Registering baby as US Citizen

I am a USC with ILR and my husband is a UKC. Our first child is due in December. Do we have to register the birth with the US embassy, apply for passport, etc? I'm thinking that as long as baby is registered here and we get it a UK passport, do we need a second one? We will be travelling to the States to visit family, no doubt. But I'm also thinking waaay far ahead about FATCA and FBAR and don't want my child to be liable for reporting, especially if he/she never lives in the US. Any advice welcome.

Your child will be an automatic US citizen at birth and it is illegal for a US citizen to enter the US on a foreign passport, so you must get both a US passport (to enter and leave the US) and a UK passport (to enter and leave the UK) for the baby.

From the US Embassy FAQ (https://uk.usembassy.gov/u-s-citizen-services/u-s-passports/u-s-passport-faqs/u-s-citizenship/):

I am a U.S. citizen, but also have a foreign passport. Can I travel to the United States on the foreign passport?

No. U.S. citizens must enter and leave the United States on valid U.S. passports, even if they hold a passport from another country. If your U.S. passport has been lost or stolen, or if it has expired, you must apply to replace it before traveling to the United States.

Once the baby is born, you will need to make an appointment at the US Embassy to register the birth and apply for a US passport for them.

See here for how to do this: https://uk.usembassy.gov/u-s-citizen-services/birth/

But I'm also thinking waaay far ahead about FATCA and FBAR and don't want my child to be liable for reporting, especially if he/she never lives in the US. Any advice welcome.

As the child will be a USC they will be liable where applicable for tax returns and reporting requirements whether or not they have a US passport. As ksand24 mentioned though, if you wish your child to visit the USA, they must have one.

As the child will be a USC they will be liable where applicable for tax returns and reporting requirements whether or not they have a US passport.

Yes, I was going to mention this too.

They are a US citizen, whether they have a passport or not, and therefore have automatic tax obligations to the US, regardless.

There are some people around the world who don't even know they are US citizens ('accidental Americans') and have never lived or worked in the US, but find out later in life that they should have been filing US tax returns for years!

Thank you all for the replies, even if they were as I feared. Fingers crossed, the FATCA/FBAR/income tax reporting rubbish gets modified before this baby is old enough to get a paper route!