There are three essential aspects of positioning in a baby carrier.
Baby's legs should always be in a frog position, bottom down knees up, straddling you, with legs up at a 90° angle to the spine. (except for in cradle carries) This is the best, most correct and most desirable position for baby.
Baby should be high and snug in any carrier.
A good baby carrier will mimic the way you hold baby naturally in your arms.
Some other important general points:
Baby should be close to you, not hanging away from you. This keeps your centre of gravity balanced and prevents strain on your back.
Young babies' developing spines should always be supported by the carrier in some way- by having the fabric snug, or Mei-tai strap tied at their back, or carrier straps tightened properly to bring the baby in close. Avoid carriers that cannot do this.
Baby's breathing should never be affected by a carrier. If her chin is touching her chest it will adversely affect her airways and this can be fatal for young and prem babies. Also beware of stale air pockets, baby's face should never be covered by fabric. In a cradle carry babies should be lying facing upwards, not towards you.
Avoid unintentional twists of the carrier fabric, this will create pressure points on you or baby.
Before they are approx 11-12 weeks old, babies' legs are better to be tucked inside the carrier, up underneath them as they would be when you hold them in-arms. The fabric of the carrier will ideally support them enough that their feet are fine and won't get squished. Once you notice they are long and mature enough, you may encourage baby's legs up and straddling your tummy- knees up bottom down, in the frog position mentioned above.
Positioning in a Pouch:
Baby's spine should always be level with the curved seam, and their bottom on the seam. Baby & carrier should be high and snug - only handbags are supposed to swing off you! Baby should NEVER be in the sling lengthwise- it will literally fold her in half and cut off her airways. Instead, she can be in either the nursing cradle -spine in line with seam, head away from capped shoulder- or diagonal cradle carry -bottom on seam and in closer towards you, head at capped shoulder and touching outside edge. For cradle carries it is often practical to pre-fold their legs in the hand you are resting baby on as you put them in the sling. This means they are already comfy and no toes get squashed once they're in. (see pouch instructions)
Positioning in an Open-Tailed Ring Sling:
Generally the same as in a pouch- without the guidance of a curved seam. Baby should have frog legs, be worn snug and high, be supported by the fabric at their back. The sling fabric should also be pulled well up underneath them from knee to knee, to stop them slipping out the bottom. The fabric should always be straight and as spread as possible around baby and you. The rails may be individually tightened to support baby in upright/reclined positions.
Positioning in a Closed Tail, Padded Rail Ring Sling:
This is a little more tricky. The padded rails are difficult to pull through the rings, limiting the variety of carries. With a young baby it is recommended you use a diagonal cradle carry. Make sure baby's head is touching the padded rail, and their bottom is more in towards you- diagonal in the sling. If they are lengthways (as is tempting and commonly done) then they get folded in half. With a hip carry bring as much of the sling fabric up to baby's armpits as possible. The underneath rail should be well tucked in up to their knees to create a pouch for baby. It is extremely important that you wear this type of sling very snug and high. Tighten it as much as you can and get it as high as you can- it should be at your belly button at the least.
Positioning in an Asian-style carrier:
Again, baby needs to have his legs tucked in underneath until around 11-12 weeks. When this young, it is also crucial to tie the straps off at baby's back, not under their bottom as for older children. They need their spines supported so the weight of the baby doesn't compact their lower vertebrae. When baby is older you may tie under the bottom, and this will help support the weight of the baby to stop them sagging down. As above, when their legs are big enough they can go into the frog position in the carrier. Asian style carriers are best worn high and snug. Always start with your carrier tied on apron-style, so as you pull up the panel it creates a 'pocket' for baby.
Positioning in a Soft-Structured carrier:
Although they profess to suit from newborn to preschooler age, SSC's are not *really* suitable for newborns. Unless you wrap baby in a blanket or special insert, and put them in diagonally, it is impossible to get a snug enough fit to support a newborn's body. However, they are ideal for older babies and children, as the width of the panel base encourages an excellent seated position. SSC's differ from other Asian Style carriers, in that you do not put them on 'apron style', instead you wear the waist belt as normal, with the panel facing up. They are also comfortable when worn down low on the hips of short people. With a SSC the wearer's hips take 95% of the child's weight, which is beneficial and makes it easy to wear heavier children for longer.
Positioning in Wraps:
As above, baby's legs should be in a frog position. Baby should be high and snug, well supported by the fabric, and have her face uncovered. If using a stretchy wrap, you may need to re-adjust it a few times to take as much slack out as possible, so baby is snugly held. Be aware that once baby passes around 10kg, a stretchy wrap may not hold their weight up as well, and need re-adjusting more often. As wrapping often involves up to 3 layers of cloth, you will need to keep an eye on baby's temperature- they will probably need one less layer of clothing. Spread each layer of fabric out as much as you can if intended for that 'carry', especially under baby's bottom from knee to knee. This is doubly important if you choose to face baby out- spread their legs as much as possible, knees up. (See below for the issues about facing outwards)
.....So what about Frontpacks?
Let me start by saying that I would much rather see a baby worn in a frontpack, than in a pram/exersaucer/etc. But there is more to frontpacks than meets the eye.............
As stated above, a 'good' baby carrier mimics the way you would naturally hold your baby- either cradled in your arms, straddling you on your hip, or piggy backed.
Frontpacks can do none of this. Although they are loosely based on Asian Style carriers, frontpacks encourage bad positioning for your baby. Frontpacks are difficult to get snug enough to properly support baby's spine, meaning a lot of their weight bears down on an immature spine which can't cope with it. This is exacerbated by the legs dangling down, instead of being in the desirable 'frog' position. Baby ends up dangling from the wearer by their crotch, which is very unnatural and extremely uncomfortable for them. (How many parents do you see grab their baby by the crotch and go for a walk?) Plus, their dangling legs encourage the ball of their femur out of the hip socket with every stride you take. Not good!
Frontpacks hold baby in a position that means their weight pulls down and away from you. This throws off your centre of balance and means you subconsciously compensate by leaning back a little. The straps are often thin, digging into the wearer's shoulders and back. Very few brands use a waist belt, which would take some of the weight from the shoulders.
For all these combined reasons, frontpacks often get uncomfortable after around 4 months old. For the amount of money you pay for a frontpack compared to one of the carriers above, you would be better advised to invest in a decent baby carrier you will get years of use from and will be comfortable for you AND baby.
.....What about facing outwards then?
This is a problematic question. While some babies decide they like to see more at around 3-4 months, please consider these points before turning them forward facing in your carrier, and especially a frontpack.
Overstimulation- baby is forced to look at everything in front of them. They can't get away, can't retreat when the sensory overload gets too much for them to cope with.
Crotch-dangle- is made even worse by facing baby outwards. A lot of weight is resting on baby's crotch/genitals, which is unhealthy especially for baby boys!
Gravity pull- suspending baby from your front means their weight is pulling down and out on you, making your body compensate. This is not desirable at all, and can make you quite sore.
Exposed- baby is more vulnerable to objects, people, and weather conditions when facing out.
Remember, baby is more comfortable, and better positioned, when facing you in a carrier. There is plenty to see if they turn their head. You could try a hip carry if they are old enough, or a back carry if they really want to see.
If you do decide to face baby out, watch them carefully for signs of overstimulation. Turn them back towards you when you notice this happening. Dress baby appropriately. Be aware of who is 'getting in baby's face' and try to protect them.
If you decide to face outwards in a Mei-tai or SSC, remember to tilt their hips like Kelley at Kozy Carriers does, so their legs are angling UP, and they are sitting instead of dangling. If in a wrap, spread the fabric as much as you can between the legs so they are seated. Cloth nappies often provide a nice bit of crotch bulk to spread the weight.
In most good carriers you can face baby forward but with their legs folded up in front of them, called a Kangaroo or Buddha carry. This is more desirable than leaving the legs to dangle, and is perfectly comfortable for your baby. (They've folded them up for over 9 months already!)
Source : http://www.slingbabies.co.nz/Site/Positioning_2.ashx
