1. What is NSW Health Gestation Calculator?

The NSW Health Gestation Calculator estimates pregnancy duration in weeks based on the Last Menstrual Period (LMP) and current date. It follows the standard NSW Health protocol for calculating gestational age.

2. How Does the Calculator Work?

The calculator uses the NSW Health gestation formula:

Where:

• \( Current Date \) — Today's date or specified date
• \( LMP \) — First day of last menstrual period
• \( \lfloor \rfloor \) — Floor function (rounds down to nearest integer)

Explanation: The calculation determines the number of complete weeks between the LMP and current date, providing the gestational age in weeks.

3. Importance of Gestation Calculation

Details: Accurate gestation calculation is essential for prenatal care, fetal development monitoring, determining due dates, and scheduling important prenatal tests and screenings.

4. Using the Calculator

Tips: Enter the current date (defaults to today) and the first day of your last menstrual period. Ensure dates are entered in the correct format (YYYY-MM-DD).

5. Frequently Asked Questions (FAQ)

Q1: Why use the floor function in gestation calculation?
A: The floor function ensures we count only complete weeks of gestation, which is the standard practice in obstetric care.

Q2: How accurate is LMP-based gestation calculation?
A: LMP-based calculation is generally accurate for women with regular menstrual cycles. Ultrasound dating may be more precise for women with irregular cycles.

Q3: What if I don't know my exact LMP?
A: If LMP is uncertain, an early pregnancy ultrasound provides the most accurate gestational age assessment.

Q4: Does this calculator account for leap years?
A: Yes, the date calculation automatically accounts for leap years and varying month lengths.

Q5: What is considered full-term gestation?
A: Full-term pregnancy is typically 37-42 weeks. Gestation beyond 42 weeks is considered post-term.