I agree with Jean that there are two real issues in positioning:
postural support and depth of latch.  The way the mom aligns and
supports the baby's body is vital to the baby's ability to use his jaw
and tongue well.  Occupational and physical therapists know that
proximal stability promotes distal function.  This means that if you
support the structure closer to the center of the body than the one that
is being used, it improves the precision and ease of motion. For optimal
tongue and jaw motions, babies need slight hip flexion, trunk alignment,
shoulders brought forward a bit (bringing the baby's lower arms across
his chest will do this)and neck aligned with the rest of the body and
supported.  The head should also be aligned with the neck (rotation
wise) but can be extended to improve depth of latch.  The mom should
hold the baby against her body, not drop the child on a pillow and hold
his head or neck.  Newborn infants get all their stability from the
support their environment gives.  While some moms need to have their
baby lay on a pillow (twins, a mom without arm function) and some babies
cannot tolerate being held close (tactile defensive, some cases of
autism) babies have better jaw and tongue function when supported this way.
The second stability issue is the depth of latch.  The tongue and breast
need to fill the infant mouth for tongue stability.  If the latch is
shallow, the tongue will lose it's stable base of support and the baby
will need to use some compensation to get milk, usually by increasing
jaw compression.  The tongue also needs to be where the milk is - the
tongue peristaltically elevates to press milk along the breast from
areola to nipple, then the back of the tongue depresses to create
negative pressure to pull it into the mouth.  Woolridge has wonderful
pics of this.  THe idea behind an asymetric latch is to increase the
bolus size by allowing more of the tongue to contact the breast.  It
also places the nipple out of harms way, and prevents most babies from
needing to use sucking compensations, improving moms comfort.

Certainly moms and babies can manage to breastfeed without being
textbook perfect, but using good alignment and support and  a deep latch
improve comfort and effectiveness of breastfeeding even for moms and
infants who seems to be doing well. For moms and infants with any kind
of challenge, they are essential.  Just my humble, research based opinion!
--
Catherine Watson Genna, IBCLC  New York City  mailto:[log in to unmask]

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