Download Stage of Differentiation

CONGENITAL ABNORMALITIES OF THE FEMALE
REPRODUCTIVE TRACTS:
In this chapter congenital anomalies of the genital tract will be
discussed under two headings; Anomalies of the external genital
organs (ambiguous genitalia), which can result in disturbance of the
fetal phenotype, and anomalies of the internal genital organs
(Müllerian Ducts Anomalies).
Anomalies of the external genital organs:
A) Ambiguous Genitalia (Defect of the clitoris and labia):
The term ambiguous genitalia describe genitalia with unrecognizable
sexual features. In case of female fetuses, ambiguous genitalia usually
occur as a result of in utero exposure to androgen hormones during
critical time of development of the genital tract. This will result in
variable degree of virilization of the external genitalia, mainly in the
form of elongation of the clitoris and/or labial fusion.
Ambiguous genitalia can result from administration of
androgenic substances to pregnant mothers particularly during the
early weeks of embryogenesis. However the condition is more
commonly seen in infants with congenital adrenal hyperplasia. This
syndrome
is
an
inherited
autosomal
recessive
syndrome.
Characterized by deficiency of some of the enzymes involved in the
biosynthesis of cortisol, the most common variety is deficiency of the
21-hydroxylase enzyme.
In response to a low cortisol level the
pituitary produces increasing amount of ACTH to further stimulate
the fetal adrenal in attempts to compensate for the low cortisol level.
However some of the adrenal products are androgenic and will result
in virilization of a female fetus e.g. elongation of the clitoris and
fusion of the labia.
Anomalies of the internal genital tract "Müllerian anomalies"
Normal development of the internal female genitalis (fallopian tubes,
uterus, cervix, and the upper two thirds of the vagina) depends on
three consecutive embryologic processes; first the differentiation of
two paired mullerian ducts, second, lateral fusion of the lower
segment of the mullerian ducts in the midline to form the uterus,
cervix and upper two third of the vagina and finally resorption of the
central septum between the two mullerian ducts in order to form a
single uterine cavity and cervix. The lower third of the vagina
embryologically originates from the sinovaginal bulb. A normal
patent vagina depends on complete vertical fusion of the ascending
sinovaginal bulb with the descending müllerian system (i.e., fusion of
the lower one third and upper two thirds of the vagina).
Etiology of Mullerian Duct anomalies:
The pathogenesis of mullerian anomalies is not very well understood
but in some cases there may be a genetic linkage as evident by the
occasional association with other somatic anomalies as well as reports
of familial recurrence (Stelling J.R., et al 2000). It has been suggested
that some cases may be due to genetic defect in Mullerian Inhibitory
factor or its receptors. Most probably however the major genetic
mechanism is polygenic or multifactorial. Some cases may result
from in utero exposure of the fetus to teratogenic substances during a
critical period of its development such as in case of exposure to
diethylstilbestrol.
Frequency of Mullerian Ducts Anomalies:
The actual incidence of müllerian anomalies is unknown. This is due
to a number of factors most important is the source of data. When
data are obtained from women with recurrent pregnancy loss the
prevalence of müllerian anomalies is 8-10% (Stray-Pedersen, 1984;
Stampe Sorenson, 1988). This is in contrast to the reported prevalence
rate of 2-3% among in the general population (Ashton, 1988; Simon,
1991). The incidence is higher among women with late miscarriage
and preterm deliveries (Table from ref # 87 page 145 Speroof).
Classification of mullerian anomalies
Classification of mullerian anomalies is based on its embryological
origin as well as its anatomical type. The classification system
recommended by the American Society for Reproductive Medicine in
1998 categories the mullerian anomalies into seven categories
(Table….). The vaginal anomalies are considered separately since it
is mostly obstructive in nature and the uterus is usual present (table
...). In attempt to simplify the matter other classification system which
is related to the nature of the surgical disorder has been described
(Rock JA, Adam RA: 2000).
In this classification four classes of
Mullerian anomalies are identified; the two major ones are; disorders
that compromise patency of the reproductive tract (obstructive
mullerian anomalies) and disorders of lateral fusin of patent
reproductive tract (longitudinal fusion anomalies). The remaining two
classes are agenesis/hypoplasia (as in AFS class 1) and other
miscellaneous anomalies that are difficult to classify
Obstructive Müllerian anomalies:
Obstructive Mullerian anomalies include disorders compromising
patency of the reproductive tract these include; transverse vaginal
septa and cervical agenesis and dysgenesis with or without
obstruction. Imperforate hymen is embryologically not of mullerian
origin although clinically have a similar presentation. Obstructive
Müllerian anomalies preclude the outflow of menstruation and allow
the collection of blood in the uterus and the vagina. Patients with this
type of anomaly will usually presents with amenorrhea or pain due to
accumulated menstrual flow.
Management goals are relief of symptoms such as pain, as well as
preservation of sexual and reproductive function.
The true incidence of obstructive Müllerian anomalies is unknown,
but studies reports an incidence of between 0.1% and 3.8%.
b) Imperforate Hymen:
The hymen represents the junction of the sinovaginal bulbs with the
urogenital sinus; hence it is formed form the endoderm of the
urogenital sinus epithelium. Normally it is perforated during
embryonic life. The incidence of imperforate hymen is estimated
around 1 in 2,000 girls or even less (Parazzini F., and Cecchetti G.
1990, Dickson C.A., et 1985). There have been reports of familial
occurrence of imperforate hymens suggesting a genetic background.
An acquired condition similar to imperforate hymen has been
described due to scarring at the vaginal introitus secondary to child
sexual abuse (Botash A.S., Jean-Louis F. 2001).
An imperforate hymen may be discovered at birth because of
the presence of a suprapubic mass "mucocolpos or hydrocolpos"
which is formed by retention of fluid secretion behind the imperforate
hymen. This fluid results from maternal estrogen effects on the
vaginal epithelium and/or cervical glands. It may cause urinary
obstruction due to pressure on the anterior urethra.
More commonly however an imperforate hymen remains
undetected until puberty when over time repeated accumulation of
menstrual flow in the vagina produce a condition known as
hematocolpos. The fluid component of the menstrual flow gets
absorbed and the remaining blood and debris acquire an altered
chocolate thick appearance. In more advanced cases the uterus and
the fallopian tubes becomes distended with retained menstrual blood
resulting
in
hematometra
and
hematosalpinx,
respectively.
Eventually the retained menstrual flow may trickle back, into the
pelvic peritoneal cavity, with the risk of development of
endometriosis.
Typically patients with imperforate hymen presents at puberty
with primary amenorrhea despite apparently normal pubertal
development. They often complain of recurrent cyclic pelvic pain in
the absence of menstrual flow. The pain tends to be localized to the
lower abdomen or perineum, although it can be referred to the lower
back as a result of irritation of the sacral plexus by a posteriorly
positioned vaginal mass. Nonspecific symptoms, such as nausea,
vomiting, or diarrhea, can also occur.
On abdominal examination, a suprapubic mass is rarely felt and
if present it usually reflects a distended bladder rather than a
hematocolpos. On local inspection the accumulation of menstrual
blood behind the hymen gives the blue bulging pathognomonic
appearance of imperforate hymen (Figure 1). Variations of an
imperforate hymen include microperforation, septate, stenotic, and
cribriform hymen.
Imperforate hymen should be differentiated from low
transverse vaginal septum. This can be accomplished with Valsalva.
Imperforate hymen should bulge with Valsalva and transverse vaginal
septum should not (Burgis J 2001). A pelvic ultrasound scan will
confirm the diagnosis and demonstrate normal internal anatomy.
The treatment of imperforate hymen is by surgical release of
the retained contents in the hematocolpos. The components of the
hematocolpos are a very receptive medium for bacterial growth.
Thus during surgical release of hematocolpos, complete antiseptic
measures should be undertaken and prophylactic antibiotics have
been recommended. Most importantly no vaginal examination or
mopping inside the vagina should be made during operation. The
operation is accomplished by a cruciate incision in the hymen
extending between 2, 10 and 6 o’clock. Because of the viscosity of
this material, a double suction apparatus is sometimes required. After
adequate drainage the vaginal mucosa some have suggested suturing
the hymenal ring to prevent re-accumulation of menstrual blood.
Long-term follow-up of patients with imperforate hymen reveals
normal fertility rates. Imperforate hymen is usually not associated
with any other Müllerian abnormalities (Gidwani G, Falcone T.
1999).
Cervical Atresia:
Congenital atresia of the cervix is a relatively rare mullerian
developmental disorder less than 100 cases have been reported in the
literature (Fujimoto V. Y, et al 1997). Patients present with primary
amenorrhea and cyclic pelvic pain, and the condition is often
associated with absence of all or part of the vagina (Figure …a, b).
Some cases are also associated with uterine anomalies (Fujimoto V.
Y, et al 1997). In a large number of patients in the literature
endometriotic implants have been described at the time of
laparoscopy or laparotomy.
The optimum management of cervical atresia remains controversial.
The options are between either conservative management in which a
surgical canalization is performed in order to provide patients some
potential (albeit limited) opportunity for fertility or hystrectomy. The
choice depends on whether the vagina is present or absent and if the
there are associated uterine anomalies.
Careful preoperative
evaluation and counseling is required. In most of the reported cases
the nature of uterine outflow obstruction was only confirmed
intraoperatively. Presently magnetic resonance imaging (MRI) is the
gold standard and should offer better chance for preoperative
assessment and delineation of pelvic anatomy (Markham S, et al
19787). In some cases menstrual suppression with continuous oral
contraceptive pills or medroxyprogesterone acetate (Depo-Provera)
may be used to relieve symptoms and delay the need for surgery. It
also provides valuable time for discussing the options for therapy
(Rock JA. 1997).
In patients with little or no vagina, hysterectomy is generally
recommended, as canalization is usually unsuccessful and may be
associated with infection, sepsis, and even death(Breech LL, Laufer
MR. 1999, Rock JA. 1997, Fujimoto MD, et al 1997). Surgical
recanalization is reserved for selected patients with functional
vaginas. In a minority of patients spontaneous pregnancy has been
reported (Fujimoto V. Y, et al 1997).
Vaginal Agenesis:
Absence of the vagina (vaginal atresia or agenesis), can be
encountered either as an isolated developmental defect or within a
complex of more extensive anomalies such as Bardet-Biedl syndrome
(BBS), or McKusick-Kaufman syndrome (MKKS). Both syndromes
are autosomal recesssive disorders with multiple anomalies other than
vaginal agenesis.
However as an isolated anatomical defect in the presence of normal
female phenotype there are two verities of vaginal agenesis either
complete or incomplete. Complete vaginal agenesis, the most
common one (80%-90%), is the Rokitansky-Mayer-Küster-Hauser
(RMKH) syndrome in which there is absence of most or all the entire
vagina, all or almost all of the uterus and cervix. Ovarian function is
normal thus growth and development are normal. Complete vaginal
atresia occasionally is termed müllerian agenesis. Incomplete or
partial vaginal agenesis is due to failure of canalization of the
contribution made by the urogenital sinus to the caudal part of the
vagina (Leduc B, et al 1968). In this type the lower fifth to third of
the vagina is replaced by 2 to 3 cm of fibrous tissue, above which lie
a well-differentiated upper vagina, cervix, uterine corpus, and
fallopian tubes (Figure …). This variant is due to different
pathophysiologic events and more correctly classified as a variant of
transverse vaginal septum.
The etiology of vaginal agenesis is unknown, and most cases occur
sporadically. Approximately 4% of reported cases are familial, with
affected siblings (Cramer, 1987). Mutation in either the müllerian
inhibitory substance (MIS) gene or its receptor gene has been
suggested (Lindenman, 1997, Amesse, 1999). Vaginal agenesis has
been associated with
variants of the galactose-1-phosphate
uridyltransferase enzyme, suggesting that increased exposure to
galactose is responsible for abnormal vaginal development (Chen,
1981; Cramer, 1987; Aughton, 1993).
Frequency: Müllerian agenesis is a relatively common cause of
primary amenorrhea (1 in 4000 live female births) more frequent than
congential androgen insensitivity and second only to gonadal
dysgenesis (Reindollar RH, et al 1981, Speerof page 441). Partial
vaginal agenesis is less common, with a reported incidence of 1 in
70,000 females (Banerjee R, Laufer MR 1998).
Clinical Presentation: The most common presentation is at presents
at puberty with primary amenorrhea. In the rare cases the
endometrium in rudimentary uterus may function causing cyclic
abdominal or cramping pain. On examination the appearance of the
vagina can be diverse; it can be completely absent, a short vaginal
pouch, or a short vaginal dimple 1-2 cm superior to the hymenal ring.
On rectal examination the uterus is either absent or replaced by
rudimentary structure. The main differential diagnosis is from cases
of androgen resistance syndrome or the XY female (Table…).
Investigations include karyotyping to exclude cases of androgen
resistant syndrome (XY female), an ultrasound examination or if
necessary magnetic resonance imaging examination for defining the
uterus and detailed anatomy of the pelvic organs. Rarely if MRI can
not define the degree of uterine development, laparoscopy may be
necessary to define the uterus and the ovaries . Approximately one
third of cases of mullerian aplasia are associated with renal anomalies
(Carson SA, et al 1983). The most frequent renal anomalies are pelvic
kidney, renal ectopia and unilateral aplasia. Skeletal anomalies,
especially vertebral anomalies, are also not uncommon.
Treatment of vaginal atresia:
The timing of treatment whether it is surgical or non surgical requires
certain level of psychological and sexual maturity. Surgical treatment
is better planned to coincide with subsequent opportunity for
intercourse in order to maintain vaginal patentcy. However it may be
instituted sooner if a patient presents with vaginal outflow
obstruction, abdominal or pelvic pain, or is at risk for secondary
endometriosis.
The objective of treatment is to creat a functioning vagina. In the rare
instances in which a well formed uterus and cervix are present it may
be
possible
to
restore
potential
fertility
function
through
recanalization. Each case should be assessed carefully. Preoperative
MRI is very helpful in assessing the status of the cervix. In some
cases laparotomy should be performed and if the cervix is atretic the
uterus should be removed (Ref 74 page 478 in Sperof). In the
majority of cases of mullerian aplasia it is hardly necessary to remove
rudimentary uteri unless it is a functioning one.
Non surgical treatment (Frank technique or perineal dilation):
The technique involves the forceful dilation of a shallow rudimentary
vaginal pit with the sequential application of progressively wider and
longer dilators which may be administered either manually or using a
specially designed bicycle-seat stool to hold a dilator in place. The
goal is to create a blind-ending vaginal pouch. The technique requires
strong patient motivation and compliance. Patients with a vaginal
dimple or no vagina may experience discomfort and abandon the
dilator. However the method has been successful in creating an
adequate vagina for normal sexual activity (Hendren WH, Donahoe
PK: 1980).
Surgical treatment of vaginal agenesis "vaginoplasty": Surgical
treatment should be considered only when the patient wishes to
become sexually active. The aim of surgical treatment is to create a
neovagina. Various methods of vaginal reconstruction have evolved,
and more than 100 different surgical variations have been reported
(Fedele, 1994; Ghirardini, 1994). The principle is dissection and
creation of vaginal space between the rectum posteriorly and the
urethra anteriorly. This new vaginal space is maintained by using
epithelial tissue obtained either from partial skin graft (as in McIndoe
technique), an ileal loop or amniotic membrane. Any of these tissues
may be stretched over a formed mould and should be kept in place
until the epithelial graft is well taken after about 7-10 days.
Subsequently the
patient needs to reinsert the mould into the
neovagina every day and night for 3 months, followed by nightly
insertion for 3 more months to prevent contraction
William's vaginoplasty is a simpler operation with no risk for damage
to the urethra or rectum. In this operation vulval flap is used to make
a vaginal tube. Still dilation is needed for a lengthy period, and the
neovagina has a physiologically abnormal angle. More recently a
technique of laparoscopic-assisted creation of a vagina
was
described, which thought to provide effective and safer mean for
creation of a new vagina.
Genetic offspring has been achieved in patients with mullerian aplasia
using surrogate uteri to carry the fertilized oocytes of patients. The
experience reported so far with more than 34 offspring none of them
showed inheritance of the condition suggest that the most logical
explanation
for
müllerian
aplasia
inheritance (Petrozza JC, 1997).
Transverse Vaginal Septum:
is
polygenic/multifactorial
A transverse vaginal septum results from failure of fusion
and/or complete canalization of the urogenital sinus and müllerian
ducts. It is a very rare anomaly occurs in approximately 1 in 30,000 to
1 in 80,000 women (Rock, JA, Azziz, R. 1987). These septa may
occur at any level in the vagina with the following frequencies: 46%,
upper vagina; 40%, mid vagina; and 14%, lower vagina (Gidwani G,
Falcone T. 1999) (Figure ----). Vaginal septa may be complete or
incomplete with a small central or eccentric perforation which is not
adequate to drainage of the menstrual flow.
Complete vaginal septa have a similar presentation to cases of
imperforate hymen. Except that on local examination the sign of a
bulging bluish hymen, which is more prominent with Valsalva's
maneuver, is not present. Instead the vagina appears as a closed short
pouch. Patient with incomplete transverse septum may have little
bleeding, however over time they develop hematocolpos and
hematometra and may complain of foul-smelling vaginal discharge.
Ultrasonographic or magnetic resonance (MR) imaging helps to
define the location and thickness of the septum and to differentiate
between a high septum and congenital absence of the cervix.
The treatment depends on the thickness of the vaginal septum.
Usually the septum is thin (< 1cm) and is treated more or less similar
to cases of imperforate hymen. However, a thick septum requires
formal dissection in order to remove the septum. The vaginal skin in
the upper and lower parts of the vagina should then be undermined,
mobilized and stitched together with interrupted absorbable sutures.
Subsequent utilization of the vagina is also necessary in order to
prevent stenosis. In more advanced cases, split thickness skin graft
may be required to join the two ends of the vagina. Transverse
vaginal septum has been reported in diethylstilbestrol (DES) exposed
females.
Defects of Mullerian Duct fusion:
Non obstructive anomalies of the mullerian ducts are relatively
common (2-3%). Unlike obstructive anomalies that usually presents
with primary amenorrhea, fusion anomalies are often associated with
gynecological as well as obstetrics complications such as infertility,
recurrent pregnancy loss and poor obstetrics outcome in pregnancy
(Ref 83-86 Speerof page 145). Some case where there is partial
obstruction e.g. a unilateral rudimentary horn, may present early in
the
years
following
puberty
usually
with
primary
cyclic
dysmenorrhea.
Anomalies of lateral fusion of the mullerian ducts: This may be
partial or complete failure of fusion.
Complete failure of fusion of mullerian ducts is characterized
by duplication of the vagina, uterus and cervix a condition known as
"didelphic uteri". This anomaly is usually asymptomatic until
menarche. The most frequent complaint is failure of a tampon to
obstruct menstrual flow. Occasionally one side may be obstructed and
causes cyclic pelvic pain, despite the presence of normal menstrual
flow. In such cases there is often ipsilateral renal agenesis, and early
diagnosis and excision of the obstructing vaginal septum preserve
fertility and prevent development of endometriosis. In general in
patients with didelphic uteri, fertility is not affected but reproductive
outcomes is compromised with a high spontaneous abortion rate
(40%) (Propst, 2000). Patients who carry a pregnancy to term have
no obstetrical difficulties (Rock, 1985).
The treatment for uterus didelphys with an obstructed unilateral
vagina is surgical excision of the obstructing vaginal septum in order
to preserve reproductive capacity and
prevent impairment of the
uterus and tubes on the obstructed side, reduce the risk of
development of endometriosis and pelvic adhesions (Olive, 1987).
For uterus didelphys with a non-obstructed vagina, indications for
surgical correction are limited. The place for metroplasty operation is
very limited and should only be considered in selected cases. In
pregnancy the optimum management of a non-obstructed longitudinal
septum in pregnancy is not clear. Some authors advocate excision,
while others recommend leaving it undisturbed unless it becomes
obstructed during labor (Rock, 1985).
Partial failure of Mullerian tubes fusion is characterized by the
presence of one vagina and one cervix and a ‘bicornis uteri. In this
anomaly, the lower uterus and cervix are completely fused, but the
uterine chamber is divided into 2 separate but communicating
endometrial cavities with a muscular uterine septum which varies in
length. Cases in which the septum is confined to the fundal region is
considered partial bicornuate. Complete bicornis uteri are cases in
which the septum reach down to the cervix. The complete verity
could be "bicornuate unicollis" if the septum extends to the internal
os, or "bicornuate bicollis" if the septum reach down to the external
os.
Pregnancy outcome has been reported as near normal.
Approximately 60% of patients can expect to deliver a viable infant
(Rock, 1977). However, the rate of early miscarriage, preterm labor
and breech presentation is still higher than normal (ref 86, 92 Sperof).
Apparently this depends on whether the bicornate uterus is partial or
complete. In one study, women with a partial bicornuate uterus
experienced a spontaneous abortion rate of 28%; the preterm delivery
rate was 20%. This contrasts to a spontaneous abortion rate of 66%
and a higher rate of preterm deliveries in women with complete
bicornuate uterus (Heinonen, 1982).
A bicornuate uterus should be distinguished from a septate uterus for
several important reasons; a bicornuate uterus is associated with
minimal reproductive problems, but septate uterus has a high
association with reproductive failure. Additionally, corrective surgical
approaches markedly differ in the two cases.
Surgical reconstruction is seldom required in cases of bicornuate
uterus (Jones, 1992). However several surgical methods for that aims
at unification of the two cavities "Metroplasty" have been described.
It should be reserved for women who have experienced recurrent
spontaneous abortion, midtrimester loss, premature birth, and in
whom no other etiologic factor has been identified (Patton, 1988;
Propst, 2000). Strassman procedure and its modified approach is the
surgical treatment of choice for bicornuate uterus and didelphys
uterus. It involves the removal of the septum by wedge resection,
with subsequent unification of the 2 cavities.
Septet Uterus: Septate uterus is the most common structural abnormality
of all müllerian duct defects. In this condition the two mullerian ducts
have completely fused together but there is failure of resorption of the
intervening fibromuscular septum. The septum is considered
complete if it extends to the internal os, thus dividing the endometrial
cavity, and partial if it does not. In addition, septa may be segmental,
which results in partial communication between the endometrial
cavities (Candiani, 1983). A total failure in resorption can cleave a
longitudinal vaginal septum (a double vagina). Externally, the uterus
appears as a normal single uterine body, which differentiate it from
bicornuate uterus.
Septate uterus is not a cause of infertility but associated with the
poorest reproductive outcomes of all mullerian duct anomalies.
Spontaneous abortion rate occur in 80% of cases (Daly, 1984).
Treatment by hysteroscopic resection yield excellent results with
posttreatment miscarriage rate around 10%. However because septate
uterus is not always associated with an unfavorable obstetrical
outcome its presence alone is not an indication for surgery. Therefore
the decision to perform metroplasty should be based on poor
reproductive performance rather than the presence of a septate uterus
(Heinonen, 1982). Candidates for surgery include women who have
had recurrent spontaneous abortion, a single second-trimester loss, or
history of preterm delivery (Simon, 1991).
The Arcuate Uterus:
A term that describes a mild form of fusion defect in the uterine
cavity in which there is a small indentation at the uterine fundus. It is
the most commonly observed uterine anomaly detected on
hysterosalpingography findings. Arcuate uterus is benign condition
with probably has no consequences and require no treatment.
Anomalies due to unilateral defects of Mullerian duct development:
Failure of development of one mullerian duct results in "unicornuate
uterus" where there is a single uterine horn, single cervix and vagina.
There is almost always a missing kidney and ureter on the same side.
Such a uterus can support a pregnancy but there is an increased rate
of obstetric complications. In a rare type, there may be a unilateral
non-functioning rudimentary horn. A functioning horn however may
be the site of pregnancy with subsequent high risk of obstetric
complications. Most obstetric complications occur within the first 20
weeks and can result in abortion, uterine rupture, and maternal death
(Kirschner, 1979; Raman, 1993). A non-communicating functioning
horn can be a cause of chronic pain and surgical exesion is indicated.
Excision of a rudimentary horn can now be accomplished through
laparoscopic hemi-hysterectomy (Donnez J, Nisolle M: 1997, Nisolle
M, Donnez J 1996)
Cases of unicornuate uterus should undergo urological
assessment because of high rate of associated urological anomalies
(44%), especially when the rudimentary horn is obstructed.
Associated urological anomalies include ipsilateral renal agenesis at a
rate of 67%, horseshoe kidneys, and ipsilateral pelvic kidney at a rate
of 15% (Rock, 1985).
Diethylstilbestrol Associated anomalies:
DES is a synthetic estrogen that was prescribed to women for
recurrent pregnancy loss, premature delivery, and other pregnancy
complications during the late 1940s and early 1970s. Latter it was
realized that the exposure to high level of estrogen during mullerian
development was associated with increased rate of vaginal clear cell
adenocarcinoma and various benign vaginal, cervical and uterine
abnormalities (Herbst, 1971).
DES-related uterine anomalies are quite common in women with a
history of in utero DES exposure. In one study, 69% of 267 women
exposed to DES in utero demonstrated uterine abnormalities
identified based on hysterosalpingography findings (Kaufman, 1980).
Uterine anomalies associated with in utero DES exposure include a Tshaped endometrial cavity, a widened lower uterine segment, midfundal constrictions, endometrial filling defects, irregular margins,
and a hypoplastic uterus (Patton, 1988). Cervical structural
abnormalities were also detected in 44% of these women. These
anomalies included hypoplasia, an anterior ridge, a collar, and
pseudopolyps. Vaginal adenosis and vaginal constrictions are
associated abnormalities (Kaufman, 1980; Patton, 1988).
This group of anomalies are probably associated with high rate of
obstetric complications although no specific anomaly has been
associated with any form of adverse obstetric outcome (Kaufman,
1980; Patton, 1988). However cervical incompetence may be an
associated factor in these women and cervical cerclage is the only
prophylactic treatment that can be offered (Goldberg, 1999).
Complications and Clinical Presentations of Uterine Anomalies:
Müllerian duct anomalies (MDAs) are often recognized after the
onset of puberty. In the prepubertal period, the presence of normal
external genitalia and age-appropriate developmental milestones often
mask abnormalities of the internal reproductive organs. After the
onset of puberty, young women with müllerian anomalies often
present to the gynecologist with menstrual disorders. Later
presentations include infertility and obstetric complications.
Uterine anomalies usually present as cases of obstetric
complications in the form of repeated miscarriages, premature labor
intrauterine growth retardation, malpresentation, or retained placenta.
A
unilateral
functioning
rudimentary
horn,
which
fails
to
communicate with the other horn, may present early in the years
following puberty usually with primary cyclic dysmenorrhea.
Recurrent miscarriages, due to uterine anomalies, usually occur
as a result of failure of the uterus to accommodate the growing
pregnancy. The timing of miscarriage is usually in second trimester
miscarriage and the duration of pregnancy tends to increase in
subsequent pregnancy.
Hence, conservative management of such
cases will eventually lead to the achievement of a successful
pregnancy. Early first trimester miscarriage is more common in cases
of septet uterus if the developing embryo gets implanted on the
septum where there is often deficient vascular development.
Delayed obstetric complications in the form of malpresentation,
breech or transverse lie may occur in cases of uterine anomaly due to
loss of the normal pear-shaped uterine cavity, which encourages the
cephalic presentation.