Gestation

The period of embryonic and fetal development from conception to birth

Definition

Gestation is the period during which an embryo and fetus develop inside the uterus, from conception to birth. In humans, it is approximately 40 weeks (280 days) from the last menstrual period (LMP), or 38 weeks from conception.

Nägele's Rule

Calculates estimated due date: LMP + 7 days - 3 months + 1 year. Example: LMP March 10, 2025 → EDD December 17, 2025.

GTPAL

  • G (Gravida): Total pregnancies including current.
  • T (Term): Deliveries ≥ 37 weeks.
  • P (Preterm): Deliveries 20 to 36 6/7 weeks.
  • A (Abortions): Losses before 20 weeks.
  • L (Living children).

Trimesters

  • 1st: 1 to 12 weeks
  • 2nd: 13 to 27 weeks
  • 3rd: 28 to 40 weeks

NCLEX Relevance

GTPAL calculations are high-yield. Know trimester milestones and prenatal care schedule.