Flamm VBAC admission score

Flamm VBAC score

Sum the Flamm 1997 admission VBAC points (max 10) from caller-assigned age, vaginal-birth history, first-cesarean indication, and admission cervical factors, and return the published 49% or 95% success rates only for scores 0–2 and 8–10.

LIVE $0.005 USDC GET /api/calc/flamm_vbac

Markdown: /docs/flamm-vbac.md · Canonical: https://magentlab.com/docs/flamm-vbac

Not a medical device. Not a diagnosis, dose, or listing recommendation.

What it computes

When to use

When an agent already has Flamm 1997 admission factors and needs the published point total, not a trial-of-labor order, cervical exam, Grobman nomogram, or invented intermediate percents.

When not to use

Not a medical device and not a trial-of-labor or cesarean order. magent does not examine the cervix.
Flamm 1997 published VBAC success of 49% for scores 0–2 and 95% for scores 8–10. Scores 3–7 return the point total without a success percent.
Does not implement the Grobman VBAC nomogram. This tool has no race input.

Formula

Flamm VBAC = age_lt_40 2 + vaginal_birth (none 0, before_first_cesarean 1, after_first_cesarean 2, before_and_after 4) + non_ftp_indication 1 + effacement (gt_75 2, from_25_to_75 1, lt_25 0) + dilation_ge_4 1; Flamm 1997; max 10; published VBAC success 49% scores 0-2 and 95% scores 8-10

Citation

Title: Vaginal birth after cesarean delivery: an admission scoring system
Authors: Flamm BL, Geiger AM
Source: Obstet Gynecol. 1997;90(6):907-910
DOI: 10.1016/S0029-7844(97)00531-0

Worked example

Age under 40 only (score 2, published 49%)

Given: age_lt_40=truedilation_ge_4=falseeffacement=lt_25non_ftp_indication=falsevaginal_birth=none

age_lt_40 true → 2; vaginal_birth none → 0; non_ftp_indication false → 0; effacement lt_25 → 0; dilation_ge_4 false → 0
score = 2 (max 10); scores 0-2 publish 49% VBAC success

All lowest (score 0, published 49%)

Given: age_lt_40=falsedilation_ge_4=falseeffacement=lt_25non_ftp_indication=falsevaginal_birth=none

All Flamm 1997 factors at the 0-point value
score = 0 (max 10); scores 0-2 publish 49% VBAC success

Maximum published score (score 10, published 95%)

Given: age_lt_40=truedilation_ge_4=trueeffacement=gt_75non_ftp_indication=truevaginal_birth=before_and_after

age_lt_40 2 + before_and_after 4 + non_ftp_indication 1 + gt_75 2 + dilation_ge_4 1
score = 10 (max 10); scores 8-10 publish 95% VBAC success

Also searched as

Flamm VBAC score
Flamm Geiger score
VBAC admission score
Flamm 1997
trial of labor after cesarean score
successful VBAC score
TOLAC admission scoring system
vaginal birth after cesarean admission score

Try

Opens the live endpoint. Unpaid browser requests show the paywall; agents should send Accept: application/json.

/api/calc/flamm_vbac?age_lt_40=true&vaginal_birth=none&non_ftp_indication=false&effacement=lt_25&dilation_ge_4=false

Full URL: https://api.magentlab.com/api/calc/flamm_vbac?age_lt_40=true&vaginal_birth=none&non_ftp_indication=false&effacement=lt_25&dilation_ge_4=false

Call

Expect HTTP 402 until you retry with PAYMENT-SIGNATURE. Incomplete query params return HTTP 400 before any quote or charge.

curl -i -H "Accept: application/json" "https://api.magentlab.com/api/calc/flamm_vbac?age_lt_40=true&vaginal_birth=none&non_ftp_indication=false&effacement=lt_25&dilation_ge_4=false"

Parameters

Name	Type	Required	Description
`age_lt_40`	boolean	required	Maternal age under 40 years as assigned by the caller (Flamm 1997). true scores 2. true or false. magent does not date the patient.
`vaginal_birth`	string	required · none, before_first_cesarean, after_first_cesarean, before_and_after	Prior vaginal birth history as assigned by the caller (Flamm 1997). Choose one: none scores 0; before_first_cesarean scores 1; after_first_cesarean scores 2; before_and_after scores 4. magent does not read the obstetric history.
`non_ftp_indication`	boolean	required	First cesarean was for a reason other than failure to progress (Flamm 1997). true scores 1. true or false. magent does not read the operative indication.
`effacement`	string	required · gt_75, from_25_to_75, lt_25	Cervical effacement at admission as assigned by the caller (Flamm 1997). gt_75 scores 2; from_25_to_75 scores 1; lt_25 scores 0. magent does not examine the cervix.
`dilation_ge_4`	boolean	required	Cervical dilation at or above 4 cm at admission as assigned by the caller (Flamm 1997). true scores 1. true or false. magent does not examine the cervix.

Bulk (POST)

POST the same path with a JSON items array. The first item is the GET unit; each additional item is $0.002. Invalid items return HTTP 400 before settlement.

POST /api/calc/flamm_vbac Max 25 unit_amount + extra_item_amount * (n - 1) extra $0.002 PREVIEW

1 to 25 items. Each item uses the same keys as the GET query parameters.
POST of 1 item costs the same as GET. Lists longer than 25: chunk into multiple POSTs. Extra items still execute; do not pad dummy rows.
The first invalid item fails the whole request (index in the 400 JSON). You are not charged.
HTTP 200 is {count, path, items}. Each items[i] is the GET 200 body for that row.
Catalog misses (empty matches, found=false) stay paid 200s inside that slot.
x402 resource URL is this path plus n and body_sha256. Browsers that prefer text/html get the same paywall as GET; Pay retries POST with the same items.

Example request (fixture)

{
  "items": [
    {
      "age_lt_40": "true",
      "dilation_ge_4": "false",
      "effacement": "lt_25",
      "non_ftp_indication": "false",
      "vaginal_birth": "none"
    },
    {
      "age_lt_40": "true",
      "dilation_ge_4": "false",
      "effacement": "lt_25",
      "non_ftp_indication": "false",
      "vaginal_birth": "none"
    }
  ]
}

Open bulk paywall →

Opens a two-item fixture on the API host. Unpaid browsers get the same MetaMask paywall as GET; Pay retries POST with those items.

Example 200 (fixture)

{
  "count": 2,
  "path": "/api/calc/flamm_vbac",
  "items": [
    {
      "components": [
        {
          "factor": "age_lt_40",
          "points": 2,
          "present": true
        },
        {
          "value": "none",
          "factor": "vaginal_birth",
          "points": 0,
          "present": false
        },
        {
          "factor": "non_ftp_indication",
          "points": 0,
          "present": false
        },
        {
          "value": "lt_25",
          "factor": "effacement",
          "points": 0,
          "present": false
        },
        {
          "factor": "dilation_ge_4",
          "points": 0,
          "present": false
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Flamm BL, Geiger AM",
        "doi": "10.1016/S0029-7844(97)00531-0",
        "id": "flamm-1997",
        "pmid": "9397335",
        "source": "Obstet Gynecol. 1997;90(6):907-910",
        "title": "Vaginal birth after cesarean delivery: an admission scoring system"
      },
      "formula": "flamm_vbac",
      "formula_expression": "Flamm VBAC = age_lt_40 2 + vaginal_birth (none 0, before_first_cesarean 1, after_first_cesarean 2, before_and_after 4) + non_ftp_indication 1 + effacement (gt_75 2, from_25_to_75 1, lt_25 0) + dilation_ge_4 1; Flamm 1997; max 10; published VBAC success 49% scores 0-2 and 95% scores 8-10",
      "max_score": 10,
      "score": 2,
      "vbac_success_percent": 49
    },
    {
      "components": [
        {
          "factor": "age_lt_40",
          "points": 2,
          "present": true
        },
        {
          "value": "none",
          "factor": "vaginal_birth",
          "points": 0,
          "present": false
        },
        {
          "factor": "non_ftp_indication",
          "points": 0,
          "present": false
        },
        {
          "value": "lt_25",
          "factor": "effacement",
          "points": 0,
          "present": false
        },
        {
          "factor": "dilation_ge_4",
          "points": 0,
          "present": false
        }
      ],
      "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
      "citation": {
        "authors": "Flamm BL, Geiger AM",
        "doi": "10.1016/S0029-7844(97)00531-0",
        "id": "flamm-1997",
        "pmid": "9397335",
        "source": "Obstet Gynecol. 1997;90(6):907-910",
        "title": "Vaginal birth after cesarean delivery: an admission scoring system"
      },
      "formula": "flamm_vbac",
      "formula_expression": "Flamm VBAC = age_lt_40 2 + vaginal_birth (none 0, before_first_cesarean 1, after_first_cesarean 2, before_and_after 4) + non_ftp_indication 1 + effacement (gt_75 2, from_25_to_75 1, lt_25 0) + dilation_ge_4 1; Flamm 1997; max 10; published VBAC success 49% scores 0-2 and 95% scores 8-10",
      "max_score": 10,
      "score": 2,
      "vbac_success_percent": 49
    }
  ]
}

Response

Field	Type	Description
`formula`	string	flamm_vbac
`formula_expression`	string	Exact expression used
`score`	integer	Flamm 1997 points 0-10
`max_score`	integer	Always 10
`vbac_success_percent`	integer	Flamm 1997 published VBAC success: 49 when score is 0-2, 95 when score is 8-10. Omitted for scores 3-7; those scores are not given invented percents.
`components`	array	Per-factor Flamm 1997 points
`citation`	object	Flamm and Geiger Obstet Gynecol 1997 citation
`disclaimer`	string	Not-a-device notice

Example JSON

Machine form of the same example. Frozen fixture. Not a live lookup.

{
  "components": [
    {
      "factor": "age_lt_40",
      "points": 2,
      "present": true
    },
    {
      "value": "none",
      "factor": "vaginal_birth",
      "points": 0,
      "present": false
    },
    {
      "factor": "non_ftp_indication",
      "points": 0,
      "present": false
    },
    {
      "value": "lt_25",
      "factor": "effacement",
      "points": 0,
      "present": false
    },
    {
      "factor": "dilation_ge_4",
      "points": 0,
      "present": false
    }
  ],
  "disclaimer": "Not a medical device. Deterministic published-formula or published-code output for autonomous agents. A licensed clinician remains responsible for patient care and billing submissions.",
  "citation": {
    "authors": "Flamm BL, Geiger AM",
    "doi": "10.1016/S0029-7844(97)00531-0",
    "id": "flamm-1997",
    "pmid": "9397335",
    "source": "Obstet Gynecol. 1997;90(6):907-910",
    "title": "Vaginal birth after cesarean delivery: an admission scoring system"
  },
  "formula": "flamm_vbac",
  "formula_expression": "Flamm VBAC = age_lt_40 2 + vaginal_birth (none 0, before_first_cesarean 1, after_first_cesarean 2, before_and_after 4) + non_ftp_indication 1 + effacement (gt_75 2, from_25_to_75 1, lt_25 0) + dilation_ge_4 1; Flamm 1997; max 10; published VBAC success 49% scores 0-2 and 95% scores 8-10",
  "max_score": 10,
  "score": 2,
  "vbac_success_percent": 49
}

Client errors (HTTP 400)

Invalid params return 400 without charge. Shared HTTP 402 and 503 meanings: Payments.

HTTP	Code	When
400	`invalid_flamm_vbac`	Flamm VBAC score inputs must match Flamm 1997 age, prior vaginal birth, cesarean indication, and admission cervical factors from that paper. Returned before settlement; you are not charged.
400	`invalid_items`	POST body must be a JSON object with only an items array Returned before settlement; you are not charged.
400	`invalid_item_count`	items must be an array of 1 to 25 objects Returned before settlement; you are not charged.
400	`invalid_item`	each items entry must be a JSON object Returned before settlement; you are not charged.

Related tools

Bishop score — Return the Bishop 1964 pelvic score as the sum of five caller-assigned integer components (dilation, effacement, station, consistency, position).

Payment

Unpaid requests return HTTP 402 even if query parameters or POST items are missing or invalid, so CDP and agents can index the path. After a PAYMENT-SIGNATURE, invalid params return HTTP 400 JSON before settlement. magent does not charge. Fix the params, then request a new 402 quote for that complete URL. Catalog misses (empty matches, found=false) are valid paid 200s. Unpaid valid requests return HTTP 402 with a base64 PAYMENT-REQUIRED header. HTTP 503 is not a new quote: retry the same PAYMENT-SIGNATURE. Full handshake and shared payment errors: Payments. Stdio MCP: /docs/mcp.

Guarantees

HTTP 402 is unpaid, including a missing query. After PAYMENT-SIGNATURE, invalid parameters return HTTP 400 before settlement. You are not charged. HTTP 402 never includes the tool JSON.
exact: settlement finishes before the tool (paymentFlow upfront). batch-settlement: verify/deposit before the tool; chargedCumulativeAmount commits after HTTP 2xx. Uncertain or failed settlement fails closed (HTTP 503). Retry the same PAYMENT-SIGNATURE.
HTTP 402 is unpaid only. Do not sign a second authorization because of a 503.
Execution is timeout-bounded and concurrency-capped.
Calculator inputs are stored encrypted for allowlisted operators (Magent Console). They are not in public logs, SSH lookups, catalog, or rollups. Request logs store path without query.