Getting Pregnant - The Basics

From the first moment you saw him smile, you knew he was the man for you. Well, perhaps it didn't happen quite that quickly. Maybe you dated each other for months or possibly even years before that mysterious and very wonderful feeling took over and you knew you were in love. Regardless of when in your relationship it occurred, if you are like many women, finding that special someone may have elicited another, even more powerful feeling: the desire to have a baby. While childbearing was once the farthest thing from her mind, many an obstetrical patient has told me that from almost the instant she met her mate her babylust began.

For other women, however, things can work just the opposite: the desire for motherhood may come long before a potential partner appears. In fact, some patients confide to me that it was their unrelenting desire to have a baby that prompted their search for a soul-mate — or at least a suitable parenting partner!

While no one is really certain what causes a woman's baby alarm to ring, the recognition that it exists was one of the elements that led researchers to a key discovery about how and why you get pregnant. What was it they discovered? The vital role of reproductive hormones. It was once believed that getting pregnant was strictly a physiological function of your reproductive organs, but today research shows that the same biochemicals that influence your desire to have a baby also play a key role in helping you achieve conception. In fact, without your reproductive hormones, you could not get pregnant!

THE NEW CONCEPTION CHEMISTRY: HOW IT WORKS

From the moment puberty starts and throughout your childbearing years, your body and your brain work together in a unique biological partnership, to produce a series of chemicals called reproductive hormones.

Research shows that the activity of your reproductive hormones can affect everything from your mood to your desire for sex — even your appetite for certain foods. Some new studies also suggest that hormones are what cause a woman's baby alarm to ring, stimulating a natural mothering instinct, the feeling perceived as a desire to get pregnant. The strength of this feeling and when (and how often) in your childbearing years it occurs are also thought to be influenced, at least in part, by hormonal activity.

Even more important, however, is the way hormones affect your ability to get pregnant. Although the total number of eggs your ovaries can produce is predetermined before you are born (in most women, about 400,000 follicles exist), we now know that for you to get pregnant these follicles must be able to develop and grow and then be released from your ovary into your fallopian tube. Ultimately they must be able to be fertilized, and finally, your embryo must implant into your uterus, and grow as well. While it is your reproductive organs that actually perform these vital tasks, the latest research shows that it is your reproductive hormones that provide the biochemical signals necessary to put these organs into motion.

THE HORMONES THAT HELP YOU GET PREGNANT

All told, five reproductive hormones are necessary for conception. They send their signals to your various organs by rising and falling in a distinct and carefully timed pattern throughout the course of a single monthly menstrual cycle. The effects of all five are felt in your body, but three of these hormones are continually being manufactured and released into your bloodstream, by your brain. The first two are:

Follicle-stimulating hormone (FSH). Secreted by your pituitary gland (which is located at the base of your brain), it stimulates the follicles inside your ovaries to produce eggs.

Lutenizing hormone (LH). Also secreted by your pituitary gland, it signals to your egg when the time is right to leave your ovary and be ovulated into your fallopian tube so that fertilization can take place.

Collectively they are called gonadotropins. Although some FSH and LH remain in your body at all times, both are secreted in great amounts during the first half of your menstrual cycle, and levels of both drop sharply after ovulation. It was recently discovered that in order for this fluctuation to occur, another hormone must enter the fertility equation:

Gonadotropin-releasing hormone (GnRH). This helps release the proper amounts of gonadotropins (FSH and LH) into your bloodstream. Secreted by your hypothalamus, a tiny gland located near your pituitary, GnRH functions as a kind of biochemical radar system that pulses through your body every 90 to 120 minutes, twenty-four hours a day. It monitors your bloodstream for levels of FSH and LH and then at the proper time directs your pituitary to release more of each into your bloodstream.

BALANCING YOUR FERTILITY EQUATION

Getting pregnant also requires estrogen and progesterone, two more fertility hormones. They are manufactured in your ovaries (and elsewhere in your body) and also rise and fall in a precisely timed pattern throughout each menstrual cycle. Their purpose is to orchestrate various steps in the egg production and release process.

After you become pregnant it is estrogen and progesterone that help maintain your pregnancy and protect you from miscarriage.