Pregnancy Trimester 1

As an expecting Dad you will want to know what is happening to your partner – the expecting mother. The information below will keep you updated!

Here we discuss Pregnancy week 4 to week 8 and Pregnancy weeks 10 to 12. Click on the links below to read about the weeks that are important to you.

Pregnancy Weeks 4 – 8 of First trimester

Fetus development 6 week 6 day

Your Partner may miss her period though this doesn’t always happen.

About 70% of expecting mothers are affected by morning sickness (pregnancy nausea which is not usually accompanied by vomiting)

A home urine test will confirm the pregnancy.   Follow up with a visit to your Doctor – who may do a repeat urine test or blood test.

The first few weeks are crucial as the foundations for baby’s organs are laid down – so Mom needs to be very careful of all drugs: alcohol, nicotine, prescription medications and illegal drugs.   All of these could affect your baby long term.

Diseases that can occur in pregnancy which are dangerous to the develping fetus:

TOXOPLASMOSIS – Cats, particularly carry the parasite that causes this disease.   Parasite is found in faeces and in soil.
•    Meat needs to be properly cooked
•    Hand hygiene is important after handling meat
•    Wash all vegetables well before eating or cooking
•    Wear gloves if there is a chance of picking up the parasite when gardening, or disposing of pet faeces etc
•    Don’t handle cats and if you have to make sure you wash your hands afterwards.

CYTOMEGALOVIRUS –  a virus from the Herpes family.  Varicella zoster (Chicken Pox), Herpes Simplex which causes cold sores, and Glandular Fever (Epstein-Barr) – are all related viruses.
Mum can be infected by: genital contact, mucous membranes in mouth.   Virus can be airbourne, or spread in blood urine or faeces..

LISTERIOSIS – this bacteria lives in the  soil.
•    Basically it is best if an expecting mother eats fresh home made foods as this bacteria can be found in processed meats, pre-prepared salads left standing, all soft cheeses, like Stilton and Brie.   With chicken – be sure it is properly cooked

•    Gonorrhoea
•    Chlamydia
•    Genital Herpes
•    HIV/Aids
•    Syphilis

In Western Countries you are likely to be screened for some of these diseases.   The expecting mother needs to protect herself during sex if their is a risk her partner has one of the above diseases
XRAYS are very dangerous for a developing fetus

Possible Effects on You

•    Breasts sore or tender
•    Frequency – going to the toilet to pass urine often
•    Feel a bit sick/nauseaus
•    Feel very tired
•    May feel light- headed
•    No period – that at least is a bonus
•    If Mom-to-be has never been pregnant before – an awareness of how her body is changing

Baby Week by Week

4 Weeks pregnant –fetus size smaller than a grain of rice
5 Weeks pregnant – neural tube developing which eventually becomes the brain and spinal cord
6 Weeks pregnant – Embryo 3mm in length
7 Weeks pregnant –  fetus heart starts to beat;  embryo has it’s placenta and the amnio sac.   The placenta attaches to the wall of the uterus (womb) to get oxygen and nutrients for your baby-to-be!
8 Weeks pregnant – Embryo 1.3mm (about 1/2inch).   Large head compared to the body – and the spinal cord looks like a tail.

Pregnancy Weeks 10 – 12 of First Trimester

The most crucial weeks of pregnancy are the early weeks and at 10 weeks to 12weeks, when tests are done to see if the fetus has abnormal chromosomes or any risk of inherited problems.

Possible Effects on You:

Expecting mothers can still have morning sickness (nausea of pregnancy) and feel extremely tired and exhausted.   You still need to go to the toilet to empty your bladder frequently.   Breasts are tender and getting bigger, and if you have been eating normally – you may have put on some weight.   Remember all drugs, alcohol, nicotine, prescription and illegal drugs can permanently damage your unborn baby – so discuss this with your Doctor.

You are likely to be

  • sensitive to heat
  •  a dark line under your  navel (belly button) to your pubic area called a “linea nigra” may develop
  • By 12 weeks of pregnancy – the uterus (womb) is no longer pressing on your bladder as it lifts up out of the pelvic area – so visits to the bathroom are less often.
  • You can actually start to feel the womb just above your pubic bone.
  • Usually you are adjusting to the fact that you are going to have a baby, and you decide who to tell.

Most expecting moms visit their Doctor by 10 weeks and the doctor usually recommends various tests.

  • One of the tests is to see if you’ve been exposed to German measles (Rubella).   Rubella can cause serious damage to the fetus during the first few months of pregnancy.   The baby can be born deaf, blind (congenital cataracts), have heart problems, lung, liver and learning difficulties.   Make sure you stay away from anyone with German measles.
  • Blood count – are you anaemic (low red blood cells), white blood cells to see how healthy your immune system is, and assess your platelet count.   All pregnant women are at risk of anaemia and need to take iron supplements (iron tablets are better absorbed with orange juice), and to increase food intake of foods containing iron.
  • Blood Group and Rhesus (Rh) status:   It’s important to know what your blood type is (A B AB or O type) and whether you are RH negative or positive.  The RH factor is important because RH negative mom’s-to-be can develop antibodies – if her unborn baby is RH positive.   If this is the Mom’s first pregnancy – it is not a problem for the unborn baby.   The risk is for future pregnancies where Mom’s antibodies destroy the blood cells of the fetus which can cause anaemia and jaundice in the unborn baby.   In order to prevent this, a RH negative Mom who has antibodies is given ANTI -D (RH immuno-globulin) at 28 and again at 34weeks of pregnancy.   Within 72 hours of giving birth the expecting mother is given another dose of ANTI-D.   If Mom and Dad are both RH negative – the baby is not at risk.
  • HIV testing is usually done unless you specifically ask for it not to be done.   With modern day antiviral drugs, plus delivery by Caesarian section and avoiding breastfeeding, the baby only has a very slight risk of developing HIV (down from 20% to 2%)
  • Syphilis – in Western countries Syphilis is rare.   It is easily treated with antibiotics.   Untreated it can cause severe brain damage in the fetus.
  • Hepatitis B – if you are Hep B positive – a vaccination is available for the baby after birth.


Ultrasounds and other Diagnostic Tests:

Some fetal abnormalities can be picked up very early in the pregnancy.   These days ultrasounds are a non-invasive way of testing to see if the unborn baby is likely to be normal.   High frequency sound waves are emitted which show up as images – and show the development of the unborn baby’s organs.   For some expecting mothers knowing if the baby is abnormal makes no difference, but for others they may want to terminate the pregnancy – which is best done before 16 weeks of pregnancy.   The Ultrasound test also shows the development stage of the fetus so you can estimate when the baby should be fully developed (due date for delivery).   Assessing how the unborn baby is developing inside the womb is important, because if things go wrong and the baby is not developing as expected, the Obstetrician may offer some suggestions as to how to improve the likely outcome for your baby.

Ultrasound (roughly 11 -12 weeks pregnancy):
This is an exciting time as you can can see the tiny body of the fetus.  You may see movements and heartbeat

  • Ultrasound is done by a Specialist called a Sonographer.
  • The ultrasound shows the size of the fetus, the amount of fluid surrounding the fetus, and where the placenta (afterbirth) is attached to the womb.
  • The ultrasound is usually done by placing a transducer on your abdomen and moving it over your uterus, as images are sent back to the computer.   It is also possible to do the ultrasound via the vagina.   You usually have to drink extra fluids before the test but you will be given these instructions before hand.
  • The sonographer is particularly looking for Downs Syndrome babies, who have a “nuchal fold”.
  • If you want to know the sex of your unborn baby – very often the sonographer can see what sex your baby is.   If you don’t want to know make sure you let the Sonographer know that before they start the test.


Chronic Villus Sampling (CVS) and Amniocentesis and Fetal blood sampling (These are more invasive diagnostic tests done if your Doctor thinks you have an increased risk of your baby being born with an inherited abnormality like Down’s syndrome – also called Trisomy 21.  The CVS is done at about 11 weeks – 13 weeks.   An ultrasound is done to find where the placenta is.   A local anaesthetic is given into the abdominal wall and a small sample of tissue is taken from the placenta.

These cells are sent to the laboratory for testing.   There is an increased risk of miscarriage – discuss this with your doctor.   Some of the test results are available in a few days, other more complicated DNA tests can take a few weeks.   It can be quite stressful waiting for results so it’s great if you have support people around you.

Other possible tests include:

  • Amniocentesis – discussed at 16 weeks of pregnancy
  • Maternal Serum alpha-fetoprotein – discussed 16+ weeks of pregnancy
  • Fetal Blood sampling –  discussed at 18- 20 weeks pregnancy


Birth choices:   who will care for you in your pregnacy, doctor or midwife, and where will you deliver your baby?

If you have never given birth to a baby before – your body will not yet have been tested so you are not likely to know if you can have a natural childbirth or if you are likely to need some help from an Obstetrician.   In the early weeks it’s important to see your GP and discuss your options with him/her.   This is a big decision as you want to be in the hands of a qualified and experienced Doctor/Midwife you feel safe with, in case you need some help during labor or delivery.

Each country has their own rules and regulations as to how much care an experienced Midwife can give.   You need regular monitoring throughout your pregnancy so that your health and that of your baby can constantly be assessed.   In some countries home birth is an option, or birthing centers affiliated with a maternity hospital, or delivery in a Maternity hospital which may be private or public.   Discuss this as early as possible with your doctor as your options do depend on availability and your health/pregnancy health.

You can explore your options here:

Your baby at 12 weeks pregnancy:

The fetus looks like a baby fully formed, the toes and fingers have separated, head in proportion to the body.   Fetus size is about 61mm or 2 ½ inches.
Development of all organs continues, importantly the brain and nervous system too.   As pregnancy continues, the neurons (brain cells), become sensitive to the hormones in the Mom’s blood, particularly  stress hormones, and even the environment (what is going on in the Mom’s life) affects the way your baby’s brain develops so what is happening now will affect how your baby’s future.
More on this in 20 weeks of pregnancy/stress hormones effect on your baby.