Higher Tier: fertility hormones and IVF
| English | 中文 | Pinyin |
|---|---|---|
| IVF/ˌaɪ viː ˈef/ | 体外受精 | tǐ wài shòu jīng |
| embryo transfer/ˈembrɪəʊ ˈtrænsfɜː/ | 胚胎移植 | pēi tāi yí zhí |
What would explain this observation?
- Higher Tier: Fertilisation in a laboratory is only one stage of IVF 体外受精. The sequence also requires maturing eggs, developing embryos and transfer to the uterus.
- Start with a prediction. State the quantities or features you would compare, then decide what evidence could distinguish two explanations.
Build the model
- FSH and LH can be used as fertility drugs to stimulate egg maturation and release, after which pregnancy may occur through the usual route. In IVF these hormones stimulate maturation of several eggs. Eggs are collected and fertilised with sperm in a laboratory; fertilised eggs develop into embryos before transfer to the uterus.
- IVF: Fertilisation outside the body followed by embryo development and transfer; embryo transfer 胚胎移植: Placement of an embryo into the uterus during fertility treatment.
Which sequence fits IVF?
The acquired specification describes transfer of one or two tiny embryos. This is its teaching sequence, not a current clinical recommendation about embryo number. Treatment can be physically and emotionally stressful, success is uncertain and multiple births can carry risks to mother and babies. Evaluate benefits and risks using the stated evidence and perspectives rather than promise a guaranteed baby.
Match each technical term to its precise meaning.
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- The acquired specification describes transfer of one or two tiny embryos. This is its teaching sequence, not a current clinical recommendation about embryo number. Treatment can be physically and emotionally stressful, success is uncertain and multiple births can carry risks to mother and babies. Evaluate benefits and risks using the stated evidence and perspectives rather than promise a guaranteed baby.
- Arrange an anonymized model IVF sequence and analyse fictional success data with a clearly defined outcome. Distinguish fertilisation, embryo transfer, pregnancy and live birth; rates for these outcomes are not interchangeable. Actual treatment is professionally supervised and does not become a school performance task or experiment on participants.
Which two habits make the investigation or model in this case more defensible?
Arrange an anonymized model IVF sequence and analyse fictional success data with a clearly defined outcome. Distinguish fertilisation, embryo transfer, pregnancy and live birth; rates for these outcomes are not interchangeable. Actual treatment is professionally supervised and does not become a school performance task or experiment on participants.
Work from known quantities
- State the known values and their units. Choose the relation because its assumptions fit this case, then rearrange before substitution.
- Known: a fictional dataset records 18 stated successful outcomes among 60 treatment cycles. Observed rate = 18/60×100 = 30%. This is a per-cycle rate for that definition, not a cumulative chance for a person after several cycles. Independence cannot be assumed without supporting information.
A fictional dataset has 16 specified successes among 80 cycles. Calculate the rate. Use the same sequence: known quantities → model → relation → substitution → unit and interpretation.
A fictional dataset has 16 specified successes among 80 cycles. Calculate the rate.
The result is 20 %. Known: a fictional dataset records 18 stated successful outcomes among 60 treatment cycles. Observed rate = 18/60×100 = 30%. This is a per-cycle rate for that definition, not a cumulative chance for a person after several cycles. Independence cannot be assumed without supporting information.
Check the conclusion and its limits
- IVF does not place an unfertilised egg directly into the uterus as its final defining step. Fertilisation and implantation are different events. The course model must not be used to prescribe hormone doses or embryo numbers.
- Return to the original observation. Explain what the result supports, which conditions it assumes, and one way to test a competing explanation.
A per-cycle success percentage is automatically a person’s cumulative chance after repeated cycles. This claim is false: IVF does not place an unfertilised egg directly into the uterus as its final defining step. Fertilisation and implantation are different events. The course model must not be used to prescribe hormone doses or embryo numbers.
Higher Tier: fertility hormones and IVF: The acquired specification describes transfer of one or two tiny embryos. This is its teaching sequence, not a current clinical recommendation about embryo number. Treatment can be physically and emotionally stressful, success is uncertain and multiple births can carry risks to mother and babies. Evaluate benefits and risks using the stated evidence and perspectives rather than promise a guaranteed baby.
A per-cycle success percentage is automatically a person’s cumulative chance after repeated cycles.
IVF does not place an unfertilised egg directly into the uterus as its final defining step. Fertilisation and implantation are different events. The course model must not be used to prescribe hormone doses or embryo numbers.
Fertilisation outside the body followed by embryo development and transfer: write the technical term.
IVF means Fertilisation outside the body followed by embryo development and transfer.