Average size of mature follicles, usually 18-25mm.
If diagnosed, enter days. Usually 10-14 days. Enter 0 if not applicable.
Your Estimated Due Date & Key Metrics
Estimated Due Date (EDD)—
Estimated Conception Date—
Estimated Gestational Age at Due Date (Weeks)—
Estimated Days Post-IUI at Due Date—
Formula Used: The Estimated Due Date (EDD) is calculated by adding 280 days (40 weeks) to the estimated conception date. The estimated conception date is derived from the IUI date plus the estimated gestational age at IUI, adjusted for any diagnosed Luteal Phase Defect.
Estimated Gestational Progression
Estimated Gestational Age (Days)
Estimated Days Post-IUI
Chart showing the progression of estimated gestational age and days post-IUI over a typical 40-week pregnancy.
Key Variables and Their Impact
Variable
Meaning
Unit
Typical Range
Impact on Due Date
IUI Procedure Date
The exact date the Intrauterine Insemination was performed.
Date
N/A
Establishes the baseline for all subsequent calculations.
Estimated Gestational Age at IUI
The estimated number of days from the Last Menstrual Period (LMP) to the IUI date.
Days
10-21 days (approx. 2-3 weeks)
Crucial for determining the conception date relative to the IUI.
Average Follicle Size
The average diameter of mature follicles measured just before the IUI.
mm
18-25 mm
Indirectly influences the accuracy of the estimated gestational age at IUI. Larger follicles suggest ovulation is imminent or has occurred.
Luteal Phase Defect (LPD)
A condition where the luteal phase is shorter than normal, potentially affecting implantation.
Days
0-7 days
Can slightly adjust the estimated conception date if accounted for, though standard EDD calculations often don't directly incorporate LPD adjustments. This calculator uses it as a potential modifier.
Standard Pregnancy Length
The typical duration of a full-term pregnancy.
Days
280 days (40 weeks)
The primary duration added to the conception date to estimate the EDD.
What is a Due Date Calculator with IUI?
A due date calculator with IUI is a specialized tool designed to help individuals and couples estimate their baby's expected delivery date (EDD) following an Intrauterine Insemination (IUI) procedure. Unlike standard due date calculators that often rely on the Last Menstrual Period (LMP), this calculator uses the specific date of the IUI procedure and other relevant fertility treatment data to provide a more tailored estimation. Understanding your estimated due date is crucial for monitoring pregnancy progress, planning appointments, and preparing for the arrival of your baby.
Who Should Use It?
This calculator is primarily intended for individuals or couples who have undergone or are planning to undergo an IUI procedure as part of their fertility treatment. This includes those using ovulation induction medications, timed intercourse following IUI, or other assisted reproductive technologies where the IUI date is a key reference point. It's also useful for healthcare providers to quickly estimate EDDs for their IUI patients.
Common Misconceptions
Misconception: The IUI date is always exactly 40 weeks before the due date. Reality: The IUI date is the *procedure* date. Conception typically occurs shortly after, and the 40-week countdown usually starts from the LMP or estimated conception date. This calculator helps bridge that gap.
Misconception: All IUI pregnancies result in the same due date calculation. Reality: Factors like the exact timing of ovulation relative to IUI, the individual's cycle length, and potential luteal phase issues can influence the actual conception timing and thus the EDD.
Misconception: The due date is an exact deadline. Reality: The EDD is an estimate. Full-term pregnancies can range from 37 to 42 weeks. Only about 5% of babies are born on their exact due date.
IUI Due Date Calculation Formula and Mathematical Explanation
The core principle behind calculating an estimated due date (EDD) after IUI is to determine the most likely date of conception and then add the standard duration of a full-term pregnancy, which is typically 280 days (40 weeks) from the Last Menstrual Period (LMP) or 266 days (38 weeks) from the estimated date of conception.
Step-by-Step Derivation
Determine Estimated Conception Date: This is the most critical step.
Start with the IUI Procedure Date.
Add the Estimated Gestational Age at IUI (in days). This represents the number of days that have passed since the LMP before the IUI.
Subtract the Luteal Phase Defect (LPD) days, if applicable and known. This adjustment is less common in standard EDD calculations but can refine the estimate if LPD is a significant factor in the individual's cycle.
The result is the Estimated Conception Date.
Calculate Estimated Due Date (EDD):
Add 266 days (38 weeks) to the Estimated Conception Date. This is the most direct method when conception date is known.
Alternatively, add 280 days (40 weeks) to the Estimated Gestational Age at IUI date. This method assumes the gestational age at IUI correctly reflects the LMP date.
This calculator primarily uses the first method: finding the estimated conception date and adding 266 days.
Variable Explanations
Let's break down the variables used in the calculation:
Variable
Meaning
Unit
Typical Range
IUI Procedure Date
The specific date the IUI was performed.
Date
N/A
Estimated Gestational Age at IUI
Days from LMP to IUI. This is often estimated based on follicle size and hormone levels.
Days
10 – 21 days (approx. 2-3 weeks)
Average Follicle Size
The size of the dominant follicle(s) when ovulation was triggered or expected.
mm
18 – 25 mm
Luteal Phase Defect (LPD)
Duration of the luteal phase if shorter than the standard 10-14 days.
Days
0 – 7 days
Estimated Conception Date
The calculated date when fertilization likely occurred.
Date
N/A
Estimated Due Date (EDD)
The estimated date of delivery.
Date
N/A
Estimated Gestational Age at EDD
Total weeks and days of pregnancy at the EDD.
Weeks & Days
40 weeks 0 days (full term)
Estimated Days Post-IUI at EDD
Total days from IUI to EDD.
Days
Approx. 266 days (38 weeks)
Practical Examples (Real-World Use Cases)
Let's illustrate how the due date calculator with IUI works with practical scenarios:
Example 1: Standard IUI Cycle
Scenario: Sarah and Tom underwent an IUI procedure on March 15, 2024. Based on her monitoring, her doctor estimated her gestational age at the time of IUI was 14 days (2 weeks) from her last menstrual period. She has no diagnosed luteal phase defect.
Inputs:
IUI Procedure Date: March 15, 2024
Estimated Gestational Age at IUI (Days): 14
Average Follicle Size: 21 mm
Luteal Phase Defect (Days): 0
Calculation:
Estimated Conception Date = March 15, 2024 + 14 days = March 29, 2024
Estimated Due Date (EDD) = March 29, 2024 + 266 days = December 21, 2024
Estimated Gestational Age at EDD = 40 weeks 0 days
Estimated Days Post-IUI at EDD = 266 days
Interpretation: The calculator estimates Sarah's due date to be December 21, 2024. This aligns with a standard 40-week pregnancy from LMP, with conception occurring approximately 2 weeks after LMP.
Example 2: IUI with Potential Luteal Phase Considerations
Scenario: Maria and David had an IUI on April 10, 2024. Her monitoring indicated an estimated gestational age of 16 days at the time of IUI. Her doctor noted a potential mild luteal phase defect and advised a 3-day progesterone supplement starting post-IUI, suggesting a slight adjustment might be considered for conception timing accuracy, though standard EDD calculations often don't explicitly adjust for this. For this calculator, we'll input the LPD days.
Inputs:
IUI Procedure Date: April 10, 2024
Estimated Gestational Age at IUI (Days): 16
Average Follicle Size: 20 mm
Luteal Phase Defect (Days): 3
Calculation:
Estimated Conception Date = April 10, 2024 + 16 days – 3 days = April 23, 2024
Estimated Due Date (EDD) = April 23, 2024 + 266 days = January 14, 2025
Estimated Gestational Age at EDD = 40 weeks 0 days
Estimated Days Post-IUI at EDD = 266 days
Interpretation: By inputting the LPD days, the estimated conception date shifts slightly later, resulting in an EDD of January 14, 2025. This highlights how subtle cycle variations can influence the EDD estimate.
How to Use This Due Date Calculator with IUI
Using this specialized calculator is straightforward. Follow these steps to get your estimated due date:
Enter the IUI Procedure Date: Select the exact date your Intrauterine Insemination was performed using the date picker.
Input Estimated Gestational Age at IUI: Provide the number of days from your Last Menstrual Period (LMP) to the IUI date. This is often estimated by your fertility clinic based on cycle monitoring (e.g., follicle size, hormone levels). A typical range is 14-16 days.
Enter Average Follicle Size: Input the average size (in millimeters) of your mature follicles measured around the time of your trigger shot or ovulation. This helps confirm the estimated gestational age.
Adjust for Luteal Phase Defect (Optional): If you have been diagnosed with a Luteal Phase Defect (LPD) and know the number of days your luteal phase is typically short, enter that value. If not, leave it at 0.
View Results: Once you've entered the required information, the calculator will instantly display:
Estimated Due Date (EDD): Your primary estimated delivery date.
Estimated Conception Date: The calculated date of fertilization.
Estimated Gestational Age at Due Date: Typically 40 weeks 0 days for a full-term pregnancy.
Estimated Days Post-IUI at Due Date: The number of days from your IUI to your EDD (usually around 266 days).
Understand the Chart and Table: The accompanying chart visualizes the pregnancy progression, and the table provides context on the variables used.
Use the Buttons:
Copy Results: Click this to copy all calculated results and key assumptions to your clipboard for easy sharing or record-keeping.
Reset: Click this to clear all fields and reset them to default values.
How to Read Results
The Estimated Due Date (EDD) is your primary target. Remember it's an estimate, and babies arrive on their own schedule. The Estimated Conception Date helps pinpoint when fertilization likely occurred. The Gestational Age metrics confirm the pregnancy duration.
Decision-Making Guidance
Your EDD is a vital piece of information for your healthcare provider to track your pregnancy's progress. It helps schedule important prenatal tests and appointments, such as anatomy scans and glucose tolerance tests, which are timed based on gestational age. Use the EDD as a guide for planning, but stay flexible.
Key Factors That Affect IUI Due Date Results
While this calculator provides a tailored estimate, several factors can influence the accuracy of your due date calculator with IUI results:
Accuracy of IUI Date: The precision of the date the IUI procedure was performed is fundamental. Any error here directly impacts all subsequent calculations.
Timing of Ovulation Relative to IUI: The effectiveness of IUI relies on sperm being present when the egg is released. If ovulation occurred significantly before or after the IUI, the actual conception date might differ from the estimate. This is why precise cycle monitoring is crucial.
Individual Cycle Variability: Not everyone has a perfectly predictable cycle. Variations in follicle development, hormone levels, or ovulation timing can occur even with fertility treatments.
Luteal Phase Length: A shorter luteal phase (LPD) can sometimes indicate issues with progesterone production, potentially affecting implantation or early pregnancy. While this calculator includes an LPD adjustment, its precise impact on EDD can be complex and debated.
Follicle Size and Maturity: While follicle size is a good indicator of maturity, it's not the sole determinant. The exact moment of ovulation and fertilization is the key, and follicle size is just a proxy.
Medication Effects: Fertility medications used to stimulate ovulation can sometimes influence cycle length or the timing of ovulation, requiring careful monitoring.
Implantation Timing: While conception is the fertilization event, implantation (when the embryo attaches to the uterine wall) occurs several days later. Standard EDD calculations are based on LMP, implicitly accounting for ovulation and implantation timing, but variations can exist.
Assumptions in Standard Calculations: The 280-day (from LMP) or 266-day (from conception) calculation is a statistical average. Individual pregnancies naturally vary.
Frequently Asked Questions (FAQ)
Q1: How accurate is a due date calculated after IUI?
A: It's generally more accurate than a standard LMP-based calculation if the IUI date and gestational age at IUI are precise. However, it's still an estimate. Full-term pregnancies can range from 37 to 42 weeks.
Q2: What if I don't know my exact gestational age at IUI?
A: Use the typical range provided (14-16 days) or consult your fertility clinic's records. Your clinic's monitoring data (like follicle size) can help estimate this value.
Q3: Does the follicle size directly determine the due date?
A: No, follicle size helps estimate when ovulation occurred or will occur, which in turn helps determine the gestational age at IUI. The IUI date and the estimated conception date are more direct inputs for the EDD calculation.
Q4: How is the conception date calculated from the IUI date?
A: It's estimated by adding the days from LMP to IUI (gestational age at IUI) to the IUI date. For example, if IUI was on day 14 of a cycle, conception is estimated around that time.
Q5: What does "Days Post-IUI at EDD" mean?
A: This represents the number of days that will have passed from your IUI procedure date to your estimated due date. For a standard 40-week pregnancy, this is typically around 266 days (38 weeks).
Q6: Can I use this calculator if I had IVF?
A: This calculator is specifically designed for IUI. For IVF, the due date calculation depends on the date of embryo transfer and the age of the embryo (e.g., 3-day or 5-day transfer). You would need a different calculator or method.
Q7: What if my due date falls on a weekend or holiday?
A: The EDD is a calculated date. Labor doesn't follow a calendar strictly. If your EDD falls on a weekend or holiday, your healthcare provider will likely schedule your next appointment or induction (if needed) on the nearest business day.
Q8: Should I rely solely on this calculator for my due date?
A: No. Always confirm your estimated due date with your healthcare provider. They use comprehensive data and clinical judgment to establish the most accurate EDD.
Related Tools and Internal Resources
Ovulation CalculatorHelps predict fertile windows and ovulation dates based on cycle length.
function getElement(id) {
return document.getElementById(id);
}
function formatDate(date) {
var d = new Date(date);
var month = " + (d.getMonth() + 1);
var day = " + d.getDate();
var year = d.getFullYear();
if (month.length < 2) month = '0' + month;
if (day.length < 2) day = '0' + day;
return [year, month, day].join('-');
}
function addDays(date, days) {
var result = new Date(date);
result.setDate(result.getDate() + days);
return result;
}
function calculateDueDate() {
// Clear previous errors
getElement('iuiDateError').style.display = 'none';
getElement('gestationalAgeError').style.display = 'none';
getElement('follicleSizeError').style.display = 'none';
getElement('lutealPhaseDefectError').style.display = 'none';
var iuiDateInput = getElement('iuiDate');
var gestationalAgeInput = getElement('gestationalAge');
var follicleSizeInput = getElement('follicleSize');
var lutealPhaseDefectInput = getElement('lutealPhaseDefect');
var iuiDateStr = iuiDateInput.value;
var gestationalAgeDays = parseInt(gestationalAgeInput.value);
var follicleSize = parseInt(follicleSizeInput.value);
var lutealPhaseDefectDays = parseInt(lutealPhaseDefectInput.value);
// — Input Validation —
var isValid = true;
if (!iuiDateStr) {
getElement('iuiDateError').textContent = 'Please enter the IUI procedure date.';
getElement('iuiDateError').style.display = 'block';
isValid = false;
}
if (isNaN(gestationalAgeDays) || gestationalAgeDays 30) {
getElement('gestationalAgeError').textContent = 'Please enter a valid gestational age between 0 and 30 days.';
getElement('gestationalAgeError').style.display = 'block';
isValid = false;
}
if (isNaN(follicleSize) || follicleSize 30) {
getElement('follicleSizeError').textContent = 'Please enter a valid follicle size between 10 and 30 mm.';
getElement('follicleSizeError').style.display = 'block';
isValid = false;
}
if (isNaN(lutealPhaseDefectDays) || lutealPhaseDefectDays 7) {
getElement('lutealPhaseDefectError').textContent = 'Please enter a valid LPD between 0 and 7 days.';
getElement('lutealPhaseDefectError').style.display = 'block';
isValid = false;
}
if (!isValid) {
resetResultsDisplay();
return;
}
// — Calculations —
var iuiDate = new Date(iuiDateStr);
// Estimated Conception Date = IUI Date + Gestational Age at IUI – LPD Days
// Note: We add LPD days here because the 'gestational age at IUI' already accounts for the cycle length up to IUI.
// If LPD is present, it means the luteal phase was shorter, implying ovulation might have occurred slightly later relative to the *start* of the cycle,
// or that the conception window is shifted. A simpler approach is to consider the conception date as IUI date + (standard luteal phase duration – actual luteal phase duration).
// However, a more direct interpretation for EDD calculation is often: Conception Date = IUI Date + (Days from LMP to IUI) – (Days of LPD).
// Let's refine: Conception Date = IUI Date + (Estimated Gestational Age at IUI) – (Luteal Phase Defect Days)
// This assumes Gestational Age at IUI is days from LMP.
// A common simplification is: Conception Date = IUI Date + (Standard Luteal Phase Length – LPD Days)
// Let's use the most common approach: EDD = LMP + 280 days.
// Estimated LMP = IUI Date – Gestational Age at IUI.
// Estimated Conception Date = Estimated LMP + 14 days (approx).
// OR Estimated Conception Date = IUI Date + (14 – Gestational Age at IUI) days. This is complex.
// Let's use the calculator's logic:
// 1. Calculate Estimated LMP: IUI Date – Gestational Age at IUI
var estimatedLMP = new Date(iuiDate);
estimatedLMP.setDate(iuiDate.getDate() – gestationalAgeDays);
// 2. Calculate Estimated Conception Date: Estimated LMP + 14 days (standard ovulation window)
// Adjust for LPD: If LPD exists, conception might be closer to IUI date.
// A simpler model: Conception is assumed to happen ~1-2 days after trigger/IUI if ovulation is timed.
// Let's assume conception is roughly IUI Date + (14 – Gestational Age at IUI) days.
// If Gestational Age at IUI = 14, Conception = IUI Date.
// If Gestational Age at IUI = 12, Conception = IUI Date + 2 days.
// If Gestational Age at IUI = 16, Conception = IUI Date – 2 days.
// Let's use: Conception Date = IUI Date + (14 – gestationalAgeDays)
var estimatedConceptionDate = new Date(iuiDate);
estimatedConceptionDate.setDate(iuiDate.getDate() + (14 – gestationalAgeDays));
// Adjust for LPD: If LPD is present, it means the luteal phase was shorter. This might imply ovulation happened slightly later relative to LMP, or implantation was affected.
// A common approach is to consider the EDD based on LMP + 280 days.
// Estimated LMP = IUI Date – Gestational Age at IUI.
// EDD = Estimated LMP + 280 days.
var eddFromLMP = new Date(estimatedLMP);
eddFromLMP.setDate(estimatedLMP.getDate() + 280);
// Alternative: EDD = IUI Date + (280 – Gestational Age at IUI) days.
// This assumes the IUI date is the reference point and we add the remaining pregnancy duration.
var eddFromIUI = new Date(iuiDate);
eddFromIUI.setDate(iuiDate.getDate() + (280 – gestationalAgeDays));
// Let's use the EDD = LMP + 280 days approach as it's standard.
// And calculate Conception Date based on IUI date and GA at IUI.
// Conception Date = IUI Date + (14 – GA at IUI)
// EDD = Conception Date + 266 days.
var conceptionDateCalc = new Date(iuiDate);
conceptionDateCalc.setDate(iuiDate.getDate() + (14 – gestationalAgeDays));
// Let's add LPD adjustment here: If LPD is X days, it means the luteal phase was X days shorter.
// This implies ovulation might have occurred X days later relative to the start of the cycle.
// So, Conception Date = IUI Date + (14 – gestationalAgeDays) + lutealPhaseDefectDays
conceptionDateCalc.setDate(conceptionDateCalc.getDate() + lutealPhaseDefectDays);
var finalEDD = new Date(conceptionDateCalc);
finalEDD.setDate(conceptionDateCalc.getDate() + 266); // Add 38 weeks (266 days) from conception
var finalConceptionDateStr = formatDate(conceptionDateCalc);
var finalEDDStr = formatDate(finalEDD);
// Calculate Gestational Age at EDD (should be ~40 weeks)
var diffDaysEDD = (finalEDD.getTime() – conceptionDateCalc.getTime()) / (1000 * 3600 * 24);
var weeksEDD = Math.floor(diffDaysEDD / 7);
var daysEDD = Math.floor(diffDaysEDD % 7);
var gestationalAgeAtEDDStr = weeksEDD + " weeks " + daysEDD + " days";
// Calculate Days Post-IUI at EDD
var diffDaysPostIUI = (finalEDD.getTime() – iuiDate.getTime()) / (1000 * 3600 * 24);
var daysPostIUIAtEDDStr = Math.floor(diffDaysPostIUI) + " days";
// — Update Results Display —
getElement('estimatedConceptionDate').textContent = finalConceptionDateStr;
getElement('estimatedDueDate').textContent = finalEDDStr;
getElement('gestationalAgeAtEDD').textContent = gestationalAgeAtEDDStr;
getElement('daysPostIUIAtEDD').textContent = daysPostIUIAtEDDStr;
// — Update Chart —
updateChart(iuiDate, finalEDD, gestationalAgeDays, lutealPhaseDefectDays);
}
function resetResultsDisplay() {
getElement('estimatedConceptionDate').textContent = '–';
getElement('estimatedDueDate').textContent = '–';
getElement('gestationalAgeAtEDD').textContent = '–';
getElement('daysPostIUIAtEDD').textContent = '–';
// Clear canvas
var canvas = getElement('gestationChart');
var ctx = canvas.getContext('2d');
ctx.clearRect(0, 0, canvas.width, canvas.height);
}
function resetCalculator() {
getElement('iuiDate').value = "; // Clear date
getElement('gestationalAge').value = '14';
getElement('follicleSize').value = '20';
getElement('lutealPhaseDefect').value = '0';
resetResultsDisplay();
// Clear errors too
getElement('iuiDateError').style.display = 'none';
getElement('gestationalAgeError').style.display = 'none';
getElement('follicleSizeError').style.display = 'none';
getElement('lutealPhaseDefectError').style.display = 'none';
}
function copyResults() {
var edd = getElement('estimatedDueDate').textContent;
var conceptionDate = getElement('estimatedConceptionDate').textContent;
var gaAtEDD = getElement('gestationalAgeAtEDD').textContent;
var daysPostIUI = getElement('daysPostIUIAtEDD').textContent;
if (edd === '–') {
alert("No results to copy yet. Please calculate first.");
return;
}
var assumptions = "Key Assumptions:\n" +
"IUI Date: " + getElement('iuiDate').value + "\n" +
"Estimated Gestational Age at IUI: " + getElement('gestationalAge').value + " days\n" +
"Average Follicle Size: " + getElement('follicleSize').value + " mm\n" +
"Luteal Phase Defect: " + getElement('lutealPhaseDefect').value + " days";
var textToCopy = "— IUI Due Date Calculation Results —\n\n" +
"Estimated Due Date (EDD): " + edd + "\n" +
"Estimated Conception Date: " + conceptionDate + "\n" +
"Estimated Gestational Age at Due Date: " + gaAtEDD + "\n" +
"Estimated Days Post-IUI at Due Date: " + daysPostIUI + "\n\n" +
assumptions;
navigator.clipboard.writeText(textToCopy).then(function() {
alert('Results copied to clipboard!');
}).catch(function(err) {
console.error('Failed to copy: ', err);
prompt("Copy manually:", textToCopy); // Fallback for browsers without clipboard API
});
}
function updateChart(iuiDate, finalEDD, gestationalAgeAtIUI, lutealPhaseDefectDays) {
var canvas = getElement('gestationChart');
var ctx = canvas.getContext('2d');
ctx.clearRect(0, 0, canvas.width, canvas.height); // Clear previous drawing
var chartWidth = canvas.width;
var chartHeight = canvas.height;
var padding = 40;
var chartAreaWidth = chartWidth – 2 * padding;
var chartAreaHeight = chartHeight – 2 * padding;
// Calculate data points
var numPoints = 10; // Number of points to plot
var totalDurationDays = (finalEDD.getTime() – iuiDate.getTime()) / (1000 * 3600 * 24);
var stepDays = totalDurationDays / (numPoints – 1);
var chartData = [];
for (var i = 0; i < numPoints; i++) {
var currentDayOffset = i * stepDays;
var currentDate = new Date(iuiDate.getTime() + currentDayOffset * 24 * 60 * 60 * 1000);
// Calculate estimated gestational age in days at currentDate
// Estimated LMP = IUI Date – gestationalAgeAtIUI
var estimatedLMP = new Date(iuiDate);
estimatedLMP.setDate(iuiDate.getDate() – gestationalAgeAtIUI);
var currentGestationalAgeDays = (currentDate.getTime() – estimatedLMP.getTime()) / (1000 * 3600 * 24);
// Calculate estimated days post-IUI
var currentDaysPostIUI = (currentDate.getTime() – iuiDate.getTime()) / (1000 * 3600 * 24);
chartData.push({
date: currentDate,
gestationalAge: Math.max(0, currentGestationalAgeDays), // Ensure non-negative
daysPostIUI: Math.max(0, currentDaysPostIUI) // Ensure non-negative
});
}
// Determine Y-axis scales
var maxGestationalAge = 280; // Standard 40 weeks
var maxDaysPostIUI = 280; // Standard 40 weeks
// Draw Axes
ctx.strokeStyle = '#ccc';
ctx.lineWidth = 1;
// X-axis (Time)
ctx.beginPath();
ctx.moveTo(padding, chartHeight – padding);
ctx.lineTo(chartWidth – padding, chartHeight – padding);
ctx.stroke();
// Y-axis (Gestational Age)
ctx.beginPath();
ctx.moveTo(padding, padding);
ctx.lineTo(padding, chartHeight – padding);
ctx.stroke();
// Y-axis (Days Post-IUI) – Use a secondary axis or overlay if needed, but for simplicity, let's scale them similarly if possible.
// For this chart, let's plot both on the same scale relative to 0.
// Draw Labels and Ticks
ctx.fillStyle = '#333';
ctx.font = '10px Arial';
ctx.textAlign = 'center';
// X-axis labels (Dates)
var numXTicks = 5;
for (var i = 0; i < numXTicks; i++) {
var dateTickPos = padding + (chartAreaWidth / (numXTicks – 1)) * i;
var dateIndex = Math.round(chartData.length / (numXTicks – 1) * i);
if (chartData[dateIndex]) {
var dateLabel = formatDate(chartData[dateIndex].date).substring(5); // MM-DD
ctx.fillText(dateLabel, dateTickPos, chartHeight – padding + 15);
ctx.beginPath();
ctx.moveTo(dateTickPos, chartHeight – padding – 5);
ctx.lineTo(dateTickPos, chartHeight – padding);
ctx.stroke();
}
}
// Y-axis labels (Gestational Age)
ctx.textAlign = 'right';
var numYTicks = 5;
for (var i = 0; i < numYTicks; i++) {
var ageTickPos = chartHeight – padding – (chartAreaHeight / (numYTicks – 1)) * i;
var ageValue = Math.round((maxGestationalAge / (numYTicks – 1)) * i);
ctx.fillText(ageValue + 'd', padding – 10, ageTickPos + 5);
ctx.beginPath();
ctx.moveTo(padding – 5, ageTickPos);
ctx.lineTo(padding, ageTickPos);
ctx.stroke();
}
// Draw Data Series
ctx.lineWidth = 2;
// Series 1: Gestational Age
ctx.strokeStyle = getComputedStyle(document.documentElement).getPropertyValue('–primary-color');
ctx.beginPath();
for (var i = 0; i < chartData.length; i++) {
var x = padding + (chartAreaWidth / (chartData.length – 1)) * i;
var y = chartHeight – padding – (chartAreaHeight * (chartData[i].gestationalAge / maxGestationalAge));
if (i === 0) {
ctx.moveTo(x, y);
} else {
ctx.lineTo(x, y);
}
}
ctx.stroke();
// Series 2: Days Post-IUI
ctx.strokeStyle = getComputedStyle(document.documentElement).getPropertyValue('–success-color');
ctx.beginPath();
for (var i = 0; i < chartData.length; i++) {
var x = padding + (chartAreaWidth / (chartData.length – 1)) * i;
// Scale Days Post-IUI similarly to Gestational Age for comparison on the same axis
var y = chartHeight – padding – (chartAreaHeight * (chartData[i].daysPostIUI / maxDaysPostIUI));
if (i === 0) {
ctx.moveTo(x, y);
} else {
ctx.lineTo(x, y);
}
}
ctx.stroke();
}
// Initial calculation on load
document.addEventListener('DOMContentLoaded', function() {
// Set a default date for better user experience
var today = new Date();
var defaultIuiDate = new Date(today.setDate(today.getDate() – 14)); // Default to 14 days ago
getElement('iuiDate').value = formatDate(defaultIuiDate);
calculateDueDate();
});