Macones et al developed a nomogram for predicting the probability of cesarean section for a woman undergoing a trial of labor after cesarean section (TOLAC). The authors are from Washington University in St. Louis and Saint Louis University.
Patient: woman undergoing a trial of labor after cesarean section (TOLAC)
Outcome: probability of cesarean section
Parameters:
(1) age in years (from 18 to 42)
(2) fetal-pelvic index (FPI, from -60 to +40)
(3) race
(4) medical comorbidity (pre-existing diabetes mellitus, heart disease, hypertension, autoimmune disease, kidney disease or neurologic disorder)
(5) labor method
points for age =
= (1.042 * (age)) - 18.18
points for fetal-pelvic index =
= (fetal-pelvic index) + 60
|
Parameter |
Finding |
Points |
|
race |
Black |
8.6 |
|
|
non-Black |
0 |
|
medical comorbidity |
no |
0 |
|
|
yes |
4.7 |
|
labor method |
spontaneous |
0 |
|
|
augmented or induced |
4.3 |
total score =
= SUM(points for all 5 parameters)
Interpretation:
• minimum score: 0
• maximum score: 142.8
• The higher the score the greater the probability of cesarean section.
|
Total Score |
Probability in Percent |
|
< 39 |
< 1% |
|
39 to 66 |
(0.03333 * ((points)^2)) - (2.802 * (points)) + 59.61 |
|
66 to 89 |
(2.639 * (points)) - 154.7 |
|
89 to 102 |
(-0.06451 * ((points)^2)) + (13.5 * (points)) - 610.5 |
|
> 102 |
> 95% |
Specialty: Obstetrics & Gynecology
ICD-10: ,
