Twin Weight Discordance Calculator
Twin EFWdiscordance using explicitly larger-weight denominator, retaining equal-weight ties. Not actual growth disorder, chorionicity-specific diagnosis or intervention threshold; qualified measurements/dating required.
Description
Twin weight discordance expresses the difference between two estimated weights relative to the larger estimate.
Twin weight discordance expresses the difference between two estimated weights relative to the larger estimate.1
Estimation uncertainty and scan matching remain separate from the arithmetic percentage.
When to use Twin Weight Discordance Calculator
Use this tool to calculate or review the supplied observations under the stated rules. Establish the observation date, units, measurement context and independently applicable clinical reference or calibrated model.
How to use Twin Weight Discordance Calculator and understand its results
- Establish the observation date, units, measurement context and independently applicable clinical reference or calibrated model.
- Enter twinOneIndependentlyEstimatedWeightGrams, twinTwoIndependentlyEstimatedWeightGrams, using the field meanings and rules below, then run the tool.
- Read result.observedEstimatedWeightDiscordancePercent, result.largerEstimatedTwinIndices. Use the units and sign conventions below.
- Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| twinOneIndependentlyEstimatedWeightGrams | Twin one independently estimated weight grams | number | Required |
| twinTwoIndependentlyEstimatedWeightGrams | Twin two independently estimated weight grams | number | Required |
Both independently estimated twin weights must be positive. Divide their absolute difference by the larger weight and multiply by 100. Return all indices of the larger twin as one-based positions 1 and 2; equal weights return zero discordance and both positions.
discordancePercent=100×abs(weight1−weight2)/max(weight1,weight2) Use the matching field units and the exact boundary, ordering and reference rules above.
| Output field | Meaning | Value type |
|---|---|---|
| result | Structured result; its nested fields below contain the actual calculation or selected reference | object |
| result.observedEstimatedWeightDiscordancePercent | Observed Estimated Weight Discordance Percent | number |
| result.largerEstimatedTwinIndices | One-based positions 1 and 2 identifying the larger estimate; both positions on a tie | list |
{
"input": {
"twinOneIndependentlyEstimatedWeightGrams": 1000,
"twinTwoIndependentlyEstimatedWeightGrams": 1200
},
"output": {
"result": {
"observedEstimatedWeightDiscordancePercent": 16.666666666666668,
"largerEstimatedTwinIndices": [
2
]
}
}
}Limitations and assumptions
Dating evidence, acquisition conditions and applicable clinical references remain independently established. The output describes supplied observations or a conditional model without diagnosing an outcome, choosing a dose or verifying clinical applicability.
Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite. Extremely large composite outputs are rejected.
Alternative or Complementary methods
For a related step, use Fetal Growth Velocity Calculator: Estimated fetal-growth velocity compares matched weight estimates over an actual scan interval. For a complementary comparison, use Fetal Weight Percentile Calculator: Estimated fetal-weight percentiles depend on an adopted growth reference and scan context.
References
-
Twin Weight Discordance Calculator — tool.io
Similar or alternative tools
- Fetal Growth Velocity Calculator
Estimated fetal-growth velocity compares matched weight estimates over an actual scan interval.
- Fetal Weight Percentile Calculator
Estimated fetal-weight percentiles depend on an adopted growth reference and scan context.