Contraception, Infertility & Inherited Conditions
Methods of Contraception
Contraception allows individuals and couples to plan if and when to have children. Methods fall into three broad categories: barrier methods (which physically block sperm from reaching the egg), hormonal methods (which alter the body's hormones to prevent ovulation or implantation), and natural/other methods (which use cycle awareness or permanent procedures). No single method is 100% effective in typical use, and the choice depends on health, lifestyle and whether a temporary or permanent solution is sought.
Barrier methods include the male condom (98% effective with perfect use; also protects against STIs), the female condom (95% effective), the diaphragm or cap (used with spermicide; 92-96% effective). All work by preventing sperm from reaching the egg. Hormonal methods include the combined oral contraceptive pill (99%+ effective with perfect use; contains oestrogen and progestogen to prevent ovulation), the progestogen-only pill (mini-pill), the contraceptive injection (Depo-Provera; effective for 13 weeks), the contraceptive implant (a small rod inserted under the skin of the arm, effective for three years), and the hormonal IUS (intrauterine system). The copper IUD (intrauterine device) is non-hormonal; copper ions are toxic to sperm. Emergency contraception (the morning-after pill or copper IUD fitted within five days) is a backup, not a regular method.
Male and female condoms are the only contraceptive methods that also protect against sexually transmitted infections (STIs). Other methods prevent pregnancy but do not provide protection against STIs. This dual protection makes condoms particularly important for individuals who may be at risk of infections such as chlamydia or HIV.
Natural Family Planning
Natural (fertility awareness-based) methods involve monitoring signs of fertility — basal body temperature, cervical mucus changes and cycle length — to identify the fertile window and avoid unprotected intercourse during that time. When followed precisely with trained support they can reach 99% effectiveness, but typical-use failure rates are considerably higher (around 76-88%). These methods involve no hormones or devices and are therefore preferred by some individuals for health, personal or religious reasons. They require consistent recording and do not protect against STIs.
Causes of Infertility
Infertility affects roughly one in seven couples in the UK. Causes are roughly equally split between female and male factors, with some cases involving both or remaining unexplained. Female causes include: problems with ovulation (e.g. polycystic ovary syndrome, PCOS, which disrupts hormone balance and egg release); blocked or damaged fallopian tubes (often from pelvic inflammatory disease caused by untreated chlamydia); endometriosis (where tissue similar to the uterine lining grows outside the uterus, causing scarring); and age-related decline in egg quality and quantity (fertility falls notably after 35). Male causes include low sperm count (oligospermia), poor sperm motility, abnormal sperm morphology, and blockages in the vas deferens. Lifestyle factors such as obesity, smoking and excessive alcohol worsen fertility in both sexes.
When natural conception is unsuccessful, couples may be offered assisted conception. In vitro fertilisation (IVF) involves stimulating the ovaries with hormones to produce multiple eggs, collecting those eggs surgically, fertilising them with sperm in a laboratory, and transferring one or two resulting embryos back into the uterus. IVF success rates vary significantly with age: around 32% per cycle for women under 35, falling to under 5% for women over 42. Intrauterine insemination (IUI) involves placing prepared sperm directly into the uterus around the time of ovulation and is used when sperm count or motility is mildly reduced, or for single people and same-sex couples using donor sperm. Other techniques include ICSI (intracytoplasmic sperm injection, where a single sperm is injected directly into an egg — used for severe male-factor infertility) and egg donation (using eggs from another woman for women whose own eggs are unsuitable).
Inherited and Genetic Conditions
Genetic conditions arise when a gene mutation is passed from one or both parents to a child at conception. Some conditions are autosomal recessive, meaning a child must inherit one faulty gene copy from each parent to be affected. Examples include cystic fibrosis (CF) and sickle cell disease. In cystic fibrosis, a mutation in the CFTR gene causes the body to produce thick, sticky mucus that clogs the lungs and digestive system. In sickle cell disease, a mutation in the haemoglobin gene produces abnormally shaped red blood cells that block blood vessels and cause episodes of severe pain (sickle cell crises) and anaemia. If both parents are carriers of the faulty gene, there is a 1 in 4 (25%) chance with each pregnancy that the child will be affected.
Some conditions are autosomal dominant, where only one copy of the faulty gene is needed for the condition to appear (e.g. Huntington's disease), and X-linked conditions such as haemophilia are carried on the X chromosome, meaning they affect males far more commonly than females. Chromosomal conditions such as Down's syndrome (trisomy 21) result from an error in cell division during egg or sperm formation, giving the embryo an extra copy of chromosome 21, rather than a gene mutation.
Cystic fibrosis and sickle cell disease are both autosomal recessive genetic conditions. If both parents carry one faulty gene copy (they are carriers and are unaffected themselves), each pregnancy carries a 1 in 4 (25%) chance of the child inheriting both faulty copies and being affected by the condition.
Genetic counselling provides specialist information, support and risk assessment for individuals or couples who have a family history of a genetic condition or who belong to an ethnic group with a higher prevalence (e.g. sickle cell is more common in families of African, Caribbean, Middle Eastern and South Asian heritage; cystic fibrosis is most common in those of Northern European background). A genetic counsellor explains the probability of passing a condition to children, discusses the option of carrier testing before conception, and outlines reproductive choices such as preimplantation genetic diagnosis (PGD) — where IVF embryos are tested for the faulty gene before being transferred — or prenatal testing. Crucially, genetic counselling is non-directive: it provides information to enable informed decision-making but does not tell couples what to decide.