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There are two types of car seats you'll have a choice between, an infant seat & a convertible car seat...
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An infant seat is portable, a convertible is not. Meaning that if your baby falls asleep in the car (which he/she will, guaranteed) you can just lift out the infant seat (the seat has a base which remains attached to your seat) & keep them asleep. (fingers crossed) With a convertible car seat you have no choice but to take the baby out of the seat or sit in a parking lot twiddling your thumbs waiting for them to wake up.
The other big bonus of a portable seat is you'll have somewhere to put the baby when you arrive at your destination. Set the infant seat in your shopping cart or keep them in it at a restaurant. In fact many restaurants have infant seat holders called "slings" that you can set the infant seat right into. (much safer than the old upside down highchair trick). Until your baby is old enough to sit in a high chair (around 6-8 months) you'll be stuck holding them or bringing the stroller unless you have an infant seat.
My other reason for endorsing an infant seat is that although newborns can technically ride in a convertible car seat I think they're far too slumpy for it.
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So with that said the choice is yours (obviously).
If you're really tight on money then you might want to only spend the cash once & get a convertible seat. If you can afford to start off with an infant seat & switch to a convertible later than that's the route I'd definitely recommend.
As for brands, I'll give you my two cents on what I've purchased for my girls & then hope you experienced moms will comment with what has/hasn't worked for you with your car seats!
My first car seat was a Chicco Keyfit 30 Infant Car Seat
When it came time for a convertible seat we once again did our homework on all the different brands as well as checking out the displays in person at my local baby store & finally chose the Britax Boulevard 70 Convertible Car Seat
. I love this seat. It's very easy to install, has great padding, super soft fabric & wonderful safety features like side-impact head padding which many other seats haven't yet included. We've done a lot of car seat shopping in this house & I must say I'm a Britax girl through & through. If we ever have another baby (I can sense my husband's nervous twitch from me just typing that) I would probably buy the Britax Chaperone Infant Carrier
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