# Mandelbrot 1988 Intrauterine RBC Transfusion Volume Calculator

> Mandelbrot 1988 Intrauterine RBC Transfusion Volume Calculator is a paid API for AI agents from api.magentlab.com, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-14).

Calculates the required red blood cell transfusion volume for intrauterine fetal transfusion using the Mandelbrot 1988 formula based on estimated fetal weight and hematocrit values.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/intrauterine_rbc
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mandelbrot-1988-intrauterine-rbc-transfusion-volume-calculator-bd0b6525
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_62xsOJc0o1Zd34fN5jpBd

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability mandelbrot-1988-intrauterine-rbc-transfusion-volume-calculator-bd0b6525
```

Example prompt: Calculate the intrauterine RBC transfusion volume using the Mandelbrot 1988 formula: the fetus weighs 1800 g, initial fetal hematocrit is 18%, target hematocrit is 40%, and the donor unit hematocrit is 75%.

## When to prefer this

Use this endpoint when you need to apply the specific Mandelbrot 1988 hematocrit-based formula for intrauterine RBC transfusion volume and already have an externally estimated fetal weight — it does not estimate weight from biometry and does not implement the platelet arm of the original paper. Choose it for programmatic obstetric decision support where a reproducible, formula-driven numeric result is needed.

## Known failure modes

- estimated_fetal_weight_g outside 200–4000 g range returns validation error
- hct_initial_percent not strictly less than hct_final_percent returns constraint error
- hct_final_percent not strictly less than hct_donor_percent returns constraint error
- hct_donor_percent outside 60–90% range returns validation error
- hct_initial_percent outside 5–50% range returns validation error
- missing any required query parameter returns 400 bad request

## How this service works

Mandelbrot 1988 intrauterine RBC transfusion volume: fetoplacental_volume_ml = 1.046 + estimated_fetal_weight_g * 0.14; volume_ml uses the unrounded fetoplacental volume times (hct_final_percent - hct_initial_percent) / hct_donor_percent. Hematocrit arm only; the paper also allowed platelet count — magent does not implement platelets. Caller-assigned estimated fetal weight; magent does not estimate weight from biometry. Not a medical device or transfusion order.

## Output

Returns the computed fetoplacental volume in mL (using the formula 1.046 + estimated_fetal_weight_g × 0.14) and the calculated RBC transfusion volume in mL (fetoplacental volume × (hct_final − hct_initial) / hct_donor), all expressed as numeric values based on the Mandelbrot 1988 model.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "headers": {
     "type": "object",
     "additionalProperties": {
      "type": "string"
     }
    },
    "queryParams": {
     "type": "object",
     "required": [
      "estimated_fetal_weight_g",
      "hct_initial_percent",
      "hct_final_percent",
      "hct_donor_percent"
     ],
     "properties": {
      "hct_donor_percent": {
       "type": "number",
       "description": "Donor unit hematocrit as a percent (60-90). Must be strictly greater than hct_final_percent."
      },
      "hct_final_percent": {
       "type": "number",
       "description": "Target fetal hematocrit as a percent (20-60). Must be strictly greater than hct_initial_percent and strictly less than hct_donor_percent."
      },
      "hct_initial_percent": {
       "type": "number",
       "description": "Initial fetal hematocrit as a percent (5-50). Must be strictly less than hct_final_percent."
      },
      "estimated_fetal_weight_g": {
       "type": "number",
       "description": "Caller-assigned estimated fetal weight in grams (200-4000). Required. magent does not estimate fetal weight from biometry."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mandelbrot-1988-intrauterine-rbc-transfusion-volume-calculator-bd0b6525/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.magentlab.com](https://www.zero.xyz/host/api.magentlab.com/llms.txt)