Soon after conception, the fertilized egg attaches itself to the mother's uterus, where it begins to develop cell by cell. In the weeks and months that follow, a human being will take shape. And as this miracle unfolds, your body will experience many transformations to support the new life within you. This section describes the changes mothers-to-be will go through during the 9 months of pregnancy.

Here are the topics we'll discuss in this section:

First Trimester Changes

Second Trimester Changes

Third Trimester Changes

First Trimester Changes

In early pregnancy, physical changes in the mother's body are mainly due to elevated hormone production. The most common physical sensations in early pregnancy include:

• Increased fatigue
• Frequent need to urinate
• Sensitive breasts
• Increased vaginal secretion
• Irregular bowel movements
• Morning sickness or nausea

By the twelfth week, morning sickness will probably diminish and so will the frequent need to urinate. By this time you may notice some weight gain.

Second Trimester Changes

By the fourth month, you'll begin to notice more obvious signs of pregnancy. Your waistline will grow larger and weight gain will increase. Eating well and eating enough are especially important at this time, as your baby will also start growing much more rapidly.

As your belly continues to grow, you may develop stretch marks. These will fade after delivery. Wearing unrestrictive clothing will help you to feel more comfortable.

Your nipples and areolas will grow deeper in colour, and your breasts will continue to grow larger and heavier. These changes prepare you for lactation. And now is a good time to discuss infant feeding with your partner and your healthcare professional. Breast milk is nature's ideal food for the healthy newborn baby.

By about the fifth month, you'll begin to feel the baby turning and kicking. As the baby grows larger inside of you, you may begin to experience some side effects typical of this stage in pregnancy. These include indigestion, constipation, heartburn, haemorrhoids, water-retention and / or high blood pressure. A good diet and regular exercise can ease or eliminate these discomforts, which we'll discuss later.

Third Trimester Changes

As the baby's weight now begins to rapidly increase, so will yours. It is very important that you continue to eat well through this last stage of pregnancy to ensure a healthy birth-weight for your baby. It is likely you'll feel increasingly fatigued due to the growing weight of the baby, so you should rest as much as you feel you need to.

You can see and feel the movements of the baby from the outside now. Your growing baby may start to put pressure on your bladder, causing you to feel the need to urinate - even when you don't really need to. You may also experience shortness of breath as your growing uterus puts pressure on your lungs and diaphragm. The enlarged uterus may also put pressure on your stomach, causing indigestion. Or put pressure on your bowels, causing constipation.

You will probably begin to feel painless contractions which serve to strengthen your muscles, preparing them to assist with labour. You may also perspire more as body fluids increase dramatically.

During the final months of pregnancy, you may be concerned that the fetus seems to be less active than it was previously. Most of the time, this change in activity is perfectly normal. The fetus has grown so large that it is cramped in the uterus and its movements are constricted.

By the 40th week, the baby fills the uterus entirely. After nine months, you have transformed what was once a single celled egg into a six trillion celled human being. Delivery is near and soon a new phase of parenthood will begin.

Do no hesitate to talk to your doctor should you have any questions regarding your body changes during pregnancy.