In-Vitro Fertilisation- Embryo Transfer (IVF-ET)

Frozen-Thawed Embryo Transfer (FET)

FET is performed if a couple has previously undergone IVF and have elected to have their embryos frozen. FET is the procedure where the previously frozen embryos are thawed and replaced into the uterus.

Previously the traditional 'slow freezing' technology has been used. Nowadays, the new vitrification method of IVF embryo freezing is employed.

The 'post thaw survival' and pregnancy rates are much higher with vitrification.

Different Protocols:

Natural FET cycle

Attend clinic about 18 days before the next expected menstruation. A pelvic ultrasound will be performed to assess follicle size
Daily urine LH testing if follicle is ≥14mm.
Once ovulation is detected, a blood test will be performed for confirmation.
Day 2 frozen embryo cycles are done with transfer on day 3-4 after the LH surge.
Blastocyst FET cycles are done with transfer on day 7-8 after the LH surge.。
Pregnancy test will be done 11-14 days after embryo transfer.

Hormone replacement cycle

Oral Estradiol 2mg twice a day starting on the third day of the cycle. This dose may need to be increased according to endometrial thickness.
When the endometrium is 8mm, progesterone is started. Embryo transfer is planned for 2-5 days later. Oestrogen and Progesterone are continued into the luteal phase. Pregnancy test is done 12-14 days after transfer. If pregnancy occurs, oestrogen and progesterone are continued until 8 weeks of pregnancy.

Clomid Induced Cycle

Clomid is given from day 3-7
Tracking of ovulation and embryo transfer is the same as in natural FET cycle

Q&A

Q: How do I know whether I ovulate?

If your menstrual cycle is between 28-35days, most often ovulation do occur.
You can have ovulation assessed in 3 ways

Blood LH surge tests at around ovulation time
Follicle tracking by ultrasound at around ovulation time
Blood progesterone test 7 days after ovulation

Q: If I have regular menstrual cycles, will oral ovulation induction medicine improve
my pregnancy rate?

Probably not. Regular monthly cycles indicate that you most probably ovulate regularly. Oral ovulation induction medicine like clomid may decrease the thickness of the inside lining of the uterus, making implantation of the embryo difficult.

Q: Is there medicine that can improve semen parameters?

Poor semen parameters is usually genetic in origin. Taking medicine like clomid, testosterone or steroid will not improve semen parameters. Male infertility usually necessitates in vitro fertilization treatment, with or without intracytoplasmic sperm injection (ICSI).

Q: If a couple has been diagnosed as being suffered from infertility, is the chance of
getting pregnant very slim?

No, on the contrary, if you get appropriate management of your infertility problem early, the chance of pregnancy is still pretty high. Although simple advice and measures can help for the initial stage, aggressive treatment may have to be employed at a later stage. According to Nice guideline (Feb2013), in vitro fertilization (IVF) will be offered to women with unexplained infertility, mild endometriosis and mild male infertility who have not conceived after 2 years.

Q: Will I have premature menopause after a few cycles of IVF, since many eggs have been
used up during each treatment cycle?

No. Each woman have 400,000 eggs at puberty and one egg will reach maturity to ovulate every menstrual cycle. There is a total of 400-500 menstrual cycles for the whole reproductive life span. The rest of the eggs will become atretic. Infertility treatment recruits some of the eggs that will regress anyway. Menopause is a stage when all the eggs have naturally regressed and therefore you do not have to worry about premature menopause.

Q: I have tried intrauterine insemination (IUI) for 3 times, why am I still not pregnant?

Usually, IUI is considered a milder form of treatment for infertility if the fallopian tubes are normal. The success rate is around 10 percent per cycle even if gonadotropins injection is employed. You do not have to be discouraged even if you have failed to get pregnant after 3 cycles of IUI. We can employ in vitro fertilization for treatment as the success rate is 3-4times higher than IUI. Some cases do require IVF for success.

Q: Will ovarian stimulation medicine cause ovarian cancer?

Up to date, literature has shown that ovarian stimulation will not increase the chance of ovarian cancer.

Q: What is considered completion of one cycle of in vitro fertilization?

One cycle of ovarian stimulation for in vitro fertilization may result in producing many embryos. For every subsequent cycle, we put back 1-2 embryos into the uterus, if pregnancy has not been achieved. It is not until we have put back all the frozen embryos that it is considered we have completed one full cycle of IVF.

Q: Is the pregnancy rate employing frozen thaw embryos less than fresh embryos?

No. Nowadays, we employ ultra rapid method (vitrification) for freezing embryos, which will not lead to crystal formation that is damaging to the embryos. Moreover, we usually employ natural non stimulated cycle which involves a lower estradiol levels, when we put back frozen thaw embryos and this result in a better pregnancy rate.

Q: Usually how many IVF cycles should I undergo?IVF

Usually we will advise at least 3 cycles of IVF before giving up as the cumulative pregnancy rate increases. Of course, it depends on assessment after each cycle.