"Is it normal that she hasn't rolled over yet?" "Should he be more interested in food by now?" "Is it true that four-month-olds are supposed to..."
Every child develops at their own pace. But a little guidance about what's typical for a given age never hurts. Babysential's timeline gives you a week-by-week overview tailored to your baby — or your fetus if you're pregnant.
Two Timelines in One
The timeline covers two phases of life:
Pregnant? From week 1 to 40, you get weekly updates on fetal development. How big is it this week? Which organs are developing now? What's happening in your body?
Baby born? The timeline follows your baby's development month by month through the first year of life. Motor development, language, social skills, and what you can do to support their growth.
How to Use the Timeline
Step 1: Enter Your Date
For pregnant users: enter your due date. The timeline automatically calculates which week you're in. For parents with a newborn: enter the birth date. The timeline shows what's relevant right now.
Go to the timeline and enter your date. You can use the tool without logging in, but with an account your settings are saved.
Step 2: Read This Week's Update
Each week (during pregnancy) or month (after birth) has its own page with:
- Development — what's happening with your fetus or baby right now
- Your body — symptoms and changes you may experience
- Tips — concrete things you can do this week
- Milestones — what many children master at this stage
Step 3: Explore Milestones
Under milestones you can mark developmental achievements your baby has reached. First smile, first time she grabs a toy, first word. This is both useful documentation and a lovely way to celebrate progress.
Step 4: Browse Forward and Back
Curious about what's coming? Browse forward in the timeline to see what next week or month brings. Or browse back to read about developmental stages you may have missed.
Use the timeline as a conversation starter with your partner. "Look what the baby is learning this month!" It makes it easier to understand your baby's behavior and needs together.
What's in Each Pregnancy Week?
For pregnant users, the timeline is organized by gestational week. Each week contains:
Weeks 1–12 (first trimester): Organ development, the heartbeat begins, embryo to fetus. Tips on nausea, fatigue, and the first ultrasound.
Weeks 13–27 (second trimester): Your baby grows rapidly and you feel the first kicks. Tips on exercise, nutrition, and preparations.
Weeks 28–40 (third trimester): Your baby gains weight, lungs mature, the head engages. Tips on birth preparation, packing the hospital bag, and signs of impending labor.
Go directly to pregnancy weeks to read about your specific week.
The development descriptions in the timeline are based on medical literature and current clinical guidelines. Remember that every pregnancy is unique — deviations from "the norm" are most often completely normal.
What's There After Birth?
After birth, the timeline focuses on five areas of development:
- Motor development — head control, grasping, rolling, sitting, crawling, walking
- Language and communication — cooing, babbling, first words, two-word sentences
- Social development — smiling, laughing, separation anxiety, playing with others
- Cognitive development — object permanence, problem-solving, imitation
- Sleep and feeding — changes in sleep needs and eating patterns
Read more about development in our guide to baby development month by month.
When Should You Pay Attention?
All children develop at different paces. The fact that the baby next door crawled at 7 months doesn't mean your baby is behind at 9 months.
But sometimes it makes sense to speak with your pediatrician:
- Your baby has lost skills they previously mastered
- A very large difference between right and left side
- No eye contact after 3 months
- No response to sounds
The timeline gives you reference points — not diagnoses. Use it as a tool for understanding, not for worry.
Frequently Asked Questions
How accurate are the development descriptions?
The timeline describes what is typical for a given age, based on documented clinical evidence. But the range of normal is wide. A baby who crawls at 6 months is just as normal as one who crawls at 10 months.
Can both parents use the timeline?
Yes. If you share a baby profile, both parents see the same timeline and milestones. Practical for keeping each other updated.
Does the timeline update automatically?
Yes. Based on the due date or birth date, the timeline always shows the correct week or month. You don't need to do anything — just open it.
Combine with Other Tools
The timeline is most valuable when used together with the rest of Babysential:
- Milestones — mark and celebrate developmental achievements
- Journal — note observations and memorable moments
- Memory book — collect photos and memories chronologically
- Sleep tracker — see how sleep changes with development
Ready to follow the journey? Open the timeline now and see what's happening this very week.