Pregnancy week 12

Your baby’s development

In week 12 the baby is about as big as a plum, 5.4 cm long and weighing around 14 grams. The organs are in place and starting to work. The kidneys make urine, which passes into the amniotic fluid. The liver makes bile and the bowel starts to contract. The brain develops especially fast this week and reflexes appear: the baby can curl its fingers, open and close its mouth, and even react to something approaching its mouth. The facial profile becomes clear, with forehead, nose and chin visible. The neck lengthens and the head sits more upright. Muscles strengthen, so the baby moves often, though you cannot feel it. Nails and hair follicles form. This week is a suitable time for the NT scan: the thickness of the clear area at the back of the neck is measured on ultrasound and, if needed, assessed together with blood tests. It is a screening test and does not give a definite diagnosis; your doctor will talk the results through with you. Your baby now looks like a small but complete person, and from here the main job is growing.

Changes in the mother

Many people relax as they near the end of the first trimester. The risk of miscarriage falls noticeably after this stage, and many decide to share the news with those close to them; when to do so is entirely your choice. Nausea and tiredness may ease and appetite grows. The lower belly may round out. As the womb begins to rise out of the pelvis, pressure on the bladder eases and trips to the toilet may lessen a little. Hormones can make hair look fuller at this time. Some people still have dizziness and palpitations; getting up slowly and drinking enough helps. If an NT scan is planned, a full bladder may be requested during the ultrasound, so ask about appointment instructions beforehand. Normal results are what is most often expected; if the result differs, further tests and support are offered, and you are not alone in making decisions.

To do this week

• Confirm your NT scan appointment.
• Find out instructions such as whether to have a full bladder.
• Decide when to share the news at your own pace.
• Review blood and urine test results with your doctor.

Tip for the partner

Go with them on screening day and say clearly you will be there whatever the result.

Nutrition tip

Eat a varied diet for iron, calcium and vitamin D needs; follow your doctor's advice on vitamin supplements.