This calculator provides general insights into age-related fertility trends. It is not a substitute for professional medical advice.
Female
Male
Fertility Insight
Understanding Age and Fertility
Fertility is a complex biological process that naturally declines with age, particularly for women. This calculator aims to provide a general understanding of how age typically influences fertility potential based on broad biological trends. It considers factors like age, assigned sex at birth, and general menstrual cycle characteristics for females.
Female Fertility and Age
For individuals assigned female at birth, fertility is most optimal in their 20s. Key factors influencing this include:
Egg Quantity (Ovarian Reserve): Women are born with all the eggs they will ever have. The number of eggs significantly decreases over time.
Egg Quality: The genetic quality of eggs diminishes with age, increasing the risk of chromosomal abnormalities, which can lead to difficulties in conception, miscarriage, and birth defects.
Menstrual Cycle Regularity: While this calculator uses average cycle length and variability, hormonal changes associated with aging can lead to more irregular cycles, making it harder to pinpoint ovulation.
General trends show a noticeable decline after age 30, with a more significant drop after age 35, and considerably lower chances of conception naturally after age 40.
Male Fertility and Age
While the decline is generally less steep and later than in women, male fertility also declines with age. Factors include:
Sperm Quality: Sperm count, motility (movement), and morphology (shape) can decrease with age.
DNA Fragmentation: The integrity of sperm DNA can be compromised, potentially affecting fertilization and increasing miscarriage risk.
While men can father children throughout their lives, the time to conception may increase, and certain risks may be elevated for offspring born to older fathers.
How the Calculator Works (General Principles)
This calculator uses simplified models based on widely accepted biological observations:
Age Calculation: It first determines the current age from the Date of Birth.
Female Fertility Assessment: For females, it assigns a general fertility "score" or "insight" based on age brackets known for typical fertility levels (e.g., optimal, moderate decline, significant decline). The menstrual cycle data is informational but not directly used in the simplified age-based scoring.
Male Fertility Assessment: For males, it also assigns a general fertility insight based on age, reflecting the more gradual decline.
Disclaimer: Fertility is highly individual. This calculator provides a generalized perspective. Many factors beyond age, such as lifestyle, genetics, medical history, and underlying health conditions, significantly impact fertility. Always consult with a healthcare professional for personalized advice and accurate assessments.
function calculateFertility() {
var dobInput = document.getElementById("dob");
var sexInput = document.getElementById("sex");
var cycleLengthInput = document.getElementById("cycleLength");
var cycleVariabilityInput = document.getElementById("cycleVariability");
var resultValueDiv = document.getElementById("result-value");
var resultNotesDiv = document.getElementById("result-notes");
var resultContainer = document.getElementById("result-container");
// Clear previous results and notes
resultValueDiv.innerHTML = "";
resultNotesDiv.innerHTML = "";
resultContainer.style.display = "none";
// Input validation
if (!dobInput.value) {
resultNotesDiv.innerHTML = "Please enter your Date of Birth.";
resultContainer.style.display = "block";
return;
}
var dob = new Date(dobInput.value);
var today = new Date();
var age = today.getFullYear() – dob.getFullYear();
var monthDiff = today.getMonth() – dob.getMonth();
if (monthDiff < 0 || (monthDiff === 0 && today.getDate() < dob.getDate())) {
age–;
}
var sex = sexInput.value;
var fertilityInsight = "";
var additionalNotes = "";
if (sex === "female") {
if (age = 25 && age = 30 && age = 35 && age = 40) {
fertilityInsight = "Significantly Reduced Fertility";
additionalNotes = "Conception naturally becomes much more challenging. Egg quality and quantity are substantially lower, and risks are elevated.";
}
// Validate and use cycle length/variability for more nuanced notes, not a core score change
var cycleLength = parseInt(cycleLengthInput.value);
var cycleVariability = parseInt(cycleVariabilityInput.value);
if (!isNaN(cycleLength) && !isNaN(cycleVariability)) {
if (cycleLength 35) {
additionalNotes += " Note: Very short or very long cycles can sometimes indicate hormonal imbalances or ovulation irregularities that might affect fertility.";
}
if (cycleVariability > 7) {
additionalNotes += " Note: High cycle variability suggests less predictable ovulation, potentially making it harder to time intercourse for conception.";
}
} else {
additionalNotes += " Please ensure cycle length and variability are valid numbers for more specific notes.";
}
} else if (sex === "male") {
if (age = 31 && age = 41 && age 50) {
fertilityInsight = "Reduced Fertility Potential";
additionalNotes = "Fertility potential is reduced. Sperm quality is likely lower, and certain risks may be slightly elevated.";
}
additionalNotes += " While male fertility declines more gradually, it's still a factor.";
} else {
// Fallback for unexpected sex input
fertilityInsight = "N/A";
additionalNotes = "Please select a valid sex.";
}
// Display results
resultValueDiv.innerHTML = fertilityInsight;
resultNotesDiv.innerHTML = additionalNotes;
resultContainer.style.display = "block";
}