Let's talk about Progesterone (prog)! Like its name suggests, it is a PRO-GESTational-hoRmONE i.e. it is critical to the successful continuation of a pregnancy! It's important for the implantation of the embryo & for the pregnancy continuing in the 1st trimester. It also plays a big role in preventing Preterm birth in the 2nd/3rd trimester but today, I'm talking about its importance for the 1st trimester. At the beginning of a pregnancy, except in frozen embryo thaw (FET) cycles, prog is made by the follicle/egg house which released/ovulated the egg(s). Once the egg is released, that empty egg house takes on a special name... 'The Corpus Luteum cyst' & makes prog to support the early pregnancy until the placenta can take over. The placenta starts making enough prog after the 8th week of the pregnancy! So, if prog is low, a pregnancy either will not form or continue! However, diagnosing & using the information of low prog is not clear cut! For example, some women go on to have perfectly normal pregnancies despite having low circulating blood levels of prog & some women with high prog levels still miscarry or do not get pregnant. So, my point? It's nuanced! We, Fertility Specialists, have basic thresholds that we like to see for prog levels but beyond that, we also use special 'gestalt'. Meaning, we look at the whole picture to determine when certain individual patients may benefit from additional prog supplementation. Supplements can be oral, vaginal, or by injection. Fertility specialists primarily prescribe vaginal or injection forms of prog! What I would also tell you, though, is that if you have been diagnosed with "low progesterone" you should not be on continuous prog replacement while you are trying to conceive (TTC). As a matter of fact, you should not be starting prog until AFTER ovulation! While there are many types of Providers who prescribe prog to patients who are TTC, I can also tell you that many are prescribing/dosing it at the WRONG time in your menstrual cycle! If you are TTC & really think low progesterone is an issue, you should speak to your Gynecologist or Fertility Specialist! This is their wheelhouse!











