Trimester One

The ‘secret time’

Getting yourself fit and healthy is one of the best things you can do to increase your chances of having a healthy baby. It is really important you do not consume alcohol or smoke during pregnancy – if you are unable to stop either or both of these, discuss this with your LMC or doctor. Another important thing to do is to make sure you take a folic acid supplement. It’s important to take extra care of yourself right from the beginning.

The first few weeks of pregnancy can be wonderful but strange. It’s a very special time, when so much is happening, but you may not feel like it’s ‘official’ yet, perhaps because you haven’t told anyone. The early months are special for another reason too this is the time when your baby is growing most rapidly, and so it’s also the time when you need to take extra care over what you eat to keep yourself healthy to protect your baby.

As soon as you know you are pregnant, check with your doctor or LMC about any medicines you might already be taking. And always ask a pharmacist for advice on over-the-counter medicines, including things you usually take for colds, headaches, hayfever and so on, and any complementary therapies. Some are not suitable when you’re pregnant.

You need to find an LMC and arrange your first appointment. They will discuss blood tests and screening and you will have a chance to ask questions about your care, including where you want to have your baby.

Until then, though, unless you need special care, you may not need to see any health care staff. Some women find this lonely or worrying. If there’s anything that concerns you, check in with your doctor or LMC. If you need someone to talk to, find friends or relatives you can confide in.

Week 1-12

Week 1-4

What’s happening this week

Your baby…

is called an embryo
is the size of a grain of sand
consists of two layers of cells
amnion develops which will fill with amniotic fluid to surround and protect the embryo
yolk sac develops producing blood and nourishment until the placenta takes over.

You…

are already technically four weeks pregnant by the time your period is due
the embryo continues to implant into your uterus
start to produce hCG – a hormone that helps maintain the lining of the uterus – signals to the ovary to stop releasing an egg each month which in turn stops your periods – causes some pregnancy symptoms, ie fatigue, breast tenderness or nausea.

You may suspect you’re pregnant even before you take the test. That’s because your hormones go into overdrive very early on! Most practitioners recommend women planning a pregnancy should supplement their diet with 0.8mg daily of folic acid, at least one month prior to conception and continue until 12 weeks gestation. Discuss this with your GP as some women require higher doses.

Week 5

What’s happening this week

Your baby…

is about 1.5-2.5 mm long, the size of an apple seed
embryo changes into a distinct shape
is developing the neural tube, which will form your baby’s brain, spine and nerves
has begun to form a heart, which will soon begin to pump blood
major divisions can be seen in the brain
placenta begins to develop – your baby’s source of nourishment from you through fingerlike projections called “chorionic villi”.

You…

may feel pregnant, your period is now about a week late
may have mood swings, increased frequency of urination, breast tenderness and nausea
some women do not experience any of these symptoms.

Week 6

What’s happening this week

Your baby….

is about the size of a single peppercorn (usually measured from crown to rump as embryo is curled up and makes full length measurements difficult = CRL)
is developing tiny buds that will become arms and legs
brain and nervous system developing rapidly
optic vesicles developing along sides of the head (eventually eyes)
inner ear begins to form, so does the larynx
beginning of digestive and respiratory systems forming
has a heart the size of a poppy seed, beings to beat around this time and can be detected by ultrasound scanning.

You…

for some the full force of pregnancy symptoms may “hit” this week
areola (dark pigment around the nipples) may darken
placenta begins to exchange nutrients and remove waste – two circulation systems are completely separate.

Week 7

What’s happening this week

Your baby…

is about the size of a gummy bear
digestive tract and lungs are continuing to form
face is gaining definition – mouth, nostrils, ears and eyes
the arm bud that developed last week now has a hand on the end of it
the genital tubercle is present but gender is not distinguishable by sight.

You…

may be on an emotional rollercoaster; up one minute and down the next
face may break out in spots due to increased hormone levels
flushing of face/hands due to an increased blood supply may occur
your cervix now has a mucus plug which has formed to seal off the uterus for protection
may experience some breast heaviness.

Week 8

What’s happening this week?

Your baby…

is about as big as a chocolate kiss
average length 13 mm
weighs about 1 gram – as much as 1 paperclip
eyes more obvious as they have begun to develop colour in the retina
fingers and toes beginning to form
floats in a pool of protective liquid called amniotic fluid
the gonads become either ovaries or testes
bones are beginning to harden (ossification)
heart is beating around 120-160 beats per minute.

You…

placenta covers approximately 1/3 of the lining of the uterus
uterus has doubled in size (although you can’t see anything yet)
could notice that you need to urinate more often as the growing uterus presses on your bladder.

Week 9

What’s happening this week

Your baby…

is approximately the size of a blueberry
measures approximately 18 mm
weighs about 2 grams
the tail at the bottom of the spine has shrunk and nearly disappeared
nose can be seen on profile
has elbows now
has skin over the eyes which is beginning to shape into eyelids and seal shut
the anus is forming and intestines continuing to grow
genitals are now well defined
may make first movements but you won’t feel them yet.

You…

may experience nasal congestion or stuffiness
nose bleeds are common in some women
your blood volume has increased by as much as 40%.

Week 10

What’s happening this week

Your baby…

approximately the size of a lego brick
measures about 30 mm
weighs about 4 grams
is now entering the fetal period as the vital organs are formed and starting to work
assumes a more human shape
external ears and upper lip is formed
tooth buds form inside the mouth
tail has now disappeared
blood and bone cells form
if a boy, his testes will begin producing testosterone.

You…

your waistline may be slowly disappearing
might notice sickness starting to fade.

Your body is gradually growing and changing as your baby develops, but many of these changes will be invisible to everyone but you. Some women have health issues which need special attention during pregnancy.

Week 11

What’s happening this week

Your baby…

now measures about the diameter of a pingpong ball, approximately 4 cm
weighs about 7 grams
head is about 1/2 size of your baby!
fingernails appear
pancreas is producing insulin and the kidneys are producing urine
maybe able to hear your baby’s heartbeat at an antenatal visit.

You…

may notice an increase in perspiration
placental blood vessels increasing in size and number to provide more nutrients
may have bleeding gums.

Week 12

What’s happening this week

Your baby…

approximatley the size of a piece of sushi
weighs abut 14 grams
vocal cords are formed
intestines make their way into the abdomen now there is room for them
after swallowing amniotic fluid the baby can pass it out as urine
lungs have taken shape and primitive breathing motions begin
may suck their thumb.

You…

people may comment about your ‘pregnant glow” (the increased blood volume and pregnancy hormones working together)
may suffer from acne
risk of miscarriage is reduced now
abdomen is beginning to expand
nausea and tiredness may start to subside now
placenta takes over and acts as your baby’s lungs, kidneys, liver, digestive and immune system.