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Gender Selection Through IVF: How PGT-A Works and What to Expect
Gender selection through IVF is one of the most searched and least clearly explained topics in reproductive medicine. For some families, it's medically indicated — a genetic condition linked to sex chromosomes makes selecting an unaffected embryo a medical necessity. For others, it's a deeply personal choice about family composition — sometimes called family balancing. Whatever your reason, if you're considering gender selection in Connecticut, this guide explains exactly how it works, what PGT-A involves, what the science shows, and what to expect at New England Fertility Institute.
What Is Gender Selection and How Is It Done?
In the context of IVF, gender selection is achieved through preimplantation genetic testing, specifically PGT-A (preimplantation genetic testing for aneuploidies, formerly known as PGS). This technology analyses the chromosomal composition of embryos created through IVF before they are transferred to the uterus, allowing the identification of each embryo's sex chromosomes (XX for female, XY for male) alongside a comprehensive screen for chromosomal abnormalities.
It is important to understand that gender selection in the US is not a standalone procedure — it occurs within a full IVF cycle. You cannot select a gender without first going through egg retrieval, fertilization, embryo culture to blastocyst stage, and biopsy. Gender information is one output of PGT-A; chromosomal health screening is the other — and both are delivered in the same results report.
💡 PGT-A is highly accurate for sex chromosome identification — with accuracy rates exceeding 99% when performed by experienced embryology laboratories. The procedure involves biopsying a small number of cells from the trophectoderm (the outer layer of the blastocyst that will become the placenta, not the embryo itself), which does not harm the embryo's developmental potential.
Medical vs Elective Gender Selection
Medical gender selection is indicated when a family carries a sex-linked genetic condition — a disorder caused by a mutation on the X or Y chromosome that predominantly or exclusively affects one sex. Examples include Duchenne muscular dystrophy (X-linked recessive, primarily affecting males), haemophilia A and B (X-linked recessive), fragile X syndrome, and certain other X-linked conditions. In these cases, selecting embryos of the unaffected sex (typically female for X-linked recessive conditions) is a medically supported and widely accepted use of PGT.
Elective gender selection — also called family balancing — is the choice to select an embryo of a preferred sex for personal or family composition reasons, without a medical indication. This is legal in the United States and offered at NEFI, though it is not available in many other countries. It is most commonly requested by families who already have one or more children of one sex and wish to have a child of the other, or by individuals and couples for whom family composition is a deeply held personal value.
The PGT-A Process at NEFI: Step by Step
Step 1 — IVF stimulation and egg retrieval. The process begins with a standard IVF cycle: ovarian stimulation, monitoring, trigger injection, and egg retrieval under light sedation. The number of eggs retrieved is the most significant variable in the outcome — more eggs mean more embryos, which means a higher probability of having at least one chromosomally normal embryo of the preferred sex.
Step 2 — Fertilization and embryo culture. Retrieved eggs are fertilized in the NEFI embryology laboratory using the intended father's or donor sperm via ICSI (intracytoplasmic sperm injection). Fertilized eggs are cultured for 5–6 days until they reach the blastocyst stage — the optimal developmental point for biopsy.
Step 3 — Embryo biopsy. At the blastocyst stage, an embryologist removes 3–8 cells from the trophectoderm — the outer layer that will form the placenta — using a laser. This biopsy does not damage the inner cell mass that becomes the baby. Biopsied embryos are immediately vitrified (flash-frozen) while biopsy samples are sent to a specialist genetics laboratory.
Step 4 — Genetic analysis. The genetics laboratory analyses each biopsy sample using next-generation sequencing (NGS) — a technology that provides a comprehensive chromosomal map of each embryo, identifying: the sex chromosomes (XX or XY), any aneuploidies (extra or missing chromosomes across all 24 chromosome pairs), and in some cases segmental imbalances. Results are typically returned within 7–14 days.
Step 5 — Embryo selection and transfer. Results report identifies each embryo as chromosomally normal (euploid) or abnormal (aneuploid), and by sex. Intended parents, in consultation with their NEFI physician, select the embryo(s) to transfer based on chromosomal health first, sex preference second. A frozen embryo transfer (FET) cycle is then prepared — the uterine lining is optimized with hormone supplementation, and the selected embryo is transferred in a brief, non-invasive procedure.
What the Research Shows About PGT-A
PGT-A has a substantial and growing evidence base, though its application continues to evolve as the technology improves.
A 2020 randomised controlled trial in ASRM — one of the most rigorous studies to date — found that PGT-A significantly improved the ongoing pregnancy rate per transfer in women aged 36–40 compared to morphology-based embryo selection alone, by ensuring only euploid embryos were transferred. The study confirmed that selecting chromosomally normal embryos reduces miscarriage risk and improves the probability of a live birth per transfer.
A 2022 meta-analysis in Human Reproduction pooled data from multiple randomized trials and found that PGT-A was associated with a significant reduction in miscarriage rates — from approximately 20–25% in unscreened cycles to under 10% in PGT-A cycles — alongside improved live birth rates per transfer in women over 35. The miscarriage reduction benefit was particularly pronounced for women 38 and older.
Realistic Expectations: What PGT-A Can and Cannot Guarantee
PGT-A can identify sex chromosomes with over 99% accuracy — but it cannot guarantee a pregnancy. A euploid embryo of your preferred sex still requires successful implantation and a healthy uterine environment. Implantation failure can occur even with chromosomally normal embryos, and success rates vary based on age, uterine health, and other factors.
PGT-A also cannot screen for all possible genetic conditions — it identifies chromosomal copy number changes, not single-gene mutations (which require a different test, PGT-M). If you have a known single-gene condition in your family, discuss PGT-M with your NEFI physician.
Finally, there is no guarantee that any given IVF cycle will produce an embryo of a specific sex. The distribution of XX and XY embryos in any cycle is approximately 50/50, but the actual numbers are subject to chance — particularly in cycles with a small number of embryos. NEFI's team will counsel you honestly on the probability of achieving your goals based on your specific embryo numbers.
Gender Selection at NEFI: Legal, Ethical, and Inclusive
Gender selection is legal in Connecticut and across the United States. NEFI offers both medically indicated and elective (family balancing) gender selection as part of its comprehensive PGT programme, and does not impose value judgements on families' reproductive choices.
NEFI's approach is fully inclusive — serving individuals and couples of all family structures, genders, and sexual orientations. For LGBTQ+ families in particular, the ability to make informed decisions about embryo selection is often a meaningful and empowering part of a journey that already involves considerable planning and intention.
For a full overview of how IVF, embryo creation, and genetic testing fit into the surrogacy journey, read: How Surrogacy Works in the US: A Complete Step-by-Step Guide for Intended Parents
Frequently Asked Questions
How accurate is gender selection through PGT-A? Sex chromosome identification via PGT-A using next-generation sequencing is highly accurate — exceeding 99% in experienced laboratories. Errors are extremely rare and are typically disclosed by the testing laboratory with quality assurance documentation.
Does PGT-A affect the embryo's health or development? The trophectoderm biopsy used in PGT-A has been studied extensively and is not associated with harm to embryo development or pregnancy outcomes. Multiple large studies have confirmed equivalent birth weight, developmental outcomes, and health profiles in children born from biopsied versus non-biopsied embryos.
What if I only have embryos of one sex? This is a real possibility, particularly in cycles that produce a small number of embryos. If all euploid embryos are of a sex different from your preference, your NEFI physician will discuss options — including whether to proceed with transfer, complete another IVF cycle to create additional embryos, or transfer the embryos available. There is no obligation to transfer embryos that do not meet your preferences, and NEFI will support whatever decision is right for your family.
Is gender selection covered by insurance in Connecticut? PGT-A for medical indications (sex-linked genetic conditions) may be covered under Connecticut's fertility insurance mandate. Elective gender selection is typically not covered. NEFI's financial counsellors will clarify coverage specifics for your plan.
Can I combine gender selection with egg donation? Yes. PGT-A is performed on embryos regardless of whether they are created from the intended parent's own eggs or donor eggs. For families using donor eggs, PGT-A remains a valuable tool for chromosomal screening and gender selection and is routinely offered as part of NEFI's donor egg IVF program.
Informed, Empowered, Supported
Gender selection through IVF is one of the most personal decisions a family can make — and it deserves clear information, honest counselling, and genuine support. NEFI's team brings all three. Whether your reason is medical, personal, or somewhere in between, we are here to help you make the decision that is right for your family — without assumption and without judgement.
Written and reviewed by: Dr. Michael M. Guarnaccia, MD, MPH