This document summarizes irregular periods and polycystic ovary syndrome (PCOS). It discusses how women with PCOS often have fewer than eight periods per year due to absent or delayed ovulation. This can cause the lining of the uterus to thicken and increase the risk of cancer. While periods typically indicate ovulation, this is not always the case for women with PCOS symptoms like excess hair growth and obesity. Ultrasounds and hormone tests may be needed to determine if ovulation is occurring. The document includes figures illustrating hormone levels and ovulation in regular versus irregular menstrual cycles.

1. Irregular Periods and Polycystic Ovary Syndrome
Dr. Burak HACIHANEFİOĞLU
WOMEN'S HEALTH AND RESEARCH & POLYCYSTIC OVARY CENTER
Büyükdere Cad. Melek Ap. No:17 Kat:3
Şişli / İstanbul / Türkiye
Tel: 00 90 (212) 296 78 95 -00 90 (212) 296 78 96
Gsm : 00 90 530 561 89 96
www.bhkadinsagligi.com
Absent or delayed periods are common symptoms in women with polycystic
ovary syndrome. These women usually have less than eight periods each
year. Absence of periods causes thickening of inner lining of
uterus (endometrium). These women with thickened inner lining of uterus
may have bleedings which are long lasting, heavy and including dark
coagulum. The women with thickened inner lining of uterus have also an
increased risk of developing cancer in the inner lining of uterus.
The menstrual cycle is the time from the first day of a woman's period to the
first day of her next period (For example; 30 day cycle). The beginning of a
woman's period in the end of a menstrual cycle generally accepted as a sign
of ovulation.
For example; a woman ovulates about 12 times a year if she gets periods
once a month, a woman ovulates about 6 times a year if she gets periods
every two months, a woman ovulates about two times a year if she gets
periods every six months.
But, the beginning of a period or having regular periods may not be a sign of
ovulation in some women with polycystic ovary syndrome. For this reason,
ovulation should be determined in these women with regular monthly
periods having symptoms such as excessive hair growth, acne, male type hair
loss or obesity. Ultrasound scan or some hormone tests should be done to
know whether these women are ovulating or not.

2. The picture (below) demonstrates an ultrasound image of polycystic ovary.
The red arrow in the picture shows fluid filled small sacs containing eggs
which surrounds the increased amount of white central area (stroma) of the
ovary.
Figure-1 (below) shows the changes in blood levels of some hormones
called FSH (Follicle Stimulating Hormone), LH (Luteinizing Hormone),
Estradiol, and Progesterone during a menstrual cycle with ovulation. The
changes in the production of these hormones during a menstrual cycle leads
to growth of small sac with an egg and results in ovulation.
The yellow line in figure-1 (below) illustrates the changes in the amount of
FSH in a menstrual cycle. FSH leads to growing of a sac which contains
egg starting from the first day of a menstrual cycle. The
blue line in figure-1 (below) demonstrates the changes in the amount of
estradiol. At the same time with the growing a sac containing egg, estradiol
leads to thickening of inner lining of uterus (endometrium).
The green line in figure-1 (below) illustrates the changes in the amount of LH
in a menstrual cycle. The wall of a growing sac with egg ruptures and egg is
released from the ovary,
36 hours after the highest level of LH in the menstrual cycle. The release of
an egg from the ovary is known as ovulation.
Pregnancy can occur if an egg which is released from the
ovary (ovulation) meets with a sperm. Otherwise, menstrual bleeding usually
will begin about 14 days after ovulation if the egg does not meet with a
sperm.

3. The red line in figure-1 (below) illustrates the changes in the amount of
progesterone in a menstrual cycle. Progesterone reaches its highest level 7
days after ovulation in a menstrual cycle. Progesterone levels can be
measured by a blood test to determine whether ovulation has occurred or
not.
Menstrual bleeding usually will begin about 7 days after the progesterone
reaches its highest level in a menstrual cycle. The menstrual cycle shown
in figure-1 (below) lasting 28 days ends when menstrual bleeding begins 7
days after the progesterone has reached its highest level. The all events
happening in a menstrual cycle repeats themself every 28 days in a women
with regular menstrual cycles.
FIGURE-1

4. Figure-2 (below) shows that there is no change in blood levels of FSH,
LH, Estradiol, and Progesterone throughout a menstrual cycle without
ovulation (anovulation). For this reason, the small
sac with an egg does not grow and the egg is not released from the ovary
which is shown in figure-2 (below).
Pregnancy does not occurin women with anovulation because there is no egg
released from the ovary to meet with a sperm and also menstrual bleeding
will not happen in these women.
FIGURE-2

5. The small sac containing an egg does not grow or grows slowly which causes
lack of ovulation and periods or delayed ovulation and periods in some
women with polycystic ovary syndrome (Group A and B) that is shown in
the left side of blue arrow in figure-2. However, there is no problem in the
right side of blue arrow (figure-1) in women with polycystic ovary syndrome.
That's why, menstrual bleeding of a woman will begin about 14 days after
ovulation whether she has polycystic ovary syndrome or not.
For example; if the sac containing an egg grows and therefore ovulation
occurs in 14 days, intervals between periods will be (14+14): 28 days. If the
sac containing an egg grows and therefore ovulation occurs in 60 days,
intervals between periods will be(60+14): 74 days. If the sac containing an
egg grows and therefore ovulation occurs in 180 days, intervals between
periods will be (180+14): 194 days.
FIGURE-3