To make an informed decision for your situation, we suggest you read this article and the following articles:
*If your babies have any medical conditions—including prematurity—you should seek one-on-one guidance from your child’s pediatrician about developmental readiness for babywearing.
In regard to known safety concerns and assuming the carrier is properly fitted, a child may be safely carried on the back in a TwinGo if he meets all three criteria for development, size and age. Please note that ALL criteria must be met for readiness. Even if your baby meets all three criteria for Back Carry, please wait until you are mentally and physically ready.
Baby must have strong and consistent head/neck control when awake and asleep—This criteria is the most important to avoid positional asphyxiation (suffocation). Head control should not be a new skill but a well-established skill where you (and your pediatrician) are not worried about your child’s ability to lift his own head to maintain an open airway. Your child should be tall enough that his head is positioned outside the carrier at all times and he has the ability to move his head freely to maintain proper breathing.
Baby must be tall enough his head is outside the carrier and his legs must be long enough to comfortably straddle the panel with knees extending over the edge of the carrier—This criteria is important to make sure the child can be held snuggly in an upright, centered position, which will aid in keeping the child’s head outside the carrier at all times (i.e. the carrier should be fitted in such a way he should not be able to slump or lean enough to position his head under the shoulder strap or inside the carrier). TwinGo’s panel and shoulder straps can be adjusted to snuggly fit an average-size full-term 4-month old baby on an adult as small as 5 feet. If your child has head control and is older than 4 months but is slumping or leaning in the carrier, it is likely due to improper use or improper positioning. If your child's head is not outside the carrier, either your child is not tall enough or you are wearing the carrier incorrectly.
Baby must be 4+ months corrected age in good health— US Consumer Product Safety Commission mandates inward-facing front carry position in ANY style baby carrier or sling for babies 0-4 months. TwinGo LLC is adding the “corrected” criteria to account for possible premature births and encourages families to wait for their child to be in good health. If your baby is 4 months but does not meet the other criteria or has any medical concerns, he is NOT ready for back carry.
*The baby's head should be positioned outside the carrier at all times and airway unobstructed. We recommend that you position the carrier high enough on your waist that you can see your child in your peripheral vision. Please refer to this article for positioning tips: Tandem Babywearing: Proper Positioning for Babies in the TwinGo