Pregnancy in humans

An exploratory study.

1. Introduction

This project is about the pregnancy in humans. Pregnancy is the time between the fertilization and birth: the state of carrying a developing embryo inside of the female body.

2. What is pregnancy?

2.1 Reproduction in mammals

Humans are mammals. Reproduction is the process by which new organisms are produced. By reproduction in mammals they give birth to alive young and the organisms grow inside the mammal’s body. Mammals feed their young milk produced by their body. Reproduction is needed to maintain the species.

2.3 Facts and figures

The average length of a pregnancy is 280 days, 40 weeks or 9 months. However, the length of a normal pregnancy can be anywhere around 37 weeks and 42 weeks.
The earliest a baby has been born and survived is 21 weeks and 5 days: 152 days. A woman called Beulah Hunter claims that she carried her baby for 53 weeks and 4 days: 375 days.
The average age of a woman’s first pregnancy in the USA is 26 years old. The youngest mom in the world was five (!) years old and the oldest mom was 67 years old.
The most babies born in one time are 7, named the McCaughey septuplets.
The weight of an average new-born baby is 5 pounds, 8 ounces (2,500 grams) and 8 pounds, 13 ounces (4,000 grams). The lightest baby was 8,6 ounces (243 grams) and the heaviest was 22lb and 8oz (10,205 grams).
The length of an average new-born baby is 19-20 inches (50 cm), but it can vary between 18 inches and 22 inches (45.7 to 60 cm). The smallest baby born and survived was 9,5 inches (24.1 cm) and the biggest was 28 inches (71,1 cm).

2.4 Glossary

Conception/fertilisation (bevruchting): the process of a male and a female sex cell joining, causing a baby to form.

Implantation (implantatie, innesteling): the early embryo connects to the uterine wall, this is the first phase of the placenta

Reproduction (voortplanting): the production of offspring by a sexual or asexual process.

Egg cell (eicel): the female reproductive cell, with half of the normal number of chromosomes)

Sperm cell (zaadcel): the male reproductive cell, with half of the normal number of chromosomes)

Differentiation in humans (differentiatie bij mensen): the process of development of gender differences in humans.

Stem cell (stamcel): a cell that can produce other cells (by dividing, mitosis) which are able to develop into any kind of cell in the body.

Uterus (baarmoeder): the organ in a woman’s body in which a baby develops before birth.

Placenta: the temporary organ that feeds the developing baby inside the mother's womb.

Embryo: an unborn animal/human in the very early stages of development.

Fetus (foetus): an unborn animal/human more than eight weeks after conception.

Menstruation (menstruatie): a process, were blood and tissue from your uterus comes out of your vagina, that occurs once a month, when no conception implantation of a fertilized eggcell has taken place

Ovulation (ovulatie): the release of an egg in women, once every month.

Fallopian tubes/Uterine tubes (eileiders): the pair of tubes that carry the egg from the ovary to the uterus.

Ovaria (eierstokken, ovaria): Organ where the eggcell develop ands and is released into the fallopian tube.

Uterine wall (baarmoederwand): the inside of the uterus.

3. Stages and changes of development in the uterus.

Pregnancy is commonly grouped into 3 trimesters:

Trimester 1 (week 1 until week 12).

During the first trimester a woman’s body undergoes a lot of changes. The hormonal changes affect almost all the body parts, which lead to a lot of symptoms, even in the very first week. These symptoms include:

Extreme tiredness.
(trouble having bowel movements)
Cravings or distaste for certain foods. Like salty, spicy or sweet things.
Mood swings.
Weight gain or loss.
Upset stomach and morning sickness.
Frequent urination.
Tender, swollen breasts.

Trimester 2 (week 13 until 28).

Most women think the second trimester of pregnancy is easier than the first one. But it’s still important to stay informed about your pregnancy. For example, in the end of this trimester your baby begins to move!
You might notice that symptoms from the first trimester are going away, but other new changes and symptoms begin to form:

Body aches.
Stretch marks.
Darkening of the skin around your nipples.
A line on the skin running from belly button to pubic hairline
Patches of darker skin, usually over the cheeks, forehead, nose, or upper lip.
Numb or tingling hands.
Itching on the abdomen, palms, and soles of the feet.
Swelling of the ankles, fingers, and face.

Trimester 3 (week 29 until week 40).

The baby is getting bigger and it is putting more pressure on your organs. Some of the same discomforts from the second trimester will continue, plus more, like:

Shortness of breath.
Swelling of the ankles, fingers, and face.
Tender breasts, which may leak a rich pre-milk called colostrum.
Your belly button can stick out.
Trouble sleeping.
The baby "dropping” or moving lower in your abdomen.
Contractions, which can be a sign for real or false labour.

4. Development inside the womb.

It all begins with conception: when a sperm cell meets and penetrates an egg. It is now a fertilized egg and within three days, it is dividing rapidly into many cells. The placenta also starts to form at the implantation phase.
At 4 weeks, the baby starts to develop structures that will form the face and neck later on. The lungs, liver and stomach begin to develop, and the heart and blood vessels continue to develop. On echo image the heart is viably pounding after day 16^.
When the baby is 8 weeks old, it’s more than half an inch, around 1,25 cm. You can see the tip of the nose, the arms and legs are formed, the fingers and toes are growing longer. Ears and eyelids are forming.
At 12 weeks, the baby is 2 inches (more than 5 cm) and it will make its own movements. The sex organs will be clear and with special instruments, you can hear the baby’s heartbeat!
When 16 weeks, the baby is 4,3-4,6 inches (10,9-11,7 cm). The baby can blink, the heart and blood vessels are totally formed, and the baby’s toes and fingers have fingerprints.
If the baby is 20 weeks old, it’s around 6 inches (more than 15 cm). The baby can yawn, suck its thumb stretch, and make faces. An ultrasound is usually done by all woman that have a 20 weeks pregnancy, to see if the placenta is healthy and attached properly and the baby is growing well.

The baby is 24 weeks now and it responds to sounds now, by increasing its pulse or moving! It can maybe sense now, because the ears are fully developed.
When the baby is 28 weeks old, it can already be born with a good change to survive. For example, the baby already weights about 2 pounds and 6 ounces (more than 1075 gram) and it will change position a lot. That’s why most women (and men) take birthing classes now, to prepare for different aspects of the pregnancy.
Later on, at 32 weeks, the baby will move often and will weigh 4 pounds (1815 grams). Between now and the delivery, the baby will gain up to half his birth weight.

At 36 weeks, the baby’s lungs are fully developed, the brain has been developing a lot and it’s considered ‘on term’ now.
Then it’s over: usually around the 38 weeks and the 42 weeks, the birth takes place!

5. What can go wrong?

4.1 Pregnancy complications

Miscarriage is the loss of a pregnancy before 20 weeks, after that it is called stillbirth
Preeclampsia is a serious condition that affects about 5 percent of pregnant women. Woman diagnosed will have a high level of protein in their urine and often have swelling in their legs, feet and HELLP is a variant of preeclampsia.
When a pregnant woman uses medicines, this can have an influence on the baby’s development. These can be products like alcohol and cocaine, but also some medicines that seem innocent.
Three important examples are Isotretinoin, Thalidomide (softenon) and DES. Isotretinoin increases the risk of miscarriage and can cause serious birth defects in the child. Thalidomide can cause deformed children. DES can cause a lot of reproductive changes and fertility problems later in life.
Gestational diabetes is a condition where a woman without diabetes develops high blood sugar levels during her pregnancy.

4.2 (Genetic) Birth defects

The things that can go wrong with the mother during the pregnancy are described above, but there are also a lot of things that can happen with the child or during the birth. This can be genetic, but it doesn’t have to be. There are more than 7000 different (partially) genetic birth defects, I’ll be naming five:

Congenial heart defects: when something is wrong with the baby’s heart. There are more than 18 different types, like Septal Defect and ASD.
Neural tube defects: birth defects of the brain, spine, or spinal cord.
Down syndrome: this causes delay in physical and mental development.
G6PD deficiency: a genetic disorder that happens when the baby doesn't have enough of the enzyme glucose-6-phosphate dehydrogenase.

5. Social aspects of pregnancy

5.1 In general

When you are pregnant, people have a lot of opinions. It’s like people sometimes forget there is a person with feeling attached to the belly: they think it’s okay to comment on everything from the mom’s weight, size, age and lifestyle till everything about the baby. Or think that it is completely acceptable to ask other completely inappropriate questions make (dry) jokes about the mom, touch her belly all the time and laugh.

Getting advice about breastfeeding to cloth diapers is a little too much too.

Maybe people will say something about how big you are, or how small you are. Most people think you shouldn’t say both: it’s basically body shaming or it’s making the woman worry about the baby’s size.

It’s important to have a healthy lifestyle while pregnant: exercising, drinking enough water, eating healthy, sleep enough. This is because it can impact your growing baby. However, having people constantly judging your lifestyle and giving advice, is a bit over the top. When somebody is pregnant, it is suddenly okay to do that?

‘Isn’t she too young to be pregnant? She is still a child!’
‘Isn’t she too old to be pregnant? She could be a grandma!’
Getting weird looks, talks behind your back or right in your face when you are not the ‘desired’ age for being pregnant: it’s quite a struggle. People thinking you and/or your partner aren’t ready for a child and can’t raise one properly. People thinking you are too old to properly raise a child.

And the worst of all: how you are going to raise your child. Like everything isn’t stressful enough: questioning your abilities as a parent or start to wonder if they have what it takes.

5.2 Abortion

One of the most discussed subjects about pregnancy, is abortion. Abortion is the intentional ending of a pregnancy. This can be because of different reasons:

Because of the health of the mother, including her mental health.
When a pregnancy is a result of a crime like incest, rape, or child abuse.
When the child of the pregnancy would have serious physical handicaps, serious genetic problems or serious mental defects. Like down syndrome.
Because social reasons, such as poverty, a mother that can’t cope with a child or another child, a mother who is too young to deal with a child.
Because of a government policy: for regulating population size, regulating groups within a population or improving the population.

The most important reason is that the mother is too young, often a teen mom. This is mostly because she didn’t use protection (like the pill or condoms) or was raped.
The opinions about abortions vary: pro-abortion: ‘Boss about own belly’ or anti-abortion: ‘Murder’?
Some arguments pro-abortion:

Women have the right to decide what to do with their bodies.
The right to abortion is essential for independent a woman to achieve their full potential.
Banning abortion can put a woman at risk, because she is forced to get an illegal, unsafe abortion.

Arguments anti-abortion:

It is discrimination towards the unborn, innocent baby.
Everyone should have a change to live and have a future.
Unborn babies have feelings too. However, there is no proof about that.
Religious reasons.

It varies per country until when you can get an abortion, and it’s illegal in a lot of countries. In every state of the United States it is legal though, and in most countries abortion is legal until 24 or 26 weeks of pregnancy.

6. Opinion

I learned a lot from this project, and I liked writing it. It is exciting and handy to know things about pregnancy, because most woman have at least one pregnancy in their lives! While searching for information, I often saw things like ‘Congratulations, you are pregnant! Sign up to see the growth of your baby!’, which I found pretty funny. Some things I thought were pretty scary, like some pregnancy complications and tiny, premature babies. Thanks for reading!

Sources

https://en.wikipedia.org/wiki/Pregnancy
https://www.toptenz.net/10-births-set-world-records.php
https://www.healthline.com/health/parenting/average-baby-length
https://en.wikipedia.org/wiki/McCaughey_septuplets
https://www.merriam-webster.com/dictionary/conception
https://en.wikipedia.org/wiki/Multiple_birth
https://www.mirror.co.uk/news/uk-news/top-10-crazy-amazing-and-world-789842
https://www.drsherry.com/blog/what-is-the-longest-healthy-pregnancy-on-record/
https://www.dailymail.co.uk/health/article-3608560/Mother-gives-birth-heaviest-girl-born-world-weighing-15lb-fortunately-delivered-C-section.html
https://www.foxnews.com/health/worlds-smallest-baby-thriving-after-premature-birth
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https://en.wikipedia.org/wiki/Mammalian_reproduction
https://en.wikipedia.org/wiki/Reproduction
https://www.healthline.com/health/birth-defects#diagnosis
https://www.webmd.com/heart-disease/types-congenital-heart-defects#1
https://www.webmd.com/baby/news/20060130/top-5-genetic-birth-defects-named
https://www.marchofdimes.org/complications/congenital-heart-defects.aspx
https://www.verywellfamily.com/what-to-say-to-people-with-opinions-about-your-pregnancy-4174384
https://www.todaysparent.com/pregnancy/being-pregnant/things-not-to-say-to-a-pregnant-woman/http://www.bbc.co.uk/ethics/abortion/legal/when_1.shtml
https://dictionary.cambridge.org/dictionary/english/abortion
https://www.nemokennislink.nl/publicaties/softenon-vloek-en-zegen/https://www.apotheek.nl/medicijnen/isotretinoine
http://www.bbc.co.uk/ethics/abortion/mother/for_1.shtml
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https://www.webmd.com/baby/ss/slideshow-fetal-development
https://www.merriam-webster.com/dictionary/implantation
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https://www.medicalnewstoday.com/articles/150870.php
https://www.sense.info/nl/seks-abc/b/baarmoederwand
https://en.wikipedia.org/wiki/Abortion_in_the_United_States

Written in April 2019