Your First Trimester: A Week-by-Week Guide

The first twelve weeks are the strangest part of pregnancy. Almost nothing is visible from the outside, you may feel terrible, and most women are keeping it quiet. Here is what is actually happening, and what to do about it.

Weeks 4 to 6: confirmation

A home pregnancy test becomes positive roughly two weeks after conception, at around week four counted from your last period. If your test is positive, start a folic acid supplement of 400 micrograms daily straight away — or 5 milligrams if you have diabetes, a raised BMI, epilepsy, or a previous baby with a neural tube defect.

Your first clinic visit is usually best at six to nine weeks. Earlier than six weeks, an ultrasound often cannot yet show a heartbeat, which causes unnecessary worry.

Weeks 6 to 9: the first visit

At this appointment we confirm the pregnancy is inside the uterus, check the heartbeat, and date the pregnancy accurately — the measurement taken now is more reliable than any later scan, and it determines every future appointment.

Booking bloods are taken at the same time: blood group and Rhesus status, full blood count, haemoglobin, thyroid function, vitamin D, glucose, rubella immunity and infection screening.

Symptoms that are normal, even when they feel extreme

• Nausea and vomiting, often peaking around weeks 8 to 10
• Exhaustion that arrives suddenly in the late afternoon
• Breast tenderness and heaviness
• Mild cramping, similar to period pain, as the uterus grows
• Food aversions, a metallic taste, and a suddenly hostile relationship with coffee

Symptoms that need a phone call

• Any vaginal bleeding, even light spotting
• One-sided pain, shoulder-tip pain, or pain with dizziness
• Vomiting so persistent you cannot keep fluids down for 24 hours
• Fever above 38°C or burning on passing urine

Weeks 11 to 13+6: screening

This is the window for the nuchal translucency scan, combined with either the standard blood screening or NIPT, a cell-free DNA blood test that examines fetal DNA circulating in your blood.

Two things are worth understanding before you have any of it. First, these are screening tests, not diagnostic tests: they tell you a probability, not a fact. Second, you are allowed to decline them — but decide before the appointment rather than in the moment.

The same scan also checks the number of babies, the placental position, and the developing anatomy in surprising detail.

Eating, working and living

Avoid unpasteurised dairy, raw or undercooked meat and eggs, liver, high-mercury fish such as shark, swordfish and king mackerel, and unwashed produce. Caffeine is fine below roughly 200 milligrams a day — about two small coffees.

Exercise is not only safe but beneficial. Walking, swimming and light strength work can all continue. Stop and call if you develop bleeding, dizziness or pain with activity.

In the Abu Dhabi summer, dehydration makes first trimester nausea and headaches significantly worse. Two to three litres of water a day, and avoid the heat between noon and four.

Miscarriage: the honest picture

Around one in five recognised pregnancies ends in miscarriage, the great majority in the first trimester, and the great majority because of a chromosomal problem that could not have been prevented. It is not caused by working, exercising, arguing, lifting a toddler, or having intimacy.

Once a heartbeat is seen at eight weeks in a woman with no bleeding, the risk falls to roughly two to three percent. That is the number worth holding on to.

What comes next

By week 13 the nausea usually eases, energy returns, and the pregnancy becomes something you can start to enjoy rather than endure. Your next appointment will be around week 16, and the detailed anomaly scan follows at 19 to 22 weeks.

This article is general information and does not replace a consultation. If anything here applies to you, book an appointment rather than acting on it alone.