Grobman 2007 first prenatal visit logistic probability of vaginal birth after ce
Grobman 2007 first prenatal visit logistic probability of vaginal birth after cesarean from maternal age, prepregnancy BMI, caller-assigned ethnicity (african_american, hispanic, or other), any prior vaginal delivery, prior VBAC after cesarean, and recurrent cesarean indication. Ethnicity uses the paper terms; magent does not assign race or ethnicity. Not the 2009/2010 admission model and not Grobman 2021. Not a trial-of-labor order.
Asked 1.4x its listed price for its own exampleour last check, 2026-09-28
1 of 1checks answered this week
301 msmedian answer time
$0.005listed price per call
$0.007price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://api.magentlab.com/api/calc/grobman_vbac
| Category | Everything else |
|---|---|
| Provider host | api.magentlab.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 0 from 0 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-28 | valid payment request | 402 | $0.007 | 301 ms |
Example input (from the provider)
{
"body": {
"items": [
{
"age": 30,
"bmi_kg_m2": 25,
"ethnicity": "other",
"prior_vaginal": false,
"prior_vbac": false,
"recurrent_indication": false
},
{
"age": 30,
"bmi_kg_m2": 25,
"ethnicity": "other",
"prior_vaginal": false,
"prior_vbac": false,
"recurrent_indication": false
}
]
},
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"items": {
"items": {
"properties": {
"age": {
"description": "Maternal age in years (integer 12-55). Grobman 2007 coefficient -0.039 per year. 12-55 is a clinical range for TOLAC; the paper does not print that clamp. magent does not take a date of birth.",
"type": "integer"
},
"bmi_kg_m2": {
"description": "Prepregnancy BMI in kg/m^2 (15-70). Grobman 2007 coefficient -0.060. 15-70 is a clinical range; the paper does not print that clamp. Caller-supplied; magent does not compute BMI from height and weight.",
"type": "number"
},
"ethnicity": {
"description": "Caller-assigned ethnicity as used in Grobman 2007: african_american, hispanic, or other (mutually exclusive paper terms; other is the reference). magent does not assign race or ethnicity.",
"enum": [
"african_american",
"hispanic",
"other"
],
"type": "string"
},
"prior_vaginal": {
"description": "Any prior vaginal delivery as assigned by the caller (Grobman 2007). true scores +0.888. true or false. magent does not read the obstetric history.",
"type": "boolean"
},
"prior_vbac": {
"description": "VBAC after prior cesarean as assigned by the caller (Grobman 2007). true scores +1.003. true or false. magent does not infer this from prior_vaginal.",
"type": "boolean"
},
"recurrent_indication": {
"description": "Recurring indication for cesarean as assigned by the caller (Grobman 2007). true scores -0.632. true or false. magent does not read the operative indication.",
"type": "boolean"
}
},
"required": [
"age",
"bmi_kg_m2",
"ethnicity",
"prior_vaginal",
"prior_vbac",
"recurrent_indication"
],
"type": "object"
},
"maxItems": 25,
"minItems": 1,
"type": "array"
}
},
"required": [
"items"
],
"type": "object"
},
"headers": {
"additionalProperties": {
"type": "string"
},
"type": "object"
},
"method": {
"const": "POST",
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}