Remember, this egg began its journey in your grandmother’s womb and has been maturing since the first day of your last period (the length depending on your hormonal and health balance). The journey of gestation rapidly advances after conception and the experience of your pregnancy is being set in place, literally, before you even know it.

By approximately five days after conception, the cells of this conceived baby are separating within a ball of cells called a blastocyst.  With incredibly powerful microscopes, the cells that will become the placenta can be seen gathered in one area while the cells that will become the baby will be gathered in another area.  The developing baby is moving down the fallopian tube and being attracted to endometrial lining, where it will make its bed, ideally for the next ten moons.

The rise of estrogen in the first half of your cycle, along with other fertility hormones like LH and FSH, determines when this egg is released.  Too much estrogen, and the uterine lining can grow up into the fallopian tube.  Too little estrogen and you may not ovulate or may not get the signal to increase progesterone production.  A balanced level of estrogen and fertility-supporting hormones help guide this developing baby out of the fallopian tube (preventing a tubal pregnancy) and into the top area of the uterine lining (to discourage miscarriage).  While I can’t find scientific evidence that indicates placental location has anything to do with hormonal levels, logic indicates this is likely true.

Progesterone supports estrogen by continuing to thicken the endometrial lining, making a robust place for the placenta to grow within.  With low levels of estrogen, and especially progesterone, the uterine lining will not grow as adequately as it should, and the egg will continue making its way down the uterus, and eventually out (which we call a miscarriage).  I’ve often wondered if low levels of progesterone cause anterior and low-lying placentas.  While these placenta locations don’t typically present any significant problems, they occasionally do impact pregnancy and birth.

The fundus of the uterus (the very top part) thickens and becomes the powerhouse during the pushing part of labor.  With balanced hormones, this is the most likely location of implantation, as it is closest to the fallopian tube.  This usually allows for a very easy separation of the placenta after birth.  A lower lying placenta may attach to the lower uterine segment (which is a little more passive in labor and postpartum) and can increase the likelihood of excess bleeding after childbirth.  When it implants even lower, the edge may be affected by cervical dilation and abnormal bleeding may occur during labor, or even during pregnancy.  A placenta that develops in the anterior (front) part of the uterus may influence a baby’s position and how movements are felt in pregnancy.  While we can’t guarantee this is all a result of low progesterone levels or other imbalanced hormones, it can’t hurt to optimize health well before conception.

Regardless of what your hormones are doing, the cells of your developing baby are finding their way to the thickened endometrial lining somewhere.  Currently, researchers believe that the endometrial lining is coated with carbohydrate molecules, and the ball of baby cells are covered with a protein called L-selectin, which are attracted to each other.  The cells within the developing baby that will eventually become the placenta reach into the uterine lining with finger-like projections and connect with the mother’s blood supply.  Now, at around seven to eight days after conception, the placenta begins to develop within the uterine lining, and we call this implantation.

Some women experience light spotting (a small amount of blood that no pad is needed to catch) at this time.  Some women may even feel a slight amount of cramping.  It is possible for implantation to take longer than a week as well.  The way implantation occurs and what is experienced along with it, is directly a result of genetic health from the sperm and egg, and wellness balance from the mother.  It is also at this time that maternal-fetal circulation begins developing, and conditions like pre-eclampsia and gestational glucose intolerance are set into place. The mother may start to have other symptoms of pregnancy.  She is now considered three weeks pregnant but may mistake some of these symptoms, like tender breasts and a desire for more inward reflection and healing rest, for pre-menstrual symptoms.  But this is exactly what the pregnancy needs in this phase.