Your baby and body at 6-10 weeks
Your baby From around the eighth week the embryo is referred to as a fetus. By the end of the 10th week, it measures 30mm (lV4in) and weighs 3 to 5g (O.loz).
The neck and forehead start to develop, and the eyes start to move to the front of the head. Toothbuds that will form the milk teeth are in place in the jawbone.
The limb buds are now developing into limbs and webbed hands become separate fingers by the end of week 10.
The little tail has almost completely disappeared,
Vertebrae develop on each side of the spinal column and the increasingly complex nervous system evolves.
The fetus can be seen making small, jerky movements.
By 10 weeks, the heart’s four chambers are visible on an ultrasound scan. It pumps blood through the fast-developing circulatory system at around 180 beats per minute, twice the normal adult resting heartrate.
The stomach, liver, kidneys, and other parts of the digestive system are all in place.
Between six and eight weeks, the fetus is developing facial features that are recognizably human.
The amniotic sac’s outer layer, or chorion, begins to develop finger-like projections called villi, and these become concentrated on one side, burrowing into the uterine wall with the help of newly formed blood vessels. These villi will eventually form the placenta, which will protect your baby. However, the fetus is still vulnerable to toxins (176).
Your body Your metabolic rate has increased. Pregnancy hormones relax your muscles, including your heart muscle. The blood vessels also relax (become more dilated) to allow a greater volume of blood to be pumped around your body without your blood pressure rising to dangerous levels.
The skin around your nipples (the areola) will probably be darker than usual thanks to the increase in blood flow and blood volume. Your breasts have started to swell and are much more tender because the milk ducts are beginning to prepare themselves for lactation at the end of pregnancy.
Your baby By the end of the 13th week, all the major fetal organs, muscles, and bones have been formed.
H Elbows, wrists, and hands are clearly visible, and the lower limbs are also continuing to develop.
Calcium deposits in the limbs and teeth begin the process of bone formation (ossification) by the 12th week. This continues until birth, although the actual hardening of the skeleton will not cease until adolescence. B The fetus will have a reflex response to an outside stimulus, so if the mother’s abdomen is prodded, it will try to move away.
The fetus’ ovaries or testes are fully formed, although external genitalia (the penis and clitoris) are not yet distinguishable.
At 13 weeks the rapidly developing nervous system and limbs allow the fetus to move freely.
Your body By the end of the first trimester, about one quarter of your cardiac output (the amount of blood pumped around your body) will be directed towards your uterus, compared to only 2 per cent in your non-pregnant state. You may find that you occasionally feel breathless as your lungs adapt to take in an increased amount of oxygen with every breath.
If you have been suffering from tiredness and sickness these symptoms should start to diminish now. You will be able to start eating normally again and will soon be back to feeling like your old self.
Your waist will probably have thickened slightly and you will have put on a little weight. Your breasts will continue to develop. As your uterus enlarges and the ligaments attaching it to the side of your pelvis are
stretched, you may experience an occasional ache or twinge.
By the end of the 13th week, your pregnancy is no longer supported by your hormones but by the fully established placenta instead. The placenta acts as the lungs and kidneys of the fetus. Between the placenta and the fetus runs the umbilical cord, which consists of a large vein carrying oxygenated blood and nutrients from the mother to the baby and two small arteries carrying waste products and de-oxygenated blood back to the mother from the fetus. The fetal and maternal circulations are separated by a thin membrane and never mix, which is why the placenta acts as a barrier, preventing the passage of most harmful substances from
Mature placenta The placenta grows rapidly to supply all the baby’s needs throughout pregnancy. By the end of the third trimester, it measures 20-25cm (8-1 Oin) in diameter and weighs around 700g (11/2lb).
the mother to the fetus (176). Even if there is blood loss from the mother, or the placenta is damaged, the fetal circulation is protected.
miscarriages are simply down to bad luck. .Occasionally, there is a hormonal or physical reason why a woman miscarries (such as a uterine abnormality or a weak cervix). Smoking increases the risk of miscarriage and having a previous miscarriage raises the chances of having another one. In a very small number of women, there is an autoimmune problem, which causes recurrent miscarriages. Infections such as listeria, rubella, and some STIs can also cause a pregnancy to end.
However, despite what you may have been told, the following do not cause miscarriages: normal exercising, lack of rest, lifting, eating spicy food, sex, travel, sitting at a computer screen, and constipation. In some instances, they may not be good for pregnancy, but babies are well protected in the uterine environment, and, unless you are a high-risk pregnancy, you should carry on as normal and aim to have as healthy a diet and lifestyle as possible.