Assisted hatching during IVF – the risks

11 Sep Assisted hatching during IVF – the risks

Assisted hatching may help certain patients during IVF. But, like any invasive procedure, there are risks involved. Here’s the lowdown on assisted hatching and what fertility patients really need to know.

Assisted hatching is quite new. The first study was published in 1990. Like so many IVF add-ons, there are no large-scale, randomized trials conclusively saying it works. Don’t be put off by that: new medical techniques can be good medical techniques. It’s just that more ‘big’ data would be nice.

So what exactly is assisted hatching? Well, research suggests that IVF embryos with a thinner or softer shell, or zona pellucida, may implant better. With assisted hatching, the embryologist makes a small puncture in the zona pellucida a day or two before embryo transfer. It’s only done on the best embryos. Laser technology is often used, but an acidic solution or a micro-needle is still common. Helping the blastocyst to hatch out of its shell is thought to aid implantation, since the ‘naked’ cells of the embryo are introduced to the uterus quicker.

But assisted hatching may not benefit all IVF patients. For some, the embryos are best left alone. Research suggests assisted hatching is most suited to IVF patients in their late thirties or older, with low AMH levels, poor embryo quality or with a history of IVF failure. Doing assisted hatching on the embryos of a 25-year-old is probably a waste of time.

Some key research on assisted hatching was done in 2014. It was a systematic review of past studies, including a big Cochrane study, done by the American Society of Reproductive Medicine. It highlights the possible benefits of assisted hatching to poor-prognosis IVF patients, who seem to have slightly higher clinical pregnancy rates after the procedure. However, live birth rates linked to assisted hatching were harder to quantify. So the study doesn’t, in the end, recommend routine assisted hatching to low-prognosis patients. Or indeed to any IVF patients. It stressed the need for more live-birth data. Disappointed? So were we.

It’s all about the risk-reward ratio. Assisted hatching can sometimes damage the embryo or its internal blastomeres, leading to poor IVF outcomes. So, to an extent, it comes down to embryologist skill and the technique used. A number of studies have found that assisted hatching can increase the chance of a twin pregnancy, which carries a higher risk to mother and babies. And patients having assisted hatching are often treated with low-dose steroids and antibiotics. These can have side effects.

Our verdict on assisted hatching? There’s no concrete evidence it works and no concrete evidence it doesn’t. So assisted hatching joins other fertility ‘extras’ like Prednisone and intralipid infusions. There they sit, in a kind of fertility no-man’s land, patiently waiting for research to prove them right. But, for many patients – and clinics too – the mere possibility that assisted hatching may benefit patients is enough to keep it on the price list.

IVF is new. Limited research doesn’t mean something can’t work. Or eventually be proved to work: see embryo glue. Until we see more pro-AH studies, we call upon clinics to offer assisted hatching for free. It seems only fair than an (as yet) unproven, albeit fascinating technique should come with an affordable price tag.