How to do it

Feeling negative

Isn’t it satisfying to feel special. In fact for years I’ve managed to be amazingly smug about something which was a complete accident of birth – having O- blood. Although it’s a relatively rare blood type in the UK, it’s hugely useful as it can be given to anybody who needs a transfusion. Almost certainly worth a second biscuit at the blood donor sessions.

Well, it’s payback time now I’m pregnant. Oh, I still get to be ‘special’ but it’s not working in my favour any more. Being one of the 15% of the population with a rhesus negative blood type (not just O-) means that if my baby has a positive blood group, which is highly likely, they’re at risk if any blood crosses between child and mother, as my body can see the foetus as a foreign body and try to attack it.

Luckily, it’s less of a problem these days than a generation ago, when in worst case scenarios, babies needed complete blood transfusions while still in the womb. All mothers are tested and are booked in for an ‘Anti-D’ injection at 28 weeks and 34 weeks as a matter of course, as well as after birth if the baby does have a positive blood group.

It’s also more of an issue in second (or later) pregnancies as there’s a lower chance of blood crossing until birth. Except, of course, there’s always a possibility of a problem beforehand, however small.

Which is why I was whisked to the Early Pregnancy Unit at Hammersmith Hospital after a scare at 12 weeks, given a string of tests and scans, and an Anti-D injection just in case.

There’s a 72-hour window to have the injection if you think there might be a problem, and it lasts for six weeks, helpfully covering the next trip I had planned. But would I go anywhere where I couldn’t get the injection if I needed it, or couldn’t get back in time? Not any more.