Pregnancy Timeline

Pregnancy Timeline: Here is what is happening to your body as pregnancy progresses

The pregnancy timeline is, for many women, an exciting time as one anticipates the arrival of their baby. So, you have missed your period, and are starting to notice your breasts have become bigger. You are also exhausted lately, so you buy a pregnancy test kit and use it at home. The two lines appear and confirm what you had been thinking all along – You are pregnant! Congratulations! The next most important thing is to see your gynaecologist in order –to know how far along the pregnancy is.

Pregnancy test
Image by Steid from Pixabay

Pregnancy Timeline and due dates

Pregnancy takes approximately 40 weeks, or roughly nine months leading to the birth of the baby. The pregnancy timeline is divided into three trimesters:

– The first trimester which lasts from week 1 to week 12
– The second trimester which lasts from week 13 to week 26
– The third trimester which lasts from week 27 to the end of the pregnancy.

Each trimester brings with it changes and growth, both for the mom and the foetus. In addition to the trimesters, pregnant women also find it helpful to know their due dates. This information is provided at a woman’s first antenatal clinic.

How is the due date calculated?

As mentioned above, the average pregnancy lasts for 40 weeks, or 280 days. The due date, which is also known as the Expected Day of Delivery (EDD) is calculated by adding 40 weeks to the first day of the Last Menstrual Period (LMP). This formula assumes the use of a 28 day cycle. It is for this reason that the menstrual period and ovulation are considered to make up the first two weeks of the pregnancy.

It is important to note that the due date is an estimate as every pregnancy is unique. Many women will deliver between the 38th and 42nd week of pregnancy, and only a small fraction of pregnant women deliver on the precise EDD. If you have any questions, be sure to talk to your health care provider and share your concerns.

Read More: Pregnancy and the role of the midwife

Pregnancy Timeline by Trimester

First Trimester

The first trimester marks the beginning of the pregnancy timeline. It helps to understand how fertilization happens. To do this, we look at the process of ovulation. Ovulation, for many women, happens about 14 days after the last menstrual cycle. Ovulation refers to the process by which a mature egg is released from the ovary, and goes down to the fallopian tube. Here, it is made available for fertilization following sexual intercourse just before, during or a day after ovulation. Sperms from the man travel up the fallopian tubes and fertilization occurs.

The first trimester refers to the first 12 weeks of the pregnancy. During this time, the baby is referred to as an embryo. This trimester is also characterized by symptoms that mark early pregnancy. These include:

– Morning sickness which is defined as nausea during pregnancy. According to the Gastroenterology Clinic North America Journal, it is estimated that up to 80% of expectant women experience morning sickness. This nauseous feeling is caused by hormonal changes attributed to the pregnancy (Lee & Saha, 2011). Contrary to its name, the nausea does not only occur in the morning and can affect expectant women at any time.
– Increased urination
– Exhaustion
– Swollen breasts
During this stage, the embryo’s cells undergo multiplication to form the baby’s body. The placenta is also formed during this time. This is a critical part of the pregnancy as the placenta transports water, nutrients and oxygen to the baby. By the end of the first trimester, the embryo measures around 10cm, and weighs in at about 28 grams.

Read More: Nausea during pregnancy

Second Trimester

The second trimester begins from week 13 all the way to week 26 of the pregnancy timeline. The beginning of this trimester also marks the end of the embryonic stage and the start of the foetal stage. In the 13th and 14th week, the foetus begins to move within the womb. For many expectant women however, it is still too early to feel the movements. This increases in week 15 all through to week 18 when the movements become more pronounced, owing to the growth of the foetal muscles.

In the second trimester, the foetus develops vernix. This is a white substance that forms on the skin, and whose role is protection from the amniotic fluid. It is also during this trimester that the foetus begins to make facial expressions in-utero. For expectant women who get a 3D ultra scan, it is not unusual to catch a glimpse of the foetus smiling expressions.

It is fascinating to learn that the middle ear also develops in the second trimester. This allows the foetus to hear its mother’s voice. In this stage, the reproductive organs are fully formed, and it is possible for expectant women to know the sex of the baby. Towards the end of the second trimester, the foetus measures about 30 cms, and weighs about 1020 grams (American Pregnancy Association, 2016).

PS: If the baby is delivered in the second trimester, there is a chance it could survive with assisted medical technology and modern practice.

Third Trimester

In the third trimester, foetus develops rapidly in preparation for birth. From about week 27, the foetus begins to store fat, calcium and iron in its body. Even though the foetal lungs have not matured completely, the foetus begins to show breathing movements.
From about week 33, the foetus descends and takes the head down position in readiness for birth. The lanugo hair that covers its body also disappears. At week 38, the foetus is at full term and ready to be born. It is important to note that, as the foetus increases in size, you should still be able to feel its movement. If movement reduces or stops altogether, make sure you talk to your health care provider or your midwife immediately as this is a danger sign and the baby could be in distress.At the end of the third trimester, the foetus measures about 50cms, and weighs between 2.8 and 4.5kgs (American Pregnancy Association, 2016).

Labour and Delivery
As mentioned above, only 5 % of women deliver on their due dates. Do not panic if your baby is born before or after the due date as this is very common. Look out for signs that labour is not too far away. These include a bloody show, loose stool and contractions.

Tunza Mama runs birth preparation classes to help you be prepared and relax before birth. The best thing about these classes is that one person can join you for the sessions completely free of charge! Get in touch with us on 0709 256 200 for more information. Click here to see more services offered by Tunza Mama caregivers