IVF (in-vitro fertilisation) was developed over 40 years ago and is today the most common and effective type of fertility treatment. In 1978 it was Louise Brown who is the first child successfully born after her mother received IVF treatment. Brown was born as a result of natural IVF cycle.
IVF in a nutshell
Hormones are given to the woman to stimulate the ovaries to produce excess follicles, where eggs develop. Approximately 9-14 days after stimulation has begun, an injection of human chorionic gonadotropin (hCG) is given 36-40 hours before egg collection. Egg collection is performed under general anaesthetic and lasts approximately 10-15 minutes. Once the eggs are removed from the follicles, they are mixed with the sperm.
The next morning the embryologists will assess the eggs for microscopic signs of fertilisation. A fertilised egg will divide and grow from one cell into 2, 4, 8 and more cells called an embryo. Viable, fertilised embryos are transferred to the uterus usually three or five days after egg collection. The remaining good quality embryos can be cryopreserved for future use. Approximately 14 days after the embryo transfer, a blood or urine pregnancy test is performed.
IVF is a type of fertility treatment where fertilisation takes place outside of the body. It’s suitable for people with a wide range of fertility issues and is one of the most commonly used and successful treatments available for many people.
IVF is a common treatment for people who are unable to conceive naturally. It involves collecting a woman’s eggs and fertilising them manually with sperm in the lab. If fertilisation is successful, the embryo is allowed to develop for between two and six days and is then transferred back to the woman’s womb to hopefully continue to a successful birth.
Often several embryos will be created through fertilising the eggs. In these cases it's normally best practice to freeze the remaining embryos rather than having two embryos put back in the womb, as this increases your chance of having twins or triplets. You can then use your frozen embryos later on if your first cycle is unsuccessful or you want to try for another baby.
Stimulated, sometimes also called Conventional IVF, is necessary for many patients. It utilises drugs to obtain multiple eggs and create multiple embryos to increase your chances of becoming pregnant. During a standard monthly reproductive cycle a single egg grows and matures inside an ovarian follicle. This egg is then release and becomes available to be fertilised once woman's hormones reach a certain level. In a stimulated IVF cycle, a woman takes fertility medication to stimulate both of her ovaries to grow and mature multiple egg follicles, which are being monitored by a treating clinician with ultrasounds and bloodwork to track the follicle growth.
An egg retrieval (egg collection) procedure is performed once the follicles reach a certain size under anaesthesia to remove the eggs from the follicles. The retrieved eggs are then fertilised with sperm (donor sperm or partner's sperm) in order to create embryos.
The embryos then grow until embryologist can identify the most suitable one(s) for Embryo Transfer procedure (transfer of the embryo(s) back into the woman's uterus), alternatively for freezing for future use (Embryo Freezing treatment). At the same time, any surplus embryos of a good quality that are not transferred can be frozen for future use.
Natural Cycle IVF is not new. The first IVF baby in the world was from a natural cycle in 1978 in UK. At that time, the IVF pregnancy rates were low, so stimulated IVF using fertility drugs became the standard in order to produce more eggs and embryos so that multiple embryos could be transferred back into the uterus. Over time stimulated IVF resulted in greatly improved pregnancy rates. However, some concerns have been raised as to side effects resulting from the use of stimulation drugs and the risk of Ovarian Hyperstimulation Syndrome (OHSS).
Natural Cycle IVF uses no stimulation drugs to stimulate the growth of follicles and follows the natural selection of the leading follicle.
Your body naturally selects your best egg. When mature, usually around the 10th day of your cycle, the egg is retrieved. Egg collection is a straightforward procedure. With only one follicle, it takes less than 5 minutes to retrieve the egg. Many patients complete the procedure without the need for sedation or pain relief medication and are able to return to work the same day. Your egg is then fertilised with your partner’s or donor's sperm using modern laboratory techniques. Two to three days later a single embryo is replaced in the uterus during embryo transfer procedure. Two weeks later we test for a pregnancy. The entire process is based on your menstrual cycle and takes 10-14 days. You have no or minimal use of drugs and a very low chance of multiple pregnancy.
Many women opt for Natural IVF to minimise the cost and the discomfort associated with ovarian stimulation. There are cases in which the outcome with Natural IVF is predicted to be the same as with stimulated IVF, in which case we would advise it as the treatment of choice.
- No or minimal ovarian stimulation drugs
- Considered less stressful by many
- Less costly
- Can be repeated with back-to-back cycles
- No risk of Ovarian Hyperstimulation Syndrome (OHSS)
- Cumulative pregnancy rates may be similar to one stimulated IVF
- Age less than 45
- Regular menstrual cycles
- No hydrosalpinx
- Normal uterus
- No medical contraindications
May treat patients who have
- Low ovarian reserve
- No or poor response to conventional IVF
- Previous unsuccessful stimulated IVF treatments
- Male factor subfertility
- Tubal occlusion
- Pelvic Adhesions
What About the Natural Cycle IVF Pregnancy Rates?
The concern with Natural Cycle IVF has focused on the lower success rates and the need for multiple treatment cycles to achieve the same pregnancy rates as a single treatment cycle of stimulated IVF. Current medical literature contains many reports showing acceptable clinical pregnancy rates using Natural Cycle IVF ranging from 15-25% per embryo transfer. This includes patients who are known to be “poor responders” to stimulatory drugs.
Philosophy Regarding Stimulated and Natural Cycle IVF
At City Fertility, we believe in an individualised approach to your fertility challenges and a bespoke fertility treatment plan. Natural Cycle IVF is certainly one of many treatment options that we will discuss with you. There are many patients who have failed or are not candidates for stimulated IVF and have nevertheless achieved a successful pregnancy using Natural Cycle IVF. Some were told that their only option for pregnancy was through egg donation or adoption. Some experts now recommend that patients consider Natural IVF prior to undergoing egg donation or adoption (Kadoch et al., 2011, Fertility/Sterility).