Denise,
Sometimes when a baby has a poor suck, the syringe at breast needs to be
maintained for a few weeks.  This mom's hx of low third trimester weight gain
may have affected baby's neuro development.  Have you tried having mom give
baby a lot of support during nursings (a football hold with baby's tummy
cuddled against mom's hip with her elbow, the rest of the arm supporting
baby's back and mom's hand holding baby's head or neck is my favorite for
weak/unsustained suckling).  This allows baby to use her energy on sucking
rather than holding up her body.  Another little trick that helps unsustained
suckling is GENTLE sublingual pressure- mom GENTLY strokes or presses the
underside of the chin to stimulate the tongue muscles there whenever baby
stalls.  Another thing that might be helpful is to have mom nurse more
frequently, pump after every other nursing, and use that milk to complement
the next feeding.  So she alternately pumps and complements with the syringe
at the breast.  This way the pump picks up what baby did not....and mom feeds
more frequently, hopefully increasing fat content of the milk.  Only doing one
technological thing at each nursing (pump or complement) may help the mom's
psyche.
        Diet is very poorly related to fat content (percentage) of the milk,
volume is the first thing to fall off, and the mom needs to be very
malnourished before that occurs.  Frequent nursing and increasing the degree
of milk removal are far more important in increasing calorie/lipid content of
human milk.  (Diet does affect the proportion of saturated/unsaturated fatty
acids in the milk.)
        Encourage mom to do only what she can, "all or none" thinking can
cause a mother to give up.  See if you can lighten the load on her, perhaps by
seeing if she can nurse in bed at night without complements....
        Good luck, this sounds like a challenging case.
Catherine Watson Genna, IBCLC   NYC  [log in to unmask]