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The Wheel SP

iPhone / iPad
  • Utilities
  • Health & Fitness
  • Medical
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The Wheel SP is the most powerful and easiest-to-use gestational age and estimated fetal weight calculator in the App Store!

The Wheel SP (for 'SPinner') is a gestational age calculator (also known as a pregnancy wheel) that is used every day by doctors, obstetricians, midwives, nurses, and pregnant women. The Wheel SP is a professional tool that replaces and enhances the functionality of those worn-out cardboard wheels without compromise.

The Wheel SP accurately determines the estimated delivery date (EDD), or due date, of a pregnancy based on the first day of a woman's last menstrual period (LMP), or from the date of conception, or from a known gestational age (GA) on a known date, e.g. from an ultrasound measurement, or from fetal biometry like Crown-Rump Length (CRL), Femur Length (FL), and Biparietal Diameter (BPD). Additionally, for appropriate gestational ages, The Wheel SP estimates fetal weight and display the number of days completed and remaining.

The Wheel SP, besides calculating GA from ultrasound biometrics, now enables clinicians to calculate Estimated Fetal Weight (EFW) from FL, BPD, Head Circumference (HC), Abdominal Circumference (AC) using the most appropriate formula using the maximum and most appropriate parameters.

However, in its primary day-to-day role for healthcare providers, when the EDD is already known, The Wheel SP enables the precise calculation of the gestational age of a fetus at anytime during pregnancy in LARGE, easy-to-read characters.

To enter Gestational Age, CRL, FL, or BPD for a specific date, tap "Today", enter the desired date, then tap on the button displaying the gestational age to change that button to display options for entering GA, CRL, FL, BPD, and access to the EFW calculator.

To see information about the current gestational age (e.g. crude fetal weight from GA, days completed/remaining) tap the gestational age button whenever "Today" is not selected.

When using the EFW calculator, the parameter used in the calculation is noted with an asterisk.

When using the GA calculator, double-tapping on a value changes the value to the current date. When using the EFW calculator, double-tapping clears the value of the selected parameter.