When does the 1st trimester start

Everything you need to know about the first trimester (weeks 1 to 12)

Tommy's PregnancyHub

You’re pregnant: congratulations! The first weeks of your pregnancy are a vital time as your body gets busy building a baby. How exciting!

First trimester: key stages

The first trimester begins on the first day of your last period and lasts until the end of week 12. This means that by the time you know for sure you're pregnant, you might already be five or six weeks pregnant!

A lot happens during these first three months. The fertilised egg rapidly divides into layers of cells and implants in the wall of your womb where it carries on growing. These layers of cells become an embryo, which is what the baby is called at this stage.

During this trimester, your baby grows faster than at any other time. By six weeks, a heartbeat can usually be heard and by the end of week 12, your baby's bones, muscles and all the organs of the body have formed. At this point, your baby looks like a tiny human being and is now called a fetus. He or she will even be practising swallowing!

Try our Healthy Pregnancy Tool to find out everything you need to know about your pregnancy

When am I due?

Find out your due date using our due date calculator!

When will I see a midwife?

Your first midwife appointment (also known as antenatal appointment) is the 'booking' appointment. This usually happens between week 8 and 10 of your pregnancy. Find out how to register with a midwife and when your appointments will be here.

Keeping your baby safe

There are some things that you can do during pregnancy that have an effect on your baby. Find out about them by clicking the link below.

Find the complete list of pregnancy dos and don'ts (and reasons why) here

Not sure whether you are pregnant?

Find out about the symptoms that mean you may be pregnant here.

Your physical and mental health in pregnancy

We also have lots of useful tips for coping with everyday pregnancy niggles. It’s common for women to experience symptoms such as morning sickness, cramp and indigestion during the first trimester.

Don't forget that your mental health is just as important as your physical health. It's normal to feel some anxiety and stress but it shouldn't be ongoing. If what you’re feeling isn’t normal for you, talk to your GP or midwife about it. They are there to help.

Exercise, such as yoga, has been shown to reduce anxiety and is a great way to stay active during your pregnancy, too.

Read more about mental wellbeing in pregnancy

Track your baby's development

Sign up to a free pregnancy email from our midwives to track your baby's development and give you reminders of all you need to know through the 9 months of pregnancy. Click here to sign up.

Review dates

Reviewed: 28 June 2018 | Next review: 28 June 2021

This content is currently being reviewed by our team. Updated information will be coming soon.

Dos and don'ts for a safer pregnancy

Things to do during pregnancy

Take folic acid and vitamin D supplements

Folic acid significantly reduces your baby’s risk of neural tube defects, such as spina bifida.

If you are pregnant, start taking 400 micrograms of folic acid as a supplement as soon as possible until the end of the first trimester (week 12 of your pregnancy).

Some people may need a higher dose of folic acid, for example if you have diabetes or epilepsy. This is only available on prescription. Find out more about folic acid.

You are also recommended to take a Vitamin D supplement during pregnancy and during breastfeeding. This helps your baby develop healthy bones, teeth and muscles.

These 2 supplements are the only ones you need in pregnancy, alongside a healthy, balanced diet.

Find out more about pregnancy supplements.

Eat well

Having a balanced diet and eating well during pregnancy means having a good variety of foods, such as fruit and vegetable, meat, cheese, potatoes, beans and pulses. This will ensure you have the energy and nutrients you and your baby need during pregnancy.

If you feel you are struggling to follow a healthy diet during pregnancy, ask your midwife or GP for support. They might be able to refer you to a dietitian to help you.

Read all about how to eat well in pregnancy.

Stay active

Staying active during pregnancy is great for you and your baby. It can help you sleep better, reduce anxiety and help you stay healthy through pregnancy.

If you were active before you became pregnant, you can continue at the same level. But listen to your body and slow down if you begin to feel uncomfortable. If you didn’t exercise much before you became pregnant, build up slowly and aim for 30 minutes each day.

Exercise does not have to be strenuous to make a difference. Even gentle walks are good.

Read all about exercise and pregnancy.

Avoid diving or playing contact sports

Most exercise is safe and healthy to continue during pregnancy. But there are some activities you should not do.

Read about activities that are best to avoid during pregnancy.

Monitor your baby’s movements

Feeling your baby move is a sign that they are well. You usually start to feel your baby moving when you’re between 18 and 24 weeks. If this is your first baby, you might not feel movements until after 20 weeks.

The movements can feel like a gentle swirling or fluttering. As your pregnancy progresses, you may feel kicks and jerky movements.

Get to know your baby’s pattern of movements and contact your midwife or maternity unit immediately if you think these have slowed down, stopped or changed. You should feel your baby move right up to and during labour.

Find out more about monitoring your baby’s movements.

Go to sleep on your side in the third trimester

Our advice is to go sleep on your side in the third trimester because research has shown that this is safer for your baby. This includes night sleep and daytime naps. If you wake up on your back, try not to worry, just settle back to sleep on your side.

Find out more about sleeping on your side in the third trimester.

Take care of your mental health

Your mental health is just as important as your physical health during pregnancy. Being pregnant is an emotional experience and it can be normal to experience mood swings or feel low from time to time. However, it’s important that you ask for help if these feelings become unmanageable or last longer than a couple of weeks.

You won’t be judged for how you feel. As many as 1 in 5 women develop mental health issues when they are pregnant and up to a year after birth. Your pregnancy care team understand that mental health conditions can affect anyone at any time.

Find out more about taking care of your mental wellbeing during pregnancy.

Consider having vaccinations that are offered

You’ll be offered vaccinations during pregnancy.

The whooping cough vaccine

Whooping cough (pertussis) is a respiratory infection that develops into severe coughing fits. This illness can be very severe, especially in very young babies. Pregnant people are recommended to have the vaccine to protect their baby until they are old enough to have their first vaccinations.

The best time to get vaccinated to protect your baby is from week 16 up to 32 weeks of pregnancy. But you can have the vaccine anytime from 16 weeks right up until labour. However, it may be less effective if you have it after 38 weeks.

There are no recommendations in the UK for your partner to have this vaccine.

The flu vaccine (between September and February)

All pregnant people are recommended to have the flu vaccine, whatever stage of pregnancy you are at. This is because having the flu in pregnancy can cause complications, particularly in the later stages of pregnancy.

Read more about having these vaccinations in pregnancy.

Covid-19 vaccine

Pregnant people are recommended to have their COVID-19 vaccination as soon as possible. Find out more about the COVID-19 vaccine in pregnancy and breastfeeding.

Carry your pregnancy notes with you

It’s a good idea to carry your antenatal notes everywhere you go as they contain all your medical and pregnancy history. This is particularly important if you need to go to the maternity unit, especially at short notice.

Make sure you’re prepared if you travel abroad

If you’re flying abroad make sure your travel insurance covers you for any pregnancy complications and take your maternity notes with you.

Long-distance travel (more than 4 hours) may increase the risk of deep vein thrombosis (DVT) or blood clots. Try to:

wear compression or support stockings (available from the pharmacy or the airport), which will help reduce leg swelling
drink plenty of water
move around often.

If you intend to fly after 28 weeks check the airline’s policy. They may ask for a letter from your doctor or midwife confirming your due date, and that you aren't at risk of complications. Find out more about flying in pregnancy.

Be aware of red-flag symptoms

There are some symptoms that should always be checked with a midwife or doctor as they could be a sign that the baby is unwell. This include:

bleeding from the vagina
painful urination
sudden, sharp or continuing abdominal pain or cramps
persistent or severe headache
swelling in face, hands or legs
blurred vision, spots in front of eyes
itching, especially on hands or feet
baby’s movements slowing down or changing
excessive or smelly vaginal discharge or if you think your waters have broken.

You should always contact your midwife if you feel that something is wrong with you or the baby. Even if you don't know exactly what it is. It's important to trust your instincts in pregnancy.

Things to avoid during your pregnancy

Try not to ‘eat for two’

Your baby will take all they need from you as they grow, so there’s no need for extra calories in the first or second trimester. In the third trimester, you might need an extra 200 calories if you are active. This is the equivalent to around half a sandwich.

Find out more about how much to eat in pregnancy.

Avoid losing weight during pregnancy

Cutting out food groups to try to lose weight may stop your baby getting nutrients they need for growth. Instead of restricting your diet, the best thing to do is manage your weight through eating a healthy, balanced diet, with a variety of foods from each of the main food groups.

Find out more about managing your weight during pregnancy.

Avoid certain foods during pregnancy

Some foods carry a small risk of infections during pregnancy, such as toxoplasmosis or listeriosis. These infections are rare but can cause problems for your developing baby.

Take a look at our list of foods to avoid during pregnancy.

You may also find it useful to read more about how to avoid infections during pregnancy.

Avoid caffeine

High levels have been linked to pregnancy complications, so it is best to limit your caffeine intake as much as possible.

The current NHS guidelines recommend that you should have less than 200mg a day. This is about 2 cups of instant coffee.

Find out your daily caffeine intake with our caffeine calculator.

If you smoke, try to quit

If you smoke, quitting is one of the best things you can do for you and your baby.

Smoking during pregnancy increases the risk of serious complications in pregnancy, including miscarriage, stillbirth and premature birth.

Quitting smoking can be difficult, but it’s never too late to stop. Get support to quit smoking.

Avoid drinking alcohol

Drinking in pregnancy can lead to long-term harm to the baby. The more you drink, the greater the risk. There is no known safe level for drinking alcohol during pregnancy, so it’s best to avoid it completely during pregnancy.

Find out more about drinking alcohol during pregnancy.

Stay away from recreational drugs

Cocaine, meta-amphetamines, cannabis, psychoactive substances (so called ‘legal highs’) are all likely to increase risks of health problems.

If you are taking illegal drugs, it is important to talk to your midwife or doctor. They will not judge you and can give you the right care and support during your pregnancy. The more they know, the more they can help you and your baby to get the right treatment.

You can also get confidential (they will not speak to anyone else about your drug-use) extra support from Talk to Frank.

1st trimester of pregnancy: what happens to the fetus

1st trimester of pregnancy: what happens to the fetus - Private maternity hospital Ekaterininskaya Clinics

1st trimester: 1st-12th weeks

The gestational age is calculated from the first day of the last menstruation, since it is difficult to determine the exact day of conception. Since conception usually occurs in the middle of the menstrual cycle, you are not actually pregnant during the first two weeks, but this period is counted as the beginning of pregnancy.

As soon as the fertilization of the egg takes place around the 3rd week, the hormones begin to produce changes in your body little by little. As a result, you may experience some of the following symptoms:

Morning sickness. As a result of rising levels of hormones characteristic of pregnancy, up to 80% of women in the 1st trimester experience morning sickness with symptoms such as nausea and vomiting. The idea that such malaise is observed only in the morning is a common misconception. In fact, symptoms can appear at any time of the day or night. Up to 1 in 5 women experience morning sickness in the 2nd trimester of pregnancy and can sometimes persist throughout pregnancy.
If you experience morning sickness, avoid foods that make you sick, eat little and often, avoid fatty and spicy foods, drink more water. If you experience severe symptoms or symptoms that bother you, see your doctor.
Breast changes. The mammary glands will begin to increase in size, soreness may appear. The nipples will increase in size, become darker and more protruding.
Fatigue. High levels of the hormone progesterone can make you feel tired and sleepy. Rest as often as possible in a horizontal position with your legs up and eat as well as possible, which is not easy if you are experiencing morning sickness!
Increased emotionality. A higher level of emotionality, manifested as a result of an increase in hormone levels, is normal. Understanding and patience on the part of your partner and loved ones is very important here.
Food likes and dislikes. You may find yourself intolerant of one food and addicted to another. This is usually not a problem, unless you feel like eating weird foods like chalk. If you are concerned about the situation, contact your doctor.
Frequent urination. As your fluid levels increase and your uterus puts pressure on your bladder, you will become more likely to visit the toilet. Go to the toilet as soon as you feel the need - this minimizes the pressure on the bladder.
Feeling of dizziness. Sometimes you may feel a little dizzy (this is due to hormonal changes). Try not to stay on your feet for a long time and slowly rise from a sitting or lying position. If you experience severe dizziness, contact your doctor immediately.
Heartburn and constipation. Your digestive system will slow down to give you more time to digest your food. This can lead to heartburn and constipation. To help manage heartburn, try to eat small meals at regular intervals and avoid fried or spicy foods and carbonated drinks. Constipation is helped by eating a diet rich in fiber, maintaining physical activity and drinking plenty of water.

1st trimester milestones

Approximately 7 days after fertilization, the embryo implants in the uterine wall. The placenta, umbilical cord and amniotic sac will begin to form to provide nourishment and protection to the embryo.
By the end of the first 12 weeks of pregnancy, the uterus is palpable through the wall of the abdomen, the abdomen will begin to grow.

Child development in the 1st trimester of pregnancy

By the end of the 1st trimester:

All the main organs of the baby are formed, the circulatory system works.
The development of the sexual organs has begun.
Fingers are formed on the hands and feet, nails have appeared.
Facial features have formed.
The length of the baby's body is about 6 cm from the head to the lower part of the body, he is already recognizable. The baby moves in the amniotic sac, but you don't feel it move yet.

Clinic mobile app

You can make an appointment with a doctor, get tests
and much more...

Fill out the form to make an appointment or order a call back

I agree with personal data processing policy and user agreement I also give my consent to the processing of personal data.

By continuing to use rd.clinic23.ru, you agree to the use of cookies. How to ban the use of certain cookies can be found in Politics

Critical stages of pregnancy - why are they dangerous?

Services

Virtual tour. Clinic "ARNIKA"

The wonderful period of expecting a baby for almost every woman is far from serene: how many anxieties, worries and doubts arise in expectant mothers at this time - they simply cannot be counted. In most cases, all fears are in vain - the baby develops and grows safely. However, it must be remembered that there are also so-called critical periods of pregnancy, when inattention to oneself and one's body can lead to a disastrous result - its spontaneous termination.

First trimester

The beginning of a new life in a woman's body, or 2-3 weeks of pregnancy, is considered the first critical period. This is due to the fact that the egg can be fertilized, but due to changes as a result of inflammation, hormonal imbalances, the presence of nodes, scars, fibroids or synechia on the inner mucous membrane of the uterus, implantation does not occur, the embryo dies and is removed from the mother's body during menses. However, even if implantation has occurred, the embryo may stop developing and early miscarriage , and the main reason for this course of events is chromosomal abnormalities.

The second critical period of the first trimester begins at 8 and ends at 12 weeks of gestation. At this time, the main cause of interruption is considered to be hormonal deficiency, which disrupts the process of placental formation. This condition may be associated with reduced work of the corpus luteum of the ovaries, excessive production of androgens by the adrenal glands - male sex hormones, as well as malfunctions of the pituitary gland or thyroid gland. The threat of termination of pregnancy can be eliminated with the help of properly selected and timely prescribed hormonal treatment, which will allow the baby to live safely before the due date.

In addition, throughout the first trimester of pregnancy, the fetus may stop developing due to the following adverse environmental factors:

harmful working conditions
bad habits
physical effects - radiation, vibration, intense sports training, etc.
acute infectious diseases (influenza, cytomegalovirus, herpes, rubella and others)
severe stressful situations

And even if the fetus develops further, the negative impact of most of these factors may appear after a few months of pregnancy or even after the baby is born: these may be anatomical disorders or severe malformations. Therefore, the entire first trimester of the development of a new life can be considered "critical".

Second trimester

The third critical period of pregnancy occurs at 18-24 weeks of gestation and is largely associated with the active growth of the uterus. At this time, spontaneous interruption most often occurs due to isthmic-cervical insufficiency (ICI), as a result of which the fetal egg descends under the influence of gravity, loses its integrity and triggers the mechanism of labor activity. However, shortening and expansion of the cervical canal, detected in time, allows suturing the cervix or installing an obstetric pessary and safely prolonging the pregnancy. Here we should also remember about infectious diseases, including intrauterine infection, which can disrupt the functions of the placenta, lead to the outflow of water from the fetal bladder and late miscarriage.

Another common reason for interrupting the process of gestation at this time is placenta previa or its low location: for various reasons, it can exfoliate, cause severe bleeding and death of the fetus. In addition, at this time, pregnancy may stop developing due to violations in the development of the brain and the most important functional systems of the baby, caused by the harmful effects of various negative factors on them in the first trimester.

Third trimester

In this trimester - at 28-32 weeks - the fourth critical period takes place. The threat of premature birth may arise due to insufficiency of the placenta, its premature detachment, severe forms of late toxicosis of pregnant women, ICI and various hormonal disorders. In addition, due to the overdistension of the uterus, most multiple pregnancies end at this time. Children born during this period are already viable, but they need long-term qualified medical care.

In addition to all the periods listed above, the critical periods for women who have had reproductive losses in the past are the days of planned menstruation, miscarriages or "fading" of pregnancies. Doctors believe that during these periods the body can “remember” the need for hormonal changes, so they carefully monitor the condition of the expectant mother and baby and prescribe treatment in a timely manner if any threat arises.

Welcome

Find us on iTunes!

Popular Posts