5 weeks and 2 days pregnant

The centre of this image shows the baby’s developing heart (darker grey), a very primitive structure at this stage. The baby’s head is to the right of the image. The embryo is almost completely transparent.

There won’t be any visible signs of pregnancy on the outside for some time, but there are many changes taking place inside.

At this early stage, all your unborn baby’s needs will be met by the yolk sac. Attached to the embryo by a connecting stalk, this essential balloon-like structure indicates the site of your pregnancy and can usually be seen through a microscope as early as this week as a sphere 3–4mm across. At first, the yolk sac is as large as the disc of embryonic cells that will eventually become your baby.

The yolk sac contains cells that perform a similar function to the liver. It releases several pregnancy hormones and produces the embryo’s first red blood cells. After week 9 the liver will take over these functions as the yolk sac gradually disappears and the placenta takes over, by around the 10th week of pregnancy.

Over the next seven days, a primitive circulatory system develops, well before any blood circulates to the placenta in the 10th week. And, by the end of this week, using the highest quality ultrasound equipment, it is just possible to see the embryo’s heartbeat. At this early stage, the heart is simply a tube.

Should I be eating for two?

Unfortunately, pregnancy is by no means a licence to eat anything and everything you’d like. “Eating for two” is a myth, and if you do so, you’ll end up consuming too many calories and gaining too much weight. The best advice is to use your common sense. Studies show that pregnant women who eat according to their appetite naturally eat the proper amount and gain a healthy amount of weight.

Calorific needs in pregnancy vary greatly from woman to woman, depending on pre-pregnancy weight and physical activity. In general, energy needs increase by approximately 300–500 calories per day during pregnancy. In the first trimester, calorific needs are a bit less, more at the lower end of this range.

In the first trimester, when up to 80 per cent of women are nauseous or vomiting, getting enough calories can sometimes be a challenge. Like many pregnant women, you may feel most nauseous when your stomach is empty. One good trick is snacking. Eating five small meals rather than three large ones can be soothing to a nauseous stomach, while at the same time giving you the calories you need.

If you can’t stomach big plates of food, try eating a combination of small portions at mealtimes and as snacks.

You should continue to take a 400mcg folic acid supplement daily until the 12th week of pregnancy.

This supplementation is in addition to a well-balanced diet that includes green vegetables and pulses. Many fortified cereals also contain folic acid, as do some fruits, such as oranges, papaya, and bananas.