Short answer: two previous pregnancies, one kept for more than and one less than 20 weeks (G3P2Ab1).

It's kind of a trick question. Gravidity means number of pregnancies initiated regardless of the outcome so this woman who is currently pregnant has had two previous pregnancies (total of 3). Parity means the number of pregnancies kept more than 20 weeks. She is currently 23 weeks so that counts as one parity and she kept one of the previous two pregnancies more than 20 weeks as well. The other previous pregnancy terminated before 20 weeks.

Acutally, the above answer is incorrect. Gravida 3 means she has had 3 total pregnancies (one of which is currently 23 weeks). Para 2 means that the final outcome of 2 prior pregnancies was at least 20 weeks. The current pregnancy is not counted in the para until after it's finished. So...she has delivered 2 times (maybe alive, maybe not...but they were at least 20 weeks), and she is pregnant right now.

To further complicate the answer, those para could have included twins also...the simple GP system does not have any way to acknowledge twins, triplets, etc.

A more accurate method is G, TPAL.

G = total # of pregnancies (including current pregnancy)

T = # of term ( 37+ weeks) pregnancies

P = # of preterm (less than 37 weeks) pregnancies

A = # of abortions (includes induced & spontaneous)

L = # of living children (this is where stillborns & multiples become evident)

Someone who is pregnant for the first time is a G1 P0 (or P0-0-0-0)

After delivery (beyond 20 weeks) she becomes a G1 P1. (If it was 37+ weeks, she is a G1 P1-0-0-1. If it was before 37 weeks, she is a G1 P0-1-0-1)

If the above delivery was twins, she is still a G1 P1 (or a G1 P1-0-0-2)

Someone with a full term delivery and preterm twins who is currently pregnant again would be a G3 P1-1-0-3...in the simple GP system she is a G3 P2 (even though she has 3 living children).

Someone who is currently pregnant and also had a previous miscarriage before 20 weeks is a G2 P0-0-1-0...in the simple GP system she is a G2 P0

Someone who is currently pregnant and also had an abortion is a G2 P0-0-1-0...in the simple GP system she is a G2 P0

(Notice there's no differentiation between abortion & miscarriage)

Someone who is pregnant now and previously delivered a 24 week baby who survived would be a G2 P0-1-0-1...in the simple GP system she is a G2 P1

Someone who is pregnant now and previously delivered a live 24 week baby who then died would be a G2 P0-1-0-0...in the simple GP system she is a G2 P1

Someone who is pregnant now and previously delivered a 24 week stillborn would be a G2 P0-1-0-0...but in the simple GP system she is a G2 P1

(notice how the last 3 are all G2 P1, even though they are very different scenarios?)

The same patient above delivers a full term baby, so she is now a G2 P1-1-0-1...but in the simple GP system she is a G2 P2.