Obesity and Infertility
Q & A: Can
being overweight affect my chances of getting pregnant?
There
are two sources of estrogen in the body: the ovary (directly) and the adrenal
gland (indirectly). The ovary makes estrogen in phases--up and down--in
what are part of the variations within the normal menstrual
cycle. The adrenal glands, among other things (like adrenaline), make
something called "androstenedione." All of these hormones are related
to cholesterol, actually--even testosterone and progesterone, so it's common
that hormones often are converted back and forth. In the case of the adrenal
androstenedione, fat cells can convert it into an estrogen called estrone.
Besides causing increased risk of heart disease,
hypertension, and diabetes, obesity can also cause biochemistry to gang
up on your chances for decent ovulation. If you're significantly overweight,
while your ovaries are trying to behave and cycle normally, the steady
input of estrone from this other pathway will interfere. A steady supply
of estrogen from the peripheral
conversion of androstenedione to estrogen will blunt the peaks and
valleys of the ovary's function, which ultimately interferes with ovulation
and can cause infertility.
Also, all of this estrogen can even lead to pre-cancerous
changes in the womb (uterus).These changes are usually reversible,
but nevertheless any woman who is overweight and experiencing menstrual
irregularities should be evaluated.
How can you tell whether you're a woman whose ovulations
are affected by being overweight? If you're having regular periods, then
you can assume you're probably having regular ovulations. But if the periods
are sporadic ("dysfunctional uterine bleeding"), then probably so are
your ovulations. If your periods are continuous or absent, then any expectation
of ovulation will be unreliable.
Another point to remember is that if you walk into
a gynecologist's office, he or she is likely to be prejudiced by gynecological
thinking. In other words, certainly irregular menstrual cycles are
because of hormone problems, right?
Not always. Thyroid problems can cause both
irregular periods and obesity, so it isn't unreasonable to begin your infertility
work-up with blood work to check for this. Thyroid problems are easy to
diagnose and usually easy to fix, but if this abnormality isn't even
ruled out and you have this problem all of the hormonal manipulation in
the world isn't going to help
you. Prolactin the milk let-down hormone
that's high in breast-feeding womenˇVis used to advantage when lactating
women use the resulting interruption of their periods as birth control.
It's not foolproof, but this property has been used somewhat successfully
for thousands of years.
Being overweight affects everything. You can
take lists of diseases from every specialty and find some obesity-related
ones in each. Hypertension, coronary artery disease, pulmonary problems,
diabetes, skin health...the benefits of losing weight are significant.
One of them is becoming a regular ovulator.