For most people going through IVF, the laboratory is the most mysterious part of the journey. You hand over something deeply personal – your eggs, your sperm, your embryos, and then wait days for a phone call, often with questions that no one explains in plain language. Into that silence, myths grow: stories from forums, half-remembered facts from a clinic consultation, marketing claims dressed up as science.
At Family By Choice, we believe you deserve honest, evidence-based answers, no matter which path to parenthood you are on. Some of the most common things patients are told about the IVF lab are partly true, partly outdated, or simply wrong, and the gap between what patients believe and what the research actually shows can lead to unnecessary anxiety, money spent on unproven add-ons, or feeling powerless to ask the questions that matter.
Here are eight of the most common myths about the IVF lab, and what the latest peer-reviewed evidence actually says about each.
Myth 1: “Embryos and sperm get mixed up all the time”
This fear is one of the most emotionally heavy, and it is fueled by the rare but high-profile cases that made international headlines. The reality is that modern IVF labs are specifically designed to make mix-ups nearly impossible.
For decades the global standard has been double witnessing: every transfer of biological material is verified in real time by two embryologists. Today, many high-quality labs go further with electronic witnessing systems using RFID (radio-frequency identification) tags attached to every dish, tube, and straw. A 2024 study published in Reproductive Biology and Endocrinology found that RFID-based witnessing achieved a 100% error detection rate in simulated mismatch tests, compared with about 88% for paper labels alone. A real-world analysis of over 21,000 witnessing steps using the RI Witness™ system found a true mismatch interception rate of just 0.11%, well below typical human-error rates for comparable laboratory activities.
The truth: Mix-ups have happened, and when they do they rightly make news, precisely because they are so rare. But it is a fair and important question to ask any clinic before you sign a consent form: “What witnessing system do you use, and is it electronic?”
Myth 2: “The embryologist just picks the best-looking embryo”
This myth is partly true, but the picture is far more nuanced than most patients are told.
Embryologists use morphology (the visual appearance of the embryo) to grade quality, most commonly through the Gardner scale for blastocysts, which scores three things: how much the embryo has expanded, the quality of the inner cell mass (which becomes the baby), and the quality of the trophectoderm (which becomes the placenta).
Morphology is an imperfect predictor. A multicenter study on inter-observer agreement in embryo grading found that while embryologists agreed strongly on some criteria, such as the number of cells and the clinical decision to transfer or freeze, agreement was only “moderate to very poor” for other features like degree of fragmentation and size of the blastomeres. In plain language: two skilled embryologists can look at the same embryo and grade it slightly differently.
This is why two newer tools are reshaping the field: time-lapse imaging (continuously photographing embryos inside the incubator without disturbing them) and AI-assisted embryo selection. We already talked about this in our article “How Artificial Intelligence Is Revolutionizing Fertility and Reproductive Medicine”.
Also, a 2025 review concluded that time-lapse imaging shows real promise, particularly for reducing unnecessary biopsies in PGT-A cycles, but does not universally improve live birth rates compared with standard incubation. A 2025 scoping review of deep learning models found the field expanding rapidly, with most applications still classed as experimental rather than standard of care.
The truth: Embryo grading is structured, skilled judgment. Not luck. But it is not infallible. We already learned that even “lower-graded” embryos can still become a perfectly healthy baby, and a “top-graded” embryo can fail to implant.
If you are interested in how this process works in depth, we cover it lesson by lesson in the Family By Choice IVF course for education of intended parents.
Myth 3: “ICSI is always better than conventional IVF”
ICSI, intracytoplasmic sperm injection, where a single sperm is injected directly into the egg under a microscope, has been one of the most important advances in reproductive medicine. For couples with severe male-factor infertility, it has made fatherhood possible where it would otherwise have been impossible.
It is also one of the most over-prescribed procedures in modern IVF.
A large 2025 multicenter randomized controlled trial (INVICSI) followed 824 women undergoing their first IVF cycle without severe male-factor infertility, randomized to either ICSI or conventional IVF. The cumulative live birth rate was 43.2% in the ICSI group versus 47.3% in the conventional IVF group. ICSI was not superior, and possibly slightly worse!. A critical review estimated that about 33 couples would need to be treated with ICSI unnecessarily to prevent just one case of total fertilization failure, at significantly higher cost and with concerns about offspring safety that are still being studied.
The truth: ICSI is the right choice for severe male-factor infertility and for many cases of donor sperm IVF where sperm quality is limited, but it is not automatically better for everyone. If your clinic recommends ICSI without a clear male-factor reason, it is reasonable and responsible to ask: “Why is ICSI being recommended in my specific case, rather than conventional IVF?”
Myth 4: “PGT-A guarantees a healthy baby”
Preimplantation genetic testing for aneuploidy (PGT-A) screens embryos for chromosomal abnormalities before transfer. It is heavily marketed, often expensive, and one of the most misunderstood add-ons in IVF.
The most authoritative recent statement on PGT-A is the 2024 ASRM Committee Opinion, which states clearly that the value of PGT-A as a routine screening test for all IVF patients has not been demonstrated, and that recent multicenter randomized trials show overall pregnancy outcomes via frozen embryo transfer are similar between PGT-A and conventional IVF for many populations. A landmark 2021 study in the New England Journal of Medicine randomized women aged 20–37 with three or more good-quality blastocysts to either PGT-A or conventional IVF, and found that conventional IVF produced a cumulative live birth rate that was non-inferior to PGT-A.
PGT-A has a real role for specific patients, particularly those of advanced maternal age, with recurrent pregnancy loss, or with known genetic risks. But it also carries a false-positive risk: embryos can be labeled abnormal that, if transferred, might have resulted in a healthy birth, in part because of the embryo’s natural ability to self-correct some early chromosomal abnormalities. And PGT-A does not screen for everything. It does not detect monogenic conditions unless specifically tested for (PGT-M), and it cannot predict miscarriages caused by other factors.
The truth: PGT-A is a tool, not a guarantee. It is a conversation to have with your reproductive endocrinologist based on your specific situation, not a default add-on to accept.
Myth 5: “Frozen embryos are weaker than fresh”
This belief is decades out of date and worth retiring for good.
The freezing technique now used in nearly every modern lab is called vitrification, an ultra-rapid cooling process that prevents the formation of damaging ice crystals by transforming the embryo and its surrounding fluid into a glass-like state. It has transformed embryo cryopreservation.
A WHO-commissioned systematic review and meta-analysis pooled data from seven randomized controlled trials covering 3,615 embryos and found that vitrification produced significantly better survival rates than the older slow-freezing method (RR = 1.59, 95% CI: 1.30–1.93). Modern vitrification routinely achieves post-warming survival rates above 90% for blastocysts.
Beyond survival, frozen embryo transfers (FET) often perform as well as or better than fresh transfers in many clinical scenarios, particularly for patients at risk of ovarian hyperstimulation syndrome, when PGT-A has been performed (since results take time), or when the uterine lining benefits from preparation in a “rested” cycle without active ovarian stimulation.
The truth: A frozen embryo is not a weaker embryo. For a large and growing share of IVF patients today, FET is the preferred option, and the right one.
Myth 6: “Day 5 blastocyst transfer is always better than Day 3”
Most modern clinics prefer Day 5 transfers because blastocyst-stage embryos have already passed important developmental hurdles, and selecting from a smaller pool of survivors generally improves the predictive value of grading.
But “generally” does not mean “always.” For patients with only a few embryos, pushing every cycle to Day 5 can mean ending up with no embryo to transfer at all, when a Day 3 transfer might have given that embryo a better environment (the uterus itself) to continue developing in. Some “slower” embryos that look behind on Day 5 catch up by Day 6 and become perfectly healthy pregnancies.
The truth: The right transfer day depends on your specific cycle, your embryo numbers, and your history. A clinic that follows a rigid one-size-fits-all rule, in either direction, is worth questioning. A flexible, individualized lab strategy is a sign of a thoughtful clinic.
Myth 7: “Transferring more embryos means more chance of success”
This was the standard approach two decades ago, and it produced a generation of IVF twins and triplets, along with the real medical risks that multiple pregnancies carry, for both the person carrying the pregnancy and the babies, including preterm birth, low birth weight, preeclampsia, and higher rates of neonatal intensive care.
Modern practice in most countries is now elective single embryo transfer (eSET) for most patients with good-quality embryos, especially after PGT-A has confirmed a euploid embryo. Vitrification means any additional embryos can be safely frozen for future cycles, so transferring one at a time does not waste them; it spaces out the chance of pregnancy across multiple safe attempts.
The truth: Quality over quantity. One good embryo at a time, with the rest safely stored, is generally safer and just as effective cumulatively.
Myth 8: “All IVF labs are the same”
This is probably the most important myth to dismantle, and the one your clinic is least likely to bring up.
IVF labs vary enormously in air quality, incubator technology, embryologist experience, quality assurance protocols, accreditation status, and outcome rates.
This matters because when you choose a clinic, you are also choosing a laboratory. And the lab may matter more than the doctor’s name on the door.
Questions worth asking before you commit to a clinic:
- Is your laboratory accredited? (CAP, ISO 15189, or your country’s equivalent)
- What is your live birth rate per embryo transfer for patients in my age group?
- What is your blastocyst conversion rate?
- Do you use electronic witnessing (RFID or barcode-based)?
- How do you maintain air quality and incubator backup during power failures?
- How experienced are the embryologists, and how many are on the team?
A clinic that answers these questions openly and confidently is a clinic worth trusting. A clinic that deflects or refuses is telling you something important too.
When in doubt, ask, but ask the right voices
There is a particular kind of exhaustion that comes with IVF. It is not just the injections, the appointments, the hormones, or the cost. It is the cognitive load of trying to make life-changing decisions while drowning in conflicting information: your sister-in-law’s success story, a Facebook group thread from 2018, a Reddit comment from someone who treated fifteen years ago, a TikTok that swears coffee causes implantation failure.
We want to say this gently: not all information is equal, and a great deal of what circulates online is simply out of date.
Vitrification protocols are not what they were in 2010.
PGT-A guidance has shifted significantly in just the last few years.
ICSI recommendations have been refined.
Embryo culture media has improved.
What was true when a forum thread was posted may not be true anymore, and clinging to old information can lead you to refuse something that could genuinely help, or accept something that no longer makes sense for your situation.
The same caution applies in the other direction. Some patients reject genuinely useful technologies, like AI-assisted embryo selection or time-lapse imaging, because the idea of “a computer choosing my embryo” feels cold or frightening.
We understand that instinct.
But AI in the IVF lab does not replace embryologists.
It supports them, the same way ultrasound supports an obstetrician, or an MRI supports a neurologist. Used well, it reduces subjectivity and helps skilled humans make better decisions for you. Caution about new technology is wise. Fear of new technology is not the same thing as caution.
Trust the embryologists who take the time to explain things to you. Trust the doctors who answer your questions honestly, even when the answer is “we don’t know yet.” Trust peer-reviewed research over anecdotes, and recent research over older research. And most of all, trust yourself. You are the person making this decision. You are allowed to ask questions until you understand. You are allowed to seek a second opinion. You are allowed to take your time.
If you want a structured place to start, our guide Preparing for IVF: Questions to Ask Your Fertility Doctor gives you a list of questions worth bringing into your next consultation.
A final word
Going through IVF is hard enough without feeling like the most important part, the laboratory, is a black box. The truth is, it isn’t. The more you understand what really happens between egg retrieval and embryo transfer, the more confidently you can ask questions, weigh options, and make decisions that fit your body, your values, and your budget.
At Family By Choice, we believe informed patients have better experiences, fewer regrets, and stronger partnerships with their care teams. Our IVF & Fertility Journey courses go deeper into every stage of the lab process, with expert-led lessons from embryologists, reproductive endocrinologists, lawyers, and people who have lived this path themselves.
Wherever you are on your road to parenthood, whether you are exploring IVF for the first time, navigating donor conception, building an LGBTQ+ family, or moving toward solo parenthood by choice, you deserve clear answers, not myths. You also deserve a community that meets you with knowledge and warmth at every step.
That is what we are here to offer.
This article is for educational purposes and is not a substitute for personalized medical advice. Always discuss your individual treatment plan with a qualified reproductive endocrinologist.
