Pregnancy week 4

Your baby’s development

In week 4, which corresponds to a missed period, the tiny blastocyst has attached to the lining of the womb and begun to sink in. This week the embryo is about the size of a poppy seed, around 0.1 cm. Its cells arrange into three layers, each of which will later form different organs: one the nervous system and skin, one the heart, blood and muscles, and one the digestive system and lungs. The first cells of the placenta develop and the connection that will feed the embryo is set up. The pregnancy hormone hCG starts to be produced, and it can now be detected in urine. A small amniotic sac also forms during implantation. Nothing can be seen on an ultrasound yet. It is enough to know this is a very delicate stage that mostly unfolds by itself, beyond your control. Each week adds a new layer on top of the last. All of it happens within a few days, at a scale too small to see.

Changes in the mother

A missed period is the first clear sign for most people. A pregnancy test is usually positive this week; first morning urine is most reliable. If an early test is negative and your period does not arrive, repeating it a few days later makes sense. Tiredness, full breasts, needing to pee more often, mild nausea and mood changes are common now, but not everyone has them, and having no symptoms is normal too. During implantation a few drops of pink or brown spotting can occur. After a positive result, let your doctor or local health centre know and plan the first antenatal visit. In Turkey the Ministry of Health recommends the first pregnancy check before week 14. Your feelings may be mixed; joy, fear and doubt can exist together, and all are understandable. You can decide at your own pace what to do with the news and whom to share it with.

To do this week

• Take the pregnancy test with first morning urine.
• If positive, book the first antenatal visit (before week 14 at the latest).
• Take folic acid if your doctor advises it; check any vitamins or medicines with them.
• Stop alcohol and smoking.
• Tell your doctor about any medicines you take regularly.

Tip for the partner

When the news arrives, listen without judging and make room for feelings; planning the appointment together is reassuring.

Nutrition tip

Take folic acid and, if advised, vitamin D; avoid raw meat, raw milk and unwashed vegetables.