Gravidity and Parity: Definitions and Recording Systems
A woman's gravidity refers to the total number of pregnancies, while her parity refers to the number of deliveries of fetuses with a gestational age of at least 20 weeks. Different recording systems exist, such as GPA (gravida-para-abortions) or TPAL (term births, premature births, abortions, living births).
Core Definitions
To understand clinical obstetric history, the following definitions are essential:
- Gravidity: the number of time a woman has been pregnant.
- Parity: the number of times that she has given birth to a fetus with a gestational age of 20 weeks or more.
- Abortion: the total number of induced abortion or miscarriage or ectopic pregnancy before 20 weeks.
Classification Terminology
In medical practice, specific terms are used to categorize a woman based on her history:
Gravidity Categories
- Nulligravida: a woman who has never been pregnant.
- Primigravida: a woman who is pregnant or has been pregnant for one time.
- Multigravida or secundogravida: a woman who has been pregnant more than one time.
Parity Categories
- Nulliparous: a woman who has not given birth previously.
- Primiparous: a woman who must have to given birth once.
- Multiparous (multip): a woman who has given birth more than 1 times, or a women who produce more than one within a birth.
Standardized Recording Systems
Medical professionals use shorthand notations to record obstetric history efficiently. The GPA system stands for Gravida/Para/Abortus, which corresponds to Gravidity/Parity/Abortion. In this system, it is important to note that a multiple birth should be interpreted as a single parous event.
The TPAL system provides more detail by using the following components: T for term births, P for premature births, A for abortions, and L for living births. When combined with gravidity, this is known as the GTPAL notation (Gravidity+TPAL).
Clinical Examples
For example, a woman with two miscarriages, two live births, and currently pregnant would have a gravidity of 5 and a parity of 2 under GPA notation. Consider a woman who used to miscarriage once, and now has a 2 y/o daughter and a 3 y/o son; if she is now pregnant again, her GPA number would reflect these four events.
In another scenario, a woman who has given birth at term once and has had one miscarriage at 12 weeks would have her GTPAL number calculated based on those specific outcomes. Furthermore, if a woman is pregnant with twins and gave birth to the first fetus on 26 week and the other on 37 week, the parity recording rules must be strictly applied.