Can IVF in Thailand Choose Twins? Embryo Transfer Number and Risk Assessment

Opening: Physician Decision-Making Logic

In reproductive clinics, when deciding on the number of embryos to transfer, physicians systematically evaluate the woman's age, ovarian reserve function (AMH, FSH, antral follicle count), embryo quality (including whether PGT-A testing has been performed), previous transfer history, and the intrauterine environment. The patient's desire for twins is common, but the primary principle of medical decision-making is maternal and infant safety and healthy live birth. The following analyzes the core issues related to IVF in Thailand and twins from a clinical perspective.

Can IVF in Thailand Choose Twins?

Yes, technically, IVF in Thailand can increase the probability of twin pregnancy by transferring 2 or more embryos. However, it must be clear: transferring multiple embryos does not guarantee twins. The final result depends on whether all embryos implant and continue to develop. Clinical data shows that the twin pregnancy rate after transferring 2 high-quality blastocysts is approximately 20%–30%, not 100%. Furthermore, multiple pregnancy is considered high-risk, and the medical community generally recommends prioritizing single embryo transfer when conditions permit, especially for younger patients with high-quality blastocysts.

Risk Assessment of Multiple Pregnancy from the Physician's Perspective

From a reproductive medicine standpoint, multiple pregnancy (including twins) is considered a pathological pregnancy state, with risks far higher than those of a singleton pregnancy. When recommending the number of embryos to transfer, physicians prioritize the following risk dimensions.

Maternal Risks

• Hypertensive Disorders of Pregnancy: The incidence in twin pregnancies is 2–3 times that of singletons, with approximately 15%–20% of twin pregnancies developing preeclampsia.
• Gestational Diabetes: Increased placental volume and hormonal changes lead to a greater glucose metabolism burden, with an incidence rate twice that of singleton pregnancies.
• Anemia and Postpartum Hemorrhage: Twin pregnancies involve a greater increase in blood volume, higher iron reserve requirements, and an increased risk of postpartum uterine atony.
• Cesarean Section Rate: The cesarean section rate for twins is approximately 60%–80%, significantly higher than for singletons.

Fetal and Neonatal Risks

• Preterm Birth: Approximately 50%–60% of twins are delivered before 36 weeks, and 30% before 34 weeks. Preterm infants face risks such as respiratory distress, feeding difficulties, and intracranial hemorrhage.
• Low Birth Weight: The average birth weight of twins is about 2300–2500g, significantly lower than the 3300g for singletons. Low birth weight infants have an increased incidence of long-term developmental issues.
• Fetal Growth Restriction: Competition for resources between twins can lead to growth restriction in one fetus, with an incidence of about 20%–30%.
• Congenital Anomalies: The rate of congenital anomalies in twins is slightly higher than in singletons, approximately 2%–3% (compared to about 1.5%–2% for singletons).

Therefore, when making decisions, physicians weigh the patient's expectation of twins against these medical risks, rather than simply fulfilling a request to "transfer more."

Differences in Embryo Transfer Policies Across Countries

Regulations and medical guidelines regarding the number of embryos transferred in assisted reproduction vary significantly between countries, directly affecting whether patients can pursue twins through multiple embryo transfer.

Thailand's relatively relaxed policy provides room for patients hoping to increase the chance of twins through multiple embryo transfer, but medical risks objectively exist, and physicians have a duty to fully inform patients.

Actual Decision-Making Process for Twins in Thai IVF

In正规 reproductive centers in Thailand, the determination of the number of embryos to transfer is not arbitrary but follows a clinical evaluation process:

1. Basic Fertility Assessment: Includes AMH, FSH, LH, antral follicle count, thyroid function, hysteroscopy, etc., to evaluate ovarian reserve and uterine receptivity.
2. Embryo Culture and Evaluation: After egg retrieval, fertilization and embryo culture proceed to the blastocyst stage (day 5–6). Some patients opt for PGT-A to screen for chromosomal euploidy.
3. Pre-transfer Multidisciplinary Discussion: Reproductive physicians, embryologists, and clinical coordinators jointly evaluate embryo number, quality grade, fragmentation rate, and inner cell mass and trophectoderm scores.
4. Shared Decision-Making: The physician explains the specific risks of multiple pregnancy to the patient, presents the center's data on twin pregnancy rates, preterm birth rates, etc., and the patient signs informed consent.
5. Transfer Procedure: The selected number of embryos is placed into the uterine cavity under ultrasound guidance, followed by luteal phase support.
6. Post-transfer Monitoring: Blood HCG is tested 12–14 days after transfer. Once pregnancy is confirmed, an ultrasound is performed at 6–8 weeks to determine the number of gestational sacs and fetal heartbeats.

If a triplet or higher-order pregnancy occurs, the physician will recommend selective fetal reduction to decrease the number of embryos to 1–2, thereby reducing pregnancy risks.

Easily Overlooked Details

• Possibility of Monozygotic Twins: Even with the transfer of a single embryo, monozygotic splitting can occur, resulting in identical twins, with a probability of about 1%–2%. This cannot be predicted or chosen in advance.
• Spontaneous Reduction Phenomenon: After transferring 2 embryos, approximately 20%–30% of cases will see one embryo stop developing, resulting in only one gestational sac surviving, known as "spontaneous reduction." Patients may mistakenly think it "failed," but it is actually the body's protective mechanism against multiple pregnancy.
• Maternal Nutrition and Physical Reserve: Twin pregnancies significantly increase the demand for calcium, iron, folic acid, and protein. Nutritional supplementation is needed before pregnancy; otherwise, anemia, osteoporosis, and fetal growth restriction are more likely.
• Cervical Function Assessment: Twin pregnancies require a longer cervix. Shortening of the cervix in the second trimester is an important warning sign for preterm birth. Patients with a history of cervical surgery or multiple intrauterine procedures need early evaluation and consideration of cervical cerclage.

Common Pitfalls to Avoid

• "Guaranteed Twins" Promises: Some agencies or informal clinics attract patients with slogans like "guaranteed success" or "guaranteed twins." No medical technology can guarantee a 100% twin pregnancy; such promises constitute false advertising, and patients should be wary.
• Ignoring Personal Health Conditions: Pursuing twins without assessing underlying conditions such as hypertension, diabetes, heart disease, or uterine abnormalities. Transferring multiple embryos rashly can lead to severe pregnancy complications.
• Insufficient Understanding of Selective Reduction: Some patients consider reduction a "minor procedure." In reality, fetal reduction carries a miscarriage risk of about 2%–5%, and the risk increases the later the procedure is performed. The remaining fetuses after reduction may still be affected by preterm birth or infection.
• Overlooking Neonatal Care Costs: The rates of preterm birth and Neonatal Intensive Care Unit (NICU) admission are significantly higher for twins. Medical costs are 3–5 times those of a singleton, and the postpartum care demands double the effort. Financial and psychological preparation is essential.

Cost Factors Related to Twins

In an IVF cycle in Thailand, patients hoping to achieve twins through multiple embryo transfer may incur the following additional costs:

Additionally, twin pregnancies may lead to a longer maternal postpartum recovery period and increased childcare costs. These hidden expenses should also be considered.

Frequently Asked Questions