One Timeline from Planning to Age Three: What Actually Carries Over | Linea

The short answer

You do not need a new app when the baby is born, and yet most families install one anyway. Stage apps are built around a stage, and every stage has an end date.

Linea is built around the seam instead: planning, pregnancy, birth, postpartum recovery and early childhood on one continuous timeline through age three. Concretely, that means the bottom navigation never moves, your stage is computed from your dates rather than stored and left to go stale, and the quick-log grid changes what it offers the day the baby arrives. Parent and baby stay two subjects side by side.

It is worth saying just as plainly what continuity does not promise. It does not merge your recovery into your baby's story, and it does not guess which country's medical schedule you follow.

Why nobody wants to re-onboard at 3am

The query behind this page is usually practical: how many apps am I going to use between a positive test and a third birthday?

For most families the answer is three or four, and the handoffs are where the data dies. The bump photos sit in one app, the newborn's first-week notes in the next, and the vaccine schedule in a third — often in the local language, with dates re-keyed by hand. Each transition costs a full re-entry.

Birth is the expensive one. Every other stage change happens when you have a spare evening. Birth happens when you are not re-entering data at all, you are holding a baby and the app you installed eight months ago has just become the wrong app. There is a second, quieter cost: most stage apps treat the record as the product and the stage as a label. The moment the stage ends, the record stops being something anyone looks at. A timeline spanning three years has to stay worth scrolling at year two, or it becomes a place you visit only to file something you will never find again.

What actually crosses the seam at birth

Two mechanisms do the work, and they are different in kind.

The spine is fixed. Linea's bottom bar is five tabs — Today, Plan, Log, Learn, Me — that stay in the same positions from preconception through toddlerhood. What changes is the content inside a tab. You do not re-learn the app at 3am; you open the tab you already know and find different things in it.

The stage is derived, never stored. Your stage is computed from a last-period date or a due date, an outcome — ongoing, live birth, or loss — and, once it exists, a birth date. The app never stores "you are in your second trimester" as a fact that can drift. That distinction is the whole difference between a timeline that is continuous and one that merely contains dates.

The arithmetic is worth stating, because it decides what Linea can and cannot tell you:

• Gestational week comes from the last menstrual period, or is back-calculated as 280 days before your due date, and is clamped to the 0–42 range. A wrong date produces a clamp, not a nonsense week.
• Days until your due date are counted in calendar days and clamp to zero once you are past it, so the progress bar and the countdown can never disagree with each other.
• After birth the stage keys off the baby's age in days: under 42 days is postpartum, 42 days to a year is infant, past a year is toddler. The fourth-trimester boundary is six weeks, and it moves on its own, on a Tuesday, with nothing for you to do.
• 37 weeks is term, held as one constant that answers two different questions — when birth counts as preterm, and when contractions stop being a warning sign.

The six weeks where a single timeline usually breaks

The postpartum period is where the record's subject changes, and it is where most apps quietly break. During pregnancy the logs are about your body. After birth they are about a different person.

Linea derives that switch from the same stage value, so the quick-log grid follows your birth date rather than a settings toggle:

• Preconception offers weight and water.
• The three trimesters and labour add fetal movement and contractions — four one-tap cells.
• Postpartum, infant and toddler offer feeds, sleep, nappies and pumping.
• On the loss path the grid is empty. Not blank by bug. Empty on purpose.

Numeric entry is subtler and easier to get wrong. Weight, blood pressure and blood sugar are only offered as separate rows in stages where they carry clinical meaning, and a value that is already a one-tap cell is not repeated as a row. In pregnancy, weight is a tap and blood pressure and blood sugar get their own rows. Postpartum, all three get rows. Preconception and toddlerhood get none at all.

Two subjects, not one stream, is what makes those six weeks usable. Your recovery and the baby's care are followed together and kept separately visible. That is the correct call: the day you need your own postpartum check-up is a day the baby's chart has nothing to say to you.

The three things one timeline deliberately does not merge

The two subjects stay separate. Postpartum recovery and baby care run side by side rather than combined. Merged, your chart would disappear into the baby's.

Labour is not derivable. Everything else about your stage can be computed from dates, but "in labour" cannot — it is a transient state no date implies. It is marked explicitly instead. So Linea will not tell you that you are in labour because your due date passed.

Regional schedules differ, and it knows it. The same week of pregnancy means something different in different places. The content library carries parallel schedules rather than one universal list: separate Chinese-mainland and US entries for the preconception check, the visit rhythm, the anatomy scan, GBS screening, the newborn's first weeks and infant vaccines — 33 English explainers in all, drawn from the national health authorities and from CDC, ACOG, AAP and WHO. That is why there is no single "your week 24" answer sitting inside it. The content carries its own disclaimer that it is not medical advice, and that medical items and vaccine schedules need checking against the current official version.

Symptom warnings are a fourth thing worth naming, because they are the clearest case of a limit stated rather than guessed. Reduced fetal movement, leaking fluid, vision changes, breathlessness, one-sided leg pain and foul-smelling lochia count as reasons to seek care at any severity. Bleeding, a fever of 38°C or above, and an inflamed wound count from moderate upward. A severe headache, vomiting past eight hours, facial or hand swelling, sharp abdominal pain, sudden dizziness and severe low mood count at severe. Nausea, fatigue and back pain never count. The interesting case is contractions: a warning sign before 37 weeks, unremarkable after it — and if the gestational week is unknown, treated as a warning sign anyway. It would rather prompt an unnecessary call than miss a preterm one.

What Linea does differently

Linea is an iOS 17+ app that treats the birth transition as an architectural problem rather than a feature:

• One continuous timeline across preconception, the three trimesters, birth, the fourth trimester, infancy and toddlerhood — plus a grief path for loss, which is a stage with an empty log grid and a memorial date rather than baby-oriented tracking.
• Parent and baby together. Postpartum recovery and baby care followed in one place, each record carrying a subject so both stay visible.
• On-device first. Private records stay on the device as the default, the product is explicitly not designed around selling or sharing family data, and the only photo permission it declares is for the photos you choose to add to a bump diary and a first-year album. The limits of that promise — single-device, no server-side recovery — are covered honestly on the privacy page.
• Stage-aware tasks, logs, reminders and safety guidance for both parent and baby, covered separately in what the reminders actually track.

Where Linea actually is today

The deciding fact, stated first because it changes the decision: Linea is in development and is not on the App Store. There is no App Store id for it. It is configured to build to TestFlight automatically on a weekly cadence, but submission for review is deliberately left as a manual step rather than automated — a human decides when it goes.

If you need something installable today, that is the answer. If you are evaluating this class of app on design, the thing worth taking from it is narrower and more useful than any feature list: ask what does the app compute rather than store? The question separates a timeline that is genuinely continuous from one that merely spans the calendar.