Close-up of a pregnant woman's stomach
© Love Matters | Rita Lino

Pregnancy week-by-week

A sperm fertilises an egg and about 40 weeks later, it's developed into a fully-grown baby, ready to be born. But in the meantime, what exactly is going on inside the womb?
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Fertilisation

You can get pregnant if you have intercourse with a man around the time you ovulate – from about five days before until one day after. When the man ejaculates inside your vagina, the sperm swims up the vagina through the cervix – the neck of the womb – through the womb, or uterus, to the fallopian tubes.

It takes the sperm about 10 hours to make this journey. If there’s an egg waiting in one of the fallopian tubes, the tiny sperm tries to burrow their way inside it. If one sperm gets inside the egg, it’s fertilised. The fertilised egg then sets off down the fallopian tube to the womb.

Week 1 of pregnancy

The fertilised egg cell starts dividing – at this stage, it’s called a zygote. After a few days of division, it becomes a ball of cells called a morula. You’d need very good eyes or a microscope to see it.

The blob of cells develops a hole in the middle full of fluid, at which point it gets another new name: blastocyst. First, it floats around the walls of the womb for a while. At this stage, it could still just get flushed out of your womb with your period, and you’d never know anything had happened. But then comes a crucial moment: if the womb accepts the blastocyst, and it nestles into the lining, you’re pregnant.

Even then, all sorts of things can go wrong in the early stages of pregnancy. You might notice nothing more than your period coming a couple of days late, when in fact you were nearly going to have a baby. It’s only called a miscarriage if it happens later on after you know you’re pregnant.

Week 2 of pregnancy

The pregnancy is now properly established. Inside the blastocyst, different groups of cells develop, which will eventually form the different parts of the baby. The inner cells will grow to become lungs, stomach and intestines, a middle layer will be muscles and bones, and an outer layer will form the nerves and skin.

It's time for the blastocyst to have another new name. It’s now an embryo. The end of the second week is about day 28 of your menstrual cycle – that means your period is due. And at this stage, depending on whether or not you wanted to get pregnant, you’re likely to start getting nervous and worried, or hopeful and excited. Because your period is late.

From a couple of days before your period was due, pregnancy hormone starts getting into your urine. So as soon as your period is late, you can do a pregnancy test.

Related: 10 Tips For A Healthy Pregnancy

Week 3 of pregnancy

The bundle of cells starts developing the first signs of the different parts of the body – the brain and heart start to grow.

Weeks 4 to 8 of pregnancy

The heart starts beating, and arms, legs, eyes and ears start to form. Nipples appear, and the kidneys start producing urine. The embryo starts moving. By the end of week eight, the embryo is about the size of a small grape – about 13mm. And once again it’s time for a name change: the embryo is now called a foetus.

Weeks 9 to 12 of pregnancy

The foetus now develops a recognisable human face. Its arms and legs are properly formed and it can make its hands into a fist. What’s more, the foetus can even make sounds – even though it’s still no longer than your thumb.

Twelve weeks marks the end of what’s known as the first trimester, the first third of the pregnancy. Miscarriages are much more likely to happen in the first twelve weeks, so women sometimes prefer to wait to this point before telling everyone they know that they’re pregnant. In some countries where abortion is allowed, you can’t have the pregnancy terminated after this point, or only in special circumstances.

Weeks 13 to 19 of pregnancy

The foetus starts moving around and making sucking movements with its mouth. By week 19 the baby is waking and sleeping and can hear. It’s about 12 to 15cm long, so would still fit in the palm of your hand.

Weeks 20 to 24 of pregnancy

Butterflies fluttering inside you, or bubbles – that’s how many women describe feeling the foetus moving inside them for the first time. It usually happens around this time of the pregnancy. However, with a first baby, you may not feel it until 25 weeks – and with a second baby, it can be as early as 16 weeks.

Apart from swimming around, the foetus is now growing eyebrows and eyelashes, and nails on its fingers and toes. The senses of taste and touch are developing, and the eyes are properly developed too. With a lot of medical care, foetuses born at 24 weeks can sometimes survive.

Weeks 25 to 28 of pregnancy

The brain is growing fast and by week 28 the lungs are properly developed, so if the baby is born at this stage it has a good chance of survival. Week 28 is the end of the second trimester, the middle third of the pregnancy.

Weeks 29 to 40 of pregnancy

In this last stretch of the pregnancy, the third trimester, the foetus grows fast and puts on weight, getting ready for life outside the womb. It starts ‘breathing’ the amniotic fluid inside the womb.

The foetus hasn’t got much room to move around anymore, but it can give some impressive kicks and you can see it moving from the outside. Around week 36, all being well, it swivels around so its head is pointing downwards ready for the birth.

The due date

People usually say a pregnancy lasts nine months. And based on the first day of your last period, you’re usually given a ‘due date’ when your baby is supposed to be born. But in fact, most births happen anywhere between about 37 and 42 weeks. So within this period, you can’t really say the birth is ‘early’ or ‘late’.

Anyway, at some point around 40 weeks, the big moment arrives. Having been a zygote, a morula, a blastocyst, and an embryo, the foetus now has its last official name change of the pregnancy: it’s a baby. After that, the name is up to you!

Riddle ID

Did you learn something new?

Comments
Sandra
Mon, 06/15/2020 - 03:29 pm
So educative, am one the mother who gave birth to a premature which of 25weeks but unfortunately the baby past away at the age of 10month was having hardship in breathing during flue and cough but question is:-will I be safe if I get another pregnancy and what brings the baby at early state was not my first born while others were nine months.

Hello Sandra, thank you so much for reaching out to us. Really sorry to hear that you lost your baby.  Premature birth may be caused by a whole lot of reasons and it is indeed true that a premature birth could cause you to have other premature births in the future. If the cause of the premature birth was determined by your doctor, then try and avoid the contributing factors in the future (if possible).

Hello Dama, thank you for getting in touch and congratulations on your pregnancy dear! Increased urinary frequency is an early symptom of pregnancy in women and is completely normal. It's caused by an increase in the hormones progesterone and human chorionic gonadotropin. The urges tend to reduce in the second trimester. The uterus is also higher in the second trimester. Pregnancy-related urinary frequency and urgency usually resolve after you give birth. These symptoms will often subside about six weeks after giving birth. Your doctor may recommend strengthening your bladder muscles through exercises known as Kegels. These exercises strengthen your pelvic floor. This helps you gain better control over your urine flow, especially after giving birth. You can perform Kegel exercises daily, ideally about three times a day. Follow these steps:

  1. Tighten the muscles of your pelvic floor by imagining you’re stopping the flow of urine.
  2. Hold the muscles for 10 seconds, or as long as you can.
  3. Release the contracted muscles.
  4. Repeat 15 times to complete a single set.

You will know you’re performing Kegel exercises correctly if no one can tell you’re doing them.

Hello, heip me to know why have i tested for HIV and resuit is positive, BT the second time is negative am actually confused heip me plz

Hello Anonymous, thank you so much for your question. It is possible that you got a false positive. Although it is quite rare it does happen. The HIV strip test is sensitive to antibodies and sometimes may react to antibodies that are not HIV specific. However, like we mentioned this is very rare.

A false negative mostly occur if you take the test too early in the infection for it to show up. Take a third test three months after the last test to get a conclusive answer.

Love Matters
Wed, 12/16/2020 - 03:36 pm

Hi Dorcas! Always pleased to help. Feel free to go through more of our content to help you make more informed decisions and do not hesitate to get in touch with us in case you have any questions. Have a wonderful week and stay safe!

Love Matters
Thu, 01/28/2021 - 10:30 am

Hi Grace. First and foremost, congratulations on your pregnancy. We are so happy for you. Thank you for getting in touch with us and we are so sorry you are going through a hard time. stomach pains or cramps are common in pregnancy and usually nothing to worry about. Mild stomach pain in early pregnancy (during the first 12 weeks) is usually caused by your womb expanding, the ligaments stretching as your bump grows, hormones constipation or trapped wind.

We hope this information helps, let us know what you think and have a wonderful weekend ahead! Stay safe!

Freddie
Fri, 03/26/2021 - 10:28 am

Hi Sue, thank you for getting in touch and asking a great question. 

Cramps can vary in intensity and duration for everyone. They typically vary over the course of your period, with the pain or discomfort lessening after the first few days. This is because the level of prostaglandins is reduced as the uterine lining is shed and the prostaglandins in the lining are expelled from your body.

Often, people will have pain in their lower abdomen or back. But some will only experience pain in the lower back. Some people also experience cramping in their upper thighs.

The uterus is a muscle. When it contracts and relaxes during cramping, it can feel:

  • sharp
  • poking
  • aching or tightening similar to a muscle cramp-like pain
  • like a mild stomachache, or even a more painful stomachache, like when you have a stomach virus

Along with menstrual cramps, some women also experience:

  • diarrhea or loose bowel movements
  • constipation
  • nausea
  • bloating
  • vomiting
  • headaches

Cramps can be uncomfortable or even painful, but they shouldn’t keep you home from school or work. That level of pain or discomfort is not typical, and is something you should see your doctor about.

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