Background: The abnormal uterine bleeding represents the common complaint of women attending clinics. Abnormal thyroid dysfunction in women specifically the hypothyroidism has been related to menstrual disturbances in women at reproductive age.
Objectives: This study aimed to measure the prevalence of thyroid dysfunction in women presented with abnormal uterine bleeding in Erbil city.
Methods: A cross sectional prospective study conducted in the outpatient Clinic at Maternity Teaching Hospital in Erbil city from 1st of September, 2017 to 30th of June, 2018 on 100 women (50 women with abnormal uterine bleeding and 50 women with a normal cycle selected as control cases. The general and menstrual history in addition to investigations and thyroid function test of both study groups were assessed.
Results: There was a significant association between high thyroid stimulating hormone level and women with abnormal uterine bleeding (p=0.002). Women with abnormal uterine bleeding were significantly associated with low T4 level (p=0.04). A significant association was observed between women with abnormal uterine bleeding and hypothyroidism (p=0.003).
Conclusion: The thyroid dysfunction is common cause of abnormal uterine bleeding among women at reproductive age.
Keywords: Abnormal uterine bleeding; Thyroid dysfunction; Reproductive age women
The abnormal uterine bleeding (AUB) is defined as a symptom that represent the frequent complaint of women attending Gynecology clinics. The AUB is affecting women in pre and postmenopausal age periods . Clinically, It presented in many forms like menorrhagia, metrorrhagia, menometrorrhagia, polymenorrhea, polymenorrhagia and oligmenorrhea . New classification system was developed by International Federation of Gynecology and Obstetrics used to categorize the causes of AUB in reproductive age and based on acronym (polyps, adenomyosis, leiomyoma, malignancy and hyperplasia-coagulopathy, ovulatory disorders, iatrogenic, not classified) . The causes of AUB might be related to hormonal balance disturbances or it might be clinical presentation for benign or malignant lesions of female genital tract in reproductive age group woman. The dysfunctional uterine bleeding (DUB) is adopted in the absence of abnormal pathological changes . AUB in most of Iraqi women younger than 60 years age is found to be predominantly dysfunctional in origin. However, it is related to abnormal pathology in others .
The thyroid dysfunctions are common all over the world and the thyroid diseases are 10 times more prevalent among women than men . In Iraq, nontoxic goiter presents in about one third of women and the toxic goiter in about 25% of women while the hypothyroidism is detected in about 14.5% of women . The thyroid dysfunction in women is related to abnormal menstrual cycle . Thyroid hormones are responsible in initiation of many physiological processes in females like pubertal growth & development, menarche, menstrual cycles, fertility and menopause .
The mechanism by which the thyroid disorders is associated with AUB may be explained by altering thyroid stimulating hormone (TSH) response, increasing prolactin levels, altering luteinizing hormone (LH) response, affecting peripheral conversion of androgens to estrogens, altering sex hormone binding globulin (SHBG) and affecting coagulation pathways in addition to effect on lipid profile .
The hypothyroidism is a frequent cause of multiple disorders
in women at reproductive age ranged from sexual dysfunction,
menstrual abnormalities and infertility . Disturbed cycles
and abnormal blood flow are the first menstrual problems for
women with hypothyroidism [5,10]. The occult menorrhagia is an
earlier presentation for women with subclinical hypothyroidism
. The menstrual irregularity was the presenting symptom of
24% of Iraqi women diagnosed with hypothyroidism .
For hyperthyroidism, it delays the onset of menses if occurs
before puberty , while in reproductive age group, it is related to
oligomenorrhea and amenorrhea . In Erbil, the women have
four times risk in developing hyperthyroidism than men .
Menstrual disturbances in women with thyroid dysfunction are
sometimes the first symptoms which help in diagnosis, however,
the subclinical thyroid cases (hyper- and hypothyroidism), might
be neglected for many years . There is evolutionary increase
in the number of women attending with AUB to medical clinics
in our country [6,4]. The rationale of this study which aimed to
measure the prevalence of thyroid dysfunction in women that
presented with abnormal uterine bleeding in Erbil city.
This study is a cross sectional prospective study conducted
in the outpatient Clinic at Maternity Teaching Hospital in
Erbil city from 1st of September, 2017 to 30th of June, 2018 (10
month).Ethical approval of the study was taken from Ethical
Committee of Kurdistan Board of Medical Specialties and
administration of the Maternity hospital. Confidentiality was
taken in consideration and verbal consent was taken before
enrolling women in the study. We recruited all the women that
presented with abnormal uterine bleeding (AUB) to the clinic.
The inclusion criteria were women in reproductive age group
(18-42 years) with clinical presentation of AUB. The exclusion
criteria were pregnancy related bleeding, bleeding disorders,
use of intrauterine contraceptive device. A convenient sample
of 50 women with AUB was selected after eligibility to inclusion
and exclusion criteria. Another sample of 50women with normal
cycle selected as control cases after verbal consent. The data
was collected by researcher through direct interview with the
selected women and completed prepared questionnaire. The
questionnaire was designed by the supervisor and researcher.
It included the sociodemographic characteristics of the
participants (age, occupation and marital status), parity history,
body mass index, smoking history, contraception history, drugs
history (anti-coagulants and anti-thyroid), LMP frequency,
menstrual bleeding patterns, post coital bleeding, intermenstrual
bleeding, thyroid stimulating hormon level, triiodothyronine
level, thyroxin level. After taking full history and examination,
the eligible women were referred to Laboratory and Radiology
department of Erbil Maternity Teaching Hospital to complete
the investigations. The thyroid function tests were carried
out by the Mini Vidas ELFA (enzyme linked fluorescent assay)
method and immunoradiometric assay (IRMA). The normal limit
values of TSH, T3 and T4 were 0.4-5μU/ml, 3.5-6.5pmol/L and
All women’s data entered using computerized statistical
software; Statistical Package for Social Sciences (SPSS) .
Descriptive statistics presented as (mean±standard deviation)
and frequencies as percentages. Multiple contingency tables
conducted and appropriate statistical tests performed. In all
statistical analysis, level of significance (p value) set at ≤ 0.05
and the result presented as tables and/or graphs.
Total 50 women with AUB were included in this study with
mean age of 32.4 years; 12% were less than 20 years age, 30%
of women were in age group 20-29 years, 34% of women were
in age group 30-39 years and 24% of women were 40 years age
and more. About two thirds (70%) of women with AUB were
housewives and 82% of them were married; 17.1% of those
married women with AUB were nulliparous while 82.9% of
them had children. The smoking history was positive for 8%
of women with AUB. The women presented with AUB (26%) of
them were overweight and (42%) were obese the mean BMI was
(27.8 Kg.m2.). The history of contraception was observed among
17(34%) women with AUB, while history of thyroid replacement
therapy was observed in two (4%) women (Table 1).
Regarding menstrual cycle of women with AUB, cycle
regularity was irregular among 64% of them and 5 (10%) women
had normal menstrual cycle, furthermore 21(42%) women had
menorrhagia, 23(46%) women had oligomenorrhea and only
1(2%) woman had polymenorrhea. The post coital bleeding was
detected among 2(4%) women and intermenstrual bleeding was
detected in 5(10%) women. Among those only 3(6%) had Pap
smear which were normal (of note there is no cervical screening
provided in our country. Mean TSH of women with AUB was
2.7μU/ml; 6% of women with AUB had low TSH level and 24% of
them had high TSH level. Mean T3 of women with AUB was 1.6
pmol/L; only one (2%) woman with AUB had low T3 level. Mean
T4 of women with AUB was 85.2 pmol/L; 10% of women had
low T4. The majority of women with AUB were euthyroid (72%),
however 22% of women with AUB had hypothyroidism and 6%
of them had hyperthyroidism (Table 2).
Comparing AUB women with control women with no AUB
revealed no significant differences regarding age (p=0.9),
occupation (p=0.9), marital status (p=0.2), parity (p=0.3), BMI
(p=0.3), smoking (p=0.1) and euthyroid women wile on thyroid
replacement therapy (p=1.0). There was a significant association
between positive contraception history and women with AUB
(p=0.001). Table 3&4 showed a highly significant difference
between AUB women and controls was observed regarding LMP
frequency and meonorrhagia & oligomenorrhea (p<0.001). No
significant differences were observed between AUB women and
controls regarding post coital bleeding (p=0.1) and history of
Pap smear (p=0.07). There was a significant association between
intermenstrual bleeding and women with AUB (p=0.02). The
common interesting findings in our study were the significant
association between high TSH level and women with AUB
(p=0.002). No significant differences were observed between
AUB women and controls regarding T3 level (p=0.5). Women with
AUB were significantly associated with low T4 level (p=0.04);
10% of AUB women had low T4 level. A significant association
was observed between women with AUB and hypothyroidism
(p=0.003); 22% of AUB women had hypothyroidism while 2% of
controls had hypothyroidism (Table 4).
Abnormal uterine bleeding is accompanied by low quality of
life attributed to treatment efforts of bleeding and outcomes of
high blood loss like fatigability and anemia . The endocrine
disturbances play a major role in pathogenesis of abnormal
uterine bleeding . In our study the most common AUB was
oligomenorrhea(23%) followed by menorrhagia (21%) followed
by inter menstrual bleeding (5%). These findings are consistent
with reports of Fraser et al.  study in USA which included
the oligomenorrhea and menorrhagia within the definition
of abnormal uterine bleeding. Deshmukh et al.  and Byna
et al 9 reported the menorrhagia as the most common type of
AUB. The intermenstrual bleeding in our study was significantly
associated with AUB women (p=0.02). Similarly, Mohan et al.
 documented that intermenstrual bleeding is a frequent
presentation of abnormal uterine bleeding. Our study revealed
predominance of contraception history among women with
AUB (p=0.001). Previous American study  documented
that hormonal contraception is the major cause of AUB among
women in reproductive age period.
This study revealed a significantly higher level of thyroid
stimulating hormone among women with AUB in comparison to
controls (p=0.002). This finding coincides with results of Attia
et al.  study in Egypt which found a significant difference
in TSH between women with AUB and controls. Our study also
showed a significant association between low T4 hormone level
and women with AUB (p=0.04). This finding is in agreement with
results of large cohort study carried out in USA by Kang et al.
 which stated that low T4 hormone level was significantly
related to AUB. Abnormal thyroid hormones levels contributed
to disturbances in ovulatory hormones and predisposing to
irregular bleeding .
Our study showed that hypothyroidism constitutes 22% of
women with AUB and hyperthyroidism did present in 6% of
them. These findings are higher than results of previous Iraqi
study conducted by Al-Hakeim  which found that among
women with menstrual disturbances, the hypothyroidism
present in 16.1% of them and hyperthyroidism was present in
3.4% of them. This difference in thyroid dysfunction between
two studies might be due to geographical variation and high
prevalence of thyroid disorders in Kurdistan . Our study
finding regarding hypothyroidism is also higher than that of
Ajmani study in India  of 14% among women with menstrual
disorders. Current study showed a significant association
between women with AUB and hypothyroidism (p=0.003). This
finding is similar to results of many previous studies [24,25].
Whitaker et al.  documented the hypothyroidism is one of
the common diseases that must be assessed among women with
abnormal uterine bleeding. The prevalence of hypothyroidism
is high in Iraq country  and specifically in Kurdistan region
. The mechanism by which the hypothyroidism can affect the
menstrual cycle is not fully understood. However, some authors
attributed this relationship to irregular or no ovulation that
decreases the luteinizing hormone and elevating the estrogen
leading to menstrual bleeding .
The thyroid dysfunction is common cause of abnormal uterine
bleeding among reproductive age women. The oligomenorrhea
and menorrhagia are the prevalent bleeding types. Thyroid
hormones assessment should be taken in consideration in
assessment of women with abnormal uterine bleeding.
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