Understand how age shapes your chances of conceiving — monthly conception rates, ovarian reserve, IVF success benchmarks, and when ACOG recommends seeking specialist care.
✓ Medically reviewed✓ Updated June 2026✓ Based on ACOG, SART & CDC data✓ 12-minute read
Quick summary
Fertility peaks in the mid-20s and begins a gradual decline from about age 30, with a steeper drop after 35. At 25, roughly 1 in 4 cycles results in pregnancy; by 40, that falls to about 1 in 10. Age is the single strongest predictor of fertility — but it is not the only one. Use the calculator below to see evidence-based benchmarks for your age, then read on for the complete picture.
Select your age to see evidence-based fertility benchmarks for that stage of reproductive life.
Fertility snapshot — age
Monthly conception chance (fecundity rate)
Chance of conceiving within 12 months
IVF live birth rate per transfer (SART)
Miscarriage risk (chromosomal)
Ovarian reserve status (typical)
ACOG-recommended time to try before consult
Relative fertility potential
How to read these numbers: All figures represent population averages drawn from published studies, SART (Society for Assisted Reproductive Technology) national data, and ACOG clinical guidance. Individual fertility varies widely — these are reference benchmarks, not personal predictions. Speak with a reproductive endocrinologist for a personalised assessment.
Why age is the strongest predictor of fertility
Unlike most other organs, the ovaries begin working with a finite, non-renewable supply established before a woman is even born. A female fetus has an estimated 6–7 million eggs (oocytes) at around 20 weeks of gestation. By birth, that number has already fallen to about 1–2 million. By puberty it is closer to 300,000–500,000. Of these, only around 300–400 will ever be ovulated over a reproductive lifetime — the rest undergo a continuous process of natural cell death called atresia.
Egg quantity declines with age
Ovarian reserve (the remaining pool of eggs) shrinks every month, accelerating after the mid-30s. A woman in her early 40s may have only a few thousand eggs remaining, compared to several hundred thousand in her 20s.
Egg quality declines with age
As eggs age, chromosomal errors (aneuploidy) become more common. This is why miscarriage rates and the risk of conditions like Down syndrome rise with maternal age — the egg’s ability to divide correctly after fertilisation decreases.
Uterine environment changes
Implantation success also depends on the uterine lining. With age, conditions like fibroids and endometriosis become more prevalent, and the endometrium’s receptivity can decrease.
Hormonal changes alter cycle regularity
As ovarian reserve depletes, FSH (follicle-stimulating hormone) rises and AMH (anti-Müllerian hormone) falls — measurable signals that ovarian function is changing. Cycles may become irregular in the late 30s and 40s.
Key principle: Age affects the eggs themselves, not just the chances of ovulation. This is why donor-egg IVF, which uses eggs from a younger donor, has much higher success rates for older recipients — it largely bypasses the age-related egg-quality issue.
Fertility decade by decade
🌿 In your 20s: peak reproductive years
The early-to-mid 20s represent the biological peak of female fertility. Egg quality is highest, monthly conception rates are at their best (roughly 20–25% per cycle for healthy couples), and miscarriage risk is at its lowest (~10%). Most couples in their 20s who are trying to conceive will succeed within 6–12 months without intervention.
ACOG guidance: if you are under 35 and have been trying for 12 months without success, it is appropriate to seek an evaluation. Many clinicians suggest earlier evaluation if there are known risk factors such as irregular periods, a prior pelvic infection, or endometriosis.
🌿 Early-to-mid 30s: fertility begins to decline
Fertility starts declining in the early 30s, with a more pronounced drop around age 32–33. Monthly conception rates fall to roughly 15–20% per cycle, and the chance of conceiving within a year drops modestly. The shift is real but often overstated in popular culture — the large majority of women who try to conceive in their early 30s will do so naturally and have healthy pregnancies.
The mid-30s (35–37) mark the threshold at which ACOG recommends seeking evaluation after just 6 months of trying rather than 12, because time becomes a more important factor and early intervention can be beneficial.
🌿 Late 30s: steeper decline, but natural conception still common
After 35, the decline steepens noticeably. Monthly conception rates drop to around 10–15% per cycle. Miscarriage rates rise to 20–25%, largely due to increasing chromosomal errors in eggs. IVF success rates also begin to fall more steeply. That said, the majority of women aged 35–39 who seek treatment — and many who conceive naturally — still go on to have healthy babies.
Age 35 is a clinical threshold not because fertility falls off a cliff there, but because the decline becomes steeper and statistically significant enough that waiting longer before evaluation has meaningful costs.
🌿 Age 40 and beyond: conception possible but more challenging
Monthly conception rates in the early 40s fall to roughly 5–10% per cycle. Miscarriage risk rises substantially (40–50% by age 40, and higher at 42–44). IVF with a woman’s own eggs has significantly lower success rates (around 5–20% per transfer depending on exact age), though donor-egg IVF maintains success rates of 40–50%+ regardless of recipient age. Natural conception still occurs, but the timeline is longer and specialist care is recommended promptly.
ACOG guidance recommends immediate evaluation for women 40 and older who are trying to conceive, without a waiting period.
Age group
Monthly conception rate
Conceives within 1 year
Miscarriage risk
ACOG: seek help after
20–24
~25%
~93%
~10%
12 months trying
25–29
~20–25%
~89%
~11%
12 months trying
30–34
~15–20%
~78%
~15%
12 months trying
35–39
~10–15%
~52%
~20–35%
6 months trying
40–44
~5–10%
~36%
~40–50%
Immediately
45+
~1–5%
<20%
~50–90%
Immediately
Sources: ACOG Committee Opinion No. 589; Dunson DB et al. (2002), Fertility and Sterility; CDC ART National Summary Report 2022.
Infographic
How fertility changes across the reproductive lifespan
Approximate monthly conception rate (fecundity rate) for couples with regular unprotected intercourse, population averages.
Line chart of female fertility decline by age
Monthly conception rates start around 25% at age 20, stay high through mid-20s, begin falling around 30, drop more steeply after 35, and fall to about 5% at 42 and near zero by 47.
0%
10%
20%
30%
40%
20
25
30
35
40
45
50
Age (years)
Monthly conception rate
PEAK
DECLINE
STEEP DECLINE
~25%
~27%
~20%
~15%
~8%
~3%
Age 35 threshold
Figure 1. Approximate monthly fecundity rates by age for healthy couples. Sources: Dunson DB et al. (2002) Fertility & Sterility; ACOG Committee Opinion No. 589. Curve represents population averages; individual variation is significant.
Peak fertility (20s) Early decline (30–34) Steep decline (35+)
Egg reserve, AMH, and what the tests actually show
Ovarian reserve tests don’t tell you how fertile you are right now — they estimate how many eggs you have left, which predicts how your ovaries will respond to fertility treatment. The two most commonly used markers are:
AMH (Anti-Müllerian Hormone)
Produced by small follicles in the ovary, AMH can be measured at any point in the cycle and is the most reliable single marker of ovarian reserve. It declines with age but varies significantly between individuals at the same age — some 38-year-olds have AMH levels typical of 28-year-olds, and vice versa.
AFC (Antral Follicle Count)
An early-cycle transvaginal ultrasound counts the small follicles visible in both ovaries. A higher AFC suggests a larger pool of recruitable eggs. Combined with AMH, AFC gives a reliable picture of likely response to ovarian stimulation.
Infographic
Typical AMH levels by age
Population median values — individual variation is wide. These ranges are illustrative, not diagnostic thresholds.
Bar chart of typical AMH levels by age group
AMH levels decline with age: approximately 3.5 ng/mL at age 25, 2.5 at 30, 1.5 at 35, 0.7 at 38, 0.3 at 41, and below 0.1 at 44 and older.
0
1
2
3
4
AMH (ng/mL)
3.5
Age 25
2.5
Age 30
1.5
Age 35
0.7
Age 38
0.3
Age 41
<0.1
Age 44
Low reserve
Figure 2. Approximate median AMH values by age. Source: Seifer DB et al. (2011), Fertility & Sterility; La Marca A et al. (2012). Individual values vary widely — some women at 38 have high-normal AMH; others at 30 test low. AMH must be interpreted in clinical context.
An important caveat: AMH predicts ovarian response, not pregnancy success. A low AMH means fewer eggs available for retrieval, which matters a lot for IVF planning. But among women who do conceive naturally, low-AMH women have similar live birth rates per pregnancy as normal-AMH women of the same age. AMH doesn’t predict the quality of the eggs that remain — age does.
What if my AMH is low for my age? Low ovarian reserve for your age group means fewer eggs to work with, but doesn’t mean you cannot conceive. A reproductive endocrinologist can advise on whether treatment (such as IVF or IUI) is appropriate, how many cycles may be needed, or whether egg freezing is worth considering.
IVF success rates by age
IVF (in vitro fertilisation) does not overcome age-related egg quality decline — it simply retrieves more eggs at once, giving more chances for one to succeed. Because egg quality declines with age, IVF success rates using a woman’s own eggs (autologous IVF) fall significantly after 35, and drop steeply after 40.
Infographic
IVF live birth rate per intended egg retrieval, by age
U.S. national averages from SART 2022 data (own-egg cycles). Donor-egg rates shown for comparison.
Horizontal bar chart of IVF live birth rates by age
IVF live birth rates using own eggs: under 35 around 52%, 35-37 around 38%, 38-40 around 25%, 41-42 around 12%, 43-44 around 5%, 45 and over around 2%. Donor egg rate across all ages around 45%.
Under 35
52%
35–37
38%
38–40
25%
41–42
12%
43–44
5%
Donor egg ~45%
45+
~2%
Figure 3. IVF live birth rate per intended egg retrieval (own eggs). Source: SART National Summary 2022. Donor-egg cycles maintain ~45% success across all recipient ages because egg quality is determined by the donor’s age.
Donor egg IVF: why age matters less
When eggs from a young donor (typically under 30) are used, success rates remain consistently high regardless of the recipient’s age, because the limiting factor — egg quality — is determined by the donor. This is why a 44-year-old woman using donor eggs has a similar chance of a live birth per transfer as a 30-year-old using her own eggs. Donor-egg IVF is often the most effective option for women whose own egg quality or quantity has significantly diminished.
Preimplantation Genetic Testing (PGT-A): For women over 37 doing IVF with their own eggs, testing embryos for chromosomal abnormalities (PGT-A) can improve implantation rates per transfer and reduce miscarriage rates by selecting chromosomally normal (euploid) embryos. Talk to your reproductive endocrinologist about whether this is appropriate for your situation.
When to seek fertility help — ACOG guidance by age
ACOG (American College of Obstetricians and Gynecologists) provides clear age-specific guidance on when to seek an evaluation rather than continuing to try naturally:
Age group
ACOG recommendation
Why
Under 35
Seek evaluation after 12 months of regular unprotected intercourse without conception
Most couples in this age group will conceive within 12 months; continued failure suggests a treatable cause
35–39
Seek evaluation after 6 months
Fertility declines accelerate; earlier evaluation means more time for treatment options
40 and older
Seek evaluation immediately, without a waiting period
Time is a critical factor; waiting reduces the window for treatment with own eggs
You should also seek evaluation sooner, regardless of age, if you have:
Irregular or absent periods
A known or suspected diagnosis of endometriosis, PCOS, uterine fibroids, or polycystic ovarian syndrome
A history of pelvic inflammatory disease (PID) or sexually transmitted infections
A prior ectopic pregnancy or pelvic surgery
A partner with known male factor infertility
Two or more previous miscarriages (recurrent pregnancy loss)
A prior cancer treatment that may have affected ovarian function
Calculate your fertile window
Know which days each cycle give you the best chance — timed intercourse is the first step before any intervention.
Unlike female fertility, male fertility does not have a sharp cliff at a specific age — men produce new sperm throughout their lives. However, sperm quality does decline with age, and the effects are real and clinically relevant:
Sperm DNA fragmentation
DNA damage in sperm increases with age, raising the risk of miscarriage and certain developmental conditions even when the sperm successfully fertilises an egg.
Sperm motility and morphology
The proportion of sperm with normal shape and swimming ability declines gradually from the 30s onwards, reducing the likelihood of reaching and fertilising an egg.
De novo mutations
The number of new (de novo) genetic mutations per sperm increases with paternal age. Research links advanced paternal age (>40–45) with a modestly elevated risk of autism spectrum disorder, schizophrenia, and certain other conditions in offspring.
The practical takeaway: infertility is a couple’s issue, and a full evaluation should include a semen analysis for the male partner. In roughly 40% of couples evaluated for infertility, a male factor is identified — sometimes as the primary cause, sometimes alongside female factors. A semen analysis is non-invasive, widely available, and should be part of any initial fertility workup.
Age threshold for male fertility evaluation: ACOG and the American Society for Reproductive Medicine (ASRM) do not set a specific age at which men should seek evaluation, but recommend including a semen analysis in any infertility workup regardless of the male partner’s age.
Common fertility-and-age myths, debunked
Myth
“Fertility falls off a cliff at 35.”
Fact
Fertility declines gradually from the early 30s. Age 35 is a clinical threshold for evaluation timing, not a biological event. Many women conceive naturally in their late 30s.
Myth
“A low AMH result means I can’t get pregnant naturally.”
Fact
AMH predicts response to IVF stimulation, not your chances of natural conception. Women with low AMH conceive naturally every day. It means the window may be shorter, not closed.
Myth
“IVF can always solve age-related infertility.”
Fact
IVF using own eggs doesn’t reverse egg-quality decline — it just retrieves more eggs at once. Success rates with own eggs still fall significantly with age. Donor egg IVF is more effective for older women.
Myth
“Stress is what’s really preventing conception.”
Fact
While extreme stress can disrupt ovulation, normal life stress is not a proven cause of infertility. This myth causes unnecessary guilt. If structural or age-related factors are present, relaxation will not overcome them.
Myth
“Egg freezing at 38 gives you the same chance as conceiving naturally at 38.”
Fact
Frozen eggs preserve the quality they had at the time of freezing, but success rates per egg thawed are lower than natural conception. Earlier freezing (mid-30s or sooner) yields better-quality eggs and more of them.
Myth
“Fertility only depends on the woman.”
Fact
Male factor contributes to around 40% of infertility cases. Sperm quality declines with paternal age too, and a semen analysis should be part of any couple’s initial evaluation.
Frequently asked questions
Fertility begins declining gradually in the early 30s, with a more noticeable drop around age 32–33. The decline becomes steeper after 35, and significantly steeper again after 40. There is no single moment when fertility disappears — it is a continuous biological process.
For a healthy couple in their mid-20s having regular unprotected sex, roughly 20–25% of cycles result in pregnancy. This falls to around 15–20% in the early 30s, 10–15% in the late 30s, and 5–10% in the early 40s. These are population averages; individual variation is significant.
PCOS (polycystic ovary syndrome) can cause irregular or absent ovulation, making natural conception harder. However, women with PCOS often have a higher ovarian reserve than average — which can mean a somewhat slower age-related decline in egg quantity. The challenge with PCOS is ovulation timing, not necessarily egg quality, and it is highly treatable with medications like letrozole or clomiphene.
Yes, natural conception at 40 is possible. Monthly conception rates at 40 are approximately 5–10%, and many women conceive naturally in their early 40s. However, it takes longer on average, miscarriage risk is higher, and ACOG recommends seeking an evaluation immediately rather than waiting. Early specialist involvement can help maximise your chances.
A low AMH relative to your age means your ovarian reserve is smaller than typical for someone of the same age — sometimes called “diminished ovarian reserve” (DOR). It does not mean you cannot conceive, but it does mean: you may have fewer eggs available for IVF retrieval; the window for natural or assisted conception may be shorter; and prompt specialist evaluation is worthwhile to make an informed plan.
Yes, significantly. Miscarriage risk at 25 is roughly 10%. It rises to around 20% at 35, 40–50% at 40, and higher still at 42–44. The main reason is chromosomal errors (aneuploidy) in eggs, which become more common with age. An aneuploidy embryo typically results in early miscarriage rather than a live birth.
At 37, egg freezing can still yield viable eggs, but the number and quality recovered per cycle is lower than at 32–34. Success rates per frozen egg decline with the age at freezing. Whether it is worthwhile depends on your personal situation, your AMH/AFC, and how many eggs your RE thinks can be retrieved per cycle. Most reproductive endocrinologists recommend multiple retrieval cycles at this age to bank a meaningful number of eggs.
While men continue producing sperm throughout life, sperm quality declines with age. Sperm DNA fragmentation increases, motility and morphology may worsen, and the risk of de novo genetic mutations in sperm rises with paternal age. Research suggests elevated paternal age (>40–45) is associated with modestly increased risks for certain conditions in offspring and may also contribute to miscarriage risk. A semen analysis is an essential part of any fertility evaluation regardless of the male partner’s age.
Medically reviewed by Dr. Ruqaiya Khan, MD, FACOG
Board-Certified Obstetrician–Gynecologist
Dr. Khan reviews all fertility, reproductive-endocrinology, and age-related content on PregCalc.com for clinical accuracy against current ACOG, ASRM, and SART guidance. Last reviewed: . View reviewer credentials →
Sources: ACOG Committee Opinion No. 589 — Female Age-Related Fertility Decline·SART National Summary Report 2022·CDC ART National Summary 2022·Dunson DB et al. (2002), Fertility & Sterility·Seifer DB et al. (2011), Fertility & Sterility·ASRM Practice Committee guidelines
{
“@context”: “https://schema.org”,
“@graph”: [
{
“@type”: “MedicalWebPage”,
“@id”: “https://pregcalc.com/fertility-by-age-calculator/#webpage”,
“url”: “https://pregcalc.com/fertility-by-age-calculator/”,
“name”: “Fertility by Age Calculator — Conception Chances, Egg Reserve & IVF Rates | PregCalc”,
“headline”: “Fertility by Age Calculator”,
“description”: “Interactive calculator and medically reviewed guide to female fertility by age. Covers monthly conception rates, egg reserve (AMH), IVF success rates by age, and ACOG guidance on when to seek specialist help.”,
“inLanguage”: “en-US”,
“lastReviewed”: “2026-06-27”,
“datePublished”: “2026-06-27”,
“dateModified”: “2026-06-27”,
“reviewedBy”: { “@id”: “https://pregcalc.com/about/dr-ruqaiya-khan/#person” },
“author”: { “@id”: “https://pregcalc.com/about/dr-ruqaiya-khan/#person” },
“medicalAudience”: { “@type”: “MedicalAudience”, “audienceType”: “Patient” },
“about”: { “@type”: “MedicalCondition”, “name”: “Infertility” },
“specialty”: “Obstetrics and Gynecology”,
“isPartOf”: { “@type”: “WebSite”, “name”: “PregCalc”, “url”: “https://pregcalc.com/” },
“publisher”: {
“@type”: “Organization”,
“name”: “PregCalc”,
“logo”: { “@type”: “ImageObject”, “url”: “https://pregcalc.com/wp-content/uploads/pregcalc-logo.png” }
}
},
{
“@type”: “FAQPage”,
“mainEntity”: [
{ “@type”: “Question”, “name”: “At what age does female fertility start to decline?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “Fertility begins declining gradually in the early 30s, with a more noticeable drop around age 32-33. The decline becomes steeper after 35, and significantly steeper again after 40. There is no single moment when fertility disappears – it is a continuous biological process.” } },
{ “@type”: “Question”, “name”: “What is a normal monthly chance of getting pregnant?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “For a healthy couple in their mid-20s having regular unprotected sex, roughly 20-25% of cycles result in pregnancy. This falls to around 15-20% in the early 30s, 10-15% in the late 30s, and 5-10% in the early 40s.” } },
{ “@type”: “Question”, “name”: “Can I get pregnant naturally at 40?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “Yes, natural conception at 40 is possible. Monthly conception rates at 40 are approximately 5-10%, and many women conceive naturally in their early 40s. However, ACOG recommends seeking an evaluation immediately rather than waiting.” } },
{ “@type”: “Question”, “name”: “What does it mean if my AMH is low for my age?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “A low AMH relative to your age means your ovarian reserve is smaller than typical, sometimes called diminished ovarian reserve (DOR). It does not mean you cannot conceive, but it may mean fewer eggs for IVF and a shorter window for treatment. Prompt specialist evaluation is worthwhile.” } },
{ “@type”: “Question”, “name”: “Does miscarriage risk really increase with age?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “Yes, significantly. Miscarriage risk at 25 is roughly 10%, rising to around 20% at 35, 40-50% at 40, and higher at 42-44. The main reason is chromosomal errors (aneuploidy) in eggs, which become more common with age.” } },
{ “@type”: “Question”, “name”: “How does paternal age affect fertility?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “Sperm quality declines with age – DNA fragmentation increases, motility and morphology may worsen, and de novo genetic mutations rise. A semen analysis is an essential part of any fertility evaluation regardless of the male partner’s age.” } },
{ “@type”: “Question”, “name”: “Is egg freezing worth it at 37?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “At 37, egg freezing can still yield viable eggs but numbers and quality per cycle are lower than at 32-34. Whether it is worthwhile depends on your AMH/AFC and how many eggs can be retrieved per cycle. Your RE may recommend multiple retrieval cycles.” } },
{ “@type”: “Question”, “name”: “How does PCOS affect fertility by age?”, “acceptedAnswer”: { “@type”: “Answer”, “text”: “PCOS can cause irregular ovulation, making natural conception harder, but women with PCOS often have higher ovarian reserve. The main challenge is ovulation timing, not egg quality, and it is treatable with medications like letrozole or clomiphene.” } }
]
},
{
“@type”: “BreadcrumbList”,
“itemListElement”: [
{ “@type”: “ListItem”, “position”: 1, “name”: “Home”, “item”: “https://pregcalc.com/” },
{ “@type”: “ListItem”, “position”: 2, “name”: “Calculators”, “item”: “https://pregcalc.com/calculators/” },
{ “@type”: “ListItem”, “position”: 3, “name”: “Fertility by Age Calculator”, “item”: “https://pregcalc.com/fertility-by-age-calculator/” }
]
},
{
“@type”: “Person”,
“@id”: “https://pregcalc.com/about/dr-ruqaiya-khan/#person”,
“name”: “Dr. Ruqaiya Khan”,
“jobTitle”: “Obstetrician-Gynecologist”,
“honorificSuffix”: “MD, FACOG”,
“url”: “https://pregcalc.com/about/dr-ruqaiya-khan/”
}
]
}
(function(){
var root = document.getElementById(‘fba-root’);
if(!root) return;
// —- FERTILITY DATA BY AGE —-
function getFertilityData(age) {
if(age <= 24) return {
monthly:'~25%', year:'~93%', ivf:'~52%', mc:'~10%',
reserve:'High', seek:'12 months',
band:'Peak fertility years', bandClass:'band-green',
meter:95,
note:'Your fertility is at or near its biological peak. Monthly conception rates are highest in the mid-20s. Most couples conceive within 6 months. If you have been trying for 12 months without success, seek evaluation.'
};
if(age <= 29) return {
monthly:'~20-25%', year:'~89%', ivf:'~50%', mc:'~11%',
reserve:'High', seek:'12 months',
band:'Peak fertility years', bandClass:'band-green',
meter:88,
note:'Late 20s remain high-fertility years. Conception rates are excellent and most couples succeed within 12 months. ACOG recommends evaluation if you have been trying for a full year without success.'
};
if(age <= 34) return {
monthly:'~15-20%', year:'~78%', ivf:'~42%', mc:'~15%',
reserve:'Good to moderate', seek:'12 months',
band:'Mild decline beginning', bandClass:'band-gold',
meter:72,
note:'Fertility starts declining in the early 30s, but most women in this age range conceive naturally without intervention. Early evaluation is warranted if you have known risk factors (irregular cycles, prior pelvic infection, endometriosis). ACOG recommends evaluation after 12 months of trying.'
};
if(age <= 37) return {
monthly:'~10-15%', year:'~62%', ivf:'~38%', mc:'~20-25%',
reserve:'Moderate', seek:'6 months',
band:'Decline accelerating', bandClass:'band-gold',
meter:55,
note:'The mid-to-late 30s bring a steeper fertility decline. ACOG recommends seeking evaluation after just 6 months of trying (not 12) because time becomes more valuable. IVF with own eggs still has reasonable success rates. This is also an optimal age range to consider egg freezing if desired.'
};
if(age <= 40) return {
monthly:'~8-12%', year:'~45%', ivf:'~20-25%', mc:'~30-40%',
reserve:'Low to moderate', seek:'6 months',
band:'Significant decline', bandClass:'band-clay',
meter:38,
note:'Late 30s to 40: fertility has declined significantly. ACOG recommends evaluation after 6 months. IVF success rates with own eggs are lower but viable; PGT-A testing of embryos can improve per-transfer success. Miscarriage risk rises substantially due to egg chromosomal errors.'
};
if(age <= 43) return {
monthly:'~5-10%', year:'~36%', ivf:'~8-12%', mc:'~40-50%',
reserve:'Low', seek:'Immediately',
band:'Seek specialist care now', bandClass:'band-clay',
meter:22,
note:'ACOG recommends immediate fertility evaluation at age 40 and above, without waiting. Natural conception is still possible, but the window is narrowing. Donor-egg IVF maintains high success rates (~45%) regardless of recipient age and is worth discussing with your RE.'
};
return {
monthly:'~1-5%', year:'<20%', ivf:'~2-5% (own eggs)', mc:'50-90%',
reserve:'Very low', seek:'Immediately',
band:'Specialist care recommended', bandClass:'band-clay',
meter:8,
note:'At 44 and above, natural conception with own eggs is rare but not impossible. IVF with own eggs has very low success rates at this age; donor-egg IVF (~45% per transfer) is the most effective treatment option. A reproductive endocrinologist can help you understand all available paths.'
};
}
// —- SLIDER —-
var slider = document.getElementById('fba-age-slider');
var ageVal = document.getElementById('fba-age-val');
slider.addEventListener('input', function(){
ageVal.textContent = this.value;
slider.setAttribute('aria-valuenow', this.value);
// Clear pill active state
root.querySelectorAll('.fba-range-pill').forEach(function(p){ p.classList.remove('active'); });
});
// —- QUICK PILLS —-
root.querySelectorAll('.fba-range-pill').forEach(function(pill){
pill.addEventListener('click', function(){
var age = parseInt(this.dataset.age);
slider.value = age;
ageVal.textContent = age;
slider.setAttribute('aria-valuenow', age);
root.querySelectorAll('.fba-range-pill').forEach(function(p){ p.classList.remove('active'); });
this.classList.add('active');
showResult(age);
});
});
// —- CALCULATE BUTTON —-
document.getElementById('fba-go-btn').addEventListener('click', function(){
showResult(parseInt(slider.value));
});
function showResult(age) {
var d = getFertilityData(age);
document.getElementById('fba-res-age').textContent = age;
document.getElementById('fba-s-monthly').textContent = d.monthly;
document.getElementById('fba-s-year').textContent = d.year;
document.getElementById('fba-s-ivf').textContent = d.ivf;
document.getElementById('fba-s-mc').textContent = d.mc;
document.getElementById('fba-s-reserve').textContent = d.reserve;
document.getElementById('fba-s-seek').textContent = d.seek;
document.getElementById('fba-res-note').innerHTML = 'What this means for you: ‘ + d.note;
var band = document.getElementById(‘fba-band-tag’);
band.textContent = d.band;
band.className = ‘fba-age-band-tag ‘ + d.bandClass;
// Meter
document.getElementById(‘fba-meter-pct’).textContent = d.meter + ‘%’;
// Animate meter
var fill = document.getElementById(‘fba-meter-fill’);
fill.style.width = ‘0%’;
setTimeout(function(){ fill.style.width = d.meter + ‘%’; }, 60);
// Color meter
if(d.meter >= 70) fill.style.background = ‘var(–sage)’;
else if(d.meter >= 40) fill.style.background = ‘var(–gold)’;
else fill.style.background = ‘var(–clay)’;
// Show result
var res = document.getElementById(‘fba-result’);
res.classList.add(‘visible’);
// Scroll into view smoothly
setTimeout(function(){
res.scrollIntoView({ behavior:’smooth’, block:’nearest’ });
}, 80);
}
// —- FAQ ACCORDION —-
root.querySelectorAll(‘.pc-faq-q’).forEach(function(q){
q.addEventListener(‘click’, function(){
var open = q.getAttribute(‘aria-expanded’) === ‘true’;
q.setAttribute(‘aria-expanded’, String(!open));
q.nextElementSibling.classList.toggle(‘open’, !open);
});
});
// —- SMOOTH SCROLL TOC —-
var reduceMotion = window.matchMedia && window.matchMedia(‘(prefers-reduced-motion:reduce)’).matches;
root.querySelectorAll(‘.pc-toc a[href^=”#”]’).forEach(function(link){
link.addEventListener(‘click’, function(e){
var target = document.getElementById(link.getAttribute(‘href’).slice(1));
if(!target) return;
e.preventDefault();
target.scrollIntoView({ behavior: reduceMotion ? ‘auto’ : ‘smooth’, block:’start’ });
if(history.pushState) history.pushState(null, ”, ‘#’ + target.id);
});
});
// —- ANIMATE CHARTS ON SCROLL —-
if(‘IntersectionObserver’ in window){
var io = new IntersectionObserver(function(entries){
entries.forEach(function(e){
if(e.isIntersecting){
root.classList.add(‘fba-root-in’);
io.disconnect();
}
});
}, { threshold:0.2 });
var firstChart = root.querySelector(‘svg’);
if(firstChart) io.observe(firstChart);
} else {
root.classList.add(‘fba-root-in’);
}
})();
Our fertility by age calculator draws on established clinical research about how conception odds change over time. For a deeper look at the data behind these trends, see the ACOG committee opinion on female age-related fertility decline, and check out our Ovulation Calculator to pinpoint your most fertile days each cycle.
More free calculators
Plan, track and prepare with our other medically reviewed tools.
