loosening it from the wall of the follicle so that it comes out at egg collection. The eggs are then retrieved transvaginally under ultrasound guidance.

This is where things get really technical. The egg is then fertilized with the sperm in one of two ways. Either the sperm are left in a plastic dish with the eggs and a random sperm penetrates each egg, or, if the sperm is suboptimal then a single sperm is injected directly into each egg. This process is called Intracytoplasmic sperm injection (ICSI).

The subsequent embryos that develop are transferred to the uterus either on day 2, 3 or 5. The day of transfer is based on the quality and number of embryos available. Progesterone in the form of a vaginal pessary or gel is given over the next several weeks to support the uterine lining and keep it receptive for pregnancy. Any surplus embryos which are good enough are frozen for future use.

Dr Julie Lukic is a Sydney Obstetrician and specialist in female infertility www.theconceptionzone.com.au

 

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