Pregnancy and Your Body

A pregnancy is a truly astounding physical event, during which your body will undergo a series of changes to allow it to better host a growing life. These changes manifest themselves in many different ways, some of which can be very unexpected! This article takes you through what exactly happens to your body from the first step of a pregnancy, right through to the point where you give birth to your newborn child.

Conception and becoming pregnant

To become pregnant you will need to first conceive, which means that a male sex cell (sperm) needs to successfully fertilise a female sex cell (egg) to give rise to a fertilised egg which is called a zygote. This zygote travels from where eggs are housed in the ovary towards the womb, where it implants into the lining of the womb (called the endometrium). At this point an embryo, the very first phase of newborn life, has been formed.

The embryo starts developing its own blood supply and support structures like the placenta, all necessary to provide nutrition to a growing foetus. To trigger and maintain this process the levels of important female hormones like progesterone, oestrogen, and human chorionic gonadotropin are hugely increased, which causes many of the early signs of pregnancy like morning sickness, frequent urination, and the like.

The trimesters

At this stage the pregnancy has begun in earnest, and while different sources disagree as to whether the first trimester begins after implantation or conception, the division of a pregnancy into 3 distinct 3 month periods called trimesters is unanimous.

Each trimester involves a certain level of foetal development, and has characteristic physical signs which you are likely to experience. The first 3 months is usually the most sensitive, and unfortunately as many as 40% of pregnancies end in some way during this time. This is because the newly developing foetus is at its most vulnerable during this stage, and it is important to follow the advice your doctor gives you about looking after yourself during this period. Major events in the first trimester include the first heartbeat and the development of the central nervous system (referred to as the neural tube at this stage.

The second trimester, months 4, 5, and 6, usually begins around the 14th week. This is when the term ‘foetus’ is properly applied as the embryo has developed enough to earn this title. From this stage onwards there is a significantly reduced chance of miscarriage, which is why many couples often choose to announce the pregnancy at this stage rather than earlier on. Perhaps the most significant feature of the second trimester is the fact that you can now determine the sex of the foetus via ultrasound. The morning sickness which is characteristic of the first trimester resolves during the second trimester, which is a relief for many mothers to be! Movement is also a feature of the second trimester, and the infamous kicking of the growing foetus can be felt towards the end of the second trimester.

The third and final stage of the pregnancy will usually involve the most discomfort for the mother. This stage will involve the most weight gain and a dramatic increase in fatigue as the body is now sustaining a much larger unborn infant. Many women experience trouble sleeping thanks to the increases in size, which also places extra pressure on the bladder, resulting an increase in the need to urinate urgently (which can also badly affect sleep!). The third trimester ends at about 37-40 weeks into the frequency, after which the pregnancy is considered ‘full term’, which means that the foetus is fully developed and ready to be born.

Babies are often born a few weeks to either side of this official point, and that is usually not a cause for concern as modern medicine is more prepared than ever to care for premature and late babies. Throughout your pregnancy you will have access to support from your healthcare provider, whether the NHS or private care. The specialist doctors responsible for looking after your health during your pregnancy are called obstetricians and gynaecologists, and your care prior to the delivery of your baby is called antenatal care, while your care after delivery is called postnatal care.

« Home Pregnancy Testing What is Antenatal Care and Where do I get it? »