The Guide
Common but Controversial
These are the add-ons — tests and treatments — that come up again and again in IVF, where some doctors swear by them and others call them useless. This page is not a list of scams to avoid. Most of these have genuine reasoning behind them, and I used several of them myself. The problem is that the evidence is unsettled, the cost is often high, and clinics don't always tell you how disputed they are. The goal here is simple: know the debate before you spend the money, so you can ask your doctor the right questions and make an informed choice.
ERA — Endometrial Receptivity Analysis
The timing test. The most studied — and most doubted — of the receptivity add-ons.
The ERA analyzes gene activity in your uterine lining to estimate your personal "window of implantation," then adjusts your transfer timing in a future cycle if you're labeled non-receptive. The concept makes biological sense. The evidence for whether it actually helps is a different story.
A 2026 systematic review and meta-analysis (Glujovsky et al.) combined 44 studies. When the strongest studies — the randomized controlled trials — were pooled, ERA-guided transfer showed no improvement over standard timing: live birth rates were 52.9% with the ERA versus 53.7% with standard timing, with no difference in clinical pregnancy or miscarriage rates. The one hint of benefit appeared only in weaker, non-randomized studies, and only for recurrent implantation failure patients transferring untested embryos — a benefit that vanished when those patients transferred PGT-tested euploid embryos. A 2022 randomized trial and a 2023 reanalysis pointed the same way, with the reanalysis arguing the test may not accurately identify the window of implantation at all.
My experience: my ERA came back receptive at 125 hours of progesterone. My transfers were timed to that result. They still failed. Knowing what I know now, I question whether the number the test gave me was ever right for me — and no one measured my actual progesterone levels alongside it, so I was optimizing timing while flying blind on the level. If a clinic recommends the ERA, ask specifically what the current evidence supports for your situation, and insist your progesterone levels be measured, not just your timing managed.
Other Common but Controversial Add-Ons
Each of these comes up constantly. Here's the debate on each, and where to read more.