Gravidity, Parity, and Duration of Pregnancy
Gravidity: The total number of times a woman has been pregnant, regardless of the outcome.
- Nulligravidity: No history of pregnancy
- Primigravidity: History of one pregnancy
- Multigravidity: History of two or more pregnancies
Parity: The number of pregnancies carried beyond 20 weeks of gestation that result in the birth of an Infant weighing more than 500 grams.
- Nulliparity: No history of a completed pregnancy that reached beyond 20 weeks’ gestation or ended with a birth weight of more than 500 grams.
- Primiparity: History of one completed pregnancy that reached beyond 20 weeks’ gestation or ended with a birth weight of more than 500 grams.
- Multiparity: History of more than one pregnancy that reached beyond 20 weeks’ gestation or ended with a birth weight of more than 500 grams.
Fetal age:
- Gestational Age: Estimated fetal age (in weeks and days) calculated from the first day of the last menstrual period.
- Conceptional Age: The age (in weeks and days) of the fetus calculated from the day of conception (fertilization).
Duration of pregnancy
- Normal duration of pregnancy: 40 weeks (280 days)
- Postterm pregnancy: a pregnancy that extends beyond 42 weeks’ gestation or the estimated date of delivery plus 14 days
- Periviable birth: live birth occurring between 20-25 weeks of pregnancy
- Preterm birth: live birth before the completion of 37 weeks (<370/7) of pregnancy
- Postterm birth: live birth after 42 weeks (>420/7) of pregnancy
Trimesters of pregnancy
- First trimester (weeks 1-13)
- Second trimester (weeks 14-26)
- Third trimester (weeks 27-40)
Clinical Relevance
- Assessment: Use gravidity and parity to assess obstetric history and manage risk factors.
- Monitoring: Track fetal age to determine appropriate timing for prenatal tests and interventions.
- Adjust management plans based on the duration of pregnancy and trimester-specific needs
