Surrogacy is a fertility option where a woman—known as a surrogate—carries and gives birth to a child for intended parents. While it can be an emotional journey, the medical process behind surrogacy is structured, regulated, and scientifically advanced. This article breaks down the step-by-step medical aspects of a typical gestational surrogacy process, which is the most common form used today.
1. Understanding Types of Surrogacy
Before diving into the process, it’s important to distinguish between the two main types:
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Traditional Surrogacy: The surrogate uses her own egg and is artificially inseminated with the intended father’s or donor’s sperm. She is biologically related to the child.
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Gestational Surrogacy (most common): The surrogate has no genetic link to the child. The embryo is created through in vitro fertilization (IVF) using the egg and sperm from the intended parents or donors.
This article focuses on gestational surrogacy, which accounts for over 95% of all modern surrogacy cases in the U.S. and other developed countries (American Society for Reproductive Medicine – ASRM, 2022).
2. Medical Screening & Surrogate Selection
Intended Parents
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Complete fertility assessments.
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Sometimes contribute sperm, eggs, or both, or use donors if medically necessary.
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Undergo infectious disease screening and genetic counseling.
Surrogates
Surrogates are medically and psychologically evaluated. Criteria often include:
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Age: 21–40 years old
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At least one prior successful pregnancy
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No major complications in previous births
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Stable lifestyle and emotional well-being
Medical screenings for surrogates include:
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Pap smear, blood work, hormone levels
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Uterine evaluation via transvaginal ultrasound or hysteroscopy
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Infectious disease screening (HIV, Hep B/C, syphilis)
Note: Many agencies follow the ASRM guidelines, which stress that the surrogate must be free from substance use and have a supportive home environment.
3. Legal and Psychological Counseling
Though not purely medical, legal counseling is crucial before proceeding with any treatment. Surrogacy agreements are drawn up before embryo transfer, ensuring all parties understand their roles, rights, and obligations.
Meanwhile, psychological counseling prepares the surrogate and intended parents for emotional aspects of the journey.
4. IVF Cycle Preparation
Egg Provider (Intended Mother or Donor)
The woman providing the eggs begins an IVF stimulation cycle, typically lasting 10–14 days. She takes injectable gonadotropins to stimulate the ovaries to produce multiple eggs.
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Monitoring: Blood tests and ultrasounds track the development of follicles.
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Egg Retrieval: Once follicles are mature, eggs are retrieved under light anesthesia via a needle guided through the vaginal wall into the ovaries.
On average, 10–15 eggs are retrieved per cycle (CDC Fertility Data, 2021).
Sperm Collection
Sperm is collected from the intended father or donor and processed in the lab. If fresh sperm is not possible, previously frozen samples may be used.
5. Fertilization & Embryo Development
Eggs and sperm are fertilized in the lab through either:
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Conventional IVF (placing sperm with the egg in a petri dish), or
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ICSI (Intracytoplasmic Sperm Injection) – where one sperm is injected directly into an egg, often used for male infertility.
Over the next 3–6 days:
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Embryos develop and are monitored for quality.
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Embryologists may perform Preimplantation Genetic Testing (PGT) to screen embryos for chromosomal abnormalities.
Embryo freezing (vitrification) is often done, especially if the surrogate’s uterus needs additional preparation time.
6. Surrogate’s Uterine Preparation
The surrogate begins a hormonal protocol to prepare her endometrium (uterine lining) for implantation. This includes:
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Estrogen pills or patches (to thicken the lining)
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Progesterone injections (to prime the uterus for embryo transfer)
Monitoring via ultrasound ensures the endometrial lining is typically 8–12 mm thick — the optimal range for implantation success.
7. Embryo Transfer
Once the uterus is ready and the embryo(s) reach the blastocyst stage (day 5–6), the transfer is scheduled.
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A soft catheter is inserted through the cervix into the uterus.
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The embryo is transferred under ultrasound guidance.
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The procedure is painless and takes about 15 minutes.
Generally, only one embryo is transferred to reduce risks associated with multiple births.
8. Two-Week Wait and Pregnancy Confirmation
About 9–12 days post-transfer, the surrogate takes a beta hCG blood test to confirm pregnancy. If positive:
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Repeat tests track rising hCG levels.
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A fetal heartbeat is typically detected at 6–7 weeks via ultrasound.
Once confirmed, the surrogate is transitioned to routine prenatal care.
9. Pregnancy & Prenatal Monitoring
Surrogates attend all standard OB/GYN appointments, with medical records shared with the intended parents. Some clinics schedule additional ultrasounds to monitor fetal development closely, especially in IVF pregnancies.
Hormonal support (progesterone and estrogen) continues for the first 10–12 weeks until the placenta fully supports the pregnancy.
10. Birth and Postnatal Care
Most surrogate births are planned deliveries at partner hospitals. Intended parents are typically present for the birth.
After birth:
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The baby is handed to the intended parents.
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Legal custody is transferred if not already handled through pre-birth orders.
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The surrogate receives postnatal care and psychological support.
Global & U.S. Surrogacy Facts
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Success rates for IVF with gestational carriers are around 50–70% depending on embryo quality and surrogate age (Society for Assisted Reproductive Technology – SART).
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The average cost of surrogacy in the U.S. ranges from $100,000–$150,000, including medical, legal, agency, and surrogate compensation.
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Countries like Ukraine, Georgia, and the U.S. are top destinations for international surrogacy, while countries like India and Thailand have restricted it to locals due to ethical concerns.
