Also see fact
sheet - PCOS
Type 1 diabetes and irregular cycles
Type 2 diabetes, metformin use, & birth defects
Hypothyroidism & infertility
Hypothyroidism, weight gain, & infertility
Question: I have regular, irregular menses. Meaning, I'm on
one month, off the other, on a regular basis without fail.
It has been over three months since my last menses and I am
wondering what could be the cause. I have had Type I Diabetes
for 13 years (I am now 23), and have read that menstrual period
changes are usually a symptom of some underlying physical
or hormonal imbalance. I have a doctor’s appointment,
and wanted to know if there are any specific questions that
I should ask when I go in.
Comment: Insulin is a potent hormone that affects many organs
including the ovary. Polycystic ovary syndrome (PCOS) is associated
with insulin resistance and type 2 diabetes. However, long-term
insulin use that characterizes type 1 diabetes (or insulin
deficient diabetes) may cause some of the same averse effects
on the ovary as PCOS. I have seen a number of patients with
type 1 diabetes with irregular bleeding. An ultrasound scan
of the ovary on these patients often shows a PCO pattern.
It is permissible to oral contraceptives are used in type
1 diabetes to control bleeding. They may not be best option
for all, but it may be worthwhile to discuss this issue with
your doctor, especially if there is excessive hair growth
or acne. Another alternative would be to use monthly progesterone,
or a progestin, to regulate cycles. sst
Question: Will metformin cause birth defects? I take metformin
for type 2 diabetes and I also have PCOS.
Comment: I believe metformin to be a foundation of the treatment
of type 2 diabetes regardless of pregnancy desires. The first
evidence that metformin was useful for infertility came from
the accidental finding that diabetics using metformin began
having regular menstrual cycles and subsequently pregnant.
We are hopeful that diet, exercise, and insulin-altering drugs
will be able to keep the thousands off insulin. You may also
want to check out the American Diabetes Association site that
has good information. There is a clear relationship between
with how well the blood sugar levels are controlled, the risk
of birth defects and overall pregnancy outcome. Blood sugars
must be normalized before a pregnancy is attempted. Thus far
in preliminary studies there has been no increase in birth
defects seen after metformin use, but it has not been not
proven conclusively to be safe. At least one study has suggested
that metformin use lowers the risk of miscarriage. If you
have type 2 diabetes and are using metformin, it may be reasonable
to continue because pregnancy often worsens insulin resistance.
Pregnancy planning clearly needs some advanced thorough conversation
between you, your endocrinologist and possibly a maternal
fetal medicine specialist. sst
Question: I am 25 years old. I had a salpingo-oophorectomy
at age 15 due to torsion of an ovarian cyst. Now I have been
trying to conceive for a year. Meanwhile, I was diagnosed
with borderline hypothyroidism and treated with 50 micrograms
Levoxyl. My TSH is normal now, but I am still not pregnant.
My periods are very regular, five days in length every 28
days, and I ovulate regularly on day 14. I am due on next
cycle for a hysterosalpingogram. What could be the cause of
infertility in my case? Is it my one ovary? Or hypothyroidism?
Or what else? My husband's test results were normal.
Comment: If the TSH is normal, periods regular and temperature
charts /ovulation detection kits suggest ovulation, then there
should be concern about anatomic factors. There could be tubal
blockage, which often is seen during a hysterosalpingogram
(HSG), or it may be due to scar tissue from the previous surgery
that may only be revealed by a laparoscopy. sst
Question: I am 31 years old and have hypothyroidism. As a
result I have gained a lot of weight. I am obese. My husband
and I have been trying to conceive for almost a year. Despite
being hypothyroid, my periods were very regular -- every 28
days, prior to trying to conceive. However, over the past
year my cycle has changed from anywhere from 28 to 36 days.
I am concerned with the change as it only started changing
after we started trying to conceive. Is this normal? I know
I ovulate as I have a fertility monitor. My concern is this:
how does the change in my cycle, along with being obese/hypothyroid,
affect my chances of conceiving?
Comment: I know this will be an unpopular statement, but weight
gain due to an underactive thyroid has been shown in numerous
studies to be relatively small. Still, small changes in thyroid
function can markedly alter the way you feel as well as fertility.
Clearly, hypothyroidism can cause infertility and fertility
therapy can be as simple as thyroid hormone replacement. Replacement
therapy should not be used unless there is documented hypothyroidism.
In the past some have tried thyroid hormone to improve fertility
or to help with weight loss. It doesn't work. Individuals
taking replacement therapy should have periodic measurement
of thyroid stimulation hormone and the levels should be kept
in the mid-normal range (usually 1.5-3.0). Normalization of
TSH levels is a very important first step. I am concerned
that your cycles are as long as 36 days and would search for
a reason as to why this has occurred. Cycles over 32 days
are associated with significant decrease in fertility. A more
detailed endocrine evaluation, possibly including insulin
levels is in order, followed by a consideration of strategies
to promote timely ovulation. sst
Question: I was diagnosed with hypothyroidism after the birth
of my son who is now 10 months old. I now take 100 mg of thyroxine
daily and blood tests show all is now normal. I got pregnant
very quickly first time. I am now trying to get pregnant again
but I am not ovulating. What do you suggest? Is this likely
to be due to hypothyroidism and is it treatable?
Comment: Patients with hypothyroidism, an underactive thyroid
gland, often have irregular bleeding and ovulation problems.
The primary screening tool for thyroid disease is measurement
of thyroid stimulating hormone (TSH). As the thyroid gland
produces less thyroid hormone (thyroxine, T4), TSH levels
rise to compensate. Low levels of TSH usually indicate too
much replacement, or hyperthyroidism, while high TSH levels
indicate under active thyroid, or too little replacement.
It takes 6 weeks after initiation of thyroid therapy or a
change in dosage for the TSH to equilibrate. The goal of replacement
therapy is to keep the TSH level straight in the middle of
the normal range, usually at 2-3. If you achieve normal thyroid
status with therapy, the next step is to look for other reasons
why ovulation may not be occurring. A link has been suggested,
but not yet proven, between hypothyroidism and polycystic
ovary syndrome (PCOS). Risk factors for PCOS include a family
history of diabetes, weight and skin problems. For PCOS, metformin
may be a possible therapy, but the typical first line therapy
for anovulation is clomiphene. sst
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