1. What Is Pregnancy Due Date Calculation?

The pregnancy due date calculation estimates the expected delivery date based on the first day of the last menstrual period (LMP). This method, known as Naegele's Rule, adds 280 days (40 weeks) to the LMP date to determine the estimated due date (EDD).

2. How Does The Calculator Work?

The calculator uses the standard pregnancy due date formula:

Where:

• \( EDD \) — Estimated Due Date
• \( LMP \) — Last Menstrual Period (first day)
• \( 280 \text{ days} \) — Standard pregnancy duration (40 weeks)

Explanation: This calculation assumes a regular 28-day menstrual cycle and ovulation occurring on day 14. The 280 days represent 40 weeks of gestation from the LMP.

3. Importance Of Due Date Estimation

Details: Accurate due date estimation is crucial for monitoring fetal development, scheduling prenatal care, preparing for delivery, and identifying potential pregnancy complications. It helps healthcare providers track appropriate fetal growth and development milestones.

4. Using The Calculator

Tips: Enter the first day of your last menstrual period in the date field. Ensure the date is accurate for the most precise due date calculation. The calculator will also show your current pregnancy progress in weeks and days.

5. Frequently Asked Questions (FAQ)

Q1: How Accurate Is The LMP Method?
A: The LMP method is accurate for women with regular 28-day cycles. Only about 5% of women deliver on their exact due date, with most delivering within two weeks before or after.

Q2: What If My Cycle Is Not 28 Days?
A: For irregular cycles, the due date may need adjustment. Ultrasound dating in the first trimester is more accurate for women with irregular menstrual cycles.

Q3: When Should I Confirm With Ultrasound?
A: An ultrasound between 8-12 weeks gestation provides the most accurate due date estimation and should be used to confirm or adjust the LMP-based due date.

Q4: What Is The Range Of Normal Delivery?
A: A normal pregnancy can last from 37 to 42 weeks. Delivery before 37 weeks is considered preterm, while delivery after 42 weeks is post-term.

Q5: Can The Due Date Change?
A: Yes, healthcare providers may adjust the due date based on ultrasound measurements, especially if there's a significant difference from the LMP calculation.