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HSE Due Date Formula:
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The HSE (Health Service Executive) Pregnancy Due Date Calculator estimates the expected delivery date based on the last menstrual period using the standard Naegele's rule. This method is widely used in clinical practice throughout Ireland.
The calculator uses the standard obstetric formula:
Where:
Explanation: This calculation assumes a regular 28-day menstrual cycle and ovulation occurring on day 14. The due date represents 40 weeks gestation from the first day of the last menstrual period.
Details: Accurate due date estimation is crucial for proper prenatal care, monitoring fetal development, scheduling important tests, and determining when induction of labor might be necessary.
Tips: Enter the first day of your last menstrual period in the date field. Ensure the date is accurate for the most reliable due date estimation.
Q1: How accurate is this due date calculation?
A: This method provides a reliable estimate, but only about 5% of babies are born on their exact due date. Most births occur within two weeks before or after the estimated date.
Q2: What if my menstrual cycle is longer or shorter than 28 days?
A: For women with regular cycles that are not 28 days, the due date may need adjustment. Consult your healthcare provider for a more personalized calculation.
Q3: When should I confirm my due date with ultrasound?
A: An early pregnancy ultrasound (usually between 8-14 weeks) can provide the most accurate due date estimation and is recommended to confirm dates.
Q4: What is considered full term pregnancy?
A: A pregnancy is considered full term between 37 weeks and 41 weeks + 6 days. Babies born during this period have the best health outcomes.
Q5: When should I contact my healthcare provider?
A: Contact your GP or maternity hospital as soon as you suspect you're pregnant to begin proper prenatal care and confirm your due date.