POSTED ABOVE TOO SOON
Our son was born with undiagnosed TGA, which was detected when he was a day old, so our experience will be a little different from yours. But he had a catheter procedure immediately he arrived at the regional specialist centre - as your baby has been diagnosed antenatally, they should be there either at birth or very soon after. This procedure was to increase the mixing of red (oxygen rich) and blue (oxygen poor) blood across his heart, and involved passing a small balloon through the wall between two chambers of his heart (in his case he had a small hole in the heart (and Atrial Septal Defect), which was actually a good thing). He was stabilised for a couple of days on the Pediatric Intensive Care Unit before moving to the regualr ward, where the focus was on getting his to gain as much weight as possible ahead of surgery. He was also on a drug called Prostin E1, which prevents a connecting vessel called the ductus arteriosus from closing; this connects the pulmonary artery and aorta, and normally closes in the few days after birth. During the time on thw ward, their oxygen saturation levels, heart rate and blood pressure will be closely monitored; they will also be tested for infection markers as surgery approaches. You will get used to machines alarming; we were told not to worry unless the staff were worrying, which is sound advice and we soon got used to what was normal.
As you prepare for surgery you will have a difficult chat with the surgeon, where all the risks are made clear to you. Remember that these include those that are incredibly rare; in some ways it is easier to know that there is really no choice but to have the operation. Our son then had his corrective surgery at eight days old. It is an incredibly difficult day; leaving them in theatre, waiting for a call, and then going to see the surgeon afterwards are all pretty unpleasant. You'll be advised to do something while they are in surgery; it will be 6+ hours, and could be much longer. We went out for lunch, and had people with us all day.
We spent a few more days on PICU before going back to the ward. Be ready for ups and downs, and try to look at the overall progress, not focussing on any small blips. Your baby may come back from theatre with their chest open; this is so pressure is releved and also allows easier access if the surgeons need to do any follow-up. It's very starnge, though also fascinating, to see. We finally went home at 20 days old; though some go home sooner, some stay longer.
We've had follow-up appointments since then, to check growth, take the usual measurements and to have echos, to provide a detailed image of the heart and surrounding structures. Our first was a few days after going home and the intervals have gradually lengthened and our latest appointent is 18 months after the last. Our son has some leaks around a couple of valves but so far, no other issues.
The biggest positive I can pass on is that today, people who meet him for the first time have no idea about his condition. He is to all intents and purposes a normal four year old; he goes to nursery, rides his bike, goes to the adventure playground, plays tennis just like his heart-healthy friends. His scar is not obvious and to us is totally normal; in fact, when his little brother was born, we noticed the absence of a surgery scar on him more! The experience will never leave you, and there is always the possibility of follow-up intervention or surgery in future, but almost all TGA babies go on to live healthy and normal lives.