8 Key Considerations Before Choosing IVF

In vitro fertilisation (IVF) is a form of assisted reproductive technology (ART) where a fertility specialist retrieves eggs from a woman, fertilises them with her partner’s sperm to form embryos, and then transfers one or more of these embryos back to her womb, intending to achieve a pregnancy.

In this article, we will cover the eight essential considerations to keep in mind before consulting an IVF specialist in Singapore. Several factors contribute to infertility, including age and ovarian reserve, hormonal and uterine health, egg and sperm quality, the risk of ovarian hyperstimulation, maternal-fetal safety, and insights from any previous fertility treatments.

1. Age and Ovarian Reserve

A woman’s age is a strong predictor of IVF success rates, as increasing maternal age is associated with a deterioration of egg quality. Female fertility peaks when a woman is in her 20s, stabilises in her early 30s, and then falls sharply after 35 years of age. 

A woman’s ovarian reserve is another significant predictor of IVF success rates. It allows the fertility specialist to predict how well the ovaries are likely to respond to stimulation drugs, and hence the number of eggs that could potentially be retrieved.

Your doctor can help you assess your chances of IVF success by doing these tests:

• Semen analysis: Measures sperm count, motility, and shape to assess male factor infertility.

• Ovarian reserve testing: Uses anti-Müllerian hormone (AMH), antral follicle count (AFC) and baseline FSH to estimate how many eggs remain and how the ovaries may respond to stimulation.

• Infection screening: Checks both partners for HIV, hepatitis B & C, syphilis, rubella immunity and common STIs to ensure a safe laboratory environment and protect the future pregnancy.

• Hormonal blood tests: Consists of FSH, LH, prolactin, estradiol and TSH to assess a woman’s ovarian and thyroid status before commencing treatment.

2. Underlying Causes of Infertility

Certain medical conditions may impact your chances of getting pregnant.

• Blocked or damaged fallopian tubes: Past pelvic infections, endometriosis or pelvic surgery can cause tubal blockage, and hence prevent the fertilisation of a woman’s egg.

• Male factor infertility: Low sperm count (concentration), poor movement (motility), or abnormal shape (morphology) can reduce the odds of fertilisation; a simple semen analysis can identify these issues.

• Endometriosis: Tissue similar to the womb lining implants outside the womb, resulting in distortion and damage to pelvic anatomy.  It also results in inflammation, which can indirectly affect a woman’s eggs and fertility.

• PCOS: A hormone-related metabolic condition that often causes irregular or absent ovulation, difficulty conceiving, weight gain, insulin resistance, and cyst-filled ovaries.

• Uterine abnormalities: Fibroids, polyps or a congenital uterine septum can take up space in the womb and interfere with implantation or disturb its blood supply, hence reducing the chance of pregnancy.

It is essential to note that some couples may still experience difficulty conceiving, even in the absence of any of the above medical conditions. This is known as unexplained fertility, and IVF can be a solution for these couples.

3. Hormonal and Reproductive Health Status

Some hormones are crucial to regulating ovulation, menstruation and pregnancy. When there is a hormonal imbalance, it can interfere with conception.

Your doctor can assess your hormonal health status through the following tests:

• Thyroid panel (TSH and free T4): An underactive or overactive thyroid function can make it harder to conceive and to carry a healthy pregnancy.

• Serum prolactin: When prolactin levels are higher than normal, the pituitary gland reduces the release of LH and FSH hormones. This may cause ovulation to become irregular or stop altogether, reducing the likelihood of pregnancy.

• Luteinising hormone (LH): A high LH reading may suggest PCOS. It may affect your chances of pregnancy by having an adverse impact on the quality of your eggs and uterine lining.

• Estradiol (E2): Low baseline E2 levels may reflect a diminishing ovarian reserve. High E2 levels early in the menstrual cycle can indicate the presence of a functional ovarian cyst.

Besides achieving hormonal balance, the uterus itself must be ready to receive an embryo. Your doctor can perform imaging tests to confirm  this:

• Transvaginal ultrasound: This is an ultrasound scan to assess the uterus and ovaries, looking particularly for endometrial polyps, fibroids (intramural and submucosal) and ovarian cysts. It can also be performed on the third day of the menstrual cycle to coincide with the AFC.

• Saline hysterosonography: A small volume of sterile saline expands the cavity during ultrasound, revealing hidden polyps, sub-mucous fibroids or scar tissue without radiation or sedation.

• Hysterosalpingography (HSG): This is an X-ray study in which a contrast dye is passed through the cervix to show the shape of the uterine cavity and whether the fallopian tubes are patent.

• Hysteroscopy: This involves a scope with a camera attached to assess the interior of the womb. It also allows for the treatment of specific conditions, such as the removal of polyps, fibroids, adhesions, and septum inside the cavity of the womb.

4. Gamete and Embryo Quality Considerations

   
   

Success in IVF is determined not just by the number of eggs and sperm retrieved, but also by their health and quality. High-quality gametes give rise to embryos that divide properly, reach the blastocyst stage on time, and carry the correct set of chromosomes.

• Egg quality: High-quality eggs fertilise more readily and tend to produce more robust embryos, giving them a higher chance of implanting and progressing to a healthy pregnancy.

• Sperm quality: A higher sperm count, combined with strong motility and normal morphology, increases the probability of fertilisation and supports healthy embryo growth.

When semen parameters fall short, the laboratory can add an extra step called intracytoplasmic sperm injection (ICSI), where a single, healthy-looking sperm is injected directly into the egg. 

ICSI is considered when:

• The total motile sperm count is very low,

• The previous IVF cycle produced little or no fertilisation,

• Sperm are retrieved surgically,

• Tests reveal the presence of anti-sperm antibodies or high levels of DNA fragmentation.

ICSI eliminates the need for sperm to penetrate the egg, and improves fertilisation rates in cases of severe male-factor.

Once embryos reach Day 5 or 6, pre-implantation genetic testing (PGT) can guide the decision on which embryo to transfer first. However, PGT in Singapore is currently only offered by approved research programmes to couples who meet the selection criteria.

• Pre-implantation Genetic Testing for Aneuploidy (PGT-A) screens embryos for the presence of extra or missing chromosomes. It allows defective embryos to be set aside and for healthy embryos to be transferred back to the womb. The criteria for PTG-A are: 

  • Women who are at least 35 years old

  • Women with two or more miscarriages

  • Couples who have not conceived after two or more embryo transfers

• Pre-implantation Genetic Testing for Monogenic/Single Gene Disorders (PGT-M) is reserved for couples in which at least one partner carries a known single-gene condition (e.g. thalassaemia, spinal muscular atrophy or cystic fibrosis). Each embryo is tested for the specific mutation in question. Only unaffected embryos are considered for transfer. PGT-M is only available to eligible patients through approved providers.

• Pre-implantation Genetic Testing for Structural Rearrangements (PGT-SR) is used when one partner carries a balanced chromosomal rearrangement, such as a translocation or inversion. Although carriers are usually healthy, their embryos may inherit unbalanced genetic material, increasing the risk of miscarriage or congenital conditions. PGT-SR helps identify embryos with normal or balanced chromosome structures, so only those are selected for transfer. Like the other forms of PGT, it is only available to eligible patients through approved providers.

5. Risk of Ovarian Hyperstimulation Syndrome (OHSS)

Ovarian hyperstimulation syndrome (OHSS) is an excessive reaction by the ovaries to ovarian-stimulating medications. OHSS occurs when the ovaries develop too many follicles, resulting in a significant rise in estradiol levels, and causes fluid to leak into the abdomen, resulting in bloating, nausea, and pelvic discomfort. 

Most episodes of OHSS are mild, causing little more than bloating or mild pelvic aches. Moderate OHSS can cause abdominal pain and rapid weight gain, while severe OHSS may cause shortness of breath, blood clots, and decreased urine output.

The following factors may increase the risk of OHSS :

• High AMH or a large antral follicle count

• Polycystic ovary syndrome (PCOS)

• Previous OHSS episode

• Very high estrogen levels

If any of these risk factors are present, your fertility specialist will take preventive measures to reduce the chances of OHSS. This may include:

• Using an antagonist protocol for IVF stimulation 

• Using lower doses of stimulating hormones

• Stopping stimulation hormones while continuing GnRH antagonist agents (Coasting)

• Using a special type of hormone called GnRH agonist for egg maturation 

• Adopting a freeze-all approach to delay pregnancy

• Prescribing cabergoline or low-dose aspirin

• Close ultrasound and blood-test monitoring

6. Potential Maternal and Foetal Health Risks

While IVF is safe for most women, there are some health risks for expecting women. 

• Multiple pregnancy: Transferring more than one embryo can lead to twins, triplets, or higher-order pregnancies. This will significantly increase the risk of complications such as pre-eclampsia, gestational diabetes, pre-term birth and NICU admissions. Using a single embryo transfer is the recommended approach in modern IVF.

• Ectopic pregnancy: In 1% of cases, an embryo implants outside the womb, usually in a fallopian tube, causing pain and bleeding that need prompt medical care.

• Gestational diabetes: Women who undergo IVF may have a higher chance of developing raised blood sugar levels.

Babies conceived through IVF have a higher chance of fetal/neonatal complications:

• Preterm birth: Fetuses have a higher risk of being born prematurely, which can lead to long term health complications and the need for neonatal intensive care.

• Risk of birth defects: Babies born using IVF have a slightly increased risk of birth defects.

• Small for gestational age: IVF babies are more likely to be born small for their gestational age, which can impact their subsequent growth and developmental milestones.

7. Previous ART or Fertility Treatment History

If a previous IVF cycle produced few eggs, poor-quality embryos or no implantation, your fertility specialist will evaluate your previous IVF protocols and make the necessary modifications.

The following interventions may be considered:

• Assisted hatching: Thinning or laser-drilling the embryo’s outer shell can help “hatch” the embryos for implantation.

• Endometrial receptivity analysis (ORA): A blood-based gene test that determines when the womb’s lining is most receptive to the embryo. The results can tell us if the standard transfer window is appropriate or if some modification is required to achieve a pregnancy. 

• Intralipid infusion: Consists of an intravenous emulsion of soybean oil, egg yolk, and glycerine. It aims to create a more favourable uterine environment for embryo implantation and pregnancy maintenance by suppressing an overactive immune response.

8. Genetic and Infectious Disease Screening

Many severe conditions, such as thalassaemia, cystic fibrosis and spinal muscular atrophy, are inherited and carriers may not exhibit any physical signs.

• A couple may undergo genetic carrier screening (e.g. Natera’s Horizon Carrier Screening), which is a comprehensive test to identify whether you and your partner are silent carriers of the same genetic condition. Carrier screening is recommended by the American College of Obstetricians and Gynaecologists (ACOG). It allows couples to understand their genetic risk profile and facilitates discussion with their IVF specialist on how it may influence their treatment.

Under Singapore’s Assisted Reproduction Service regulations, couples must also complete the following blood tests before commencing IVF:

• HIV

• Hepatitis B and C

• Rubella 

• Treponema pallidum bacterium

• Thalassaemia

When to See a Reproductive Specialist

Consider seeing a fertility specialist if you are:

• 35 years old and above and is not pregnant after six months of regular, unprotected sex, 

• Below 35 years old and is not pregnant after a year of regular, unprotected sex,

• Diagnosed with a fertility condition - examples include obstructed fallopian tubes, PCOS, endometriosis, male factor.

• Have had two or more consecutive miscarriages

Are You Considering IVF in Singapore?

If you are seeking a fertility specialist in Singapore, consider scheduling an appointment with Daniel Koh Clinic. Dr Koh is an experienced obstetrician and gynaecologist with dual subspecialty interests in reproductive medicine and maternal-fetal medicine. Dr Daniel will assess your circumstances, discuss your fertility options and design a personalised treatment plan to fulfil your fertility goals.