Loss of estrogenic stimulation after menopause leads to atrophy of the endometrial
glands and stroma and the endometrium becomes thin.
Histologically, there are scanty, small glands in a dense stroma. If the
anovulatory cycles and uninterrupted estrogen secretion that occurs during
menopause results in mild hyperplasia of the endometrium, cystic atrophic
glands showing no proliferative activity are seen.
Oral contraceptives produce a range of endometrial changes depending on the
type, potencies and dosages of estrogenic and progestational agents used,
the duration and whether the drugs are given in sequential or combined regimen
or whether the progestin is given alone. In the sequential method, pills containing
estrogen and progestin are taken each day for 20 to 21 days. Estrogen is taken
each day for 15 to 16 days followed by progestin for 5 days in the sequential
method. Progestin only contraceptives can be taken as low-dose progestin pill
("minipill), given as a depot i.m. injection or as an implant.
The use of sequential pills has been discontinued and only the effects of
combined pill and progestin only contraceptives will be discussed.
Combined pills produce a markedly shortened proliferative phase with poorly
developed glands lined by a single layer of low columnar to cuboidal cells.
Secretory changes do not develop appreciably but stromal decidualization occurs
resulting in discordant appearance between glands and stroma with small inactive
glands scattered in stroma showing decidual reaction. Numerous granular lymphocytes
are also present.
Long-term use results in endometrial atrophy with sparse, narrow glands lined
by flattened epithelium set in a spindle-cell stroma with no evidence of decidual
The effects produced by progestins used alone are similar to the combined
pill but atrophy develops earlier. Some women on the "minipill"
and depot progestin develop amenorrhea and restoration of ovulation after
cessation of contraception may be delayed for a prolonged period.
Norplant is a long-acting reversible contraceptive method. Levonorgesterol
is introduced as a subdermal implant and small amounts are released at a constant
rate for up to 5 years. The main endometrial effect is glandular atrophy and
stromal decidualization. There is no delay in restoring ovulation.
Question: What major risk is associated with progestin-only contraceptive?