Are you feeling lower back pain on one side? These tight muscles will tilt your uterus; and so your baby starts tilted, and has a more difficult journey through the pelvis. 
Because a newborn’s head is malleable, usually they will make it through the birth canal to be born vaginally.
However, now their head has received uneven compression. The malleable bones have moved around, and are restricted on one side. The restricted bones squeeze cranial nerves needed for breastfeeding. The nerves aren’t damaged, but they don’t work as well. It’s like wearing a jacket that’s too tight, so you don’t have full range of motion for your arms. A restricted cranial nerve can’t fully function.
Plus, those malleable bones need to still be mobile for a baby to feed with ease. The jaw on the compressed side may not be able to open fully.
What do you see in baby?
Your baby’s head may have a flat spot or be tilted. Some people might think that their baby’s mouth is just too small to open fully for breastfeeding. Some babies fall asleep at the breast when it’s just too much work for them to keep up the feed.
What do you feel?
You feel a pinched or biting latch. It hurts to put baby on the breast. You may hurt through the whole feed. Some moms have nipple damage. 
You can get way ahead of these breastfeeding problems by taking care of yourself during your pregnancy. The aches and pains are your body’s call for help. Tend yourself for an easier birth and breastfeeding with myofascial release or Body Ready Method® .