Fertility Medicines Explained: Ovulation Triggers, hCG, IUI and IVF Treatment Options
Trying for a baby and not getting pregnant can be one of the most emotionally draining experiences a couple faces. Around one in seven couples has difficulty conceiving, and the causes are as likely to involve the male partner as the female partner. The encouraging news is that modern fertility care offers many effective options, from simple lifestyle changes and ovulation-stimulating tablets to hormone injections, intrauterine insemination (IUI) and in vitro fertilisation (IVF). This guide explains how conception works, the common causes of infertility, which fertility medicines are used and why (including ovulation triggers such as hCG and prolactin-lowering treatment), how to use them safely, and how to look after your wellbeing during treatment.
- Infertility is a shared issue: roughly one-third of cases involve the female partner, one-third the male partner and one-third both or are unexplained.
- Seek help after 12 months of trying (6 months if the woman is 35 or older, and sooner at 40 or with known risk factors).
- Fertility medicines have specific roles. Ovulation tablets, injectable gonadotropins and hCG triggers are timed carefully and monitored by scans and blood tests.
- hCG is not a weight-loss or bodybuilding product. Misuse is unsafe.
- Emotional support, sleep and stress management are part of good fertility care.
How Conception Works
For pregnancy to occur, several steps must line up. The brain releases follicle-stimulating hormone (FSH) and luteinising hormone (LH), which cause an egg to mature in the ovary and then be released at ovulation, usually around the middle of the cycle. The egg travels along a fallopian tube, where it can be fertilised by a sperm within about 12 to 24 hours. The fertilised egg then travels to the womb and implants in the lining, which has been prepared by oestrogen and progesterone. A problem at any stage can reduce the chance of conception. For a healthy couple under 35, the chance of pregnancy in any single month is about 20 to 25 per cent, and around 85 per cent conceive within a year.
Common Causes of Infertility
| Cause | Examples | How common |
|---|---|---|
| Ovulation disorders | Polycystic ovary syndrome (PCOS), thyroid disease, high prolactin, low body weight, premature ovarian insufficiency | About 25 to 30 per cent of female-factor cases |
| Tubal or uterine problems | Blocked tubes, fibroids, polyps, adhesions | About 20 to 25 per cent |
| Endometriosis | Tissue similar to womb lining outside the womb | Up to a third of women with infertility |
| Male factor | Low sperm count, poor motility or shape, hormonal issues, varicocele, previous infections | Contributes in around 40 to 50 per cent of couples |
| Age-related decline | Reduced egg quantity and quality, especially after 35 | Rises steadily with age |
| Unexplained | No cause found after full testing | About 15 to 30 per cent |
Tests and When to Seek Help
See a doctor after 12 months of regular unprotected intercourse if the woman is under 35, after 6 months if she is 35 to 39, and after about 3 months at 40 or older. Seek help earlier if periods are absent or very irregular, there is known endometriosis, pelvic infection or previous surgery, or the man has a history of testicular problems.
Typical investigations
- Semen analysis: the first test for the male partner. It assesses sperm count, movement and shape.
- Hormone blood tests: FSH, LH, oestradiol, AMH (ovarian reserve), prolactin, thyroid hormones, testosterone and mid-luteal progesterone to confirm ovulation.
- Pelvic ultrasound: checks the womb, ovaries and number of resting follicles.
- Tubal tests: hysterosalpingography (X-ray dye test) or sonohysterosalpingography.
- Infection screening and general health checks: including rubella immunity.
Fertility Medicines Explained
The right treatment depends on the cause. Fertility medicines are always individualised and monitored.
| Medicine type | Examples | What it does | Used for |
|---|---|---|---|
| Aromatase inhibitors | Letrozole | Lowers oestrogen briefly so the brain releases more FSH | First-line ovulation induction, especially in PCOS |
| Selective oestrogen receptor modulators | Clomiphene | Blocks oestrogen feedback to stimulate ovulation | Ovulation induction, some male hormone problems |
| Gonadotropin injections | FSH, hMG | Directly stimulate follicle growth | Ovulation induction, IUI and IVF cycles |
| Trigger injections | hCG, GnRH agonist | Triggers final egg maturation and release | Timed intercourse, IUI and IVF |
| Insulin sensitisers | Metformin | Improves insulin resistance | PCOS with metabolic features |
| Dopamine agonists | Cabergoline | Lowers prolactin | High prolactin causing irregular ovulation |
| Progesterone | Vaginal gel, tablets or injections | Supports the womb lining | Luteal support after IUI or IVF |
hCG and the Ovulation Trigger
Human chorionic gonadotropin (hCG) is a hormone that closely mimics LH. In fertility treatment, a single hCG injection is given when ultrasound shows that follicles have reached the right size, usually 18 to 20 millimetres. It causes the egg to complete maturation and be released roughly 36 to 40 hours later. Timing is precise, because intercourse, IUI or egg collection is planned around this window. Typical trigger doses range from 5,000 to 10,000 international units, but the dose and timing must come from your fertility specialist. You can view product information for hCG 1500 IU and hCG 5000 IU.
In men with hormonal causes of low sperm production (hypogonadotropic hypogonadism), hCG, sometimes with FSH, can restart sperm production under specialist care.
Regulators have warned that hCG “diet” regimens are unproven and unsafe, and non-medical use for performance purposes can cause serious hormonal and health problems. It should only be used for a medical reason, with a prescription and supervision.
High Prolactin and Fertility
Excess prolactin suppresses the hormones that drive ovulation, and it is a common, reversible cause of irregular periods and infertility in women and low sperm production in men. Treatment with a dopamine agonist such as cabergoline usually restores normal cycles within weeks to months. Learn more in high prolactin levels: symptoms, causes and treatment, and view Cabergoline 0.5 mg product details.
IUI and IVF
Intrauterine insemination (IUI)
Washed and concentrated sperm are placed into the womb around ovulation, often combined with mild ovarian stimulation. It is used for mild male factor infertility, unexplained infertility and some ovulation disorders. Success rates are roughly 10 to 20 per cent per cycle depending on age and cause.
In vitro fertilisation (IVF) and ICSI
In IVF, ovaries are stimulated with gonadotropins, eggs are collected under sedation, fertilised in the laboratory and the resulting embryo is transferred to the womb. With ICSI, a single sperm is injected into each egg, which helps in severe male-factor infertility. Live birth rates per cycle vary by age, from roughly 40 to 50 per cent in women under 35 to under 10 per cent after 42, and most clinics publish their own results.
Risks and Safety
- Ovarian hyperstimulation syndrome (OHSS): an excessive response to stimulation causing abdominal swelling, rapid weight gain, nausea and breathlessness. Contact your clinic urgently if these occur.
- Multiple pregnancy: ovulation drugs and IVF can raise the chance of twins or higher-order pregnancies, which carry higher risks.
- Side effects: hot flushes, headaches, mood swings, bloating, breast tenderness and injection-site discomfort.
- Ectopic pregnancy: slightly more common after fertility treatment. Seek urgent help for severe one-sided pain or shoulder tip pain.
- Monitoring: repeated scans and blood tests are essential. Never self-prescribe injections or change doses.
Lifestyle, Sleep and Wellbeing
- Folic acid: take at least 400 micrograms daily from before conception (higher doses are advised for some women).
- Healthy weight: being significantly underweight or overweight can disrupt ovulation and sperm quality.
- Stop smoking and limit alcohol and caffeine. Smoking harms both egg and sperm quality.
- Keep active with moderate exercise, but avoid extreme training.
- Review medicines with your doctor, as some drugs affect fertility or pregnancy.
- Sleep well. Shift work and chronic sleep loss are linked to hormonal disruption. Read insomnia in women: hormones, pregnancy and menopause, why sleep is important for your health and happiness and is sleeplessness harmful during pregnancy?
The emotional strain of infertility is real. Stress, anxiety and low mood are common, and treatment cycles can feel like a rollercoaster. Talk to your partner, consider counselling or a support group and use calming techniques. See 7 ways to reduce anxiety and meditation for anxiety and insomnia. If poor sleep or low mood persists, read antidepressants explained and speak to your doctor.
Frequently Asked Questions
How long should we try before seeking help?
Twelve months if the woman is under 35, six months if she is 35 to 39 and about three months if she is 40 or older, or sooner if there are known risks.
Does stress cause infertility?
Everyday stress does not usually cause infertility, but severe or chronic stress can disrupt cycles, and infertility itself is stressful. Support helps.
Can men improve sperm quality?
Often, yes. Stopping smoking, limiting alcohol, losing excess weight, avoiding overheating and treating hormone problems can all help.
When is hCG used?
As a trigger injection to prompt egg release in ovulation induction, IUI and IVF, and in selected men with hormonal causes of low sperm production, always under specialist supervision.
Are fertility drugs safe?
They are widely used and generally safe when monitored. Risks such as OHSS and multiple pregnancy are managed by careful dosing and scans.
Can I buy fertility injections and self-administer?
Only under a doctor’s prescription and instructions. Dose, timing and monitoring are critical.
Common Fertility Myths
- “Infertility is a woman’s problem.” Male factors contribute in roughly half of couples.
- “Relaxing and going on holiday will do it.” Stress reduction helps wellbeing, but it does not fix blocked tubes or low sperm counts.
- “You can ovulate any day.” Ovulation timing varies, and the fertile window is about six days ending on ovulation day.
- “IVF always works.” Success depends heavily on age and cause, and it often takes more than one cycle.
- “Fertility drugs always cause twins.” Risk is increased but most treated pregnancies are singletons when monitored carefully.
Questions to Ask Your Fertility Specialist
- What do my tests and my partner’s tests suggest as the likely causes?
- Which treatment do you recommend first, and what are its success and risk figures for my age?
- How will cycles be monitored, and what should I do if I feel unwell during treatment?
- What are the costs, number of attempts and alternatives if treatment does not work?
- Is there anything about my weight, medicines or sleep that I should change first?
Final Thoughts
Fertility treatment is a journey, and most couples who seek help early and follow a well-monitored plan eventually achieve a pregnancy. Learn the basics, get both partners tested, use medicines only under supervision, protect your sleep and emotional health and lean on support. A fertility specialist can map out the best next step for your situation.
