Thailand IVF Medication Protocol Explained: Ovulation Induction Drug Selection and Individualized Strategies

Opening: Real Consultation Scenario

Clinic Scenario
A 41-year-old woman sits in the consultation room, with an AMH of 0.8 ng/mL and a bilateral antral follicle count of 5. She had previously undergone an egg retrieval at another hospital that yielded only 2 eggs, with no embryos suitable for transfer. She takes out her phone to show screenshots of medication protocols from several Thai fertility centers and asks, "What are the differences between these protocols? What medication is generally used for someone like me in Thailand? Which protocol is more likely to be effective for me?"

Core Answer to Thailand IVF Medication Protocols

Thailand IVF medication protocols are not fixed templates but are individualized drug combination plans based on ovarian reserve markers (AMH, FSH, antral follicle count), age, body mass index, previous ovarian stimulation response history, and baseline endocrine levels. Core drug categories include:

• Follicle-Stimulating Hormone (FSH) Drugs: Gonal-f (recombinant FSH-α), Puregon (recombinant FSH-β), Li Shen Bao (urinary FSH), etc., used to directly stimulate follicle growth and development.
• Luteinizing Hormone (LH) Drugs: Luveris (recombinant LH), used to supplement LH activity, particularly in the late follicular phase to support follicle maturation and estrogen synthesis.
• Human Menopausal Gonadotropin (hMG): Menopur, Pergonal, etc., containing both FSH and LH activity, often used in cases of poor ovarian response or specific protocols.
• GnRH Antagonists: Cetrotide, Ganirelix, used to prevent premature LH surge, avoiding early ovulation, and are core components of mainstream protocols in Thailand.
• GnRH Agonists: Diphereline, Decapeptyl, used for down-regulation or trigger (final oocyte maturation), applied in long or short protocols.
• Trigger Medications: Ovidrel (recombinant hCG), hCG injection, Diphereline trigger, etc., used to induce final oocyte maturation and ovulation.
• Luteal Phase Support Medications: Progesterone injection, Crinone gel, Duphaston tablets, etc., used for endometrial support after transfer.

In Thailand, the most commonly used is the antagonist protocol (accounting for over 70% of cycles), followed by the agonist long protocol, mild stimulation protocol, PPOS protocol, and natural cycle protocol. The choice depends primarily on ovarian reserve status and previous response history.

Actual Medication Process and Timeline

A typical Thailand IVF medication cycle (using the antagonist protocol as an example) starts on day 2-3 of menstruation and lasts approximately 10-14 days, as detailed below:

*Timelines differ for other protocols: The agonist long protocol requires 2-4 weeks of down-regulation beforehand; the mild stimulation protocol usually has a shorter medication period of about 8-10 days; the PPOS protocol involves medication throughout the luteal phase.

Doctor's Perspective: Decision-Making Logic for Protocol Selection

In Thai fertility centers, doctors follow this decision-making path when formulating medication protocols:

• Step 1: Assess Ovarian Reserve — AMH < 1.0 ng/mL or AFC < 6,倾向于微刺激或PPOS方案；AMH 1.0-3.0 ng/mL 且 AFC 7-15，拮抗剂方案为标准选择；AMH > 3.0 ng/mL 或 AFC > 15，拮抗剂方案联合低起始剂量以避免过度刺激。
• Step 2: Analyze Previous Response — If there is a history of Ovarian Hyperstimulation Syndrome (OHSS), choose an agonist protocol combined with a Diphereline trigger to reduce risk; if previous response was poor (egg count < 3), consider adding LH or starting in the luteal phase (PPOS protocol).
• Step 3: Consider Age and Endocrine Status — Age ≥ 40 years and FSH > 10 IU/L, generally avoid long protocol, choose mild stimulation or natural cycle; PCOS patients优先使用拮抗剂方案联合低剂量hCG扳机。
• Step 4: Determine Trigger Strategy — Follicle count ≥ 15 and E2 > 4000 pg/mL, use Diphereline trigger (to reduce OHSS risk); fewer follicles and moderate E2 level, use Ovidrel or hCG trigger.

Some Thai fertility centers may fine-tune protocols based on season, drug supply chain, and their own laboratory preferences, but the core logic is consistent with international standards.

Differences in Medication Protocols by Age Group

Age is the strongest independent factor influencing protocol choice. In Thailand, patients ≥ 40 years old account for 30%-40% of all IVF cycles, so mild stimulation and PPOS protocols are used more frequently than in European or American countries.

Medication Characteristics of Different Hospitals in Thailand

Major Thai fertility centers have some differences in medication protocols, mainly in drug brand preference, protocol combination strategies, and trigger habits:

• One Type of Hospital (International Chain): Tend to use imported recombinant FSH (Gonal-f or Puregon), antagonist protocol dominates, trigger mainly with Ovidrel, protocols relatively standardized.
• Another Type of Hospital (Large Local Center): More frequently use Menopur (hMG) combined with FSH, especially in poor responders, higher proportion of PPOS protocol application, flexible trigger (hCG or Diphereline).
• Some Specialized Clinics: Advocate for individualized mild stimulation protocols, lower medication doses, emphasize egg quality over quantity, often use Letrozole combined with low-dose FSH.

Different hospitals' laboratory conditions (e.g., incubators, embryo grading systems) also influence medication decisions. For example, when the lab has a high success rate for culturing embryos to blastocyst, doctors tend to aim for more eggs to increase blastocyst yield, thus choosing a slightly higher starting dose protocol.

Easiest Details to Overlook During Medication

Common Misconceptions and Pitfalls

• Misconception 1: Blindly Pursuing "Imported Drugs" While Ignoring Protocol Matching — Gonal-f and Puregon have similar effects, but the specific choice should consider the patient's budget and insurance. More importantly, the type of protocol (antagonist/agonist/mild stimulation) matters more than the drug brand.
• Misconception 2: Believing "Higher Dose Means More Follicles" — Beyond a threshold FSH dose, increasing the dose does not increase egg yield and may actually reduce egg quality. In Thailand, doctors tend to follow the principle of "enough is good," especially for older patients.
• Misconception 3: Ignoring the Impact of Body Weight on Drug Distribution — Patients with a BMI > 28 kg/m² may have insufficient blood drug concentrations at the same dose and need a higher starting dose. Thai centers rarely proactively adjust BMI-related doses, so patients should actively inform about their weight.
• Misconception 4: Frequently Changing Hospitals or Doctors Leading to Discontinuous Protocols — Different centers have different medication habits and monitoring systems. Frequent changes can lead to poor protocol衔接, affecting cycle outcomes.
• Misconception 5: Self-Administering "Regulating" Products During Medication — Certain supplements (e.g., DHEA, Coenzyme Q10) may interact with stimulation drugs or affect endocrine levels and should be used under a doctor's guidance.

Frequently Asked Questions

Q1: Is there still a chance to use a conventional protocol in Thailand with low AMH (< 0.5)?

When AMH < 0.5 ng/mL, conventional antagonist protocols usually struggle to achieve a satisfactory egg yield. Thai doctors generally recommend a mild stimulation protocol (Letrozole + low-dose FSH) or a PPOS protocol (using luteal phase stimulation), yielding 1-3 eggs per cycle, possibly requiring multiple cycles to accumulate embryos. Some centers may attempt natural cycle egg retrieval.

Q2: What are the differences between medication protocols in Thailand and China?

The core difference is not in the types of drugs, but in the proportion of protocol choices and monitoring frequency. Thailand uses PPOS and mild stimulation protocols at a higher rate than China, and has greater proficiency with antagonist protocols. Regarding monitoring, Thai centers typically perform daily or every-other-day ultrasound + E2 monitoring, allowing for more precise adjustments. Additionally, the drug brands and specifications available in Thailand differ slightly from those in China, but the active ingredients are the same.

Q3: Do I need to stay in Thailand throughout the medication period?

Continuous monitoring is required from starting stimulation to egg retrieval, so it is recommended to stay in Thailand for the entire duration (12-16 days). If a fresh transfer is performed after retrieval, an additional 3-5 days are needed; for a frozen embryo transfer, you can return home after retrieval and come back to Thailand for the transfer 1-2 months later.

Q4: Can Thailand's medication protocols cause Ovarian Hyperstimulation?

Any stimulation protocol carries a risk of OHSS, but Thai doctors, through the use of antagonist protocols combined with Diphereline triggers, low-dose hCG triggers, or freeze-all embryo strategies, have controlled the incidence of moderate to severe OHSS to 1%-3%. The key is monitoring E2 levels and follicle count, and adjusting the protocol promptly.

Q5: What preparations are needed before starting medication?

Basic tests: AMH, FSH, LH, E2, P4, thyroid function, Vitamin D, semen analysis (male partner), infectious disease screening. Additionally, it is recommended to complete an endometrial assessment (ultrasound or hysteroscopy) and genetic counseling (if applicable). No special preparation is needed before medication, but maintaining a regular routine, balanced nutrition, and avoiding smoking and alcohol can help improve egg quality.

Practitioner's Observation
As a doctor who has worked in the field of assisted reproduction for many years, I see many Chinese patients coming for consultations with the preconception that "Thai protocols are gentler" or "Thai drugs are more effective." In reality, the advantage of Thai medication protocols lies in their flexibility and degree of individualization, not the drugs themselves. The same center, the same doctor, will prescribe completely different protocols every day based on different AMH, AFC, and E2 responses. What truly matters is not "what drugs are used in Thailand," but "what protocol your ovaries need." I recommend that patients complete a basic evaluation before traveling to Thailand, bringing their AMH, AFC, and records of previous cycles to the doctor. This way, the starting point for protocol formulation will be more precise.