1. The biological basis of the
oestrogen/progesterone contraceptive pill
• Known as the ‘combined oral contraceptive pill’ @ ‘the
pill’
• Works by changing the hormone balance of the body –
ovulation does not occur
• High levels of oestrogen and progesterone inhibit release
of FSH and LH (mimics luteal phase of the menstrual
cycle)
• Causes mucus made by cervix to thicken (‘mucus plug’) -
difficult for sperm to get through
• Makes lining of uterus thinner – unlikely that fertilised
egg could implant
• Can be administered orally, by injections or by slow
release skin patches
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3. Contraception
• Means taking action to avoid conception
• Some contraception result in the early death of embryos
• Biological issues:
– Mainly related to oestrogen/progesterone pills
– Reduces risk of developing certain ovarian cysts, developing
cancer of the ovary or uterus and pelvic infection (the mucus
plug may prevent bacteria getting into the uterus)
– Menstruation is more regular and it may help to relieve pre-
menstrual tension
– Some women may develop nausea and head aches
– Tiredness and mood changes
– Rise in blood pressure
– Increased risk of thrombosis (may cause a stroke or a blood clot
in the lungs)
– Small increased risk of breast cancer
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4. Social issues:
– ‘Family planning’
– Availability of contraception means that it is easier to
choose when to have children or to choose not to
have children
– Possible to plan families around careers and other
considerations, such as financial circumstances
– In some countries, the population size has not
increased to the extent that it would have done in the
absence of contraception (concern of too few children
born to sustain population in the future)
– In countries where contraception is not freely
available, there continue to be problems of
overpopulation and the implications that this has for
supply of food, water and other resources
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5. Ethical issues:
– The science of morals, the study of right and wrong
– Use of contraception is interference with a natural
process of procreation which should be left to the will
of God (enjoyment of sex should not be separated
from the purpose of creation)
– Should more advice about contraception be given to
young people? At what age? By whom?
– Should contraceptives be made more easily available?
– Should methods which prevent implantation be
avoided since a potential human life is destroyed?
– Some contraceptives may be associated with long-
term health risks (e.g. pill and RU486 – anti-
progesterone drug which aborts fetus)
– Should research into male contraception be given a
higher priority? Should men be encouraged to take
more responsibility?
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6. In vitro fertilisation (IVF)
• Test tube baby technique
• In vitro = in glass (outside the body)
• Treatment for certain forms of infertility
– mainly blocked or damaged oviducts
– Failure to produce eggs
– Male has low sperm counts or poor sperm mobility
– Woman’s cervical mucus is ‘hostile’, killing or
preventing the passage of sperm
– Woman previously sterilised
• Also used to screen embryos for genetic defects
before allowing pregnancy to proceed
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7. • Preliminary test and counselling
• Ovarian stimulation: Woman daily injected with hormone (FSH) –
stimulates growth of many eggs
• Ultrasound scanning
• Oocyte retrieval: human chorionic gonadotrophin (HCG) - ‘ripe’
eggs collected via laparoscopy (GA)
• Male partner produces sperm and special technique is used to
collect the most mobile sperm
• Eggs are matured in incubator for 4-24 hours in special sterile
culture medium
• Sperm added and left for 24 hours for fertilisation
• Help for fertilisation:
– Zona pellucida deliberately damaged to allow easier access to
egg
– Micro-injected sperm through zona pellucida (subzonal
insemination or SUZI) or into the cytoplasm of egg
• Embryo transfer: 2-3 days later, embryos that have formed are
examined and maximum of 3 suitable embryos are transferred
into the uterus using a soft tube inserted through the vagina and
cervix
• Fate of remaining embryos decided during perliminary
counselling
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10. • Factors which can influence success rate
include age of the patient, quality of eggs
and sperm and health of the uterus
• Complications of IVF: possibility of
multiple births – due to practice of
transferring several embryos to the uterus
at the same time
• Possibility of birth defects is a
controversial subject in IVF treatment
• Advantage of freezing embryos in liquid
nitrogen: if patient failed to conceive
frozen embryos can be used
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11. • Ethical implications of IVF:
– Bypassing the natural method of conception and making
pregnancy into a technological/medical process
– Expensive so unavailable for many people and may reduce
life-chances of children who cost more to create than
through natural conception
– Fertilising more embryos than will be needed and then
discarding unwanted embryos
– Freezing and long-term storage of embryos with unknown
potential effects
– The potential to create embryos for research or to grow
tissues and organs for transplant
– The potential to select and modify embryos
– IVF allows babies to be created away from the traditional
mother-father model
– Permits selection of embryos that do not contain lethal
alleles of key genes (Huntington’s disease)
– Usurping the role of God in bringing into the world the
children that He wants
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