Hormones that help female reproduction

Dr. Beth Taylor

June 20, 2022

Let’s talk hormones for a minute.  Hormones are little proteins that float around in our blood stream. They stop and bind to a cell if the cell has a receptor for them.  There are loads of hormones in humans:  estrogen, progesterone, cortisol, testosterone, prolactin, GnRH, DHEA, growth hormone, thyroid hormone, vitamin D, oxytocin, FSH, LH, and others.


In the world of IVF we are focused on the hormones that help female reproduction, which for the past 50 years we’ve understood largely to be FSH, LH, GnRH, estrogen and progesterone. 


I say this with no arrogance, but I think we understand this set of hormones and how they influence IVF and egg number and egg quality and overall outcome pretty well. What is interesting now is learning how the other, call them non-traditional, “female” hormones, impact IVF and reproduction.


I thought it would be helpful to provide a 1 minute review of two of these hormones and their role in IVF.


Thyroid - I think most of us are obsessed with our thyroid.  Thyroid hormone does a long list of things in our bodies including impacting egg maturation and endometrial health. We measure thyroid function not by checking the thyroid level directly (as there are different thyroid hormones and the levels fluctuate in a way that makes acting on blood results tricky), but we measure thyroid stimulating hormone (TSH) which is a more stable measure of thyroid function.  Most of us have a TSH between 0.4 and 2.5 mU/L.  Levels above 4 mU/L are associated with higher miscarriage rates, potentially lower embryo quality and infertility.  Levels below 4.0 mU/L have not been associated with adverse outcomes.  Every patient at Olive will have TSH checked at some point during their care.


Growth hormone - much like thyroid hormone, GH does a long list of things in our bodies.  It has become clear over the past decade that is also plays a role in the function of the support cells that surround the developing egg (granulosa and theca cells).  Over the past few years a few studies have examined GH use in women undergoing IVF.  My distillation of these studies is that there may be a benefit in women with low egg counts, particularly if they have done IVF in the past with low/poor egg yields. GH has been given at the same time as the other IVF injections i.e. during ovarian stimulation and it has been given prior to the start of stimulation.  We do not know which timing is ideal.  At Olive, if we use it we typically prescribe it during ovarian stimulation which is how most studies showing benefit have done.  This will likely evolve as more studies get published. GH is available under the brand name Saizen and is given by daily injection.

Your Olive doctor is always happy to chat about these hormones and others that might help optimize your IVF treatment


Dr. Beth Taylor

Inclusion of all gender and sexually diverse people is an important value of Olive Fertility Centre. We are continuously striving to create an environment of compassionate belonging where all of the 2SLGBTQIA+ community are supported, valued and respected.

Olive Fertility Centre resides on the traditional, ancestral, and unceded territory of the xʷməθkwəy̓əm (Musqueam), Skwxwú7mesh (Squamish), and Tsleil-waututh Nations (Vancouver and Surrey clinics), of the Lekwungen people (Victoria clinic), of the syilx/Okanagan people (Kelowna clinic) and of the Lheidli T’enneh First Nation (Blossom Fertility clinic in Prince George).

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