1. Higher Human Biology Unit 2 – Physiology and Health
Section 11 – Biology of Controlling Fertility

2. What Can You Remember? What hormone triggers puberty?
Where is the hormone in question 1 produced?
What is the receptor for the hormone in question 1?
What hormone(s) does the pituitary gland produce in response to the hormone in question 1?
What hormone(s) are produced after receipt of the hormones in question 4 in males?
What hormone(s) are produced after receipt of the hormones in question 4 in females?
Releaser hormone
Hypothalamus
Pituitary gland
FSH, LH and ICSH
Testosterone
Oestrogen

3. a – Fertility in Men and Women
We will be learning…
State that infertility treatments and contraception are based on the biology of fertility
Explain that fertile periods are continuous in the male and cyclical in the female
Calculate the fertile period using temperature
Calculate the fertile period using cervical mucus

4. Infertility Treatments and Contraception
The biology of fertilisation is used when designing treatments for infertility and devising methods of contraception

5. Fertile Periods in Males
The negative feedback effect of testosterone maintains a relatively constant level of FSH and ICSH in the bloodstream of men This means a steady stream of testosterone is secreted which secures the production of sperm Men are, therefore, constantly fertile (although production does decrease in later life) and may father children at an old age
Bruce Willis,
58 years
World’s oldest dad,
aged 97 years
Rod Stewart,
66 years

6. Fertile Periods in Females
In the female, fertile periods are cyclical, due to the pituitary and ovarian hormone activity.
This means there are times when fertilisation is more likely, i.e. from a few days before release of the ovum until 1-2 days after ovulation.
Fertilisation is less likely just before, during and just after the menstrual period.
The fertile period occurs just before, during and after the surge in LH levels which trigger release of the ovum from the follicle and lasts for a few days.
This period can be detected by an increase in blood or urine LH levels, taking intra-vaginal temperatures or simply by counting the days after the last menstrual period

7. Knowing when a woman is most fertile can assist the woman to become pregnant and to avoid pregnancy by either having or avoiding intercourse at these times.
Even though knowledge of the fertile period can aid conception, many woman have irregular menstrual cycles and therefore more effective methods of contraception can be used.
As before with fertility treatment however, this raises moral and ethical issues for some individuals

8. Calculation of the Fertile Period - Temperature
The alternating processes of menstruation and ovulation are separated by around 2 weeks.
Roughly one day after the surge in LH triggering ovulation, the body temperature of the female rises by ⁰C due to the action of progesterone.
The body temperature then remains higher for the rest of the luteal phase of the menstrual cycle.
The period of fertility lasts for 1-2 days before the infertile period returns, on average, after the third daily recording of the higher body temperature.
The unfertilised egg has then disintegrated

9. Calculation of the Fertile Period - Mucus
The cervical mucus secreted into the vagina during the fertile period is thin and watery
This allows sperm to access the female reproductive system.
Following ovulation, the mucus increases in viscosity due to the action of progesterone
This demonstrates a return to the infertile period.
The knowledge of changes in female body temperature and cervical mucus can be used to calculate the fertile period and help a couple to conceive a child.

10. Methods of Calculating Period of Fertility
Temperature
Mucus

11. Continuous versus Cyclical Fertility
Male – Continuously Fertile
Negative feedback of testosterone maintains a relatively constant level of gonadotrophic hormones (FSH & ICSH)
Results in a fairly steady quantity of testosterone being produced
Female - Cyclical Fertile
Egg will only survive 24 hours after being released due to hormone levels
Sperm, however, can survive for 72 hours (3 days)
Fertility is restricted to 3 – 4 days immediately following ovulation

12. b – Treatments for Infertility
We will be learning…
To give examples of treatments used for infertility
State that fertility treatments such as the use of drugs, stimulate ovulation in the female
State that drugs may prevent the negative feedback effect of oestrogen on FSH secretion or mimic the action of FSH and LH
Explain that drugs may lead to super ovulation resulting in multiple births or for use in IVF treatments
Describe artificial insemination as a treatment for infertility and explain that it involves collecting several samples from a male with low sperm count over a long period of time
State that a donor may be used for this treatment if the partner is sterile
Explain that Intra-cytoplasmic sperm injection (ICSI) can be used if mature sperm are defective or of a very low number
Describe the procedure used in ICSI
Explain the process of IVF and the use in conjunction with pre-implantation genetic diagnosis (PGD) to identify single gene disorders and chromosomal abnormalities

13. Infertility in Men https://www.youtube.com/watch?v=XIy0owl5IU4
The WHO (World Health Organisation) considers a sperm count (strictly 'sperm concentration') below 15 million per ml to be significantly low (the average being around 60 million per ml). The motility and health of sperm are other factors: do the sperm swim well enough to make good forward movement and do many sperm have an abnormal morphology, such as small or large heads, double heads, or a double tail? Other inherited and environmental factors must also be considered:
age - although they usually remain fertile from puberty onwards, men's fertility does gradually decline with age;
genetics - including Y chromosome microdeletions, where one or more genes are missing from the Y chromosome, and Klinefelter's syndrome, where non-disjunction in the formation of the egg has resulted in a zygote (and hence a man) with XXY sex chromosomes;
disease - mumps is a viral disease that is typically contracted during childhood although when suffered by adult males it can infect the testes and lead to a reduction in size with possible sterility. Sexually transmitted infections, such as chlamydia or gonorrhoea (caused by bacteria), can result in sterility or testicular cancer if left untreated; where the treatment involves the removal of a testis then the associated chemo- or radiotherapy may lead to reduced or complete infertility;
lifestyle - smoking tobacco, stress, obesity, drug and alcohol abuse and medications (e.g. anabolic steroids) all significantly reduce fertility.

14. Infertility in Women
Infertility in women is generally the result of an interaction of inherited and environmental factors:
Age - a woman's age is a major determining factor, with a peak in fertility during the early to mid-twenties and an accelerating decline after 35, with cessation of ovulation usually between 45 and 55 at the menopause;
Genetics - chromosomal abnormalities, such as Turner syndrome (in which one of the X chromosomes is missing or abnormal in some way), and a whole host of genetic mutations may cause a woman to be unable to produce viable ova;
Disease - as with men, sexually transmitted infections, e.g. gonorrhoea, can result in infertility by causing inflammation and scarring of the Fallopian tubes. Chronic kidney or liver diseases may also cause infertility. Eating disorders, causing a woman to be either under- or over- weight, both tend to disrupt the menstrual cycle by affecting oestrogen production;
Lifestyle - smoking tobacco reduces the body's ability to produce oestrogen, affecting the development of follicles and also causing the earlier onset of the menopause. Cannabis likewise interferes with fertility by reducing the chances of implantation of the blastocyst. Repeated courses of chemotherapy pose a high risk of infertility.

15. Treatments for Infertility in Women
A female may fail to ovulate for a number of reasons.
This may include failure of the pituitary gland to secrete enough FSH or LH.
To overcome this problem, ovulation may be stimulated using
drugs that mimic the normal action of FSH and LH
drugs that prevent the negative feedback effect of oestrogen on the FSH secretion during the luteal period of the menstrual cycle.

16. Treatments for Infertility in Women
There are, however, problems associated with taking infertility drugs.
These can include super-ovulation i.e. the release of many ova which may result in multiple births e.g. quadruplets.
Drugs that promote super-ovulation are used to promote the release of ova to be collected for use in IVF (in vitro fertilisation) treatments

17. Artificial Insemination
Artificial insemination is the introduction of semen into the female uterus by means other than sexual intercourse
Artificial insemination is particularly useful if the male has a low sperm count. This involves collecting several samples of semen over a period of time, each sample is then preserved by freezing until required
The sperm are then defrosted and released together into the partner’s cervical region when she is likely to be at her most fertile
Artificial insemination may also be used to insert sperm from a donor into the female if her partner is sterile

18. Worlds First Pregnant Man?
Thomas Beatie, the transgender man who gets pregnant by artificial insemination.
“Beatie, 34, now has has 3 healthy children - which he has carried in the womb he kept intact when he became a man 10 years ago”

19. Intra-cytoplasmic Sperm Injection (ICSI)
There is only a good chance of fertilisation occurring if a large number of active sperm are present around the ova
If the mature sperm are defective or very low in number, ICSI can be used.
This involves drawing the head of a healthy sperm into a syringe needle and injecting it directly into the ova to achieve fertilisation.
The egg is held in place by a holding tool while
this takes place.

20. In vitro fertilisation (IVF)
In vitro fertilisation is commonly used to solve the problem of infertility caused by a blockage of the oviducts (uterine tubes)
This enables fertilisation to occur in a culture dish outside the body of the female

21. IVF procedure
Hormonal treatment is given to the woman to stimulate multiple ovulation
A surgical procedure is used to remove several eggs from the ovaries
The eggs are then mixed with sperm in a culture dish containing nutrients to allow fertilisation to occur or one sperm may be injected directly into an egg as in ICSI
Following fertilisation, the zygotes are incubated in the nutrient medium for 2-3 days to allow cell division to occur and form embryos each made of eight or more cells
Two or three of the embryos are then chosen for insertion through the vagina into the mother’s uterus
The remaining embryos are frozen and stored in case a second attempt is required.

23. Pre-implantation Genetic Diagnosis(PGD)
Pre-Implantation genetic diagnosis (PGD)is used to check for a known chromosomal or gene defect
Embryos are screened after fertilisation by IVF treatment to identify single gene disorders and chromosomal abnormalities that may be present in the developing embryo to avoid implanting affected embryos into the mother’s womb
Day 3
8 cell embryo
Surgical opening
Test for genetic mutation
Transfer to uterus

24. c – Methods of Contraception
We will be learning…
To be able to describe physical and chemical methods to prevent pregnancy
To understand the biological basis of the physical method of preventing pregnancy by the use of barriers, intra-uterine devices and sterilisation procedures.
To be able to describe the biological basis of the oral contraceptive pill.
To be able to describe the biological basis of the progesterone- only mini pill.
To be able to describe the biological basis of the morning-after pill and how it prevents ovulation or implantation

25. Contraception
Contraception is the intentional prevention of conception or pregnancy by natural or artificial means

26. Methods of Contraception
Natural
Physical
Chemical
Body Temperature
Male/Female Condom
Combined pill
Cervical Mucus
Diaphragm
Progesterone Mini Pill
Rhythm Method
Intra Uterine Device
Contraceptive Patch
Vasectomy
Contraceptive Implant
Female Sterilisation

27. Natural Contraception: Summary
Body temperature - body temperature changes through the menstrual cycle under the influence of oestrogen and progesterone. It rises slightly after ovulation.
Cervical mucus - the amount of oestrogen and progesterone alters the quantity, texture and appearance of cervical mucus,
Rhythm method - calculating how long the menstrual cycle lasts

28. Physical Methods of Contraception – Barrier Method
A barrier method is something that physically stops or blocks sperm from reaching an ovum.
A male/female condom is a device that is used during sexual intercourse as a barrier contraceptive to reduce the risk of sexually transmitted infections and unintended pregnancy
The diaphragm is a dome –shaped rubber cap inserted into the vagina to block the cervix before each act of sexual intercourse
These methods are very effective but not as successful as chemical methods

29. Intra-uterine devices
An intra-uterine device (IUD)is a T-shaped structure fitted into the uterus for many months or years to prevent the implantation of an embryo into the endometrium
One form contains copper and works by reducing the motility of sperm, stopping their progress towards the ovum. It is also possible that the presence of the IUD in the uterus irritates the endometrium, thus preventing implantation. A side effect is the increased loss of blood at menstruation.
The second type of IUD releases a low dose of progesterone, which works more like the contraceptive pills.

30. Male Sterilisation Procedures
A vasectomy is a surgical procedure whereby the sperm ducts are cut and tied, preventing sperm being released during intercourse
Any sperm produced after the procedure has been checked normally undergo phagocytosis and are destroyed

31. Female Tubal Ligation
Tubal ligation involves cutting and tying the two oviducts
This prevents eggs from meeting sperm and reaching the uterus
Sterilisation in this way is normally irreversible

32. Chemical Methods of Contraception
Oral contraceptive pills normally contain synthetic progesterone and oestrogen
The woman normally takes one pill per day for three weeks from the final day of the menstrual period
This system works by alternating the concentration of hormones in the bloodstream creating a negative feedback control where FSH and LH are inhibited from entering the bloodstream and follicle maturation remains inhibited and ovulation fails to occur
Placebo pills are taken in the fourth week to allow levels of oestrogen and progesterone to drop and menstruation to occur
Little or no FSH secreted, follicle maturation inhibited, ovulation fails to occur
Also thickens the mucus in the cervix and makes the lining of the womb thinner.

33. Progesterone Mini Pills
These are Progesterone only pills as they contain synthetic progesterone
They thicken the cervical mucus reducing the viability of sperm and their entrance to the uterus

34. Contraceptive Implant
Contraceptive Patch
Slowly releases the progesterone to prevent ovulation. Similar effects to pill
Contraceptive Implant

35. Morning after Pills
These are known as emergency hormonal contraception pills
They contain high levels of the hormones progesterone and oestrogen
They are taken by the woman after having unprotected sexual intercourse to prevent the egg from implanting in the womb if fertilisation has occurred
These pills should be taken as soon as possible after unprotected intercourse

36. When a woman wants to become pregnant
A woman must discontinue the pill.
After lengthy use there may be a period of delay before their bodies readjust and return to a normal fertile state.

37. Now I can…..
a – Fertility in Men and Women
State that infertility treatments and contraception are based on the biology of fertility
Explain that fertile periods are continuous in the male and cyclical in the female
Calculate the fertile period using temperature

38. Now I can….. b – Treatments for Infertility
To give examples of treatments used for infertility
State that fertility treatments such as the use of drugs, stimulate ovulation in the female
State that drugs may prevent the negative feedback effect of oestrogen on FSH secretion or mimic the action of FSH and LH
Explain that drugs may lead to super ovulation resulting in multiple births or for use in IVF treatments
Describe artificial insemination as a treatment for infertility and explain that it involves collecting several samples from a male with low sperm count over a long period of time
State that a donor may be used for this treatment if the partner is sterile
Explain that Intra-cytoplasmic sperm injection (ICSI) can be used if mature sperm are defective or of a very low number
Describe the procedure used in ICSI
Explain the process of IVF and the use in conjunction with pre-implantation genetic diagnosis (PGD) to identify single gene disorders and chromosomal abnormalities

39. c – Methods of Contraception
Now I can…..
c – Methods of Contraception
To be able to describe physical and chemical methods to prevent pregnancy
To understand the biological basis of the physical method of preventing pregnancy by the use of barriers, intra-uterine devices and sterilisation procedures.
To be able to describe the biological basis of the oral contraceptive pill.
To be able to describe the biological basis of the progesterone- only mini pill.
To be able to describe the biological basis of the morning-after pill and how it prevents ovulation or implantation

40. Artificial Insemination (AI)
Word
Meaning
Artificial Insemination (AI)
insertion of donated sperm directly into the uterus
Intracytoplasmic Sperm Injection (ISI)
injection of sperm directly into an egg during IVF
In Vitro Fertilisation (IVF)
medical procedure involving fertilisation of eggs by sperm in laboratory containers
Pre-implantation Genetic Diagnosis (PGD)
genetic profiling of embryos prior to implantation during fertility treatments

41. Give an account of fertile periods under the headings:
men; (4 marks)
women. (6 marks)

42. Men (maximum of 4 marks):
Men are fertile from puberty to death.
Fertility does decrease with age.
Men are continuously fertile / produce sperm constantly.
Testosterone stimulates sperm production.
Testosterone production is stimulated by ICSH from pituitary.
Testosterone and ICSH interact in a negative feedback loop.
Women (maximum of 6 marks):
Women are fertile from puberty to the menopause / age
Women are cyclically fertile.
Only fertile for a few days each month around time of ovulation.
Ovulation is stimulated by a surge in LH secretion.
LH is secreted by the pituitary gland.
Oestrogen and progesterone from ovary interact in a negative feedback loop…
…with FSH and LH from the pituitary.
Time of ovulation can be determined by recording body temperature and cervical mucus.
Fertile period lasts from a few days before to a few days after ovulation.