If you want your babies to sleep through the night don't let them sleep more then 2.5 to 3 hours during the day keep them active . Make a nightly routine. Put them to bad at the same time every night. Feed them an extra oz or two of formula before bed. Maybe give them a little gripe water too for tummy discomfort and hiccup issues. My baby slept 12hrs the first night I did all of this! And she has every since