A week by week guide to what’s happening to you and your baby

WHAT'S HAPPENING WITH YOU

Congratulations - you're halfway through your pregnancy. Hopefully you're feeling good now and you've regained your energy. People are beginning to notice that you're indeed pregnant, as your uterus pushes your abdomen out at the belly button.

You may be having some trouble breathing, particularly if you're small in size or overweight. See your doctor if you have any signs of asthma, such as coughing, wheezing when you exhale or difficulty in breathing. One in every 100 women suffers from asthma during pregnancy. A recent study published in the British Medical Journal found that women with a history of asthma, who are pregnant with girls, were more likely to experience an increase in symptoms, possibly because of hormonal differences. Asthma can be easily treated, and medications safe for use during pregnancy are available. If you have asthma, it's very important to get a prompt diagnosis so you don't deprive your baby of necessary oxygen.

WHAT'S HAPPENING WITH YOUR BABY

This week, your baby weighs ten ounces and is 16cm crown to rump, or a total length of about 9 3/4 inches. A white, waxy-looking substance called vernix now protects your baby's skin. If you are carrying a girl, she has six million eggs in her ovaries - six times the number she will have at birth. Her uterus is formed and she's beginning to develop a vagina.

HEALTHY EATING

Fish is good for you and contains nutrients known to reduce the risk of heart disease. So, why all the concern for fish consumption during pregnancy? Certain fish, such as swordfish, striped bass or blue-fin tuna, may contain high levels of mercury. Freshwater fish are also susceptible to pollutants in the water. Here are some fish that get the pregnancy seal of approval:

• Sole
• Flounder
• Haddock
• Halibut
• Cod
• Salmon (farm-raised preferred)

FACT OF THE WEEK

At every antenatal visit you should have a blood-pressure check. This is the measurement of the pressure at which the heart is pumping blood through your body. A normal BP is 120/70. The top number is the systolic pressure - that is when the heart contracts, pushes out blood and beats. The bottom number is the diastolic pressure - that is the resting pressure between heartbeats. High blood pressure can indicate a number of problems, including pre-eclampsia. Any rise in the diastolic figure is a cause for concern. If the BP rises above 140/90 you will probably need bedrest in hospital.

Find out what to expect in week 21 of your pregnancy.

For a list of all the pregnancy week by week articles click here