Gestation Calculator NZ

NZ Gestation Formula:

\[ Gestation\ (weeks) = \left\lfloor \frac{Current\ Date - LMP}{7} \right\rfloor \]

NZ Gestation (weeks):

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1. What is NZ Gestation Calculation?

The NZ Gestation calculation determines the number of completed weeks of pregnancy based on the last menstrual period (LMP) and current date. This is the standard method used in New Zealand healthcare for estimating gestational age.

2. How Does the Calculator Work?

The calculator uses the NZ gestation formula:

\[ Gestation\ (weeks) = \left\lfloor \frac{Current\ Date - LMP}{7} \right\rfloor \]

Where:

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

Explanation: The calculation counts the number of full weeks between LMP and current date, providing the completed weeks of gestation.

3. Importance of Gestation Calculation

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

4. Using the Calculator

Tips: Enter the first day of your last menstrual period and the current date (or any date you want to calculate gestation for). The calculator will determine the number of completed weeks of pregnancy.

5. Frequently Asked Questions (FAQ)

Q1: Why use LMP instead of conception date?
A: LMP is used because it's typically more reliably known than conception date and is the standard method in obstetric practice worldwide.

Q2: How accurate is this calculation?
A: This method provides a good estimate, but ultrasound dating in early pregnancy (especially first trimester) is more accurate for determining gestational age.

Q3: What if I have irregular periods?
A: If cycles are irregular, LMP dating may be less accurate. An early pregnancy ultrasound is recommended for more precise dating.

Q4: Does this work for IVF pregnancies?
A: For IVF pregnancies, gestational age is calculated from embryo transfer date plus 14 days (or egg retrieval date plus 14 days).

Q5: What is the normal gestation period?
A: Full-term pregnancy is 37-42 weeks. Delivery before 37 weeks is considered preterm, while delivery after 42 weeks is post-term.