Conception include mo ceive, low coital frequ ppsx

h a

Subfertility

Definition

Epidemiology

Causes of female subfertility

Causes of male siibfertility

History and examination

Investigations

Treatment of male and female siibfertility

Assisted conception

conception include mo

ceive, low coital frequ*

of intercourse to ovul

smoking and a body i

range 20-30 (weight (k

Factors affecting fertiL

couples trying to conce:

conception advice on v

conception and to redi

plications for the rnothi

Table 7.1 Factors adve

OVERVIE W

Fifteen per cent of couples who want a baby experience an unwanted delay in conception. Although there has been no change in

the prevalence of fertility problems, more cojples seek help than did previously. The causes of fertility problems include disor￾ders oi ovjlation. sperm and the Fallopian tube, although no identifiable cause is found in a third of couples trying for a baby. In

39 per rent of couples, a problem will be found in both partners. Fertility treatment may be medical, surgical or involve assisted

conception whereby the egg and sperm are brought into close proximity to facilitate fertilization.

Female factors MaJe

Age (>37 years) Low

Of H

heal

-\fenstrual FSH Drug

level (>10u/L)

5H, follicle-stimulatin

Subfertility is defined as the failure to conceive within

1 year of unprotected regular sexual intercourse. For

couples who have had no previous conception, the sub￾fertility is defined as primary, while couples who have

had a previous conception and have then not conceived

again are defined as having secondary subferlility.

Epidemiology

Approximately 50 per cent of couples will conceive

after receiving advice and simple treatment, but the

remainder require more complex assisted conception

techniques, and 4 per cent of couples will remain

involuntarily childless. The chance of a spontaneous

conception over the first 6 months of unprotected

intercourse is approximately 60 per cent. At the end

of 1 year, 85 per cent of couples will have conceived.

The single most important factor in determining

fertility is the age of the female partner, with fertility

reducing rapidly in women over 35 years of age (Fig.

7.1). Factors that reduce the chance of a spontaneous

1.00

| 0.80

.1 0.60-

1

| 0.40

0

0.20

n nn

i

i

i \

;

i 1

0 1 6 9 12 18 24

Months

Figure 7.1 Cumulative conception rate over first 2 years of

trying to conceive. (Source: ABC of Subtertility — Extent ol the

problem. Taylor, A. Copyright 2003, BMJ.)

Preconcepti

• Tvle

J»T smoking

tap recreational

fcpiiar sexual

•tercourse, 2-3 times

Causes of female siilifertility 77

60 per cent. At the end

es will have conceived.

[ factor in determining

k partner, with fertility

per 35 years of age (Fig.

hance of a spontaneous

9 12 18 24

xrths

conception include more than 3 years of trying to con￾ceive, low coital frequency and inappropriate timing

of intercourse to ovulation, no previous pregnancy,

smoking and a body mass index (BMI) outside the

range 20-30 (weight (kg)/height (m)2

) in the woman.

Factors affecting fertility are listed in Table 7.1. All

couples trying to conceive should be given general pre￾conception advice on ways to improve the chances of

conception and to reduce the risk of pregnancy corn￾plications for the mother or fetus (Table 7.2).

Table 7.1 Factors adversely affecting conception rates

Female factors Male factors Combined factors

Age (>37 years) Low numbers Duration or"

ofrnotile, infertility

healthy sperm (>2 years)

Menstrual FSH Drug intake No previous

level (>10u/L) conception in

current

relationship

?SH, follicle-stimulating hormone.

Table 7,2 Preconception advice

lifestyle Medical

> smoking

Stop recreational

ir-gs

•egular sexual

intercourse, 2-3 times

a week

Optimize management of

medical problems

Eliminate drugs not safe for

pregnancy

Optimize body weight to a

body mass index of 2(1-30

Eliminate drugs not safe for

pregnancy

Prepregnancy assessment

by an obstetric physician

Commence folk acid

supplements

Ensure immunity to rubella

Fertility investigations are usually commenced after

I year of unprotected intercourse, but it is advisable

to start investigations after 6 months of unprotected

intercourse in women over 35 years of age. Initial

management and investigations may be commenced

by the general practitioner, who is also able to offer

advice and support to couples requiring referral for

more specialist investigations.

Causes of female subfertility

The main causes of subfertility are ovulation dis￾orders, male factors, tubal damage, unexplained, and

other causes such as endometriosis and fibroids. The

proportion of each type of subfertility varies in different

studies and in different populations. Tubai subfertility

is more common in those with secondary subfertility

and in populations with a higher prevalence of sexually

transmitted disease.

P Understanding the patho physio logy

Qogenesis and avulation

The formation and maturation of an oocyte is Known as

oogenesis (Fig. 7.2). It starts with the growth of a

primordial follicle to form a pre-antral follicle and ends

with the final maturation of a pre-ovulation follicle. The

formation of the pre-antral follicle takes 85 days in a

human, while the final maturation stage (the follicular

phase of the menstrual cycle) from the pre-antral follicle to

the pre-oviilatory follicle takes 14 days to complete. Figure

7.3 shows a pre-ovulatory follicle with its blood flow.

An intact hypotha I a mo-pituitary-ovarian axis is essential

for normal ovarian function. Gonadotrophin-releasing

hormone (GnRH) is released in a pulsatile manner to

control the pituitary and the release of follicle-stimulating

hormone (FSH) and luteinizing hormone (LH). These

hormones stimulate the development of the follicles,

while a mid-cycle surge of LH (Fig. 7.4) causes rupture of

the dominant follicle and release of the oocyte (ovulation).

Ovulation problems

Ovulation problems can arise as a result of defects in

the hypothalamus, the pituitary or the ovary. Factors

that disrupt the normal pulsatile release of GnRH will

lead to disordered ovulation. These factors include