Fertility Literacy: A Few Key Terms

Usually shortened to REI, Reproductive Endocrinology & Infertility is the correct term to describe the medical specialty of the treatment of infertility. 

A Reproductive Endocrinologist (RE) is a physician who specializes in the treatment of infertility. REI is a super-specialty which means an RE has graduated medical school, completed residency in Obstetrics & Gynecology (Ob-Gyn) followed by an REI fellowship, which is an additional 3-4 years of training under the tutelage and supervision of board certified Reproductive Endocrinologists. 

Once they complete their fellowship, the physician sits for their board certification examinations, a series of grueling exams designed to demonstrate a comprehensive understanding of the field. In short, RE's are highly-educated and extremely dedicated to their work. 

Advanced Reproductive Technology (Sometimes translated as "Assisted Reproductive Technology.)

ART is short-hand for the field of treating infertility. 

Last Menstrual Period. In the field of REI we live and die by periods!  "Day One" of a period is defined by the first day of full-flow bleeding (spotting does not count.)  An easy way to determine is the first day you begin using a tampon, maxi- pad or menstrual cup. 

Cycle Day is calculated from your LMP. For example, a woman started spotting over the weekend but didn't have full-flow bleeding until Monday morning: Monday is her LMP and her cycle day 1.

 If today is Thursday of the same week, she is cycle day 4. (Sometimes written as CD4 or d4.)

NOTE: This is true whether or not she is actually still *bleeding* by then. 

A cycle begins on first day of full-flow but after that it does not matter how many days of actual bleeding there is. 

Regardless of how long you bleed, your cycle is calculated from the start of one cycle to the start of the next, i.e. 28 days.

If your doctor asks about the *duration* of your period, that term applies to how many days of bleeding you typically experience. 

(More than you ever wanted to know about periods, right?)

This can get confusing because it depends on the context. "Cycle" may refer to your menstrual cycle. For example "My cycle is 28 days long." or "I'm on day 4 of my cycle."  

Or it could refer to a treatment cycle, which could be IUI, IVF, Donor Egg IVF, etc. An example of this context, is "I've had three IVF cycles."

Follicles are fluid-filled sacs (cysts) in the ovary. Each follicle should contain one egg. A woman is born with all the follicles she will ever have. Though there are millions to begin with, by the time she reaches adolescence a young woman usually has somewhere around 100,000 follicles. Don't worry, it's still more than enough!

At this dormant stage the follicles are called primordial follicles.  Most primordial follicles will never fully mature and the eggs inside them will dissolve. 

Each month, a cohort of primordial follicles "bubble up" to the surface of each ovary where they get one step closer to maturation. This monthly cohort is called antral follicles. The body will randomly choose just one antral follicle that goes on to mature. That lucky follicle is the dominant follicle. The other antral follicles dissolve and the eggs inside them are waisted. 

Once selected, it takes roughly 14 days for the dominant follicle to mature.  During this time the follicle secretes estrogen, which has a thickening effect on the lining of the uterus. 

When the estrogen level is sufficiently high as to indicate the egg inside the follicle is likely mature, the brain sends a surge of luteinizing hormone (LH) which does three things: 

LH causes the egg to loosen from the side of the follicle wall, bathes it in a solution that allows the egg to reach that final phase of maturity, and it causes the  follicle to burst. 

This is the process of ovulation. The egg is propelled out of the ovary  and lands in the fallopian tube, where it will live for roughly 24 hours as it travels toward its final destination: the endometrium. The endometrium is the correct term for the lining of the uterus.  

The cyst that had been the follicle is now called the corpus luteum. Its job is to produce progesterone, which affects the endometrium, causing it to become hospitable to an approaching embryo. The corpus luteum is the precursor to a placenta. 

If a live egg encounters sperm during its journey down the fallopian tube, there is a chance it will be fertilized, develop into an embryo and implant in the endometrium. Once implantation has occurred, the embryo begins to secrete a hormone called beta human chorionic gonadotropin (beta hCG) which is the hormone of pregnancy. 

Beta hCG sends the signal to the corpus luteum to keep producing progesterone, which nourishes the growing embryo and keeps the endometrium thick and vital. 

If implantation does not occur, the corpus luteum will stop producing progesterone. That rapid withdrawal of progesterone is what causes the endometrium to slough off, which the woman experiences as the start of her menstrual flow. 

Intra-Uterine Insemination

Procedure by which sperm is placed into the top of the uterus, bypassing the vagina and cervix.  In years past it was called "artificial insemination."

Donor sperm may be used for an IUI if there is no male partner or if the male partner does not produce adequate amounts of sperm. 

In Vitro Fertilization 

Procedure by which a woman's monthly cohort of eggs is retrieved prior to ovulation, then fertilized in an Embryology Lab. 

An IVF cycle differs from a natural menstrual cycle in two key ways: 

Typically each ovary contains thousands of eggs, berried deep within. Each month, a cohort of "antral" follicles  din a natural menstrual cycle usually just one follicle breaks away from the original resting cohort to become mature and ovulate a single egg mid-cycle. First, all or most of the woman's antral follicles are recruited to grow to maturity whereas 

Secondly, while ovulation is crucial in a natural menstrual cycle but there is no ovulation in an IVF cycle. Rather, the eggs are surgically removed just shy of the point of ovulation in a procedure call an egg retrieval, or TVOR (Trans-Vaginal Oocyte Retrieval.) Retrievals are done under sedation using an ultrasound-guided needle to aspirate each follicle. It is not usually painful but swollen ovaries will be tender. High-impact exercise is discouraged during an IVF cycle. 

This is accomplished by medications that must be injected daily over the course of roughly ten days leading up to the day of egg retrieval. 

IVF using conventional insemination means that the embryologist essentially pours the sperm over the eggs in a petri dish and the sperm 'duke it out' in the dish the same way they would in the body. 

Intracytoplasmic Sperm Injection (pictured above left)

ICSI (pronounced "ick-see") is an additional step in an IVF cycle that can be taken in order to help increase fertilization rates. 

Rather than simply putting eggs and sperm together in the same petri dish, ICSI involves manipulation; the embryologist physically injects each egg with a single sperm. 

This ensures the sperm is able to bypass the outer shell (zona) of the egg, but it does *not* guarantee the egg will fertilize. 

ICSI takes place in the lab; from the patient's experience there is no difference (other than the fact that it's usually an additional charge.)