One of the first things on an embryo's to-do list is to make a placenta, but to do this, it will need to work well with the decidual cells occupying the future Placenta construction site, otherwise known as the decidua or uterine lining that's beefed up for pregnancy.

There are likely many contributors to this process, but how this negotiation goes down between a specific set of immune cells called uterine natural killer cells, or uNK cells and the fetal cells from the embryo that set up the bridge between the mother's body and the placenta called the trophoblast cells, or EVTs is the subject of today's episode.

Also: why great obstetrical syndromes (preeclampsia, IUGR, stillbirth) is more of an issue for humans than other mammals.

Although your OB usually doesn’t want to see you in the early weeks of pregnancy—there’s a lot going on that is of critical importance to the ease or complications of a pregnancy—specifically , the introduction of fetus to your uterine lining, and the subsequent merging, if implantation happens.

The weeks that follow are equally consequential. Exactly how those cells of your uterine lining negotiate the migration of trophoblast cells, fetal cells that are building the placenta can be the difference between preeclampsia, premature birth intra uterine growth restriction and a normal pregnancy. One main negotiator of this migration is a specific type of immune cell, uNK cells. Today we talk to a world expert on how certain elements of the immune cell function in early pregnancy.

Dr. Ashley Moffett's 2022 paper in Nature Review Immunology: https://pmc.ncbi.nlm.nih.gov/articles/PMC9527719/#Sec1

We are going to talk about the menstrual cycle, aka the result of the conversation between your brain, pituitary and ovaries that’s going on each months to create the conditions for you to build a human.

How does your body accomplish this amazing feat?

You likely experience your menstrual cycle, and your period in particular, as an inconvenience, but evolution put a lot of hard work into this process and it turns out to be pretty nifty.

We’ll also talk about the why today. Most mammals don’t have a menstrual cycle. Why do we think humans do?

And how are the ways we have figured out to control that cycle operating in this complicated chemical conversation going on in your body?

Are the movers and shakers of the menstrual cycle, the specialized cells that make all these changes happen each month, are they good for anything else?

We’ll walk through these topics today.

Questions or comments? write to contact@makingsenseofpregnancy.com, or find me on instagram @makingsenseofpregnancy