Week by Week: The First Trimester – Your Pregnancy Calendar
The First 13 Pregnancy Weeks at a Glance
For most people, the beginning of pregnancy is marked by a positive pregnancy test. A positive result is, without question, one of the most important moments in the life of a woman. And during pregnancy, something unbelievable happens inside your body every week. In this article you will learn in detail of the miracles that take place during the 40 weeks of your pregnancy.
1st to 3rd Week of Pregnancy
Your pregnancy is counted from the start of your cycle, i.e., from the first day of your last period. That is already considered the first and second week of pregnancy, However, at that point you aren’t feeling pregnant at all. The mom-to-be perceives no indication of gestation.
In the first half of the menstrual cycle the ovules mature in the ovaries. The middle of the cycle, between day 12 and day 16, is when ovulation take place. After successful ovulation, a mature ovule progresses into the uterine tube, where it can be fertilized within 12 to 24 hours.
In case of intercourse during the fertile days, i.e., the days around ovulation, millions of sperms pass through the womb to get to the ovule while it is traveling down the tube. When sperms and ovule meet, they sometimes merge. That means that the ovule is fertilized. While the fertilized ovule is still on its journey to the womb the cell division process has already started. It is the starting point in the creation of new life. The first division occurs approximately 30 hours after fertilization. From that initial division on, the cells undergo more divisions every 20 hours. The body starts to release pregnancy hormones. Their purpose is to prepare the endometrium for the fertilized ovule to nest in it. It takes roughly a week for the fertilized ovule to arrive in the womb.
How Do You Experience the First Phase?
In the first few weeks, it is unlikely that you will experience any physical symptoms. Women who regularly take their temperature for contraception purposes, could, however, notice that their temperature doesn’t drop shortly before their period, but is slightly elevated. After ovulation and successful fertilization, the body temperature rises by 0.5°C. But then, every minor infection leads to a higher temperature. That’s why a slight increase in temperature alone is no reliable indicator for a pregnancy.
While some women sense a pregnancy very early, it normally takes at least 3 months until first indications show.
First Indications:
- Abdominal pain
- Increased discharge (hormonal changes)
- Dragging sensation in lower abdomen (stretching of ligaments, growing womb)
- Nausea (affects 80% of women during the first trimester, caused by a rapid increase of the pregnancy hormone human chorionic gonadotropin (hCG)
- Diarrhea (mostly due to the changes in diet)
- Slight spotting, also called implantation bleeding
The Pregnancy Trimesters at a Glance
On average, a pregnancy lasts 40 weeks. These are divided into three trimesters. Accordingly, one trimester has a duration of approximately three months, or 13 weeks.
- The first trimester: The first third of pregnancy (1st to 2nd week) is extremely exciting. During that time, all important organs are created in your baby. Simultaneously, you will notice some physical changes in you.
- The second trimester: In the second third of pregnancy (14th to 27th week), the initial unpleasant accompaniments of the pregnancy, like nausea or tiredness, subside. Mothers-to-be describe this period mostly as very pleasant.
- The third trimester: In the last third of pregnancy (12th to 40th week), your unborn baby grows, and you will automatically gain weight too. During this phase, make sure to get enough rest and take many breaks. Between the 38th and 42nd week, your baby is getting ready to be born.
4th Week of Pregnancy
Without using further aids, it would take some deep insight into your own cycle to be immediately sure about an existing pregnancy. However, a standard pregnancy test from a pharmacy or drug store will quickly show a positive or negative result based on the release of the hCG pregnancy hormone in your body. So, you get instant clarity.
What Is Happening Now?
While traveling down to the womb, the fertilized egg divides multiple times. It is now called an embryo. From week 4 of pregnancy, the embryo becomes implanted in the endometrium. The layers of cells develop into nervous system, skeleton, muscles, organs, and skin.
At the same time, the placenta forms. It is a flat organ, interwoven with blood vessels, that consists of both, embryonic and maternal tissue. It represents the link between your own blood circuit and your child’s. It is created by embryonic tissue growing into the endometrium. The freshly nested embryo, however, is still very tiny – about the size of a poppy seed (1–2 millimeters).
From now on, first indications of pregnancy might occur. From the fourth week of pregnancy, expectant mothers observe the following symptoms:
- Increased urge to urinate: The increase in hormones might lead to an increased need to urinate.
- Spotting: From week 4 of pregnancy, slight spotting, so-called implantation bleedings, might occur. For the time being, that is no cause for concern. However, if the bleedings persist or increase, you should see a gynecologist.
- Mood swings: Pregnancy hormones can turn your emotions topsy-turvy.
- Tautness of the breasts: Your breasts prepare for the upcoming milk production. The mammary glands start growing. Color and shape of the nipples might change too.
- Morning sickness: This can be quite different from woman to woman. Some don’t experience any sickness at all while others feel nauseous all the time. Most of the time, these ailments subside during the second trimester.
- Light-yellow discharge: A light-yellow, odorless discharge is a common symptom during the first weeks of pregnancy.
- Tiredness: Your body is creating new life. It takes time for it to get used to such hard work. Many women also suffer from an iron deficiency, which adds to the fatigue. Discuss that with your gynecologist.
What You Should Observe During Your Entire Pregnancy:
-
Balanced and healthy nutrition
-
Abstinence from cigarettes and alcohol
-
Avoid passive smoking
-
Avoid stress
-
Sufficient exercise, maybe sports (if appropriate)
-
Taking of folic acid
-
Frequent gynecologist appointments
Development of Your Baby – The Individual Weeks of Pregnancy at a Glance
From the very first moment, your unborn baby wants to grow. And it will develop fast. Incredible things happen in every week of pregnancy. Extremities grow, organs are created and, later in pregnancy, the fetus will have actual sleep and wake phases.
5th Week of Pregnancy
Congratulations, you are pregnant! Your body is already working at full power. The fertilized ovule has settled in the womb, has divided numerous times, and has formed different cell layers. From the outer layer of the cell (ectoderm), the skin, nervous system, sensory organs and teeth are created. The middle layer (mesoderm) is the basis for bones, muscles, lymphatic and blood vessels and the heart. From the inner layer (entoderm), finally, the remaining organs (liver, thyroid gland, urinary bladder as well as the complete respiratory tract) emerge.
6th Week of Pregnancy
Your belly is still flat, but your breasts might already start to feel tense. Your nipples take on a darker color and might become more sensitive. Your body is running at full speed now and already gearing up for breastfeeding. The pregnancy hormone (hCG) and the increase of estrogen and progesterone cause the formation of more mammary glands in your breast. Your body must get used to this immense hormone surge that can trigger other symptoms like nausea, tiredness and a hard, bloated belly.
Your baby’s heart is now fully developed and the first organ to commence work. This is the starting point of your child’s life. The embryo’s head accounts for more than half of the baby’s tiny body (with a total size of approximately 4 mm). Small ossicles have formed along the neural tube. From that, soon the spine and the ribs will develop.
7th Week of Pregnancy
By now, your gynecologist can confidently confirm your pregnancy. Soon, they will hand you your pregnancy passport. In it, all important examination results, particularities and potential risks will be recorded. This provides midwives and the attending physicians with all the required information on the course of your pregnancy at a glance.
At this point, the little face is being shaped. Eye-socket, nostrils and mouth are already there. The first muscle strands form. And the liver is already producing red cells. Due to its big head, your unborn child assumes a curved posture. Hence, its size is measured as crown-rump length (CRL). This designates the length from head to bum.
8th Week of Pregnancy
In this pregnancy week, you might experience increased dragging and pinching sensations in your abdomen. No need to worry. In most cases this is simply caused by your growing womb. By now, you might wonder about the right time for looking for a midwife. That question is easily answered: It is never too early. The earlier you take care of it, the better.
Meanwhile, the baby measures 15 millimeters from head to toe. It has just the width of your thumbnail. The embryo has already fingers and toes. Knee joints and elbows form at the legs and arms, respectively. The ears are now fully developed too. The eyes of your baby are still covered by a delicate film that will later become the eye lids. Most inner organs have formed and assumed their proper position. Kidneys and stomach start producing urine and gastric acid.
9th Week of Pregnancy
Finally! The first prenatal visit is pending. Generally, it should happen between the 9th and the 12th week of pregnancy. During the examination you will get to see your baby for the very first time – via sonogram! Most likely, your doctor will also take a blood sample from you to determine your blood type and the rhesus factor.
Muscles and nerves become active and start working together. Your unborn child as a lot of space and makes the best out of it. It swims, plays and does somersaults every day. As it weighs only about 1 gram, you will, apparently, not notice much of that. The neck has formed and separates the big head from the rest of the body. The small face is taking more and more shape. Eyes, ears, nose and lips are well recognizable.
10th Week of Pregnancy
During this week of pregnancy, you might still struggle with the hormonal change. In some expectant mothers, this shift in hormonal balance leads to brittle and dull hair or impure skin. Your womb is now the size of a grapefruit. At this point, you might realize that closing your pants is becoming a struggle. Maybe it’s time to consider changing to maternity pants with an elastic waistband to give your belly enough space.
This week of pregnancy marks the end of the embryonic phase. All important organs have developed and are in place. From this point, gynecology uses the term fetus. The head of your unborn baby has straightened up, and your child can bend and straighten its arms and legs. There is a thin skin membrane between fingers and toes that is now slowly receding. In the 10th week, little lines on the fingers and toes form. They shape the unique fingerprint.
11th Week of Pregnancy
Sudden food cravings might become much more frequent now. From that week on, pregnant women might be often hungry, and mostly for food that they did not even like before they got pregnant. Medical research has still not found the reason for this. It would be best, to not let the crave come up in the first place. You achieve that by making sure that your stomach is never completely empty. Ideally, you eat multiple healthy snacks over the day.
The fetus is ready for some fine-tuning. The webs between fingers and toes disappear, fingernails start growing The eyes move slowly from the sides of the head to the center of the face. The fetus can open its mouth and swallow amniotic fluid. It even excretes the ingested fluid. Sometimes the fetus has hiccups. In the jaw, the hard tissue around the teeth forms. The cartilaginous mass, which has served as your baby’s skeleton so far, begins to ossify and constantly gains hardness. The skin is getting thicker too.
12th Week of Pregnancy
At the end of the 12th week of pregnancy, you and your baby have reached a crucial milestone. The most critical phase of pregnancy is now over, and the risk of a miscarriage sinks dramatically. If you have suffered from strong nausea, this will now gradually subside.
Your unborn child starts moving its head around. It brings his hands frequently to the face. Due to the Suck Reflex it wants to suck its thumb. The rapidly evolving nerve tracts allow it to clench its fists and jiggle its feet. First learning processes stimulate the brain. However, it will still take a while until you can notice the movements.
13th Week of Pregnancy
The first trimester will end soon, and for many women the moment of officially announcing their pregnancy is approaching. You should also inform your employer of your pregnancy. Only when they know of it, they can make sure that the requirements of the Maternity Protection Act are met.
Your unborn baby starts testing its facial expressions. It frowns and tries to open its mouth. It is discovering a completely new enjoyment: rocking and bouncing. In week 13, the vestibular organ in the inner ear becomes functional and starts reacting to movements, in particular, precisely these rhythmic bouncing and rocking movements. The neural connections that transmit the stimuli from the inner ear, activate the brain areas that make your baby extremely content and calm. Correspondingly, swinging and rocking inside the womb make your child feel wonderfully comfortable. This is exactly the principle of the swing2sleep. Being the leading automatic spring cradle, its gentle rocking and swinging help your newborn arrive in this world from day one. The relaxing effect of the up and down movements make your baby feel secure like in the womb. That’s why, you will find it so much easier to soothe your child with a swing2sleep, even if it suffers from colic. The swing2sleep helps your baby fall asleep and sleep through. And it is an indispensable companion in difficult phases like growth spurts or toothing.
In the next blog article, you will learn which development steps your unborn will take in the weeks to come and what changes you and your body will be going through. The second trimester extends from the 14th to the 27th week of pregnancy. Enjoy!
