You're already tracking temps for menstrual cycles, providing basic pregnancy info. Why not step into post-partum? Right now, my sleep analysis constantly says, "It's going to be ok" or "It looks like something interrupted your sleep" - to which all I can think of sarcastically is, "Well, duh, I just had a baby, and the baby wakes up in the middle of the night a few times to eat... of course my sleep is disturbed. Why not have a new software feature that collects info from the user that they've had the baby and are now in post-partum care for the baby. Offer features for tracking whether each sleep disturbance is due to baby wanting to eat, needed a change, both, etc. Offer metrics on improved sleep from the perspective that baby isn't waking up as often to eat, or time spent awake in the middle of the night to feed baby is shortening (perhaps due to baby eating more efficiently). Provide little articles on tricks of the trade (so to speak) on how to get baby to eat more efficiently, or how parents can prepare bottles or other night-time feeding elements ahead of time to make the night-time feeding more efficient, or tricks to get baby to sleep faster, etc.

Also consider offering features for the user to log weight and track weight loss - or partner with a weight scale manufacturers to integrate their weight reading into the Oura app (and skip the manual weight entry). Provide little articles on quick exercises that can be done in a short bursts of time in between caring for baby which can help with weight loss. You could even create exercise regimens the user can use to try to accomplish some exercise in a day. For example: "Today, go for a 10 minute walk with baby." or "Today, dance with baby after a diaper change. Dance for 3 songs." Or offer a list of suggested exercise / activities that the user can choose from and then mark that it was accomplished (gamify the exercise).