Applied Physiology

The R.eproductive System

Applied Physiology
 The *el)roductive System
2) Secretary phase (14 days): After ovulation, the lining of ovarian follicle is
stimulated by LH to develop corpus luteum which produces progesterone. The
endometrium becomes oedematous, watery mucous increases. This is believed
to assist the passage of spermatozoa through the uterus to uterine tubes where
the ovum is usually fertilized.

The ovum fertilizes by 8 hours. The survival of the sperm is only for 24 hours.
The date of ovulation however, cannot be predicted with certainty, even when
the cycles are regular. If fertilization of ovum does not occur, cycle goes to a
third phase - the menstrual phase. '

3) Menstrual Phase (4 days): If the ovum is not fertilized, a high level of

progesterone in the blood inhibits the activity of pituitary gland and the production
of luteinizing hormone is reduced. The decrease in hormone causes degeneration
of corpus luteum. Thus progesterone production is decreased. Around 14 days
after ovulation, the lining of uterus degenerates and breaks down, menstruation
begins. The flow consists of extra secretion of endometrial cells, blood from
broken capillaries and the unfertilized ovum.

When progesterone levels decreases considerably, another ovarian follicle is

stimulated by FSH and the next cycle begins.
rt

What happens when the ovum is fertilized?

If the ovum is fertilized, there is no breakdown of endometrium and no menstrual
flow. The fertilized ovum travels through uterine tube to the uterus where it .
becomes embedded in the wall and produces chorion gonadotrophins as
highlighted in Figure 12.7. This keeps corpus luteum intact enabling it to continue to
secrete progesterone for the first 3-4 months of pregnancy, inhibiting the maturation
of ovarian follicles. During that time, placenta develops and produces oestrogen,
progesterone and gonadotrophins. The placenta provides an indirect link between the
circulation of the mother and that of the foetus. Through the placenta, the foetus
obtains maturational materials, 02, antibodies and gets rid of C02 and other waste

While on the topic of menstrual cycle, we must also focus on menopause.

What is menopause? -
The cessation of menstruation is menopause. Natural nienopause typically occurs
between 45 and 55 years of age. It is caused by changes in concentration of the sex

During menopause, the ovaries become less responsive to the FSH and LH and
ovulation and menstrual cycle becomes irregular, eventually ceases. Other changes
are vasodilatation, sweating palpitations, discomfort and disturbance in normal sleep
and shrinking of breasts, atrophy of sex organs etc.

The discussion above focused on menstruation and menopause. The two terms
are used commonly with respect to female reproductive system. While studying
about the female reproductive organs, you might also come across certain
accessory glands such as the mammary glands. What are these glands? Let's

12.3.4 Accessory Glands - Breasts or Mammary Glands

The breasts or mammary glands are accessory glands of the female reproductive
system. They also exist in the male .but only in a rudimentary form. Figure 12.8
I illustrates the mammary gland.
Applied Physiology

Check Your Progress Exercise 1

1) ldentify the organs of the female reproductive system.
'\

6
2) Enumerate the functions of the following organs:
a) Uterus
.................................................................................................................
.................................................................................................................
b) Fallopian tubes

.................................................................................................................
.................................................................................................................
3) What are the phases of menstrual cycle? Also mention the hormonal and
physiological changes occurring during menopause.

......................................................................................................................
......................................................................................................................
......................................................................................................................
4) Which hormones are responsible for stimulating changes in the following organs?
Also mention their roles.
a) Ovaries
.................................................................................................................
.................................................................................................................
b) Mammary glands
.................................................................................................................
.................................................................................................................
Applied Physiology
The Reproductive Systen
4p,-.ed Physiology
The Reproductive System
Applied Physiology

Weeks of Pregnancy

10 20 30 40

Foetus (g) 5 300 1500 3000-3300 .

Placenta (g) 20 ,170 430 650

Nourishes the foetus facilitates transfer of oxygen and nutrients from mother to
foetus.
Removes wastes picks up foetal waste products such as CO,, urea, bilirubin.

Foetal lung performs the respiratory, absorptive and excretory functions

that the foetus' lungs, digestive system and kidneys will
provide after birth.
Protective barrier protects the foetus from harmful agents, which are of high
molecular weight including pioteins except maternal
immuoglobulin G conferring immunity to the foetus.
transports nutrients and in some cases can store them.

Endocrine gland produces several hormones that maintain pregnancy and

prepare the mother's breasts for lactation.
Period Major developmental features Vital Statistics
4 weeks Embryo has gill like sjructures that will later become Lengh: approx. 4 mm
its jaw, neck and part of the face. Rudimentary spinal
cord appears. By end of the 31d week, the heart begins Weight: Less than a gram
to beat. In the Ydweek, the embryo enters a sensitive Crown to rump length: 2.5 cm
phase, when all the major organs are forming. Embryos
can be harmed by drugs, alcohol, smoking, infections Weight: Approx. 3 gm.
etc.
8 weeks Face begins to develop, eyes and nose appear. All Crown to rump length: 9 cm
internal organs are now present, most major structures
are formed. Tail ii reabsorbed. Muscles start to build. 48g
By 7thweek, the first embryonic movement can be
detected using ultra sound.
12 weeks Baby is fully formed, head and neck extend and grow. Crown to rump length: 13.5 cm
Bones (in the form of flexible cartilage) are rapidly
developed. Jaws show 3 2 permanent tooth buds. Weight: g
Applied Physiology Each breast consists of 15-20 lobes of glandular tissue, each lobe being made up of
a number of lobules as can be seen in Figure 12.16. The lobules consist of a cluster
of alveoli, which open into ducts and these unite to form large excretory ducts called
Iactifeous ducts. These ducts converge towards the center of the breast where
they form dilatation or reservoirs for milk. Leading these dilatations, there are narrow
ducts which open onto the surface at the nipple. Fibrous tissue supports the glandular
tissue and ducts, and covers the surface of the gland and is found between the lobes.
The nipple is a small conical eminence at the center of the breast surrounded by a
pigmented area, the areola. On the surface of areola, there are numerous sebaceous
glands which lubricate the nipple in pregnancy. The function of this gland is to secrete
milk.
The nipple contains 15-20 lactiferous ducts surrounded by modified muscle cells.
These ducts expand to form the short lactiferous sinuses in which milk may be
stored. The sinuses are continuations of the mammary ducts, which extend outward
from the nipple towards the chest wall with numerous secondary branches. The ducts
end in epithelial masses, which form lobules (1 5-20 in number). Generally,.the terminal
tubules and glandular structures are most numerous during the child-bearing period
and reach their full physiological development only during pregnancy and lactation.

There is proliferation of the terminal tubules, dilation of the tubular lamina and lining
of the acinar structures by cuboidal epithelium. During the last trimester, the clumps
of milk-producing cells progressively dilate in final preparation for the lactation process.
The breasts are capable of milk secretion sometime in the second trimester.

The placenta plays an important role. The hormones secreted by the placenta -
human placental lactogen, prolactin and chorionic gonadotropin, contribute to
mammary gland growth. Also placental estradiol and progesterone stimulate breast
development. Shortly after parturition, proliferation of parenchymal cells occurs.

Next, let us look at the physiology of lactation.

12.6.2 Physiology of Lactation

Lactogenesis is the onset of copious milk secretion around parturition, triggered by
a fall in plasma progesterone levels. Although some colostrum is secreted after
delivery (2-3 days), full lactation begins later. The first 2-3 days after delivery is a
period of rapid lactation initiation, followed by the longer period of maintenance of
lactation. This complex neuroendocrine process is facilitated by an interplay of various
hormones.

Oxytocin and prolactin instigate the lactation process, Prolactin is responsible for
milk production and oxytocin is involved in milk ejection from the breast. The basic
secretory units of the mammary gland, as you may already know now, are the alveoli
composed of a single layer of epithelial cells. The alveoli produce the secretory
product. Surrounding the alveoli are the myoepithelial cells which are contractile and
are responsible for the ejection of milk from alveoli and alveolar ducts.
A cyclic process of secretory activity, lurninal distention and expulsion of milk into the
duct system continues throughout lactation as directed by the suckling of the infant
and the letdown reflex. Regular sucking stimulates the continuation of milk secretion.
Milk removal from the breast is a product of coordinated interaction between suckling
of the infant and letdown reflex of the mother. As the infant commences suckling,
afferent impulses generated in the receptors in the areola travel to the brain where
they stimulate the release of oxytocin &om the posterior pituitary. Oxytocin travels
through the blood stream to the breast where it combines with specific receptors on
the myoepithelial cells, stimulating them to contract and force milk fiom the alveoli
into the mammary ducts and sinuses.
360
Hormone Primary Source of Principal Effects
Secretion

Progesterone Placenta Reduces gastric motility, favours maternal

fat deposition, increases sodium excretion,
reduces alveolar and arterial CO2, interferes
with folic acid metabolism.
Oestrogen Placenta Reduces serum proteins, increases
hydroscopic properties of connective tissue,
affects thyroid function, interferes with folic
acid metabolism
Human Placental Lactogen Placenta Elevates blood glucose from glycogen
breakdown
Human chorionic thyrotropin Placenta Stimulates production of thyroid hormones

'
Human growth hormone Anterior pituitary Elevates blood glucose, stimulates growth of
long bones, promotes N2 retention
Thyroid stimulating hormone Anterior pituitary Stimulates thyroxine secretion, increases
iodine uptake by thyroid gland
Thyroxine Thyroid Regulates basal metabolism (rate of cellular
oxidation)
Parathyroid hormone Parathyroid Promotes calcium resorption from bone,
increases calcium absorption, promotes
urinary excretion of phosphate
Calcitonin Thyroid Inhibits calcium resorption from bone
Insulin Beta cells of pancreas Reduces blood glucose levels to promote
energy production and fat synthesis
Glucagon Alpha cells of pancreas Elevates blood glucose levels from glycogen
breakdown
Aldosterone Adrenal cortex Promotes sodium retention and potassium
excretion
Cortisone Adrenal cortex Elevates blood glucose from protein
breakdown
Renin-angiotensin Kidneys Stimulates aldosterone secretion, promotes
sodium and water retention
Applied Physiology
12.8 DISORDERS OF THE REPRODUCTIVE SYSTEM

Disorders that may affect the proper fimctioning of the reproductive system include
abnormal hormone secretion, sexually transmitted diseases and the presence of
cancerous tissues in the region. Such problems frequently affect fertility and may
complicate pregnancy. We shall look at the different disorders specific to the female
and male reproductive system in this section. Let us start with the study of the
disorders affecting female reproductive system.

12.8.1 Disorders of the Female Reproductive System

Over the last decade, there has been a growing concern regarding the prevalence
and extent of reproductive tract infections (RTIs) and other gynaecological disorders
in women in the developing countries.

For a proper understanding of gynaecological disorders (including reproductive tract

infections - RTIs), it is important to have a common conceptual framework for
defining the different types of morbidity that can occur in women. Morbidity in
women can be categorized as reproductive or non-reproductive morbidity.

Reproductive morbidity refers to diseases that affect the reproductive system,

although not necessarily as a consequence of reproduction. Reproductive morbidity
can be subdivided into three broad categories:

1) Obstetrichaternal morbidity, which covers morbidity in a woman who is, or

has been, pregnant fiom any cause related to or aggravated by the pregnancy
or its management, but not from accidental or incidental causes. Genitourinary
prolapse and vesico-vaginalfistula are classified as obstetric morbidities. Both
conditions are usually the direct result of multiple pregnancies and prolonged or
obstructed labour respectively. Vesico-vaginal fistula can also be caused by crude
attempts at induced abortion, female genital cutting and accidental injury during
obstetric surgery and pelvic irradiation.

2) Gynaecological morbidity, which covers any condition, disease or dysfimction

of the reproductive system that is not related to pregnancy, abortion or childbirth,
but may be related to sexual behaviour.

3) Contraceptive morbidity, which covers any condition that result fiom efforts
(other than abortion) to limit fertility, whether they are traditional or modem

There is a considerable overlap between these subcategories. Infertility, for

example, can have an obstetric cause but can also be the result of a gynaecological
morbidity. However, the focus here is on gynaecological morbidity.

Gynaecological morbidity can W h e r be divided into reproductive tract infections,

endocrine disorders, infertility, gynaecological cancers, congenital malformations
or birth defects, injuries, sexual dysfunction, menopausal symptoms and others.
Let us discuss each of these.

i) Reproductive tract infections include three different types of infection that

affect the reproductive tract. These are:
Sexually transmitted infections: These include, for example, chlamydia1
infection, gonorrhoea, trichomniasis, syphilis, chancroid, genital herpes,
genital warts (caused by the human papilloma virus) and HIV. They are
caused by viruses, bacteria or other microorganisms that are transmitted
through sexual activity with an infected partner.
164
 Endogenous infections: These include bacterial vaginosis and candidiasis, The B:eproductive S ~ s t e n
which result from an overgrowth of organisms normally present in the vagina.
Iatrogenic infections. These are caused by the introduction of
microorganisms into the reproductive tract through a medical procedure.
Iatrogenic infections are acquired through a number of routes, including
unhygienic delivery conditions and other procedures such as pregnancy
termination, menstrual regulation, IUD insertion, sterilization procedures and
circumcision carried out under unhygienic conditions.
Reproductive tract infections are often categorized by the site of infection.'
Infections that cause inflammation of the external genital area and lower
reproductive tract in women are referred to as vulvovaginitis or vaginitis,
inflammation of the cervix as cewicitis, and infection of the upper reproductive
tract as pelvic inflammatory disease.

ii) Endocrine or hormonal disorders can affect several aspects of reproduction,

from menstruation to fertility. Menstrual disorders are frequently reported in
studies on gynaecological morbidity and include problems with the regularity,
frequency, volume and duration of menstrual bleeding, as well as, painhl
menstruation and premenstrual syndrome.

ii) Infertility can be caused by endocrine disorders, long-term sequelae of sexually

, transmitted infections, puerperal sepsis, post-abortion sepsis and congenital
malformations. In many societies, the social and psychological consequences of
infertility are severe. Infertility is, therefore, a component of many population-
based studies of gynaecological morbidity.

iv) Gynaecological cancers include cancers of the cervix, breast, endometrium,

ovary, vagina, vulva and rarely, the fallopian tube. Cervical cancer is the most
common cancer in women in the developing world and is often fatal if it is not
diagnosed early.

v) Other gynaecological morbidities cover congenital malformations or birth defects

of the genital organs. These occur in almost infinite variations and are often not
apparent until an adolescent fails to menstruate or a sexually active woman fails
to conceive.

vi) Injuries include those caused by traditional practices (such as female genital
mutilation), sexual abuse or accidents. Recently, sexual abuse and violence against
women have gained recognition as major causes of reproductive morbidity.

vii) Sexual dysfunction can be caused by a variety of factors, including infertility,

childhood sexual abuse, rape, female genital mutilation, fistula, genito-urinary
prolapse, vaginal infections, congenital malformations, adhesions from injuries or
inconsiderate partners.

viii) Menopausal symptoms include: (i) hormone-related gynaecological problems

that occur around the menopause, and (ii) post-menopausal uterine bleeding and
atrophic vaginitis (inflammation of the vaginal mucosa secondary to thinning and
decreased lubrication of the vaginal walls caused by a decrease in oestrogen).

ix) Other gynaecological morbidity includes endometriosis, ovarian cysts, uterine

fibroids and polyps, and non-inflammatory and inflanfmatory diseases of the
pelvic organs not attributable to sexually transmitted infections (for example,
female genital tuberculosis and genital tract schistosomiasis).

Gynaecological morbidity and family planning are closely linked. Symptoms of

reproductive tract infections may be attributed to contraceptive methods and might
Applied Physiology
Check Your Progress Exercise 4

1) What do you understand by the term 'reproductive morbidity'? What are its
three categories?
..................................................................................................................
..................................................................................................................
..................................................................................................................
2) What are the different types of gynaecological morbities? List the three
different types of reproductive tract infections, giving an example of each.
..................................................................................................................
..................................................................................................................
..................................................................................................................
3) Enlist the infections occurring in the following organs:

Organ Infections
a) Penis ......................................................................................
b) Urethra ......................................................................................
c) Epididymis ......................................................................................
and Testes
d) Prostrate Gland .......................................................................................

4) What is meant by 'infertility'? Enumerate any five causes of male infertility.

..................................................................................................................
..................................................................................................................
..................................................................................................................

12.9 CONTRACEPTION

various contraceptive methods available today. The most common artificial methods
are malelfemale condoms, spermicides, sponge, diaphragm, cervical cap, oral
contraceptives (birth control pills), injectable contraceptions (Depo-Provera), IUDs
and surgical sterilization. The following discussion presents information on the traditional,
modern, irreversible and the newest contraceptive options available tohay. Hope you
find the discussion informative.
A) "Folk" methods
People have been using birth control for thousands of years. Even quite early on,
people had a pretty good idea of what they needed to do to prevent conception.
Different folk methods have been used for ages. These included:

conventional methods. However, in practice, some of the semen frequently escapes 1

 Postcoital douche - Douching i.e. cleaning shortly after intercourse. Because The ReplroduCnve BYsIem
sperm can make their way beyond the cervix within 90 seconds after ejaculation,
this method is ineffective and unreliable.
Breasfleeding - It is not true that women cannot become pregnant while
breastfeeding. In about 6% of women, ovulation returns with the first cycle after
delivery. Women who are breastfeeding infants and do not desire another
pregnancy at that time need to use a reliable form of contraception.
B) "Traditional" methods
Certain methods ha\;e been used for long, which we have included here as traditional
methods. These include:
Condoms - Condom, you may already know, is a thin sheath (preferably latex
to also protect fiom transmission of disease-causing organisms) placed on the
'
penjs or, in the case of 'the female, within the vagina prior to intercourse. Semen
is collected inside the condom, which must be carefully maintained in place and
then removed afjer inter~ourse.Effectiveness of condoms is increased when
spennicide is also used. Condoms are readily available at low cost in most drug
arid grocery stores. Some family planning clinics may offer fiee condoms. About
14 occur over 1 year out of 100 couples usins male condoms, and
about 21 pregnancies occur over 1 year out of 100 couples using female condoms.
Yaginal spennicides - These are the sperm-killing chemical jellies, foams, creams,
or suppositories, inserted into the vagina prior to intercourse. This method is
readily available. All forms can be purchased in most drug and grocery stores.
However, this method used by itself is not very effective. About 26 pregnancies
occur over 1 year out of 100 women using this method alone, so spermicides are
often combined with other methods (such as condoms).
Diaphragm - Flexible rubber cup that is filled with spermicidal cream or jelly,
and then placed into the vagina, over the cervix, before intercourse. It should be
left in place for 6 to 8 hours after intercourse. Diaphragms must be prescribed
by a woman's health care provider, who determines the correct type and size of
diaphragm for each woman. About 20 pregnancies occur over 1 year in 100
women using this method.
Vaginal contraceptive sponge - Soft synthetic sponge, saturated with a
spermicidal, which is moistened and inserted into the vagina, over the cervix,
before intercourse. It is quite similar to the diaphragm as a barrier mechanism.
After intercourse, the sponge should be left in place for 6 to 8 hours. This
method is available without a prescription in most drug and grocery stores. About
18 to 28 pregnancies occur over 1 year out of 100 women using this method.
This method was removed fiom the market a few years ago, but plans are
u n d e m y to re-introduce it in the near future.
*
Fertilify awareness with abstinence (natural family planning) - This method
involves observing a variety of body changes in the woman (such as, cervical
mucus'changes, basal body temperature changes) and recording them on the
calendar in an attempt to determine when ovulation occurs. The couple abstains
from unprotected intercourse for several days before and after the assumed day
ovulation occurs. This method requires special education and trdining in =cognizing
the body's changes, as well as, a great deal of continuous and committed effort.
About 15 to 20 pregnancies occur over 1 year out of 100 women using this
method (for women who are properly trained).
C) "Modern" methods (.

Few modem methods of contraception include:

Oral contraceptives (the pill'^..- This method utilizes a combination of oestrogen
and progestin medications in d k e s that prevent ovulation and regulate cycles. A
36
 IrcarLn care provlder must prescrib
is highly effective if the woman
same time each day. Oral antibi
control pills. Therefore, a backup
taking antibiotics and until the next menstrual period after completion of the
antibiotic. Because of the wide variety of oral contraceptives, women who
experience unpleasant side effects on one type of pill are usually able to adjust
to a different oral contraceptive. It is important for women who are just starting
on ''the pill" to communicate with their health care provider for optimal "matching7'
of the type of oral contraceptive to each patient. About 2 to 3 pregnancies occur
over 1 year out of 100 women using this method.
Progestin-only oral contraceptive (the "mini-pill'y - This type of birth control
pill does not contain any oestrogen component. It is therefore an alternative for
those women who desire a highly effective method of contraception in a "pill"
form, but are sensitive to oestrogen or cannot take a contraceptive containing
oestrogen for other reasons. The effectiveness of progestin-only oral contraceptives
is slightly less than that of the combination type. About 3 pregnancies occur'over
a 1 year period in 100 women using this method.
Progestin implants (such as Norplant) - Six small progestin-containing rods
are implanted surgically beneath the skin, usually under the upper arm, by a
woman's health care provider. The rods release a continuous dose of progestin
that inhibits ovulation, changes the lining of the uterus and thickens cervical
mucus, which may prevent sperm from entering the uterus. The implants provide
contraceptive protection for a period of 5 years. The method is highly effective.
Less than 1 pregnancy occurs over 1 year out of 100 women using this type of '
contraception.
Hormonal injections (such as Depo-Pmvera) - A progestin injection is ordered
by a woman's health care provider and given into the muscular tissue of the
upper arm or buttocks. This injection prevents ovulation. A single shot provides
contraceptive protection for up to 90 days. This method is highly effective and
does not depend on patient compliance. Less than 1 pregnancy occurs over 1
year in ID0 women using this method.
Intrauterine contru~eptivedevice (IUD) - It is a small plastic or copper
device, placed inside the woman's uterus by the health care provider, which
changes the uterine environment to prevent pregnancy. IUDs may be left in
place for up to ten years in some patients. The method should not be used by
women who have a history of pelvic infection, ectopic pregnancy (a pregnancy
in which a tenrlized egg begin to develop outside the uterus i.e. in the fallopian
tube) or who have more than one sexual partner (and are therefore at higher risk
for acquiring sexually transmitted diseases). Depending on the IUD used, 1 to
3 pregnancies occur per year out of 100 women using this type of contraception.
I D ) Permanent or irreversible methods
A number of permanent or irreversible methods of contraception are available. These
, include:
Tzlhal Ilgation - This procedure is the most commonly used method of female
sler~lizatlon.Tubal ligations are usually done in an outpatient surgical center.
During tubal ligation, a woman's fallopian tubes are cut, sealed or obstructed by
a special clip, preventing eggs and sperm from entering the tubes, thus preventing
conception. The operation can sometimes be reversed if a woman later chooses
to become pregnant. Following tubal ligation reversal, about 60% to 80% of
women eventually become pregnant. However, it is.best to consider tubal ligation
a pedanenl form of contraception.
Vasectonij~ A vasectomy is 'a simple, permanent sterilization procedure for
men. he operation, usually done in a physician's ofice, requires cutting and
 sealing the vas deferens (tubes in the male reproductive system that carry T h e Reprodllctive System
sperm.) Like tuba1 ligations, vasedtomies can sometimes be reversed through a

However, it is best to consider vasectomy a permanent form of contraception.

Other than the methods discussed above, few new contraceptive options have emerged.
I Let us get to know these newest options.
The newest contraceptive option - the Vaginal Ring

offers protection against pregnancy without the inconvenience of barrier methods,

' spermicides or remembering to take a daily pill.

I How does it work?

118" (4 mm) thick. The ring contains hormones - oestrogen and a progestogen similar
to the ones found in combined oral contraceptives (the pill). The ring is inserted into
the vagjna. The ring is left in place for 3 consecutive weeks, the same number of
days that is in one cycle of oral contraceptive pills. During this period, it releases a
st'eady low dose of hormones which prevent pregnancy by stopping the release of a
mature egg (ovulation). After three weeks, the ring is removed to make way for a
menstrual period, after a ring-free period of 1 week a new ring is inserted for another
three weeks and so on.
How effective is it?

comfortable, the ring is in the right position and will release the hormones necessary
I for contraception.
The Mdle "Pill"
Male contraceptive research is beginning to yield a number of leads in the area of
male contraception. Studies are now underway to test hormonal methods of birth
control which will provide safe, reliable and reversible male contraception. One

an implant or injection, or a combination of these would be most effective. The

1 Finally, a word about emergency contraception.

Emergency Contraception

(ECP) one of the best-kept health secrets,'ofmodern contraception. ECP is gv-ai1,able

, from your doctor, hos~italor birth control clinic by prescription. ECP caivbe .useful
for preventing pregnancy in many situations including:
a condom slips or breaks
a diaphragm becorqt ~~[slodged
.
or moves out of position
, you forget your method of contraception and have unprotected sex
L J Y ~ ~ I
Applied Physiology you missed taking your oral contraceptive pjlls
you are forced into having sex
you miscalculate your most "fertile" days and have sex without birth control
How does emergency contraception work?
There are basically two types of emergency contraception available:
1) The Emergency Contraceptive Pill (ECP) method - The ECP method or
"morning after pill" uses a high dose of combined oral contraceptives (OCs) to
prevent conception. The OC method is effective if used within 72 hours after
unprotected intercourse.
2) The Intrauterine Device (IUD) method - This method involves the insertion of
an IUD into the uterus by your doctor. The IUD creates an unfriendly environment
for egg and sperm. The IUD must be inserted within 7 days of unprotected sex.
Emergency or the "morning after" pill consists of two doses of hormone pills
taken as soon as possible within 72 hours after unprotected intercourse. The pill
may prevent pregnancy by temporarily blocking eggs from being produced, by
stopping Eertilization or keeping a fertilized egg from becoming implanted in the
uterus. The morning-after pill is reserved for emergency situations and not as a
regular method of birth control. Emergencies include being raped, having a condom
break or slip off during sex, missing two or more birth control pills during a
monthly cycle, and having unplanned sex.
With emergency contraception, we end our study on contraception. In the next
section, we will look at the different tests recommended during pregnancy.

Check Y6ur Progress Exercise 5

1) What do you understand by the term 'contraception'? .
.............. ................................................................................................
i

...............................................................................................................
...............................................................................................................
2) List any three methods of contraception in the following categories:
. a) Traditional Methods
........................................................................................................
b) Modem Methods
........................................................................................................
3) Is vasectomy a permanent sterilization procedure?
...............................................................................................................
...............................................................................................................
...............................................................................................................
4) Enumerate the two different types of emergency contraception.
...............................................................................................................
...............................................................................................................
...............................................................................................................
3
 12.10 COMMON TESTS DURING PREGNANCY
9 - The Reprod uctivc System
- ..

Pregnancy, as you may have realized, is a period of physiological stress. To ensure . '

a successful pregnancy, few common tests are recommended. The following are
some of the more common tests performed during pregnancy:
*
alpha-fetoprotein screening (multiple marker screening)
amniocentesis
chorionic villus sampling
foetal monitoring
glucose tolerance test
Group B strep culture

genetic screening .
Let us get to know them.

What is an alpha-fetoprotein screening (AFP)?

This is a blood test that measures the level of alpha-fetoprotein in the mothers' blood
during pregnancy. AFP is a protein normally produced by the foetal liver and is
present in the fluid surrounding the foetus (amniotic fluid), and crosses the placenta
into the mother's blood. The AFP blood test is also called MSAFP (maternal serum

Abnormal levels of AFP may signal the following:

Down syndrome
Y other chrOmosoma1 abnormalities
defects in the abdominal wall of the foetus
twins - more than one foetus is making the protein
a miscalculated due date, as the levels vary throughout pregnancy
AFP screening may be included as one part of a 2-, 3-, or 4-part screening, often
called a multiple marker screen. The other parts are:

estriol - a hormone produced by the placenta.

Abnormal test results of AFP and other markers may indicate the need for additional
testing. Usually an ultrasound is performed to confirm the dates of the pregnancy and
to look at the foetal spine and other body parts for defects. An amniocentesis may
be needed for accurate diagnosis.
/
-
.-
Multiple marker screening is not diagnostic. This means it is not 100 percent accurate,
and is only a screening test to determine who in the should be offered
additional testing for their pregnancy. There can be false-positive results - indicating
a problem when the foetus is actually healthy or false negative results - indicating
5r nonnal result when the foetus actually does have a health problem.
Applied Physiology How is an alpha-fetoprotein test performea?
Although the specific details of each procedure vary slightly, generally, an alpha-
fetobrotein test follows this process:
Blood is usually drawn from a vein between the 15th and 20th weeks of pregnancy
(16th to 18th is ideal).
* The blood sample is then sent off for laboratory analysis.
Results are usually available within one to two weeks or less, depending on the

What is an amniocentesis?
An amniocentesis is a procedure used to obtain a small sample of the amniotic
fluid that surrounds the foetus to diagnose chromosomal disorders and open
neural tube defects (ONTDs) such as spina bz3da. Testing is available for other
genetic defects and disorders depending on the family history and availability of
laboratory testing at the time of the procedure. An amniocentesis is generally offered
to women between the 15th and 20th weeks of pregnancy who are at increased risk
for chromosome abnormalities, such as women who are over 35 years of age at
delivery, or those who have had an abnormal maternal serum screening test, indicating
an increased risk for a chromosomal abnormality or neural tube defect.
What is a chorionic villus sampling (CVS)?
Chor'ionic villus sampling (CVS) is a prenatal test "- -+ - ~lolvestaking a sample of
some of the placental tissue. This tissue contains the same genetic material as the
foetus and can be tested for chromosomal *abnormalitiesand some other genetic
problems. Testing is available for other genetic defects and disorders depending on
the family history and availability of laboratory testing at the time of the procedure.
In comparison to amniocentesis, CVS does not provide information on neural tube
defects such as spina bljida. For this reason, women who undergo CVS also need
a follow-up blood test between 16 to 18 weeks of their pregnancy, to screen for
neural tube defects.
Some women may not be candidates for CVS or may not obtain results that are 100
percent accurate, and may therefore, require a follow-up amniocentesis. In some
cas&;-there 'is an active vaginal infection such as herpes or gonotrhea, which will
prohibit the procedure. Other times, the physician obtains a sample that does not have
enough tissue to grow in the laboratory such that results are incomplete or inconclusive.

What is foetal monitoring?

During late pregnancy and during labour, a physician may want to monitor the foetal
heart rate and other functions. Foetal heart rate monitoring is a method of cliecking
the rate and rhythm of the foetal heartbeat. The average foetal heart rate is between
110 and 160 beats per minute. The foetal heart rate may change as the foetus
responds to conditions in the uterus. An abnormal foetal heart rate or pattern may
mean that the foetus is not getting enough oxygen or there are other problems. An
abnormal pattern may also mean that an emergency or cesarean delivery is needed.
What is a glucose tolerance test?
A glucose tolerance test, usually conducted in the 24 to 28 weeks of pregnancy.
measures levels of sugar (glucose) in the mother's blood. Abnormal glucose levels
may indicate gestational diabetes.
How is a glucose tolerance test performed?
Although the specific details of each procedure vary slightly. generally, a glucose
tolerance test follows this process:
Check Your Progress Exercise 6

1) Enumerate the various tests performed during pregnancy.

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2) What is 'amniocentesis' and what does it indicate?
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3) What does a CVS test indicates? What are the various conditions when a
CVS is not feasible or successful?
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4) What is the average foetal heart rate? What does an abnormal pattern indicate?
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5) Give at least five examples of genetic disorders that can be diagnosed before
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birth.
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.b

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Applied Physiology
The Reproductive System
ipplied Physiology