Personalized medicine is not just a new “buzz phrase” but an important paradigm in fertility care.   

I like to divide IVF up into two parts: embryo creation and embryo transfer.

When people talk about IVF they are usually talking about the embryo creation half: priming the ovaries, ovarian stimulation with injections of FSH and LH to grow the eggs, egg retrieval, egg fertilization and embryo development and freezing.  

After we have embryos frozen we then shift our attention to the uterus - the embryo transfer portion.

The embryo can be put into the uterus after a woman takes estrogen and progesterone (mediated frozen embryo transfer FET), after she just takes progesterone (natural cycle FET), after she has an HCG trigger and then takes progesterone (modified natural cycle FET) or after no mediations (unmedicated FET).  Unmedicated FETs are not recommended as they have lower pregnancy rates than the other options.

Which one is best for you? That’s where personalization comes in.  We consider whether you ovulate in your own menstrual cycle or not, whether you need help thickening the lining, where you have done endometrial testing (e.g. endomeTRIO), your time considerations, your uterine lining thickness in the embryo creation portion, where you live and other considerations.

This month in Fertility & Sterility they examined studies on natural cycle embryo transfer WITH progesterone supplementation compared to natural cycle embryo transfer WITHOUT progesterone supplementation.  This study, a meta-analysis, showed higher live birth rates when progesterone is given. It’s not clear on the optimal dose, but at least 200mg vaginally per day.  Interestingly, if you trigger ovulation (rather than just letting a woman ovulate on her own) you might be ok using oral progesterone, rather than vaginal but that wasn’t as convincing as I’d like. 

Deciding on embryo transfer protocol should really be personalized, often we add supplements, vaginal probiotics, etc.  We also should follow the evidence to achieve the highest possible live birth rates for patients and this study helps us do just that.

Yanbiao Jiang, et al. The effect of progesterone supplementation for luteal phase support in natural cycle frozen embryo transfer: a systematic review and meta-analysis based on randomized controlled trials, Fertility and Sterility, Volume 119 (4) 597-605.