I polled some non-medical friends and acquaintances on what came to their minds when they heard the word HORMONE. The responses varied greatly from raging emotions to vivid sexual imagery. Suffice it to say that this word is one for which the difference from its everyday general usage to its intended scientific meaning is huge. In medical terminology, a HORMONE is very simply a chemical substance which acts a biological messenger.
The reason we associate it with emotions and drives is because one of the
targets that hormones act on is the brain, which of course, governs our
feelings and actions. When it comes to fertility, hormones play a key role. The
brain has to talk to the ovaries to tell them prepare an egg for ovulation. The
ovaries have to tell the brain that they are responding. They also have to tell
the uterus when to get ready for possible implantation of an embryo. If a
pregnancy is successfully established, the new set of hormones produced by the
developing fetus tell the body that a pregnancy has occurred. This can lead to nausea,
moodiness, cravings, breast changes and the many other symptoms associated with
Here are some of the key hormones involved in reproduction along with the basics regarding each one.
FOLLICLE STIMULATING HORMONE (FSH): This hormone comes from the brain (more specifically the pituitary gland, which hangs from the base of the brain). It travels through the bloodstream and tells the ovaries to get an egg ready. Once the egg begins to respond, another hormone (estrogen) is sent back to message the pituitary to ease up on the FSH production. This is called feedback. Women whose eggs are all too old or too few in number will fail to respond to the FSH. When this happens, the pituitary does not ease up, but rather starts cranking out ever higher levels of FSH. This is why high levels of FSH are a sign of ovarian failure or near-failure.
A very different type of problem happens in women who are
anorexic, very stressed, or extremely thin. They may not produce FSH properly
and therefore, may not develop their eggs properly. This could result in them
not having periods.
Women with PCOS produce FSH normally. But their ovaries are surrounded by high levels of male hormones and therefore need even higher levels of FSH in order to properly develop the eggs. One way to get this accomplished is to boost your own natural FSH production using drugs like Clomid. Another way is just to supply large amounts of FSH from outside sources, rather than counting on you to produce it yourself.
ESTROGEN: This hormone is produced by the developing eggs. It is what makes the cervical mucus more watery. It is what makes the uterine lining thick and healthy and ready to support implantation. Estrogen goes back to the pituitary and shuts off the FSH.
LUTEINIZING HORMONE (LH): This comes from the same place as FSH. While FSH tells the eggs to develop, LH signals the eggs to release. Once the LH signal is sent to the ovary, the egg releases in about 36-40 hours later. This is the magic hormone that is measured in the ovulation prediction kits.
PROGESTERONE: After ovulation, this is made in large quantities by the remaining “shell” of the follicle. It is responsible for the rise in basal body temperature seen after ovulation. If the progesterone levels drop, the lining will come out as a period.
HUMAN CHORIONIC GONADOTROPIN: This hormone is made by the fetal tissue and is what makes a pregnancy test turn positive. This hCG also happens to be available as a drug to trigger ovulation because it mimics the action of LH.
Watch for more details about each of these hormones in future posts. As you can see, there is actually nothing sexy or emotional about hormones themselves. However, by regulating our reproductive systems, they actually do play a crucial role in the wonderful feeling we get from watching the babies that result.