A Surrogate Mother’s All-Inclusive Pre-Transplant Guide: Requirements, Indicators, Screening & Conditioning

Basic Requirements and Screening Criteria for Surrogate Mothers

Surrogate mothers are crucial players in the assisted reproduction process, and their physical and mental health directly affects embryo implantation and pregnancy success. To ensure the compliance and safety of the surrogacy process, surrogate mothers need to fulfill the following core requirements:

Age and Fertility Experience

Surrogate mothers are usually between the ages of 21-40 and must have had at least one healthy pregnancy and delivery. This requirement is designed to ensure that the uterus is functionally mature and capable of handling the risks of pregnancy.

Body Mass Index (BMI)

The ideal BMI should be kept between 18.5-24.9. A high BMI may increase the risk of complications such as gestational diabetes and hypertension; a low BMI may affect endometrial tolerance.

Lifestyle habits and health status

The surrogate mother should have no history of smoking or alcohol abuse and should not be on long-term antidepressant or anti-anxiety medication. In addition, she should be screened for infectious diseases (e.g. Hepatitis B, Hepatitis C, HIV, syphilis, etc.) and ensure that there is no history of hereditary or chronic diseases.

Mental Health and Social Support

Surrogate mothers need to pass a psychological assessment (e.g., SCL-90 scale) to demonstrate emotional stability and stress tolerance. Also, support from family members is needed to minimize the psychological burden of pregnancy.

Surrogate mothers need to pay attention to the core physical indicators prior to transfer

Prior to embryo transfer, the surrogate mother’s physical condition needs to meet specific medical standards in order to create an optimal environment for embryo implantation. The following are the indicators that need to be focused on:

Hormone Levels
Estrogen (E2): the optimal range during the luteal phase is 499-1580 pmol/L, too low may affect endometrial hyperplasia, too high requires screening for risk of ovarian hyperstimulation.
Progesterone (P): needs to be controlled at 5-20 ng/mL before transfer to support luteal function and early embryonic development.
Endometrial thickness and morphology
Endometrial thickness needs to be 8-12 mm and show a uniform trilinear pattern. Too thin (<7 mm) or too thick (>14 mm) may reduce the rate of implantation.
Thyroid function
Thyroid stimulating hormone (TSH) needs to be controlled at 2.5 mIU/L or less. Abnormal thyroid function may increase the risk of miscarriage or affect fetal neurodevelopment.
Metabolic and immune status
Ensure that blood glucose, blood pressure, liver and renal function are normal, and exclude autoimmune diseases (e.g., antiphospholipid antibody syndrome).

Systematic checkup process before surrogate mother’s transfer

A comprehensive pre-transfer checkup is a central part of safeguarding the health of the surrogate mother and her embryos, and usually includes the following items:

Reproductive system evaluation
Vaginal ultrasound: to monitor ovarian reserve (sinus follicle count), uterine morphology and blood flow.
Hysteroscopy: to screen for lesions such as endometrial polyps, adhesions or inflammation.
Infectious and Genetic Disease Screening
Includes testing for infectious diseases such as Hepatitis B, Hepatitis C, Syphilis, HIV and chromosomal karyotyping (to rule out abnormalities such as balanced translocations).
Hormone and Metabolism Testing
Sex Hormone 6 (FSH, LH, E2, P, PRL, T), AMH (to assess ovarian reserve), thyroid function and glucose tolerance test.
Psychological and Social Assessment
Surrogate mother’s psychological stability, surrogate motivation and family support system were assessed through questionnaires and interviews.

Pre-implantation Scientific Conditioning Program for Surrogate Mothers

The pre-transplant conditioning aims to optimize the physiological and psychological state of the surrogate mother, and the specific measures include:

Adjustment of living habits
Regular work and rest: ensure 7-8 hours of sleep per day, avoid staying up late to maintain endocrine stability.
Moderate exercise: focus on low-intensity activities, such as walking, yoga or swimming, 3-4 times a week, 30 minutes each time.
Stop smoking and drinking: Stop smoking and drinking at least 3 months in advance to minimize the risk of embryotoxicity.
Dietary management
High protein diet: consume 80-100 grams of high quality protein (e.g. fish, beans, dairy products) daily to promote follicular and endometrial growth.
Folic acid and vitamin D supplementation: Daily folic acid intake needs to be 400-800 mcg and vitamin D level needs to be >30 ng/mL to reduce the risk of fetal neural tube defects.
Avoid stimulating foods: Reduce the intake of caffeine, spicy and high-sugar foods to maintain intestinal health and metabolic balance.
Psychological Adjustment and Support
Positive thinking stress reduction training: Relieve anxiety through meditation, breathing exercises or psychological counseling.
Community support: Participate in surrogate mother exchange groups to share experiences and gain emotional resonance.
Medication and Medical Intervention
Hormonal support: Use progesterone or estrogen medications as prescribed to improve endometrial tolerance.
Immunomodulation: low molecular heparin or aspirin may be necessary in the presence of immune abnormalities.

Precautions for surrogate mothers before and after transplantation

48 hours before transplantation
Avoid strenuous exercise and sexual intercourse, keep the vulva clean to prevent infection.
Prepare the uterine lining (e.g. hormone medication or uterine perfusion) as prescribed by the doctor.
Critical period after transplantation
Bed rest: Reduce activity for 48 hours after transplantation, but absolute bed rest is not necessary to avoid increased risk of blood clots.
Symptom monitoring: Be alert for severe abdominal distension, persistent abdominal pain or vaginal bleeding, and seek prompt medical attention to screen for ovarian hyperstimulation or ectopic pregnancy.
Long-term health management
Regular obstetric checkups (e.g. NT screening, non-invasive DNA) and maintenance of balanced nutrition and moderate weight gain (weight gain during pregnancy is recommended to be 11-16 kg).

Summary and Outlook

Preparation of surrogate mother before transplantation is a systematic project, which requires all-round cooperation from physiological indicators, examination process, life conditioning to psychological support. Through scientific health management and social support, surrogate mothers can not only enhance the success rate of embryo implantation, but also bring the hope of safe and compliant fertility to the commissioned families. In the future, with the continuous progress of reproductive medicine and ethical regulation, the protection of surrogate mothers’ rights and interests and the quality of medical services will be further improved, providing a more sustainable solution for global fertility needs.