Gestational Age Calculator
Calculate current gestational age from last menstrual period
About Gestational Age
What is Gestational Age?
Gestational age is the age of a pregnancy calculated from the first day of the last menstrual period (LMP). It's used universally in obstetrics to track pregnancy progress and development.
Why Start from LMP?
While conception typically occurs about 2 weeks after LMP, LMP is used as the reference point because it's a known date, whereas conception date is often uncertain.
Pregnancy Milestones
- Viability: 24 weeks (earliest survival possible)
- Late preterm: 34-36 weeks
- Early term: 37-38 weeks
- Full term: 39-40 weeks
- Late term: 41 weeks
- Post-term: 42+ weeks
Clinical Applications
- Scheduling prenatal tests and ultrasounds
- Assessing fetal development
- Determining timing of delivery
- Managing preterm labor risk
References
- ACOG Committee Opinion No. 700: Methods for estimating the due date. Obstet Gynecol. 2017;129(5):e150-e154.
- WHO recommendations on antenatal care for a positive pregnancy experience. World Health Organization. 2016.
- Spong CY. Defining "term" pregnancy. JAMA. 2013;309(23):2445-2446.
Medical Disclaimer:
This calculator provides an estimate based on LMP. Ultrasound dating is more accurate and should be used by your healthcare provider for clinical decisions.
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