Your first trimester has four jobs: book your first antenatal appointment for 6 to 8 weeks, choose your model of care, decide about screening tests and keep taking folic acid and iodine.
What actually happens between now and 13 weeks
The first trimester is when almost all of the structural development happens, and almost none of the monitoring does. Your baby's organs are largely formed by about 10 weeks. Your first appointment will often be your first contact with the health system.
That gap is the reason this checklist exists. There is a stretch of several weeks where you are making decisions on your own.
In Australia, guidelines recommend the first antenatal visit happen within the first 10 weeks of pregnancy.¹ In 2023, 60% of women managed it.² If you have already passed 10 weeks, that is common rather than a problem.
If you were doing preconception preparation, most of it carries straight through. The Australian preconception checklist covers what to continue and what can now stop.
The Australian first trimester checklist
There are nine things worth doing before 14 weeks, and the first two unlock most of the rest:
Book your first antenatal appointment, ideally for six to eight weeks
Choose your model of care and get the referral in, because waitlists are real
Decide about aneuploidy screening, NIPT or combined first trimester screening
Have a dating scan to confirm how far along you are
Book the 11 to 14 week ultrasound, which is separate from the dating scan
Continue folic acid to 12 weeks and iodine throughout
Review every medication and supplement you take with your GP
Have the influenza vaccine if it is flu season
Ask for mental health screening if it is not offered
Reproductive genetic carrier screening is still available now if you did not do it before conceiving. Being pregnant does not disqualify you from the Medicare-funded three-gene test.
When should I have my first antenatal appointment?
Book it for 6 to 8 weeks, and book it as soon as you have a positive test. Australian guidelines recommend first antenatal contact within the first 10 weeks of pregnancy.¹
Six to eight weeks is the sweet spot for a reason. It is late enough that a dating scan can confirm a heartbeat and early enough to leave room for screening decisions, which have deadlines attached.
Your GP is usually the entry point. They confirm the pregnancy, order your first round of blood tests, calculate your due date and write the referral for whichever model of care you choose.
Ask for a longer appointment when you book. A first antenatal visit covers medical history, family history, medications, screening options and mental health, and a standard 15-minute slot will not hold it.
If you are further along than 10 weeks already, book now rather than waiting for a tidier milestone. Screening options narrow with gestation rather than disappearing.
What blood tests will I have at my first appointment?
The standard Australian first trimester panel covers a full blood count, blood group and antibody screen, rubella immunity, syphilis, hepatitis B, hepatitis C, HIV and a urine culture.¹
Two additions are worth asking for by name. The first is ferritin, which measures your iron stores and is not always included when a full blood count is ordered. Your haemoglobin can sit inside the normal range while your stores are close to empty.
The second is thyroid function, if you have a thyroid condition, a family history of one or symptoms. Thyroid demand rises early in pregnancy.
If you have diabetes risk factors, an early HbA1c is often added. Cervical screening can also be done in the first trimester if yours is overdue.
The preconception blood test guide explains what each result means, and most of it applies identically now.
Is NIPT covered by Medicare in Australia?
No. NIPT is not publicly funded in Australia, and you pay a private provider directly, typically several hundred dollars.³
This is the single most useful thing to know early, because the alternative is funded. Combined first trimester screening, which pairs a blood test at nine to 13 weeks with a nuchal translucency ultrasound at 11 to 14 weeks, attracts a Medicare rebate, although the ultrasound itself often carries a gap payment.³
RANZCOG's position is that NIPT is a highly accurate screening test for trisomies 21, 18 and 13 from 10 weeks and should be discussed with anyone interested in screening. Where NIPT is not accessed, combined first trimester screening is the recommended option.³ Both recommendations are strong, on moderate-certainty evidence.
RANZCOG also names cost as one of the most significant barriers to access, and notes that applications for public funding of NIPT have gone to the Medical Services Advisory Committee and been unsuccessful.³ Worth knowing that the choice many women describe as clinical is partly financial.
One practical detail: have a dating scan before NIPT, to confirm gestation, viability and whether it is a single pregnancy.³
What does a low chance NIPT result actually mean?
It means low chance, not no chance, and the gap between those two is bigger for some conditions than others.
For trisomy 21, NIPT is very accurate. Where it gets complicated is the expanded panels. RANZCOG's guidance is that expanded NIPT for rare autosomal trisomies and copy number variants is not sufficiently accurate to be routinely offered to everyone, a strong recommendation on moderate-certainty evidence.³
For sex chromosome differences, the pooled positive predictive value was under 50%, meaning more than half of positive results were not confirmed on diagnostic testing.³ Screening for these can still be offered, but with specific counselling first.³
Two other things worth expecting. Between 1% and 6% of NIPT tests return a "no call" result where there was not enough of your baby's DNA in the sample, and a repeat succeeds in roughly half of those cases.³ A BMI above 30 makes a no call more likely.
Any increased chance result on any screening test should be confirmed with diagnostic testing before decisions are made.³ We unpack the arithmetic in how to read NIPT results.
How many ultrasounds should I have in the first trimester?
Two, and they do different jobs. RANZCOG strongly recommends an 11 to 14 week ultrasound alongside the 18 to 22 week scan, because two scans improve timely detection of anomalies.³
Before that, an early dating scan at around 7 to 9 weeks confirms gestational age, checks for a heartbeat and identifies twins. It is what your due date is set by, and it is a prerequisite for NIPT.³
The 11 to 14 week scan is the one people conflate with the dating scan. It includes the nuchal translucency measurement used in combined first trimester screening, and it also screens structurally.
Calibrating expectations honestly: a first trimester scan detects about 37.5% of structural anomalies overall, but 91.3% of lethal ones.³ It is very good at the most serious findings and moderate at everything else.
Access matters here. RANZCOG notes that ultrasound availability in rural and remote Australia limits some women's ability to complete screening at all.³
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How likely is miscarriage in the first trimester?
About 15 in 100 recognised pregnancies end in miscarriage. A 2021 Lancet review pooled the available data and put the risk at 15.3%, with a confidence interval of 12.5% to 18.7%.⁴ That figure comes from observational studies, so treat it as a population estimate rather than your personal odds.
The more useful finding is why. A study of 1,745 first trimester losses found 50.4% were chromosomally abnormal on standard testing, rising to an estimated 67.8% when genome-wide analysis was applied.⁵ That higher number is extrapolated rather than directly measured, so it is indicative.
What that means practically is that most early miscarriage is a chromosomal event that was set at conception. It’s not caused by lifting something, working, exercising, a glass of wine before you knew or stress.
Risk does rise with age, and with very high or very low BMI, smoking and previous miscarriage.⁴
When is morning sickness more than morning sickness?
When you cannot keep fluids down, you are losing weight or you cannot function. That is the line between nausea and vomiting of pregnancy and hyperemesis gravidarum, and it is a medical issue rather than a resilience issue.
Some degree of nausea affects roughly 70% of pregnancies, usually starting around week four, peaking near week nine and settling before 20 weeks.⁶ Hyperemesis is far less common, affecting somewhere between about 0.3% and 3% depending on the population studied and how it is defined.⁶
The reason to name it early is that effective treatment exists and waiting does not help. Anti-nausea medication is used in pregnancy in Australia, and dehydration is treatable.
If you’re vomiting many times a day, losing weight or cannot keep water down, contact your GP or maternity unit rather than waiting for your next appointment. See nausea and HG.
Should I stop taking my regular medication?
Do not stop anything without talking to your GP first, because untreated conditions carry their own risks to a pregnancy.
This applies particularly to antidepressants, thyroid medication, epilepsy medication, asthma preventers and blood pressure medication. Stopping abruptly is frequently the more harmful option.
Bring everything to your first appointment, including supplements, herbal products and anything over the counter. Some of what needs reviewing is not prescribed.
If you took something before you knew you were pregnant, that is worth a conversation rather than alarm. MotherSafe in NSW takes calls from anywhere in Australia and answers exactly this question, and your GP can also consult teratology services. See accidental medication exposure in early pregnancy.
Which vaccinations do I have in the first trimester?
Influenza, if it is flu season. The influenza vaccine is recommended at any stage of pregnancy and is free under the National Immunisation Program.⁷
Whooping cough is the one people expect and it comes later. The pertussis vaccine is given between 20 and 32 weeks, timed so antibodies transfer to your baby before birth, so it is not a first trimester task.⁷
Live vaccines, meaning measles-mumps-rubella and chickenpox, cannot be given during pregnancy. If your first trimester bloods show you are not immune to rubella, you will be vaccinated after your baby is born rather than now.⁷
If a live vaccine was given before you knew you were pregnant, RANZCOG says there is no evidence of adverse outcomes for babies in that situation.⁸
What this means for you
Do three things this week. Call your GP and ask for a long first antenatal appointment. Decide roughly what you want to spend on screening, because that decision shapes which pathway you take. And keep taking folic acid and iodine.
At the appointment, ask for a ferritin test and which model of care options your area actually has and how long the waitlist is, and ask whether the quoted screening pathway has out-of-pocket costs. Ask about mental health screening if it does not come up, because Australian guidelines recommend it as early as practical in pregnancy.⁹
Write down anything you are anxious about before you go. First appointments move quickly and it is easy to leave with the questions still in your pocket.
All of this is general guidance. Your history, your results and where you live determine what actually applies, so use this to shape the conversation rather than to replace it.
References
- Australian Government Department of Health. Clinical Practice Guidelines: Pregnancy Care. 2020 edition. Canberra: Australian Government Department of Health; 2020.
- Australian Institute of Health and Welfare. Australia's mothers and babies: antenatal care. Canberra: AIHW; 2025.
- Royal Australian and New Zealand College of Obstetricians and Gynaecologists. Screening and diagnosis of fetal structural anomalies and chromosome conditions (C-Obs 35). Clinical Guideline. Version 3.0. Melbourne: RANZCOG; October 2024.
- Quenby S, Gallos ID, Dhillon-Smith RK, et al. Miscarriage matters: the epidemiological, physical, psychological, and economic costs of early pregnancy loss. Lancet. 2021 May 1;397(10285):1658-67.
- Essers R, Lebedev IN, Kurg A, et al. Prevalence of chromosomal alterations in first-trimester spontaneous pregnancy loss. Nat Med. 2023 Dec;29(12):3233-42.
- Fejzo MS, Trovik J, Grooten IJ, et al. Nausea and vomiting of pregnancy and hyperemesis gravidarum. Nat Rev Dis Primers. 2019 Sep 12;5(1):62.
- Australian Technical Advisory Group on Immunisation. Vaccination for women who are planning pregnancy, pregnant or breastfeeding. Australian Immunisation Handbook. Canberra: Department of Health and Aged Care; 2024.
- Royal Australian and New Zealand College of Obstetricians and Gynaecologists. Pre-pregnancy counselling (C-Obs 3a). Clinical Guideline. Version 13.1. Melbourne: RANZCOG; November 2024.
- Austin MP, Highet N, Expert Working Group. Mental health care in the perinatal period: Australian clinical practice guideline. Melbourne: Centre of Perinatal Excellence; 2023.
Written by Bella · BBiomedSc, MEpi · Clinical epidemiologist
I read pregnancy research so you do not have to. More about me
Published: 29th September 2026 · Last reviewed: 29th September 2026
How I review research: Editorial policy
Educational only, not medical advice. Full disclaimer
This article is for educational purposes only and does not constitute medical advice. Research findings describe patterns across populations and may not apply to you. Always discuss your own situation with your GP, midwife or obstetrician.
