In-vitro fertilisation (IVF) is one of the main forms of assisted reproductive treatment available to couples experiencing infertility. However, IVF is not automatically recommended for everyone who has difficulty conceiving.
A person may be considered for IVF when there is an identifiable fertility problem that makes simpler treatments less suitable, when other treatments have not resulted in pregnancy or when age and other factors make delaying treatment less appropriate.
Common reasons for considering IVF include blocked or severely damaged fallopian tubes, certain forms of endometriosis, ovulation disorders, reduced ovarian reserve, male-factor infertility, unexplained infertility and age-related fertility decline.
Suitability also depends on the health of both partners, previous fertility treatment, ovarian response, sperm factors and whether the patient is medically fit to undergo treatment.
For patients in Singapore, clinical suitability and eligibility for government co-funding are separate considerations. A couple may be medically suitable for IVF but not meet the criteria for public co-funding, which include requirements relating to citizenship, age and previous co-funded treatment cycles.
What Does It Mean to Be a Suitable Candidate for IVF?
Being a suitable candidate for IVF generally means that a fertility specialist has assessed the couple and determined that IVF is an appropriate treatment option based on their medical circumstances.
This assessment may consider:
- The cause of infertility
- The woman’s age
- Ovarian reserve
- Ovulation
- Fallopian tube health
- Uterine health
- Sperm quality
- Previous fertility treatments
- Previous pregnancies
- General health
- Medication use
- Ability to undergo pregnancy safely
There is no single test that determines whether someone is suitable for IVF.
Instead, the fertility team considers the overall clinical picture.
Who May Be Considered for IVF?
1. Women With Blocked or Severely Damaged Fallopian Tubes
The fallopian tubes provide the pathway through which sperm and egg normally meet.
If both fallopian tubes are blocked or severely damaged, natural conception may be significantly affected because the sperm may not be able to reach the egg.
IVF can bypass the fallopian tubes by allowing eggs and sperm to be brought together in a laboratory. The resulting embryo can then be transferred directly into the uterus.
Tubal problems can develop because of:
- Previous pelvic infections
- Previous tubal surgery
- Previous sterilisation procedures
- Pelvic adhesions
- Certain forms of endometriosis
The significance of a tubal problem depends on whether one or both tubes are affected and the extent of the damage.
2. People With Ovulation Disorders
Ovulation disorders occur when an egg is not released regularly or at all.
Possible causes include:
- Polycystic ovary syndrome (PCOS)
- Hormonal disorders
- Premature ovarian insufficiency
- Other medical conditions affecting ovarian function
Not everyone with an ovulation disorder needs IVF.
Some patients may initially be treated with medication to induce ovulation, with timed intercourse or IUI used where appropriate.
IVF may become an option when simpler treatments are unsuccessful, unsuitable or unlikely to provide sufficient benefit.
3. Patients With Endometriosis
Endometriosis can affect fertility through changes involving the ovaries, fallopian tubes and pelvic environment.
Some people with endometriosis conceive naturally, while others may experience difficulty becoming pregnant.
Treatment depends on factors such as:
- Age
- Severity of endometriosis
- Ovarian reserve
- Previous surgery
- Duration of infertility
- Other fertility factors
IVF may be considered when endometriosis is affecting fertility, particularly when other approaches are unsuccessful or when age and ovarian reserve make delaying treatment less appropriate.
4. Patients With Reduced Ovarian Reserve
Ovarian reserve refers to the remaining supply of eggs in the ovaries.
It generally declines with age, although the rate varies between individuals.
Tests that may provide information about ovarian reserve include:
- Anti-Müllerian hormone (AMH)
- Antral follicle count
- FSH and estradiol in selected circumstances
Reduced ovarian reserve does not automatically mean that IVF is required or that pregnancy is impossible.
However, if fertility treatment is needed, ovarian reserve can help the fertility team anticipate how the ovaries may respond to stimulation and plan treatment accordingly.
The decision may also be influenced by the woman’s age, previous treatment response and number of eggs expected to be retrieved.
5. Couples Experiencing Male-Factor Infertility
Fertility problems are not exclusively female-related.
Male factors can contribute to difficulty conceiving because of problems affecting:
- Sperm production
- Sperm concentration
- Sperm movement
- Sperm morphology
- Sperm transport
- Ejaculation
Examples include:
- Very low sperm count
- Azoospermia
- Poor sperm motility
- Certain testicular conditions
- Some hormonal disorders
Depending on the severity and cause, treatment may involve medication, surgery, IUI, IVF or IVF with ICSI.
Intracytoplasmic sperm injection (ICSI) involves injecting a single sperm directly into an egg during IVF and may be considered when significant male-factor infertility is present.
6. Couples With Unexplained Infertility
Sometimes, standard fertility investigations do not identify a clear cause of infertility.
This may occur when:
- Ovulation appears normal
- At least one fallopian tube is open
- The uterus appears suitable
- Semen analysis does not identify a significant abnormality
This is known as unexplained infertility.
IVF may be considered for some couples with unexplained infertility, particularly when simpler treatments have not resulted in pregnancy or when age and other factors make more prolonged treatment less appropriate.
IVF is not necessarily the first treatment for every couple with unexplained infertility. Depending on age and circumstances, a limited course of ovarian stimulation with IUI may be considered before IVF.
7. Women of Advanced Maternal Age
Age is an important factor when considering IVF.
Female fertility generally declines with age, largely because both the number and quality of eggs decrease over time.
Increasing age can affect:
- Ovarian response
- Number of eggs retrieved
- Embryo development
- Pregnancy rates
- Miscarriage risk
- Risk of chromosomal abnormalities
Singapore’s 2026 data also indicates that maternal age and underlying medical history are important drivers of IVF success, with success rates decreasing as maternal age increases.
This does not mean that every woman above a particular age is unsuitable for IVF. Rather, age is one of the factors used to assess the likely benefits and risks of treatment.
8. Couples Who Have Not Conceived With Simpler Treatments
Some couples may first try treatments such as:
- Ovulation induction
- Timed intercourse
- IUI
If these approaches do not result in pregnancy, IVF may subsequently be considered.
The number of previous treatment attempts does not by itself determine IVF suitability.
The fertility specialist may consider:
- Age
- Duration of infertility
- Response to previous treatment
- Number of follicles developed
- Sperm factors
- Previous pregnancy history
In some situations, IVF may be recommended without multiple attempts at simpler treatment if there is a clear reason why those approaches are unlikely to be effective.
Can Someone With Normal Fertility Tests Still Be a Candidate for IVF?
Yes.
Normal fertility tests do not guarantee that pregnancy will occur naturally.
For example, a couple may have:
- Regular ovulation
- Apparently normal ovarian reserve
- Open fallopian tubes
- Normal semen parameters
and still experience unexplained infertility.
IVF may be considered when pregnancy has not occurred despite an appropriate period of trying or after other treatments have been unsuccessful.
Is IVF Suitable for Everyone With Infertility?
No.
IVF is a significant medical treatment involving ovarian stimulation, egg retrieval and laboratory procedures.
Before recommending IVF, a fertility specialist may consider whether:
- The patient can safely undergo ovarian stimulation
- Pregnancy would be medically safe
- The ovaries are likely to respond to treatment
- There are untreated medical conditions that should first be addressed
- Another fertility treatment would be more appropriate
The objective is not simply to determine whether IVF can technically be performed, but whether it is a reasonable treatment option for the individual.
Does Age Affect Whether You Are Suitable for IVF?
Age affects both the expected effectiveness and the risks of IVF.
For women, the decline in egg quality becomes increasingly important with age.
This means two women with the same diagnosis may receive different treatment recommendations because their ages and reproductive circumstances are different.
For example, a younger woman with unexplained infertility may have more time to consider IUI or expectant management before moving to IVF.
A woman in her late 30s or 40s may be advised to consider IVF sooner because delaying treatment can further reduce the number and quality of eggs available.
This does not mean that IVF is guaranteed to work at a younger age or impossible at an older age. Individual assessment remains important.
Does BMI Affect IVF Suitability?
Body weight can be relevant when assessing IVF.
Being significantly underweight or overweight may affect:
- Ovulation
- Pregnancy
- Response to fertility medication
- Pregnancy-related risks
Some fertility programmes may recommend weight optimisation before IVF when BMI falls outside their treatment range.
For example, current patient information from a major Singapore fertility centre states that IVF is not recommended when BMI is above 30 or below 19 because success may be lower and risks may be higher. Individual centres may have their own clinical policies and thresholds.
Weight should therefore be discussed as part of the overall medical assessment rather than treated as a standalone measure of IVF suitability.
What Medical Conditions May Need to Be Managed Before IVF?
Certain medical conditions may need to be assessed or stabilised before fertility treatment begins.
These may include:
- Uncontrolled diabetes
- Significant hypertension
- Thyroid disorders
- Cardiovascular disease
- Certain autoimmune conditions
- Severe obesity
- Other conditions that may make pregnancy or treatment higher risk
The purpose is not necessarily to exclude a patient from IVF permanently.
In some situations, treatment of the underlying condition may allow IVF to proceed more safely.
What Tests Are Done Before IVF?
Before starting IVF, the fertility team will generally perform an assessment to determine whether treatment is appropriate.
Depending on the circumstances, this may include:
Female Assessment
- Medical and reproductive history
- Menstrual history
- Ovarian reserve assessment
- Transvaginal ultrasound
- Assessment of the uterus
- Assessment of fallopian tube health where relevant
- Blood tests
Male Assessment
- Medical and reproductive history
- Semen analysis
- Physical examination where appropriate
- Hormonal testing in selected cases
- Genetic testing in selected cases
The exact investigations depend on the couple’s medical history and previous fertility results.
What Happens If IVF Is Recommended?
Once IVF has been considered suitable, the fertility team will discuss the treatment protocol.
A typical IVF cycle involves:
- Ovarian stimulation
- Ultrasound and hormonal monitoring
- A trigger injection for final egg maturation
- Egg retrieval
- Sperm collection
- Fertilisation
- Embryo culture
- Embryo transfer or cryopreservation
- Pregnancy testing
Some patients undergo conventional IVF, while others may require ICSI based on sperm factors or previous fertilisation problems.
Does Being a Suitable Candidate Mean IVF Will Work?
No.
Being suitable for IVF means that the treatment is considered medically appropriate. It does not guarantee pregnancy or a live birth.
Outcomes can vary according to:
- Age
- Ovarian reserve
- Number and quality of eggs
- Sperm factors
- Embryo development
- Uterine factors
- Underlying medical conditions
- Previous fertility treatment
Even when an IVF cycle is completed successfully, pregnancy may not occur.
Patients should therefore discuss realistic expectations with their fertility specialist before treatment.
Who May Need ICSI Alongside IVF?
ICSI is different from IVF itself.
In conventional IVF, sperm and eggs are placed together in a laboratory to allow fertilisation to occur.
With ICSI, a single sperm is injected directly into an egg.
ICSI may be appropriate when:
- Sperm quality is poor
- Sperm count is very low
- Surgically retrieved sperm is being used
- Previous IVF resulted in poor or failed fertilisation
Routine ICSI is not recommended for everyone without male-factor infertility. Current evidence does not show that using ICSI routinely in non-male-factor cases improves live-birth outcomes.
What About Donor Eggs, Sperm or Embryos?
Some couples may require donor-assisted reproductive treatment because of specific reproductive circumstances.
Examples may include:
- Absence or severe impairment of egg production
- Certain severe male-factor conditions
- Specific genetic concerns
- Other medically appropriate circumstances
Donor-assisted reproduction is subject to Singapore’s regulatory requirements and eligibility criteria.
The suitability of donor treatment should be discussed with a licensed fertility service.
Are There Singapore-Specific Eligibility Requirements for IVF?
Yes. It is important to distinguish medical suitability for IVF from eligibility for government co-funding.
For public assisted reproduction centres, the current government co-funding scheme has specific criteria. Eligible couples must meet the applicable citizenship, age, clinical and previous-cycle requirements. For example, the current scheme provides co-funding for eligible couples where the patient starting the ART cycle is below 40, with limited exceptions for later co-funded cycles, and where either the patient or spouse is a Singapore Citizen. The couple must also have been assessed by a doctor as meeting the clinical requirements for ART.
Singapore also has regulatory requirements governing who can access assisted reproductive treatment. Current policy requires IVF treatment in Singapore to be provided within the applicable framework for married couples.
These requirements are separate from the medical question of whether IVF is clinically appropriate.
Can IVF Be Considered Before Trying Other Treatments?
Sometimes.
There is no single treatment sequence that applies to every patient.
For example, a couple with blocked fallopian tubes may be considered for IVF without first trying IUI because IUI still requires functional fallopian tubes.
For unexplained infertility, younger patients may be offered a limited course of less invasive treatment before IVF, while IVF may be considered earlier in older patients or when delaying treatment may reduce the chance of success.
The fertility specialist will consider the expected benefit, treatment burden, risks, cost and patient’s preferences.
What If IVF Is Not Suitable?
If IVF is not currently appropriate, the fertility team may recommend another approach.
Depending on the situation, this could include:
- Lifestyle or preconception management
- Ovulation induction
- Timed intercourse
- IUI
- Treatment of an underlying medical condition
- Surgery
- Fertility preservation
- Further assessment before deciding on treatment
In some cases, IVF may become an option after another condition has been treated or the patient’s health has been optimised.
A suitable candidate for IVF is not defined by one diagnosis, age or test result. IVF may be considered for couples experiencing problems such as blocked fallopian tubes, endometriosis, ovulation disorders, reduced ovarian reserve, male-factor infertility or unexplained infertility. It may also be considered when simpler fertility treatments have not resulted in pregnancy.
Age, overall health, ovarian reserve, sperm factors, previous fertility treatment and the likelihood of pregnancy all contribute to the decision. A fertility specialist will assess these factors before recommending IVF.
It is also important to distinguish clinical suitability from Singapore’s administrative and financial eligibility requirements. Government co-funding has its own criteria relating to age, citizenship, clinical assessment and previous treatment cycles.
Being considered suitable for IVF does not guarantee pregnancy or a live birth. Rather, it means that IVF is considered a reasonable treatment option based on the individual’s fertility assessment and circumstances.
For couples considering IVF in Singapore, a fertility consultation can help clarify whether IVF is appropriate, whether another treatment may be more suitable and what the expected benefits, risks and costs may be.
This article is for general information only and should not replace medical advice from a qualified healthcare professional.
