Transcript for Royal Baby: Kate Middleton in Labor at Hospital
But love what I'm Dan Cutler and New York where this ABC news digital special report a very special Monday that duchess of Cambridge in labor. Cage with secretly admitted to Saint Mary's hospital in London early this morning with Prince William by her side. Arriving by car with -- police escort. BC's nick Sheppard joins us now from a very excited London with the latest on the royal -- watched neck I know for weeks now we haven't waiting. For this moment. Then there's nothing like that music that you that you launch right at the top of the broadcasters to really get me excited in that. Royal baby mood and is a very excited city we have been waited for weeks and right now we're still waiting there's hundreds of reporters outside Saint Mary's hospital where Kate is inside in labor there's hundreds and perhaps thousands of people now at Buckingham Palace waiting for the official announcement that will be taken by police a single piece of paper by police from the hospital. To the palace so the city. Anxiously awaits -- this next royal baby will be third in line to the -- -- the interesting thing is obviously we have been keeping an -- in the hospital for days now for weeks and -- -- -- -- they almost. Slipped in undetected. Slipped in through the side door literally at about 6 AM or so two cars we believe one Range -- and one security. Vehicle took Kate and William into the side entrance only about two or 300 feet. But crucially around the corner. From where the latter city is where the series of latter's and -- -- -- set up 24 hours today to watch the front tensions today went to the side entrance right after 6 AM they made sure -- -- was comfortable the doctor soccer and then the palace emailed announcement. About an hour and hour and a half later saying up. Ha ha fooled you guys she's in the hospital and guess what nobody actually got a picture or video of her entering the hospital I have a sense that we're gonna have a few more those aha moments in the next couple of hours or days however long it may possibly take because. You know is we've been talking so much. Tons -- obviously change is since the last heir to the throne has been born obviously digital media. A lot of social networking has evolved and taken place -- Bankrate over the time so the announcement itself. We'll certainly have a lot of theatrics a lot of new developments that never happened before. And to walk me through a little bit about him -- we will find out when that baby is born. So it's okay William -- really consider the House of Windsor is most modern couple and they use FaceBook they use Twitter the palaces used social media to get out the message but giggling we're very clear that they wanted to have a nod to the historical precedence. Of this moment and so they're going back to a tradition that was started about 3132 years ago when William the father. Was born what will happen is that Kate will give birth. And at some point. One of her or his Williams press secretaries will walk out of the hospital with a piece of paper they'll be on Buckingham Palace letter head. And on that piece of paper will be the doctors' signatures on they'll say yes we were there when Kate gave birth at this time. That piece of paper will be put into a waiting car and be given a police escort. Back to Buckingham Palace to that point the gates open. The paper goes in -- -- palace they take out an easel that hasn't been taken out since William for 31 years they take out that -- bring into the four -- Buckingham Palace and put the piece of paper route and back. Is the official announcement for the royal baby and that announcement will probably have to wait. Probably not a name but it will say something. The first indication we got of williams' personality. -- was on that paper it said. He was a baby who cried -- Maybe something like that we'll be described for this new baby and that's -- the world will now that we have royal air. It is fascinating to find out those first couple -- and comments that the -- -- will make obviously when the announcement is made. I read it Queen Elizabeth had said when Prince William was born that she was happy that in fact. He did not inherit his father's years. A little bit of personality. Coming from Buckingham Palace. The royal family. And it's interesting that yes in fact that that -- was not named a week after what we're going to be focusing so intently on those gates of the palace doors to -- -- exactly the sex. The weight. And the time of the birth. And also you're looking at here -- the pictures. This is when Prince William was born and -- in the late Princess Diana and Prince Charles came out. Proudly showing off their new bundle of joy and that -- that was a historic moment because until that point. A photographer used to be brought into Buckingham Palace to capture those initial moments. That was historic for a few reasons one that everybody before William was born in Buckingham Palace and so for the first time you had an heir to the throne born. In the hospital for the first time also you had the father by the mother's bedside and think about that. When William was Gortari when Charles was -- his father Philip without playing polo car head -- Charlotte love that salary by Diana's side. And William now is sitting by Kate's side they will come out together at some point we don't know how long labor will take nor do we know how long they'll wait before they come out but they'll come out and it is a change -- not gonna come out to 45 or six cameras and the British media being very respectful they're coming out. To a hundred cameras. And countries -- reporters from all over the world and speaking -- some Japanese reporters some from Northern Europe some Australian reporters I mean everyone is -- -- in this baby and will be a huge amount of scrutiny on not only the baby but also K. And Kate will become kind of the world's most but most watch mother. Rather than the world's most watched expectant mother and -- I want you to -- This -- moment because I wanna go over to journalist and author mark Ellwood who is a royal expert and mark I want to ask you about this. This fact the matter is there is a lot of protocol and there's a lot of pomp and history that goes into the announcement of an heir to the throne as it doesn't happen very often. Will the middle tense Kate's family well let me notify the same time that we no -- the queen. That's a very good question I think -- how to put -- I think William and Kate all very Morton moment Ecstasy. I'm very sure that -- -- so close to remodel will find a way to -- hmmm I suspect obvious cellphones and under the beds and she'll be calling come on the protocol dictates that the queen will be told us of course. But I'm sure we'll find a way that Cowell will be. Right now. Interest is an interesting image I don't know how to scan of the -- -- cell -- under the bed but if they can get into the hospital without too many people capturing pictures. I suppose anything is possible. Talked a little bit about the significance of this child's birth because as we've been talking about the fact that. This child boy or girl will be the next heir to the throne. We just is kind of short -- when you think about it this person who's about to -- In the future will be a global. Icon this baby is guaranteed to be a global icon and there are very very few babies stillborn. With that kind of future guaranteed what really interest me is how they changed the lol this whole war of succession where for a long long long long time it didn't matter if you have seven -- -- and one song he would LeapFrog the line and become -- If women -- cover a little girl will she get left out that way no they've changed the -- -- it guarantees that this baby for the first time ever saw. Will be the -- of UK I get quite but it by the -- thinking about it. Play this is certainly historical and certainly it shows. You know the queen has certainly gotten a lot of credit for advancing with the times and and changing and -- you know as you and -- discussed before. There is a lot of tradition and -- very deeply in the royal family but at the same time -- the queen has said that this -- -- very passionate about. About making changes to that because she herself obviously it was an unlikely heir to the -- she didn't come didn't become heir apparent -- -- She was 1213 years old when her uncle had abdicated. I mean I think so many people have seen the King's Speech where you watched not only -- -- they get frost unexpectedly to be the moment. But this this little girl who was really a Porsche well behaved nicely go she was a staff who knew if maybe they might need her as an emergency queen. And all of a sudden she got this incredible weight force upon which are personally I think she's done a brilliant job handling. This child will be -- up from day one -- and that he or she will be. The -- of the United Kingdom and the commonwealth -- there -- sixteen other countries of which they have this this person will have technical dominion now. Pressure know that right here. Mandela I want to go back to you for a moment -- in in London -- the scene outside of Buckingham Palace I imagine crowds are gathering. Yeah we got hundreds of people right is the announcement. Came out publicly around 8 AM or so a few hours later it's now about 2 PM or so. Here and there's now thousands of people we saw some bands outside practicing saying there's a lot of expectation. A lot of anticipation. And -- as you guys were -- I think a lot of that is British I mean we've heard lots of interest -- -- today about how they'll be three million bottles of champagne purchase in this country alone so we'll get a pretty happy. Country tonight or tomorrow night -- -- -- this baby but a lot of those people outside Buckingham Palace or tourists there's a huge amount of interest. Whether American -- -- European power from all over the world. In this baby and that announcement that will come whenever it comes in that traditional form of that letter posted -- the palace -- Student -- -- -- we know -- sure to keep your I've posted on those gates as is the rest of the world and mark -- we know that you're gonna be hanging with us today. Throughout the next couple of hours maybe the next couple of days who knows of course. It will be when the baby is good and ready as they say an -- looking at the outside of Saint Mary's hospital inside the duchess of Cambridge. Kate is in labor as she was admitted early this morning almost. In total secrecy being admitted to the hospital and now the world waits for the next heir to the British the room. We have a complete report on abcnews.com. And of course as developments occur. We'll have -- right here for now I'm -- -- in New York. With this ABC news digital special reports.
This transcript has been automatically generated and may not be 100% accurate.