The first trimester - what's happening inside

Congratulations! Stunned, frightened and excited? Often all three emotions hit you at the same time when you find out you're pregnant, even if you carefully planned this conception. You may not even truly believe you are pregnant, despite the six pregnancy tests you have taken! Adding to the disbelief may be the lack of pregnancy symptoms. In fact, you could swear that your period will arrive at any second because of the cramps you've got.

Meanwhile, the fertilised egg has completed a seven- to ten-day journey to the uterus, where it settles into the endometrial lining. It has divided into two: one part becoming the placenta and the other the embryo. From a medical perspective, even though you have been pregnant for two weeks, you are technically four weeks pregnant. Pregnancy dating begins from the start of your last menstrual period.

It may be only a week since you found out that you were pregnant, but inside your uterus, a whirlwind of activity is occurring. At five weeks, your embryo measures a mere two millimetres, but every organ is already under development. Even facial features, such as eyes and ears, begin to form. Leg and arm buds are sprouting outwards!

By the time you are six weeks on, you know you're pregnant. How can something that only measures four millimetres be making you so ill? Nearly half of pregnant women suffer from morning sickness, which actually may occur at any time during the day or night, and can be attributed to a higher level of oestrogen as well as the rapid expansion of the uterus. It may be difficult to stomach those antenatal vitamins, but they are very critical at this stage of development. Antenatal vitamins contain many important nutrients, including folic acid. Studies show that folic acid helps reduce the incidence of neural tube defects.

Even in these first few weeks, you may have a host of symptoms, from dizziness and irritability to fatigue and headaches. ‘Will I have this to look forward to for the next nine months?’ You may be thinking. Don’t worry, many of these symptoms will vanish by the beginning of your second trimester.

By your seventh week, the embryo has doubled in size from just the week before. It’s about as big as a small bean. Already, it resembles a microscopic baby with a brain, heart, and limbs. Its head is nearly as big as its body, which has some catching up to do. Your doctor may suggest an ultrasound scan; this procedure is considered to be safe for the developing foetus. In addition, an ultrasound done today may even be able detect foetal heart motion.

Although you may not feel your best, none of your symptoms will make the baby uncomfortable. In fact, your indigestion has a positive effect on your baby-to-be. Food slows down as it travels through the body, which may result in gastrointestinal problems for you, but allows nutrients to be more readily absorbed by the baby. Wearing loose fitting clothes, and eating frequent, small meals may help to decrease your discomfort.

By nine weeks, your baby has grown to between half an inch to an inch. It now weighs in at a whopping one gram. Even though you won’t feel the baby move until the second trimester, he or she is very active at this point. It is already a ‘he’ or ‘she’ as testes and ovaries have formed. An ultrasound cannot identify gender yet, as external genitalia still appears sexless.

Because most miscarriages occur in the first trimester, you may be feeling nervous and be eager to advance to the second trimester. One good sign is the identification of the heartbeat, either by the doctor’s Doppler heart monitor, or by ultrasound.

As you approach the end of your first trimester, your baby is three inches long and weighs in at 14 grams. It has the ability to swallow, absorb, and discharge fluids. Hands are formed and fingernails are developing. Your baby even has tooth buds. The 12th week is an important one as the placenta takes over hormone production. By the 13th week, vocal cords are nearly formed, although it will be some time before your little one says, ‘Mummy’ !

The first trimester can be trying, both physically and emotionally. Appreciating that your body is responsible for this incredible feat of baby development, from organ formation to complex brain circuitry, makes it all worthwhile. In just a few weeks, you’ll be reacquainted with two old friends: energy and enthusiasm!