Pregnancy After 35: What Changes

Women entering their thirties may experience a rapid decline in fertility. That's why some mums can have complications when pregnant over 35.

“Advanced maternal age” is a phrase that lands badly, and it means something narrower than it sounds: from 35, you’re offered more monitoring. It’s a category that triggers extra checks, not a warning.

The great majority of pregnancies after 35 are straightforward and produce healthy babies.

Risks do rise with age, and they rise gradually, not at a birthday. A woman of 35 isn’t in a materially different position from one of 34, and the number counts mainly because it’s where guidelines start offering additional care.

What changes

Fertility declines, more steeply from the mid-thirties. This is the biggest change, and it affects getting pregnant, not the pregnancy itself.
Miscarriage risk rises, largely because of chromosomal errors in the egg.
Chromosomal conditions including Down syndrome become more likely, so screening is offered and discussed more carefully.
Gestational diabetes and high blood pressure are more common, and both are picked up by routine antenatal care and are manageable.
Pre-eclampsia risk increases modestly.
Caesarean and induction rates are higher, partly clinical and partly because thresholds for intervention are lower with age.
Stillbirth risk increases slightly, which is behind the closer monitoring in later pregnancy and the tendency to discuss induction around term.
Twins are more likely naturally, because of hormonal changes in later reproductive years.

One more thing: paternal age counts too, and it’s almost never mentioned. Sperm quality declines with age and older fathers are associated with slightly increased risks of their own. This isn’t solely a question about the mother.

Screening tests and the choices involved

Non-invasive prenatal testing (NIPT): a blood test from around 10 weeks, analysing fragments of placental DNA. Highly accurate as a screen, but it’s a screen: a high-risk result needs a diagnostic test to confirm.
First trimester screening: a nuchal translucency scan plus blood tests.
CVS or amniocentesis: diagnostic, not screening, so they give a definite answer, and they carry a small procedure-related miscarriage risk.
The detailed anomaly scan at around 20 weeks.

Decide in advance what you’d do with the information. That’s the question the tests are really asking, and it’s much harder to think about once a result is in front of you. There’s no obligation to have any of them.

What improves the odds

Pre-conception health counts for more than at any other age. Blood pressure, blood glucose, weight and thyroid function should be checked before conceiving, not at eight weeks.
Folic acid from at least a month before.
Stop smoking, both partners.
Low-dose aspirin from early pregnancy is recommended for some women at higher risk of pre-eclampsia. Ask whether it applies to you. It’s effective and frequently not raised.
Go to every appointment. The additional monitoring is the point of the label, and it’s what makes the outcomes good.
Report reduced fetal movement immediately, at any hour. Never wait until morning and never try to provoke movement first. This is more important with age, not less.

If you aren’t pregnant yet

Seek help after six months of trying if you’re 35 or over, instead of the usual twelve.
Get the semen analysis done first, and at the same time as anything else. Male factors account for close to half of infertility and it’s the fastest test there is.
Egg freezing has been available in Singapore for elective use since 2023, for women aged 21 to 37. Look into it if a delay is likely, though it’s expensive and not a guarantee.
A fertility check is reasonable to ask for before you start trying, not after a year of not succeeding.

How this gets talked about

The language around older mothers is unhelpfully alarming. “Geriatric pregnancy” is still in circulation and is a term nobody needs to hear at a scan. Women in their late thirties and forties have healthy pregnancies routinely, and the increases in risk, while real, are usually modest in absolute terms.

If your obstetrician isn’t explaining the numbers in absolute terms rather than relative ones, the actual chance, not how much it has “doubled”, ask them to. Relative risk is what makes this frightening; absolute risk is what makes it decidable.

Frequently asked questions

Is 35 too old to have a baby?

No. The great majority of pregnancies after 35 are straightforward and produce healthy babies. Risks rise gradually with age, not at a birthday, and 35 is simply where guidelines begin offering extra monitoring.

What risks increase after 35?

Declining fertility, the biggest change, and it affects conceiving, not the pregnancy. Then miscarriage, chromosomal conditions, gestational diabetes, high blood pressure, pre-eclampsia, higher caesarean and induction rates, and a slight increase in stillbirth risk, so later monitoring is closer.

What screening is offered?

NIPT, a blood test from around 10 weeks that’s highly accurate but still a screen, not a diagnosis; first trimester screening with a nuchal scan and bloods; CVS or amniocentesis, which are diagnostic and carry a small miscarriage risk; and the 20-week anomaly scan. Decide in advance what you’d do with the information. That’s the harder question, and it’s much harder once a result is in front of you.

How long should we try before seeking help?

Six months if you’re 35 or over, instead of the usual twelve. Ask for the semen analysis at the same time as any investigation of you. Male factors account for close to half of infertility and it’s the quickest test available.

What can I do to improve my chances of a healthy pregnancy?

Check blood pressure, glucose, weight and thyroid before conceiving, not at eight weeks. Take folic acid from a month beforehand, stop smoking, attend every appointment, and ask whether low-dose aspirin applies to you. It’s effective for women at higher risk of pre-eclampsia and is often not raised.

Does the father’s age matter?

Yes, and it’s rarely mentioned. Sperm quality declines with age and older fathers are associated with slightly increased risks of their own. This isn’t solely a question about the mother’s age.

What to remember

“Advanced maternal age” means more monitoring, not more danger. Most pregnancies after 35 are healthy.

Sort out blood pressure, glucose and folic acid before conceiving, and ask whether low-dose aspirin applies to you.

Six months of trying, not twelve, before asking for help. And get his test done at the same time as yours.

And report reduced fetal movement immediately, at any hour. That one matters more with age, not less.