1. What is Expected Date Pregnancy Calculator?

The Expected Date Pregnancy Calculator estimates the due date of pregnancy based on the last menstrual period (LMP). It uses the standard calculation of LMP plus 280 days (40 weeks) to determine the expected delivery date.

2. How Does the Calculator Work?

The calculator uses the standard pregnancy dating formula:

Where:

• \( LMP \) — Last Menstrual Period (date)
• \( 280\ days \) — Standard pregnancy duration (40 weeks)

Explanation: This calculation is based on Naegele's rule, which assumes a 28-day menstrual cycle and ovulation occurring on day 14.

3. Importance of Expected Date Calculation

Details: Accurate expected date calculation is crucial for monitoring fetal development, scheduling prenatal care, planning for delivery, and identifying potential pregnancy complications.

4. Using the Calculator

Tips: Enter the first day of your last menstrual period in the date field. The calculator will automatically compute the expected delivery date by adding 280 days (40 weeks).

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: This calculation provides an estimate. Only about 5% of women deliver exactly on their due date, with most delivering within 2 weeks before or after.

Q2: What if my menstrual cycle is longer or shorter than 28 days?
A: For cycles longer than 28 days, add the extra days to the due date. For shorter cycles, subtract the difference. Your healthcare provider can make this adjustment.

Q3: Can ultrasound change the expected date?
A: Yes, early pregnancy ultrasound (first trimester) is the most accurate method for dating pregnancy and may adjust the expected date.

Q4: Why 280 days instead of 9 months?
A: Pregnancy is calculated as 40 weeks from LMP, which equals 280 days. This accounts for the fact that conception typically occurs about 2 weeks after LMP.

Q5: What is gestational age vs fetal age?
A: Gestational age is calculated from LMP (40 weeks), while fetal age (conceptual age) is about 2 weeks less (38 weeks).