Interactive data explorer

PICSI and HABSelect: why it matters more the older you are

Move through the ages and watch how PICSI shifts live-birth and miscarriage odds, drawn from the HABSelect trial.

Better IVF, interactive evidence

PICSI and HABSelect: why it matters more the older you are

PICSI adds one step to IVF. Before the egg is injected, sperm are given a natural grip test, and only the ones that pass are used. Two studies matter here: the original 2019 HABSelect trial of 2,752 couples, and a 2022 mechanistic reanalysis that broke the same data down by age. We are going to start with the punchline, the age finding from the 2022 reanalysis, and then work backwards to show how the 2019 trial revealed it. Each chart is labelled with which study it comes from.

Standard ICSI PICSI (hyaluronic acid selected)

The punchline

The older you are, the bigger PICSI's edge

2022 mechanistic reanalysis

When the trial data was re-modelled by age in 2022, PICSI's advantage over standard ICSI grew steadily with age. Move the slider. (Illustrative of the modelled crossover, not raw per year trial rates.)

Her age 43

PICSI live-birth chance vs standard ICSI at this age

relative difference (not just percentage points)

How they realised it

Work backwards: the odd thing in the 2019 trial

2019 HABSelect trial

This age finding did not come from nowhere. The original 2019 trial found something strange: PICSI did not change how many women got pregnant, yet significantly fewer miscarried. On embryos that were never chromosome-tested, fewer losses with the same pregnancy rate points to better embryo quality, and embryo quality is exactly what declines with age. That clue is what prompted the 2022 age reanalysis above.

First, the clue. Of every 100 women in the trial, this many miscarried:

Standard ICSI

7.0% miscarried (96 of 1,371)

PICSI

4.3% miscarried (60 of 1,381)

That is about 39% fewer miscarriages (odds ratio 0.61, p = 0.003), real and statistically significant.

Now the full trial scoreboard. Tap each outcome:

The technique

How PICSI works, in three steps

Illustration of the PICSI technique in three stages

1. Offer

Sperm are placed in a dish with dots of hyaluronic acid, the same substance found around the egg.

2. Select

Sperm with lower DNA damage bind and hold on. The embryologist picks up one of those bound sperm.

3. Inject

That selected sperm is injected into the egg. Everything else about IVF stays the same.

From the trial's own author

What Prof Kirkman-Brown argues

Prof. Jackson Kirkman-Brown MBE PhD
Professor of Reproductive Biology, University of Birmingham; Science Lead, Birmingham Women's Fertility Centre; co-author of HABSelect. Profile

"The miscarriages are a reason not to do conventional ICSI anymore in certain groups of people. I'd argue the females that are over 35, the best thing now means that we could do PICSI."Prof. Jackson Kirkman-Brown, CooperSurgical webinar

"Wherever you can pick a sperm by PICSI, you should be doing PICSI. The data says choose that one, don't leave it to random chance."Prof. Jackson Kirkman-Brown