This is a term used to indicate significant reduction in menstrual blood flow compared to the patient’s usual pattern or menstruation lasting for less than 2 days. It could follow prolonged use of any monophasic contraceptive pill or a mirena device because of their dominant progestational effect on the endometrium. Progestogens usually downregulate their own as well as oestrogen receptors and lead to progressive atrophy of the endometrium. A higher dose of oestrogen would be needed to stimulate endometrial growth with such dominant progestational effect. This is very clearly demonstrated in patients who receive oestrogen medication to treat abnormal uterine bleeding caused by prolonged use of depo provera injections. However, hypomenorrhoea might have special anatomical significance if it followed any pelvic surgery or infection involving the uterine cavity. In these cases intrauterine adhesions should be suspected. Many patients might present with scanty menstrual flow. Others may present with amenorrhoea altogether. Trauma to the endometrium could follow such conditions as:
D&C
Evacuation of the uterus
Lower uterine segment caesarean section
Manual removal of the placenta
Myomectomy
Genital tuberculosis in certain parts of the world might cause hypomenorrhoea or amenorrhoea not responsive to hormonal treatment. This might lead to formation of intrauterine adhesions [Sharma et al, 2008] or damage of the basal endometrial layer by the tuberculosis granulomas.
It is noticeable that pregnancy is a common factor in most of these cases with superimposed infection being the direct cause leading to adhesions formation. Furthermore, more adhesions follow evacuation of missed than incomplete miscarriages. The uterine pathology could be:
Complete or partial obstruction of the uterine cavity with adhesions.
Apical adhesions covering the area of the internal cervical os only.
Damage to the basal endometrial layer without any adhesions formation.
In managing these cases previous history could be the most important diagnostic clue especially if the symptoms followed an operative procedure. On the whole, systemic and pelvic examinations would be unremarkable. However transvaginal scanning could show:
Thin endometrium even when stimulated with exogenous oestrogens.
Bright intrauterine echoes due to scar tissue bridges.
Indiscriminate interface between the endometrium and myometrium
Using saline infusion sonohysterographycould confirm the diagnosis and show the extent of intrauterine adhesions as shown below. Hysteroscopy is another method for diagnosing and treating these adhesions.
The first 2D picture above shows an irregular uterine cavity after saline infusion sonohysterography. The second picture is as 3D rendered view showing intrauterine adhesionS occupying most of the left side of the cavity. The patient presented with very light menstrual periods after an open myomectomy.
