Screening tests in pregnancy in New Zealand

What you are offered

Screening in Aotearoa New Zealand splits into three parts: a set of blood tests offered to everyone at the first antenatal visit, an optional screening pathway for Down syndrome and other conditions, and ultrasound scans that check how your pēpi is growing. Health New Zealand | Te Whatu Ora oversees the programme, and every part of it is your choice.

The money question matters here more than in most countries, because the split between what is free and what you pay for is not obvious. The blood tests are free. The scans usually are not.

The first antenatal blood tests — seven tests, one needle, no charge

At your first appointment with a midwife or doctor you are offered seven tests taken from a single blood sample, all free:

• Full blood count — checks for anaemia, most often caused by low iron, and also checks platelets and white cells.
• Blood group and antibodies — A, B, O or AB, plus antibodies that could affect your baby.
• Rhesus factor — if you are Rh negative and your blood mixes with your baby's, you can produce antibodies that cause severe anaemia and jaundice in this or a later pregnancy. An anti-D injection within 72 hours of any bleed, miscarriage, abdominal injury or the birth itself prevents that.
• Rubella immunity — if you are not immune you are offered MMR after the birth, never during pregnancy.
• Hepatitis B — about 20% of babies exposed at birth and left untreated become infected, and over 90% of those become carriers. If you are positive, your baby is offered immunoglobulin and immunisation at birth.
• HIV — treatment protects the baby and keeps you well. Results are sent in confidence to your midwife or doctor.
• Diabetes (HbA1c) — a non-fasting blood test showing your average blood sugar over the past four to six weeks.

Screening for Down syndrome and other conditions

This is a universal offer, at any age, and there are exactly two pathways. Both estimate the chance of Down syndrome (trisomy 21), Edwards syndrome (trisomy 18), Patau syndrome (trisomy 13) and some other rare genetic conditions.

If you are under 14 weeks: blood test plus ultrasound

You need both parts to get a result.

• The blood test can be taken from 9 weeks to 13 weeks 6 days, and is best at 9 to 10 weeks. It measures PAPP-A and beta-hCG.
• The nuchal translucency scan is offered between 11 and 14 weeks and is best between 12 weeks and 13 weeks 6 days. It measures the fluid at the back of your baby's neck, confirms dates and picks up a multiple pregnancy.

If you are 14 to 20 weeks: blood test only

A single maternal serum screening blood test, best taken between 14 and 18 weeks but available up to 20 weeks.

Whichever pathway you take, your results are combined with your age, weight and gestation, and your midwife or doctor gives them to you within 10 days.

The scans, and what they cost

Health New Zealand no longer recommends routine dating scans before 12 weeks unless there is a concern about the pregnancy or your health. The two scans that matter are:

• Nuchal translucency scan, 11 to 14 weeks — best at 12 weeks.
• Fetal anatomy scan, 18 to 20 weeks — about 30 minutes, checking size and growth, head, heart, spine, limbs and abdomen, and the fluid around the placenta. It cannot pick up everything, and how much can be seen depends on your baby's position and your body shape.

A fetal echocardiogram, a detailed scan of the baby's heart taking about 45 minutes, is usually done around 20 weeks where there is a reason to look more closely.

Cost is the sting. At participating providers the maximum you pay is $90 per scan, or $30 per scan if you hold a Community Services Card. Some providers charge less, and in some areas extra funding makes scans free or cheaper still. Health New Zealand publishes the participating provider list by region, and it is worth checking it before you book rather than after.

If your result shows an increased chance

Your midwife or doctor will discuss the result and offer to refer you to a specialist. That referral is your choice, as is anything that follows it.

The specialist may offer non-invasive prenatal screening (NIPS), a further blood test that gives much more accurate information about the chance of Down syndrome and other conditions. If the NIPS result comes back as increased chance, you are then offered diagnostic testing to find out for certain. Accepting the referral, and accepting anything offered after it, is your choice at every step.

Only a diagnostic test can confirm a condition. Amniocentesis, usually done from 15 weeks, takes a sample of the fluid around the baby; chorionic villus sampling takes a sample of the placenta. Both use a needle guided by ultrasound. The chance of miscarriage after a diagnostic procedure is around 3 in 1,000. Amniocentesis is the more common of the two in New Zealand.

Diabetes testing later in pregnancy

Diabetes testing is offered twice. The HbA1c comes with your first bloods. If you are not at high risk, you are then offered an oral glucose challenge test — the polycose test — between 24 and 28 weeks. You drink a sugary drink, wait an hour and give a blood sample; there is no fasting and it can be done at any time of day. If the HbA1c showed diabetes, you are offered a repeat HbA1c three months after the birth.

After the birth: the heel prick test

Newborn metabolic screening, known as the heel prick or Guthrie test, is offered to every baby and is free for all eligible pēpi. Four drops of blood are taken from the heel onto a card at or as soon as possible after 24 hours of age, and screened for rare but serious disorders that cannot be detected by examination. Early treatment can prevent permanent damage or death. Newborn hearing screening is also offered free in every region, whether your baby is born in hospital or at home.

What happens if you decline

Nothing changes about the rest of your care. Screening is optional at every stage: you can have the blood tests and skip the genetic screening, have the genetic screening and decline the referral, or accept the referral and decline the diagnostic test. Your decision will be respected and recorded.

Be aware that a screening result is never perfect. You may be told your pēpi has a higher chance of a condition when they do not, and occasionally the reverse. That uncertainty is inherent to screening rather than a failure of the test.

Where to get help

Health New Zealand | Te Whatu Ora is the governing authority and publishes the screening pathways, the participating ultrasound provider list and the newborn screening information. Your lead maternity carer — usually a midwife — arranges every test on this page and is the person to ask first. HealthEd carries the national decision-support booklet on screening and testing for Down syndrome and other conditions, written for parents rather than clinicians. Healthline is available free on 0800 611 116, 24 hours a day, if you need advice out of hours.