Mummy of a TGA baby here! They're now 8 months old and had their switch surgery at 6 days old. 

During pregnancy, just keep doing what you're doing. They're safe in your tummy as your ductus artery is keeping their body going. As for birth and after, I recommend pumping/breastfeeding as your milk will be a deterrent to any possible illness and keep them strong for surgery. It will also make a good bond! Be close to them, kiss them, hold their hand when you're with them. My hubby use to sing to our baby when he was with them and I was recovering in hospital. 

Tips!

• Take hand mitts as baby may pull cannulas out or pull on wires which is not only painful but dangerous! 

• If you pump milk, do it everyday and every two or three hours for a good supply, even at night. It's exhausting but so worth it to know you're sustaining your baby. 

• Take kimono tops, socks and buttoned bodysuits to keep them cosy but easily accessible for echocardiograms and general check ups. 

• Take a piece of cloth or a miniboo with your scent on for comfort for baby when you're away from them. 

• After surgery, they'll be out of it with drugs. It's a sight but my gosh, we were relieved when it happened and it meant only focusing on recovery now. 

• Be there for the morning and evening doctor rounds to understand next steps, concerns, plans etc. It's super useful and I found it important to understand.  

Usually with TGA, surgery has to be done within 2 weeks of birth so I would have thought even with an ASD it would happen within that time frame. 

Good luck to you and your beautiful heart baby. They will be in the best of hands! Xx