OB Datum: Pregnancy Dating

EDD, IVF & Gestational Age

Free · In‑App Purchases · Designed for iPad. Not verified for macOS.

Free LMP, conception and known-EDD dating. Lifetime Pro adds known GA, IVF, reconciliation, Health import and unlimited anonymous cases. Calculate and compare pregnancy dates with a clear explanation of every result. OB Datum is a clinician-first pregnancy-dating workspace for iPhone and iPad. It performs deterministic calendar arithmetic and shows the source, formula, equivalent dates, and calculation-engine version for review. CALCULATE FROM • First day of the last menstrual period, with optional regular-cycle adjustment • Documented conception or ovulation date • An established estimated due date Lifetime Pro adds calculations from gestational age documented on a known date and from an IVF embryo-transfer date and embryo age. LIFETIME PRO One purchase—with no subscription or advertising—unlocks known-GA and IVF/ART dating, read-only Health import, full dating reconciliation, unlimited anonymous saved cases, formatted sharing, Calendar export, and custom timeline milestones. In Reconcile, keep an established EDD locked while comparing the dates implied by LMP, ultrasound gestational age, and IVF/ART. OB Datum reports signed calendar-day differences and never changes or averages dates automatically. Guideline-based redating thresholds remain unavailable until the app's versioned clinical profile completes independent review. EXPLORE THE TIMELINE Calculate gestational age on a selected date, find the date corresponding to a gestational age, review descriptive milestones, and explore an interactive pregnancy wheel with accessible day and exact-date controls. PRIVATE BY DESIGN • No advertising or tracking • No patient names, record numbers, contact details, or notes • Anonymous saved calculations stay protected on your device • Optional Pro read-only import of the latest menstrual-cycle start from Health • Pro Calendar export includes only the EDD and no patient identifiers • The widget opens OB Datum without displaying pregnancy or case data OB Datum also provides a privacy-safe due-date action for Shortcuts, shareable calculation summaries, dark mode, Dynamic Type, VoiceOver support, and Reduce Motion support. OB Datum supports date arithmetic and clinical review. It does not diagnose, prescribe, select a delivery date, or replace professional judgment. Independently verify every input, result, and source before clinical use.

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The developer, VLR Software, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

  • Data Not Collected

    The developer does not collect any data from this app.

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    Accessibility

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    Information

    Seller
    • VLR Software LLC
    Size
    • 9 MB
    Category
    • Medical
    Compatibility
    Requires iOS 26.0 or later.
    • iPhone
      Requires iOS 26.0 or later.
    • iPad
      Requires iPadOS 26.0 or later.
    • Mac
      Requires macOS 26.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 26.0 or later.
    Languages
    • English and Spanish
    Age Rating
    16+
    In-App Purchases
    Yes
    Copyright
    • © 2026 VLR Software LLC
  • Developer Website
  • Privacy Policy

    • Supports

    • Family Sharing

      Some in-app purchases and subscriptions may be shareable with your family group when Family Sharing is enabled. Learn More

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