Free tool · Calculator · L&D / OB
GTPAL Calculator.
Turn a pregnancy history into the GTPAL shorthand — Gravida, Term, Preterm, Abortions, Living. Enter the counts and get the five-digit summary, the parity (Para = T + P), a plain-English readout, and the rules that trip people up (twins count as one birth event but two living children). Definitions follow standard obstetric nomenclature.
Enter the pregnancy history
Count pregnancy events, not fetuses, for G/T/P/A. A multiple gestation (twins, triplets) is one pregnancy and one birth event; count each baby only under Living.
Enter the counts to build the GTPAL string.
What each letter means [1]
| Letter | Meaning | Counts |
|---|---|---|
| G | Gravida | Total number of pregnancies, including the current one and any loss; a multiple gestation is ONE |
| T | Term births | Deliveries at ≥37w0d (a term twin delivery = 1) |
| P | Preterm births | Deliveries 20w0d–36w6d |
| A | Abortions / losses | Pregnancy endings <20w (spontaneous, elective, ectopic, molar) |
| L | Living children | Children currently alive (count each baby — twins = 2) |
Para (the “para” number) = T + P = number of births at ≥20 weeks. A pregnancy still in progress counts toward Gravida but not yet toward T or P. The 20-week and 37-week cutoffs are the common US definitions; some institutions vary.
References
- GTPAL / gravidity and parity terminology. Standard obstetric nomenclature; see e.g. Gravidity and Parity Definitions. StatPearls. Treasure Island (FL): StatPearls Publishing. ncbi.nlm.nih.gov/books/NBK544294. (Definitions of gravida, para, and the TPAL components; term ≥37w, preterm 20–36w6d, abortion <20w; multiples count as one parity event.)
Definitions transcribed from standard obstetric references; institutional charting conventions take precedence.
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