Making use of assisted reproductive technologies

The Latin phrase “in vitro” means “in the glass”. In vitro fertilization, thus, refers to the technology that puts eggs and sperm retrieved from the respective female and male reproductive tracts together in a glass tube for fertilization. The fertilized embryo is then transferred back into a woman’s uterus to develop into a fetus. You should get as much information about the procedures and their implications as possible before opting for IVF.

Each IVF cycle proceeds along four stages:

1. Ovulation induction – Daily injections or nasal sprays are used before treatment to suppress ovulation. This allows more time for eggs to mature and for fertility doctors to retrieve these eggs from a woman’s ovaries before she ovulates. This is followed by a course of injections of fertility hormones, which stimulates production of several eggs, as opposed to just one egg in a typical ovulation.
2. Oocyte retrieval – An ultrasounds probe will be inserted into a woman’s vagina to identify follicles. Once they mature, eggs are retrieved from a woman’s ovaries using a thin needle under light sedation.
3. Fertilization – The husband will be asked to provide sperm on the day of oocyte retrieval. Retrieved eggs will be fertilized with the husband’s or donor’s sperm in a laboratory and develop in an incubator for a few days. A point to note is that the number of eggs retrieved will differ from person to person, and not all eggs will go on to be fertilized in the laboratory.
4. Embryo transfer – Two to three days after oocyte retrieval, the viable embryo(s) will be injected through a woman’s cervix and vagina into her uterus using a thin tube. Most fertility clinic in Hong Kong recommends transferring no more than two embryos per cycle. The outcome of treatment will be confirmed with a pregnancy test two to three weeks after embryo transfer.

Things to consider before choosing IVF:

• How many embryos do you plan to transfer? – It is common for fertility clinics in Hong Kong to recommend transferring one embryo per cycle, and less occasionally, two embryos at most, to avoid multiple pregnancies.
• What will you do with unused embryos? Will you store the embryos for future use (more about cryopreservation) or donate them (more about egg donation)?
• How will you handle multiple pregnancies?
• Will you use donor sperm?

IUI refers to the procedure of placing sperm inside a woman’s uterus to increase the chance of pregnancy. This is a relatively non-invasive option compared to its counterparts like IVF. IUI is suitable for couples whose male partner has low sperm counts or sperm motility, whose female partner suffers from endometriosis or cervical issues, or in cases of unexplained infertility.

Stages involved in IUI:

• Pre-treatment check-up such as blood tests to check a woman’s hormone levels and semen analysis for male partner
• If you choose a stimulated cycle, you may start to take fertility drugs
• Your menstrual cycles will be closely monitored by the fertility care team
• A sperm sample from the male partner (or a donor) will be washed to remove chemicals from the semen to prevent complications in the uterus
• Insemination will take place at the time of or before ovulation. The procedure is relatively quick (usually lasts few minutes) and painless

Things to consider before choosing IUI:

• Will you choose a natural cycle or a stimulated cycle? – whereas a natural cycle does not involve medication and is timed to a woman’s ovulation, a stimulated cycle involves a woman taking fertility drugs to stimulate production of more than one egg to improve the odds of pregnancy
• Do you have healthy fallopian tubes? – The success of IUI relies on a woman having an open fallopian tube. Once again, you should consult a doctor before engaging in any treatment

FET is an IVF cycle that uses a frozen embryo from a previous cycle or from an embryo donor rather than fresh embryo. As with an IVF cycle, the frozen embryo is injected into a woman’s uterus for implantation and maturation into a fetus.

Below are few situations in which you may consider FET:

• You want to start a new cycle using frozen embryos from a failed, fresh embryo IVF cycle
• You got pregnant from a previous fresh cycle, and wish to give your child a sibling
• You sent fertilized embryos to laboratories for preimplantation genetic diagnosis (PGD) and have to cryopreserve the embryos while waiting for a decision

Things to consider before choosing FET:

• Will you choose a natural cycle or medicated cycle? – A natural cycle does not require medication but needs more monitoring either at home or at a fertility clinic in order to capture the time of ovulation. A medicated cycle requires medication but allows doctors to better predict the timing of ovulation and optimize the endometrial lining.

ICSI is an IVF treatment involving a direct injection of sperm into an egg, and then placing the fertilized egg back into the uterus of the woman. It is suitable for couples who have sperm-focused fertility issue (which may have an unexplained cause), or those who have previously attempted IUI but are unsuccessful in achieving fertilization. Such technology is relatively safe and has high success rate in achieving pregnancy.

PDG is a genetic examination procedure conducted before implantation in order to identity potential genetic defects in an embryo. This technology is suitable for couples who concern they might give birth to a child with abnormalities in chromosome or inherited genetic disorder. One of the key benefits of practicing PGD is that it lowers a couple’s chance of experiencing miscarriage or pregnancy cessation due to an embryo affected by abnormal genes or chromosome.

Cryopreservation is a specialized low-temperature freezing technology which could be applied to settings beyond IVF. In order to facilitate success in freezing and thawing cells and tissues without killing them, cryopreservation process makes use of cryoprotective agents and equipment for controlling temperature during preservation process. Nonetheless, risks of cell damage do exist, either due to high concentrations of cryoprotective agents used or minimal metabolism of cells at an exceptionally low temperature.