Fresh embryo transfer versus frozen embryo transfer



Recently, a few patients came in with some information from the internet with regards to frozen embryos transfers. These information suggested that Frozen embryo transfers has a higher pregnancy rates compared to fresh embryo transfers. Therefore, the patients requested to undergo the IVF cycle so that they can freeze all the embryos and have the embryos transfer back in later cycles.


This practice is not something new. With the vast improvement in freezing technology using a new technique called ‘vitrification’ or rapid freezing method, the survival rates of embryos after freezing and thawing is close to 95%. Therefore, in a reasonably good IVF cycle, apart from having 2 embryos to transfer back during the fresh cycle, majority of patients would have good number of embryos to be frozen which can be used during the next cycle. It is not unusual to find that if the patients did not manage to get pregnant during the fresh cycle, when they come back for frozen embryo cycle, the pregnancy rates are close to 80-90%. A recent study conducted at KL Fertility Centre which looked at success rates of fresh cycles and frozen cycles of all women under the age of 42 and the statistic showed a 1.4x higher pregnancy rates for frozen embryos transfers. There is also significant lower miscarriage rate whereby there is a 2.5x reduction of miscarriage.


This finding coincides with the recent paper published in Fertility & Sterility, one of the world leading medical journal in Fertility. This paper consists of a meta analysis of a few studies which looked at the pregnancy rates for Fresh embryo transfers versus Frozen embryo transfers and the result showed a significant higher pregnancy rate in Frozen embryo transfers and a lower miscarriage rate. The results favoring Frozen Embryos Transfers instead of fresh embryo transfer may be related to the adverse effects of Controlled Ovarian Hyperstimulation (the drugs we used to stimulate your eggs to grow) on endometrial receptivity (which is the term we used for how ready your womb to accept the embryo for implantation) , as well as the improved results that can be achieved with current cryopreservation methods (which is the rapid freezing method, or vitrification).  (Rogue M at el. Fresh embryo transfer versus frozen embryo transfer in in-vitro fertilization cycles: a systematic review and meta-analysis. Fertil Steril. 2013 Jan;99(1):156-62)


So, for those who have not been successful during the fresh cycle, please be reassured that when you come back for your frozen cycle, there is a higher chance of getting pregnant. Please do not beat yourselves up and turn the disappointment of the failed fresh cycle into a long-term grief. If you keep moving on, you will get there!!!!

Age and IVF success rate

Pregnant Belly

Many couples went through IVF in hope to have a child. Many view this treatment as the last resort to having a child. Therefore, it is not unusual for me to encounter couples who had exhausted ALL forms of treatment and landed in my clinic after many frustrating years. Some had come a bit too late….

Part of my job as an IVF specialist includes constantly being asked by patients on their chances of pregnancy by IVF.

This is definitely a relevant question. IVF is an expensive treatment and certainly after spending XYZ amount money on this treatment, you would like to know what is your chance of pregnancy.

In general, the chance of pregnancy depend on 3 most important factors: The woman’s age, the number of years of subfertility & whether there had been any pregnancies in the past.

Out of these three factors, the most important and relevant factor would be a woman’s age.

Studies had shown that after the age of 35, the chance of women getting pregnant naturally as well as through Fertility Treatment declined gradually. There is a further sharp declined after the age of 40.

I do not mean to press the panic button for all the women over the age of 35. However, I strongly feel that this is an important message which many Fertility Specialists like us had not been shouting loud enough to educate the general public.

Studies from Australia & US had shown that the success rate of an IVF is around 50% before the age of 35. The success rate drops thereafter and hit the range of 20-30% by the time the woman turns 40. The chance of pregnancy after the age of 44-45 is close to 0%.

The reason for a lower success rate after the age of 35 is a combination of the fact that age is associated with decrease number of follicles and quality of the eggs. For women, we are born with millions of eggs and the process of recruitment and activation of eggs started as we reached puberty. The number of eggs in our ovaries go down as we aged. By the time we each menopause, the eggs were completely depleted in our ovaries. Therefore, at the age of 35, we are expected to be producing less number of eggs. As we age, the quality of eggs also decrease and there is higher likelihood to produce eggs with abnormal chromosomes. Therefore, there is a higher risk of miscarriage and fetal anomalies.