Your Sleep Trained Baby Won't Sleep Again. Now What?
You moved. Or she got sick. Or both, somehow, in the same two-week stretch. And now the baby who was sleeping six-hour stretches is waking at 11pm, 2am, 4am, 5am, making sounds you have to respond to because you cannot tell anymore what is real distress and what is habit. You know she can sleep. She was doing it. That part makes it worse.
This is one of the more disorienting things that happens around six months, and it happens to a lot of people who did everything right.
Why it falls apart after illness or disruption
When a baby is sick, you do what you have to do. You go in faster. You nurse or rock or hold because a sick baby needs comfort, and because you are also not a monster. The NHS notes that babies' sleep patterns are naturally variable and respond to disruption, illness, and environmental change. That is not a failure of sleep training. It is just how babies work.
The problem is that three or four nights of nursing to sleep or rocking to sleep is enough to rebuild an association. The baby learned to fall asleep one way. Then she learned another way. Now she prefers the second way, in the same way you prefer a warm shower to a cold one even if the cold one would be fine.
A move adds a layer. A new room smells different, sounds different, has different light. The AAP's sleep guidance points to consistent environment and consistent routine as anchors for infant sleep. When both shift at once, the anchor drags.
Wait it out, or retrain
This is the actual question, and the honest answer is: it depends on how long it has been.
If you are in the first week after illness resolved or the move settled, give it a few more days. Some babies reset on their own once the disruption passes. Keep the bedtime routine identical. Keep wake windows where they were. Put her down awake if you can. Watch what happens.
If it has been two weeks or more and things are not trending better, you are probably not waiting it out. You are just surviving a new normal that is worse than where you started. At that point, you are looking at retraining, not failure.
The good news: it usually goes faster the second time. She already knows how to do this. You are not teaching a new skill. You are reestablishing a preference.
What to actually do
Go back to whatever method you used originally. If you used cry-it-out at four months, use it again. If you used a slower fading approach, use that. The consistency is the thing. Switching methods mid-process is the most common reason people spend six weeks on something that should take four days.
Keep one night feed if she still takes one meaningfully - a baby draining a full feed at 2am is probably hungry. A baby nursing for four minutes and falling back asleep on the breast is using you as a pacifier. Those are different situations.
If you are tracking wake windows (TandemBaby, or a notebook, or a voice memo to yourself), look at the actual pattern across the last few days before you change anything. Sometimes what looks like a sleep problem is an overtired problem, and you are putting her down at the wrong time.
Fix the environment first if the move is recent. Blackout curtains, white noise, the same sleep sack she had before. Make the new room feel like the old room as much as possible.
One thing to hold onto
She was sleeping well once. That happened. It was real. The fact that disruption broke it does not mean it cannot be reestablished - it means she responded normally to abnormal circumstances. Most parents who retrain after illness or a move are back to baseline within a week.
You did not lose everything. You just have a few bad nights ahead of you. You have had bad nights before.
Sources
- NHS — Helping Your Baby to Sleep — Notes that baby sleep patterns vary and respond to illness and environmental change.
- AAP Baby Sleep Hub — AAP guidance on infant sleep including night waking, routine, and what to expect across the first year.