Baby Sleep Regressions: Why Good Sleeper Suddenly Struggles

Has your baby, who used to drift off without much fuss, suddenly started fighting bedtime or waking frequently at night? You might be in the middle of a sleep regression. These phases can feel exhausting, but they’re completely normal—and usually linked to big developmental leaps or growth spurts. Let’s look at what sleep regression is, when it tends to happen, and how to handle it (including when it’s okay to start gentle sleep coaching).

What Is a Sleep Regression?

A sleep regression is a temporary setback in your baby’s sleep pattern. There’s no strict medical definition, but parents typically notice that their baby—who had been sleeping fairly well—suddenly begins waking more often, struggling to nap, or fighting bedtime.

When Do Sleep Regressions Happen?

Sleep regressions often show up around these ages:

4 months
8 months
9 months
10 months
18 months
2 years

Don’t panic—most babies won’t experience every one of these phases.

Signs Your Baby Might Be in a Sleep Regression

A once-good sleeper suddenly refuses naps or wakes often at night.
Your baby is learning new skills like rolling, sitting, crawling, or walking.
Feedings seem more frequent because your baby is hungrier.
Your little one’s age matches one of the common regression windows above.

What Happens During Major Regressions

4-Month Sleep Regression

Around four months, your baby’s sleep cycles mature from newborn patterns to more adult-like stages. More frequent night wakings, short naps, and irritability are all normal signs. This developmental leap can be tiring, but it’s a huge step forward in your baby’s growth.

8-Month Sleep Regression

At eight months, teething often kicks in—and so does curiosity. Your baby might be rolling, sitting, or crawling, and the excitement of new skills can make winding down harder. Add teething discomfort, and you’ve got a perfect storm for restless sleep.

9-Month Sleep Regression

Babies around nine months often learn to pull up or stand—major milestones that fuel both pride and attachment. You may notice stronger separation anxiety or more night wakings. Try daytime games like peek-a-boo to build trust and help your baby feel secure when you’re out of sight. A consistent, soothing bedtime routine also makes a big difference.

10-Month Sleep Regression

By ten months, your baby is exploring nonstop—talking more, climbing, stacking toys—and may resist rest because life is just too interesting! Keep routines steady and calm, and offer plenty of daytime opportunities for practice and play.

18-Month Sleep Regression

At 18 months, toddlers often experience bursts of independence and big emotions. Communication skills are growing fast too, which can make bedtime battles common. Stick with predictable routines and gentle reassurance to help your toddler settle.

2-Year Sleep Regression

Two-year-olds often develop intense independence and stronger separation anxiety. They may resist bedtime, want you to stay close, or test limits (“No pajamas!” “One more story!”). Consistency and calm limits are key here—your child thrives on structure, even when they push against it.

How Long Does a Sleep Regression Last?

The good news: it won’t last forever. Most regressions pass within two to six weeks, with four weeks being typical. Your baby’s sleep should gradually settle as their body and brain adjust to new abilities or routines.

Can You Start Sleep Coaching During a Regression?

During a regression, it’s okay to rely on extra comforting—rocking, cuddling, or car rides—to help everyone get some rest. Focus on keeping bedtime routines gentle and predictable. Once your baby’s fussiness eases and their appetite and naps start normalizing (usually three to four weeks in), you can consider gentle sleep coaching.

If your baby is six months or older, this can be a good time to introduce gradual, responsive sleep strategies. A certified sleep consultant can guide you through personalised, developmentally appropriate methods for teaching self-soothing and healthy sleep habits—without tears or stress.

Final Thoughts

Sleep regressions can feel discouraging, but they’re actually signs of incredible growth—your baby is developing new skills, thinking in new ways, and becoming more independent. These phases are temporary. With consistency, comfort, and connection, your little one will find their rhythm again, and better sleep will follow.

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