# RhD Immune Globulin Vial Arithmetic (ACOG PB 181 / AABB)

> RhD Immune Globulin Vial Arithmetic (ACOG PB 181 / AABB) 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 number of RhD immune globulin (RhIG) vials required after fetomaternal hemorrhage using the Kleihauer–Betke percent and maternal blood volume, following ACOG Practice Bulletin 181 and AABB Technical Manual rounding rules.

## Facts

- Endpoint: GET https://api.magentlab.com/api/calc/rhig
- 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/rhd-immune-globulin-vial-arithmetic-acog-pb-181-aabb-a8851a56
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_iUT4sDOtThm26osqcoWmH

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 rhd-immune-globulin-vial-arithmetic-acog-pb-181-aabb-a8851a56
```

Example prompt: My patient has a Kleihauer-Betke result of 0.8% fetal cells and an estimated maternal blood volume of 5000 mL — how many 300-microgram RhIG vials does she need per ACOG and AABB guidelines?

## When to prefer this

Use this endpoint when you need a fast, guideline-anchored RhIG vial count from a Kleihauer–Betke result and maternal blood volume, specifically implementing ACOG Practice Bulletin 181 arithmetic and AABB Technical Manual rounding. Prefer it over manual calculation to avoid rounding errors in high-stakes obstetric or trauma transfusion scenarios.

## Known failure modes

- fetal_cells_percent outside 0–5 range returns a validation error
- maternal_blood_volume_ml outside 3000–10000 range returns a validation error
- missing required query parameters returns a 400 error
- payment not included or insufficient returns a 402 Payment Required

## How this service works

ACOG Practice Bulletin 181 RhD immune globulin vial arithmetic. fmh_ml = fetal_cells_percent/100 * maternal_blood_volume_ml. One 300 microgram vial covers 30 mL Rh D-positive fetal whole blood. AABB Technical Manual rounding: if frac(fmh_ml/30) >= 0.5 round up then add one vial; if < 0.5 round down then add one. Minimum 1 vial. Caller assigns Kleihauer–Betke percent and maternal volume; magent does not read slides. Not a prescription or brand order.

## Output

Returns the calculated fetomaternal hemorrhage volume in mL (fmh_ml = fetal_cells_percent/100 × maternal_blood_volume_ml), the fractional vial count before rounding, and the final integer number of RhIG vials required per AABB Technical Manual rounding rules (minimum 1 vial). Does not issue a prescription or specify a brand.

## 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": [
      "fetal_cells_percent",
      "maternal_blood_volume_ml"
     ],
     "properties": {
      "fetal_cells_percent": {
       "type": "number",
       "description": "Caller-assigned Kleihauer–Betke fetal-cell percent (0-5). magent does not interpret slides."
      },
      "maternal_blood_volume_ml": {
       "type": "number",
       "description": "Caller-assigned maternal blood volume in mL (3000-10000). magent does not compute Nadler EBV."
      }
     }
    }
   },
   "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/rhd-immune-globulin-vial-arithmetic-acog-pb-181-aabb-a8851a56/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)