Infertility
Definition and aetiology
Infertility is defined as the inability to conceive after 1 year
of unprotected intercourse. It is estimated that the chances of a couple
conceiving are 85% after 1 year and 95% after 2 years (in women under the age
of 35). Infertility is primary (no previous pregnancies) or secondary (previous
pregnancy, regardless of outcome). A number of factors lead to difficulty in
conceiving (Figure 30.1):
• Age The prevalence of
infertility rises significantly with advancing female age. Fertility rates fall
moderately between age 35 and 39, and dramatically thereafter.
• Anovulation This accounts
for 20% of cases and is usually indicated by menstrual dysfunction:
amenorrhoea, oligomenorrhoea or polymenorrhoea.
• Tubal factors Pelvic
infections (pelvic inflammatory disease; PID), most commonly caused by
Chlamydia trachomatis, result in damage to the fallopian tubes in a significant
number of women, and are often clinically ‘silent’.
• Cervical mucus factors.
• Male factors.
Evaluation of the infertile couple
History
Both the male and female partner needs to be evaluated. In some
cases, such as amenorrhoea, azoospermia or bilateral tubal obstruction, the
aetiology is obvious but in most couples the cause is less clear. The history
should enquire about any previous pregnancies, previous gynaecological history,
menstrual characteristics, sexually transmitted infections, medical illnesses,
family history and drug history. In men, a history of previous testicular
surgery, trauma or orchitis should be sought. Couples should also be questioned
about the frequency and timing of sexual intercourse, and any symptoms of
sexual dysfunction such as loss of libido, erectile dysfunction or dyspareunia
(painful intercourse).
Examination
A general examination should include measurement of BMI, as women
who have a normal BMI are more likely to conceive than those who are either
under or overweight. Signs of androgen excess (acne, hirsutism) suggests a
diagnosis of PCOS (Chapter 26) while a pelvic examination can reveal nodules,
tenderness or limited pelvic organ mobility in keeping with endometriosis. BMI
should also be assessed in men, in addition to a search for features of
hypogonadism (Chapter 28).
Investigations
General health screening should include measurement of blood
pressure, BMI, urinalysis, cervical cytology and rubella immunity (Table 30.1).
Other tests include the following:
· Ovulation function Regular menstrual cycles
are a sign of ovulation in 95% of cycles. A midluteal phase (day 21) progesterone
level can help confirm the presence of ovulation. If periods are irregular then
measurement of other hormones is necessary (prolactin, thyroid function,
androgens; Chapter 25). Measurement of anti-Müllerian hormone levels can help
predict ovarian reserve.
·
Tubal assessment
Needed when ovulation status and semen analysis is normal, especially in women
with a history of PID. Laparoscopy is the gold standard.
· Uterine evaluation
Transvaginal ultrasound helps assess uter-ine morphology and neighbouring
structures.
·
Chlamydia serology
The best initial screen for tubal disease.
· Semen analysis
Semen volume, sperm count, motility and morphology are assessed. Testosterone,
FSH, LH and prolactin should be measured in men with oligospermia or
azoospermia (absent sperm). Urological assessment is needed in azoospermic men
with normal testosterone, LH and FSH as this indicates mechanical obstruction.
Management
· Tubal and uterine disease Surgery
can be considered for proximal tubal disease or uterine fibroids in selected
patients.
· Endometriosis Laparoscopic
ablation or resection of endometriotic deposits plus adhesiolysis may be
beneficial.
· Ovulatory dysfunction
Optimisation of BMI helps restore ovulatory cycles in women who are under or
overweight. Ovulation induction with pulsatile GnRH analogues or gonadotrophins
can be offered to patients with hypogonadotrophic hypogonadism. Antioestrogens
such as clomifene citrate are used first line to induce ovulation in women with
PCOS whereas patients with hyperprolactinaemia are treated with dopamine
agonists (Chapter 6).
· Intra-uterine insemination
Involves timed insemination of sperm into the uterus. Often undertaken after
failed ovulation induction in women with patent tubes.
· In vitro fertilisation
(IVF) and ICSI IVF treatment involves a series of steps that include
superovulation (ovulation induction), oocyte (egg) retrieval, IVF, embryo
transfer and luteal phase support.
· Oocyte donation
Used in women with premature ovarian failure (e.g. Turner’s syndrome,
oophorectomy, previous chemo-/radiotherapy).
· Male factor infertility
Gonadotrophins or pulsatile GnRH ana-logue therapy can improve fertility in men
with hypogonado-trophic hypogonadism (e.g. Kallmann’s syndrome; Chapter 28).
Hyperprolactinaemia is treated with dopamine agonists. Surgery or percutaneous
sperm aspiration can improve fertility in men with obstructive azoospermia.
