IVF add-ons: what the evidence says

What add-ons are

An add-on is an optional extra test, procedure or medicine offered alongside standard IVF. Clinics may suggest them with the aim of improving the chance of a pregnancy, especially after a cycle that did not work. If several transfers have not worked, our guide to recurrent implantation failure explains what doctors usually check.

Add-ons usually cost extra. When you have been through a lot, it is natural to want to try everything. But "more" is not always better, and some add-ons carry their own risks.

What expert bodies say

Two respected organisations have looked closely at add-ons:

• The HFEA (the UK's fertility regulator) rates common add-ons using a colour-coded system. The rating summarises whether good-quality studies show that an add-on increases the chance of having a baby, and whether there are safety concerns. Most add-ons it has reviewed are not rated as clearly effective.
• ESHRE (the European Society of Human Reproduction and Embryology) published good practice recommendations in 2023. It found that most add-ons lack enough evidence to recommend them for routine use.

These reviews do not mean every add-on is harmful or useless for everyone. They mean that, for most people, the benefit has not been shown.

Why does this matter? An add-on can seem to "work" simply because a pregnancy happened in the same cycle. Only careful studies that compare people who had the add-on with people who did not can show whether it made a real difference. Many add-ons became popular before those studies were done.

Common examples

The list below is not complete, and evidence changes over time. For each, the evidence of benefit for most people having IVF is limited or lacking.

Add-on	What it involves
Endometrial scratching	Lightly disturbing the lining of the uterus in the cycle before treatment
Embryo glue	A culture medium containing a substance called hyaluronan, used during transfer
Time-lapse imaging	Taking frequent pictures of embryos as they grow, to help choose which to transfer
PGT-A	Testing a few cells from an embryo for the number of chromosomes
Endometrial receptivity testing (ERA)	A biopsy of the lining to try to time transfer
Immune treatments	Medicines aimed at the immune system, such as steroids or infusions

Some of these, such as time-lapse incubators, may be part of how a laboratory normally works, and that is different from being sold as a paid extra. Immune treatments in particular can have side effects, so ask about safety as well as benefit.

Caution. Under India's PCPNDT Act, choosing or revealing the sex of an embryo or foetus is illegal. Embryo testing (PGT) must never be used for sex selection, and no registered clinic should offer it.

Questions to ask about any add-on

• What is this add-on meant to do, and for whom?
• What does the evidence show about the chance of having a baby, not just a pregnancy test?
• How does the HFEA or ESHRE view it?
• What are the risks or side effects?
• What will it cost, and is that cost included in the quote?
• Would you recommend it to everyone, or is there a specific reason for me?
• What happens if I say no?

Our appointment questions tool can help you put a list together.

Good to know. Choosing not to have an add-on is a reasonable decision. Standard IVF with good laboratory practice is what most of the evidence supports.

Signs to slow down

Be cautious if an add-on is presented as a must, if you feel rushed to decide, if the explanation is vague, or if someone links it to a promise of success. A clinic that welcomes your questions is a good sign. You can also check a clinic's registration with our ART registry check.

When to see a doctor

If you have been offered an add-on and are unsure, ask your treating doctor for the reasons in writing, or seek a second opinion before you agree. You can talk through your treatment plan in an online consultation. If you are having treatment and develop severe pain, heavy bleeding, breathlessness or fainting, call 112 or go to the nearest hospital.