Understanding Gravidity and Parity, the “G’s & Ps”
Welcome to episode number three, which is part of my introduction to the very basic elements of obstetrics and gynecology.
Before we jump in, I want to remind you that I have multiple free downloadable resources available on my website at drkcmiller.com/free-downloads. One of my most popular resources is a PDF guide containing the top 15 questions to ask during your OB/GYN residency interviews. If you're currently doing electives and sub-internships, this guide is packed with key questions to help you gather the most important information about residency programs. If you’d like to download it, just click the link in the episode show notes!
Understanding Gravidity and Parity
In the last episode, we reviewed how the maternity unit works. Today, we’re diving into gravidity and parity—also known as the G’s and P’s.
Gravidity refers to the number of times a patient has been pregnant, including the current pregnancy.
Parity refers to the number of pregnancies that have reached 20 weeks 0 days or beyond, regardless of whether they resulted in a live birth or stillbirth.
However, the definition of parity can be a bit confusing because, when we write out the G’s and P’s, parity also includes ectopic pregnancies and spontaneous abortions (pregnancy loss occurring before 20 weeks gestational age).
How to Document G’s and P’s
When documenting a patient's pregnancy history:
G (Gravida) is followed by a single number representing the total number of pregnancies.
P (Parity) is followed by four numbers, categorized using the TPAL system:
T (Term): Number of pregnancies that reached 37 weeks 0 days or beyond.
P (Preterm): Pregnancies delivered between 20 weeks 0 days and 36 weeks 6 days.
A (Abortus): Pregnancies ending before 20 weeks, including ectopic pregnancies, spontaneous abortions, and elective terminations.
L (Living): Number of currently living children.
Example Scenarios
1️⃣ A first-time pregnant patient who has never given birth before is documented as G1P0000 (or simply G1P0 for convenience).
2️⃣ A patient pregnant for the third time with a history of one spontaneous abortion and one ectopic pregnancy is documented as G3P0020 since both the ectopic pregnancy and abortion count under "A."
3️⃣ If this same patient later delivers a term live baby, she would now be G3P1021.
4️⃣ A patient pregnant for the second time with twins and a history of one preterm live birth would be documented as G2P0101.
If she delivers the twins at term and both survive, she becomes G2P1103.
If only one of the twins survives at birth, she would be G2P1102.
If neither twin survives at birth, she would be G2P1101.
5️⃣ For a patient with 12 pregnancies and 11 live term births, she would be G12P110011. After delivering the 12th baby, her documentation would change to G12P120012.
Neonatal Demise and Documentation
If a baby is live-born but passes away shortly after birth, we remove them from the L (Living) category while still documenting them under term or preterm births. A note in the birth history would indicate neonatal demise.
Final Thoughts
I know this topic can be tricky to grasp just by listening. If you needed a visual reference, I hope these show notes helped.
That’s it for today! Thanks for tuning in, and I’ll see you in the next episode.
References & Additional resources:
https://teachmeobgyn.com/history-taking-examinations/history-taking/obstetric/
