Estimate the probability of a healthy pregnancy continuation based on maternal age and gestational week.
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Estimated Statistics
Current Risk of Miscarriage:
0%
Disclaimer: This tool is for informational purposes only. It is based on statistical averages from clinical studies and cannot predict individual outcomes. Always consult with your OB-GYN for medical advice.
Understanding Miscarriage Risk by Week and Age
For many expecting parents, the early weeks of pregnancy are filled with both excitement and anxiety. Understanding the statistical probability of pregnancy loss can often provide peace of mind as the pregnancy progresses. Most miscarriages occur in the first trimester, and the risk drops significantly once a heartbeat is detected or the second trimester begins.
How Maternal Age Affects Outcomes
The age of the mother is one of the most significant factors in determining miscarriage risk. This is primarily due to the increased likelihood of chromosomal abnormalities in the egg as women age. While a woman in her 20s may face a baseline risk of approximately 10-15%, this risk increases to over 40-50% for women over the age of 45.
The "Safe Zone": Progression by Week
The risk of miscarriage is highest during the very early stages, often before a woman even knows she is pregnant (chemical pregnancies). As the weeks go by, the statistical risk decreases rapidly:
Weeks 3-4: The risk is at its peak, often estimated between 25-30%.
Weeks 6-8: Once a heartbeat is confirmed via ultrasound, the risk typically drops to about 5%.
Weeks 12-20: By the end of the first trimester, the risk falls below 1-2%.
Common Factors and Prevention
While most miscarriages are caused by random genetic issues that cannot be prevented, maintaining a healthy lifestyle—such as avoiding smoking, limiting caffeine, and managing chronic conditions like diabetes—can support a healthy pregnancy environment. If you experience severe cramping or heavy bleeding, contact your healthcare provider immediately.
function calculateMiscarriageRisk() {
var age = parseFloat(document.getElementById('maternalAge').value);
var weeks = parseFloat(document.getElementById('weeksPregnant').value);
var history = parseInt(document.getElementById('previousMiscarriage').value);
var resultDiv = document.getElementById('resultContainer');
var riskDisplay = document.getElementById('riskValue');
var probText = document.getElementById('probabilityText');
var compText = document.getElementById('comparisonText');
if (isNaN(age) || isNaN(weeks) || age < 10 || weeks < 1) {
alert("Please enter valid values for age and weeks of pregnancy.");
return;
}
// Baseline risk by week (Approximate clinical data)
var baseRisk = 0;
if (weeks = 13 && weeks = 35 && age = 40 && age = 45) {
ageMultiplier = 5.0;
}
// History multiplier
var historyMultiplier = 1.0;
if (history === 1) historyMultiplier = 1.2;
if (history === 2) historyMultiplier = 1.5;
// Final Calculation
var finalRisk = baseRisk * ageMultiplier * historyMultiplier;
// Cap the risk at a realistic maximum (85%)
if (finalRisk > 85) finalRisk = 85;
var survivalProbability = 100 – finalRisk;
// Display Results
resultDiv.style.display = 'block';
riskDisplay.innerHTML = finalRisk.toFixed(1) + "%";
probText.innerHTML = "Probability of pregnancy continuing: " + survivalProbability.toFixed(1) + "%";
var comparison = "";
if (weeks < 12) {
comparison = "Your risk will likely drop to approximately 1-2% once you reach the 13th week.";
} else {
comparison = "You have reached the second trimester, where the risk of loss is statistically very low.";
}
compText.innerHTML = comparison;
// Scroll to result
resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' });
}