The use of hormones to treat infertility (HT only)

SPEC 4.5.3.6 • PAPER 2 • HT ONLY • ⭐ PRIORITY

Treating Infertility with Hormones

Fertility drugs and the four-stage IVF process — how FSH and LH help when natural conception fails. The entire lesson is Higher Tier content.

Three Mistakes That Cost Marks Every Year

This is a HT-only topic and a guaranteed Paper 2 question every series. Examiner reports flag the same three failure points:

Failure Point 1 — Forgetting LH

Students consistently write "FSH is given" and stop there. The mark scheme wants BOTH FSH and LH. One hormone matures the egg, the other releases it — exactly as in the natural cycle.

Failure Point 2 — Where Fertilisation Happens

The "IV" in IVF stands for in vitro — "in glass." Fertilisation happens in the laboratory, not in the woman's body. Saying eggs and sperm are inserted into the uterus together voids the answer.

Failure Point 3 — Eggs vs Embryos

It's not eggs that get inserted into the uterus — it's one or two embryos, at the stage when they are tiny balls of cells. Specific numbers and stage matter for the mark.

By the End of This Lesson HT only

Four outcomes — all Higher Tier. This is one of the highest-yield Paper 2 questions on Module 5.

Objective 1

Explain how fertility drugs (FSH and LH) can treat infertility.

Objective 2

Describe the four stages of IVF: stimulation, collection, fertilisation, insertion.

Objective 3

State the three named drawbacks of fertility treatment (stress, low success, multiple births).

Objective 4

Evaluate IVF as a treatment for infertility — including ethical, social and economic considerations (WS 1.3, 1.4).

Infertility & The Role of Hormones

Some women cannot conceive naturally — often because their ovaries don't mature eggs without the right hormone signals.

Recall — from Lesson 5.07

In the natural cycle, FSH (from the pituitary) matures the egg in the ovary, and LH (also pituitary) triggers ovulation. If the pituitary doesn't release enough of either hormone, the cycle stalls and pregnancy can't occur.

The Logic of Treatment

If the body isn't producing enough FSH and LH, give them as drugs instead. Two treatment routes use this principle:

Fertility drug — hormones given so conception can happen naturally

IVF — hormones given so eggs can be collected for fertilisation in the laboratory

Treatment 1 — The Fertility Drug

The simpler option. Hormones are given as a "fertility drug" and natural conception is then attempted.

Definition

HT onlyA "fertility drug" is a treatment containing FSH and LH given to a woman. It stimulates egg maturation and release — and she may then become pregnant in the normal way (through intercourse).

Mechanism

FSH → stimulates an egg in the ovary to mature.

LH → stimulates ovulation (release of the egg).

The couple then attempts conception naturally during the fertile period.

Mark Scheme Phrasing

The spec literally says: "giving FSH and LH in a 'fertility drug' to a woman. She may then become pregnant in the normal way." Use both hormone names and the phrase "in the normal way" for maximum marks.

Treatment 2 — When IVF Is Needed

If the fertility drug alone doesn't lead to natural conception — or if there are other issues (e.g. blocked oviducts) — IVF takes the process out of the body and into the lab.

Definition

HT onlyIVF (In Vitro Fertilisation) — a reproductive technology where eggs are fertilised by sperm in the laboratory, and the resulting embryos are inserted back into the mother's uterus.

"In Vitro" — Translation

The Latin in vitro literally means "in glass" — i.e. in a culture dish in the lab. This is the central difference from a fertility drug: fertilisation happens outside the body.

Spec WS 1.1 Link

The spec notes that developments in microscopy made IVF possible — without being able to see and handle eggs and embryos, the process can't happen. This is a Working Scientifically link AQA can ask about.

The Four Stages of IVF

Memorise these four stages in order. Each stage is worth a separate mark in describe-IVF questions.

Stage 1 — Stimulate Egg Maturation

Identical hormones to a fertility drug — but with one critical difference in goal.

Hormones Given

The mother receives injections of FSH and LH.

Goal — Multiple Eggs

Unlike a normal cycle (one egg per month), IVF aims to mature SEVERAL eggs at once. More eggs → more chances of successful fertilisation → higher chance of pregnancy.

Mark-Scheme Phrasing

For IVF questions specifically, the mark scheme requires the word "several" (plural). Writing "an egg" or "one egg" in an IVF context loses the mark — even though it would be perfectly fine in a natural-cycle answer.

Stage 2 — Collect the Eggs

Once multiple eggs have matured in the ovaries, they are collected from the mother for fertilisation in the lab.

Mark-Scheme Phrasing

The eggs are collected from the mother. The mark scheme accepts "from the ovaries" or "from her body" — the key word is collected, indicating a deliberate retrieval procedure (not natural ovulation).

Why This Matters

The spec doesn't require students to know the exact retrieval procedure — just that the eggs are collected from the mother. The next step (lab fertilisation) is what makes IVF different from a fertility drug.

Stages 3 & 4 — Fertilise & Insert

The two stages that make IVF different from a fertility drug. Fertilisation happens in the lab, and only embryos are returned to the body.

Stage 3 — Fertilisation in the Lab

Eggs are mixed with sperm from the father in the laboratory (a culture dish). Successful fertilisations develop into embryos (early balls of dividing cells).

Stage 4 — Insert Tiny-Ball Embryos

At the stage when embryos are tiny balls of cells, one or two embryos are inserted into the mother's uterus to implant and develop normally.

Why "One or Two" Matters

Inserting MORE than two embryos increases the chance of multiple births — twins, triplets — which is a major drawback (next slide). One or two is the spec-stated number.

The Three Named Drawbacks

The spec explicitly names three drawbacks of fertility treatment. Memorise verbatim — they're the answer to every "evaluate IVF" question.

Drawback 1

Very emotionally and physically stressful.

Hormonal treatments cause side effects; multiple medical procedures; uncertainty over outcome; financial pressure.

Drawback 2

Success rates are not high.

Most cycles do not result in a live birth. Many couples need multiple IVF cycles. There is no guarantee.

Drawback 3

Multiple births are a risk to both the babies and the mother.

Inserting more than one embryo can lead to twins or triplets — associated with premature birth, low birth weight, and increased maternal complications.

The Counterbalance

The spec also states: "fertility treatment gives a woman the chance to have a baby of her own." When you're asked to evaluate, give both this benefit AND the three drawbacks for a balanced answer.

Worked Example — PEE Framework

A 4-mark describe-IVF question — the single highest-frequency question on this topic.

Q: A couple cannot conceive naturally because the woman does not produce mature eggs. Describe how IVF could help them have a baby. 4 marks

1

Stage 1. The mother is given FSH and LH to stimulate the maturation of several eggs.

2

Stage 2. The eggs are then collected from the mother's ovaries.

3

Stage 3. The eggs are fertilised by the father's sperm in the laboratory.

4

Stage 4. When the fertilised eggs have developed into early embryos (tiny balls of cells), one or two are inserted into the mother's uterus to develop normally.

Why this scores 4/4

One mark per stage. Each stage uses a named action (stimulate / collect / fertilise / insert) + key spec phrasing (several eggs / in the laboratory / tiny balls of cells / one or two). No fluff, no missed terms.

Your Turn

Evaluate the use of IVF as a treatment for infertility. Include both benefits and limitations in your answer. 4 marks

Plan one benefit and three limitations (or one benefit and two limitations plus a balanced conclusion). Each named point = one mark.

+

Benefit. IVF gives infertile couples the chance to have a baby of their own when natural conception is not possible.

−

Limitation 1. The treatment is very emotionally and physically stressful for the woman — multiple hormone injections, surgical procedures, and uncertain outcomes.

−

Limitation 2.Success rates are not high — most IVF cycles do not result in a live birth, and many couples need multiple cycles.

−

Limitation 3. IVF can lead to multiple births, which are a risk to both the babies and the mother (e.g. premature birth, low birth weight).

Mark-scheme matches: "chance of a baby of own" ✓ · "stressful (emotionally/physically)" ✓ · "low success rates" ✓ · "multiple births a risk" ✓. 4 / 4.

Top-band answers also note non-scientific factors (cost, ethical concerns, fairness of access) — these can substitute for one of the limitations in evaluation questions.

Common Errors to Avoid

Four mistakes mark schemes penalise every series on this topic.

✗ Wrong

"FSH is given to mature the eggs."

✓ Right

BOTH FSH and LH are given. FSH matures, LH triggers release.

✗ Wrong

"Eggs and sperm are inserted into the uterus together."

✓ Right

Eggs are fertilised in the laboratory ; only the embryos are inserted into the uterus.

✗ Wrong

"All the fertilised eggs are inserted into the uterus."

✓ Right

Only one or two embryos are inserted — inserting more increases multiple-birth risk.

✗ Wrong

"IVF is always successful."

✓ Right

Success rates are not high — many cycles fail; multiple cycles often needed.

Summary — Three Takeaways

1. Two Hormones, Same Roles As Natural Cycle

FSH — matures the egg(s). LH — triggers release.

Same hormones used in both fertility drugs (natural conception) and IVF (lab fertilisation).

Critical distinction: in IVF, the mark scheme requires the word "several" eggs (plural) — examiners penalise singular wording.

2. The Four Stages of IVF

Stimulate — FSH + LH given → several eggs mature.

Collect — eggs collected from the mother.

Fertilise — eggs + father's sperm in the laboratory .

Insert — one or two embryos ( tiny balls of cells ) inserted into the uterus.

3. The Three Named Drawbacks

Stressful — emotionally and physically.

Low success rates — most cycles fail.

Multiple births — risk to babies and mother.

Counterbalance: gives infertile couples the chance to have a baby of their own .

Next Lesson

Lesson 5.09 (HT only) — Negative feedback: how the body uses adrenaline and thyroxine, and how thyroxine levels are controlled by negative feedback loops.

Treating Infertility with Hormones

Three Mistakes That Cost Marks Every Year

By the End of This Lesson HT only

Infertility & The Role of Hormones

Treatment 1 — The Fertility Drug

Treatment 2 — When IVF Is Needed

The Four Stages of IVF

Stage 1 — Stimulate Egg Maturation

Stage 2 — Collect the Eggs

Stages 3 & 4 — Fertilise & Insert

The Three Named Drawbacks

Ethical & Social Considerations

Worked Example — PEE Framework

Your Turn

Common Errors to Avoid

Summary — Three Takeaways

2. The Four Stages of IVF

3. The Three Named Drawbacks