Development of Foetus (Baby) during the 9 months of Pregnacy

Development of Foetus (Baby) during the 9 months of Pregnacy

How is pregnancy detected?

The first sign that indicates to most women that they may be pregnant, is the stopping of their monthly periods. The uterus is preparing for the incumbent baby by thickening its lining and making it receptive to the implantation of the embryo. The pituitary gland produces hormones that stimulate the ovaries to produce eggs, which if fertilised, move through the fallopian tubes into the uterus.

Pregnancy is divided into three trimesters (three months). The first and the last trimesters are times of extra precaution for the mother-to-be, since the baby is at the most vulnerable at these times.


The first three months


Month 1 – the month starts with the implanting of the embryo in the lining of the uterus. It is still not called a 'fetus', since it is nothing more than a mass of cells. These cells start differentiating to form specialised structures which will become the amniotic sac, the placenta and the baby itself. By the end of the first month, the embryo is about one tenth of an inch long (the size of a grain of rice). A primitive brain and spinal cord begin to form and the heart starts beating. There is no perceptible change in the body proportions of the expectant mother. In fact, the first month usually slips by undetected. By the end of the month, the mother may start feeling nauseous in the morning, a condition termed as "morning sickness".

Month 2 – the embryo begins to grow in length. By the end of the second month, it is almost an inch long. The brain and the spinal cord are almost completely formed. The heart gets divided into two chambers and circulation begins. Veins are clearly visible. Buds form at the place where arms and legs are going to develop later. These buds have a webbed appearance. Blackened dots form near the eye sockets by the beginning of the month. All the major organs have started to develop by the end of the second month. The umbilical cord and the placenta also start forming.

In the mother-to-be, the breasts enlarge and the nipples become more prominent. There may be some tenderness and pain in the area due to an increase in the body hormones. There may be increased vaginal secretion and the mucous plug begins to form. The expectant mother may feel an increased urge to urinate because of increased pressure from the uterus due to the growing fetus.

Month 3 – the embryo in the third month is technically called the fetus. The fetus is now longer and the external features begin to be distinguished. The fetus has started to resemble a human baby. The internal organs are largely formed but not fully developed. The fetus may start responding to sounds and may startle, but the movement is not perceptible due to its small size. By the end of the third month, the fetus is approximately 3 inches long and weighs a little more than a grape. The baby's heart beat can be heard by an instrument called a doppler.

Morning sickness in the mother may stop. She may feel hungry more often and may have mood swings. The uterus is now big enough and the mother may feel heaviness in the abdomen.

The next three months

Month 4 – The mother may feel the baby's first kick during this month. The baby continues to grow and needs more nutrition. The umbilical cord thickens to be able to carry more blood and nutrition. This is also a hazardous period, since any tobacco or drugs may also be transferred to the baby via the same route. The baby is about 7 inches long and has fine hair on her body called 'lanugo'. A mucus-like substance called the 'vernix' begins to cover the baby's body. The sex of the baby is now easily determined.

The mother's abdomen begins to bulge and she can feel the baby move. Most women go through a period of emotional elation since the presence of the baby is now unmistakably felt. Since the baby seems to respond to sounds, parents tend to start talking to the baby or playing music in the background. This not only helps to soothe them down, but also lays the foundation of future bonding with their child.

Month 5 – this is a month of rapid growth for the baby. The baby gains maximum length and weight in this month. By the end of the month, she is approximately 30 cm long and weighs almost 400 gm. She becomes very active, moving from side to side and sometimes turning around on her head. The respiratory system starts working and the baby may drink some amniotic fluid. She also begins to urinate.

The mother's mood may be better during this month as she feels more energetic than during any other month. Her uterus feels heavy and she may have to take rest frequently during the day. There may be leg cramps, especially during the night.

Month 6 – the baby's skin has an old wrinkled look to it even though fat deposits under the skin start to form. The baby is too young to be born at this time. Most babies born so prematurely do not survive. Only some who do, have to be under intensive care with artificial breathing and precise temperature control in an incubator. The eyes open in this month. Movements become very vigorous and the baby responds perceptibly to sounds.

The mother may start feeling uncomfortable because her belly protrudes. She may experience back pain and may have to make some changes in her posture to balance her weight. Most mothers like to sleep on their backs since turning on the side is very uncomfortable. . Though the baby by now has quite a regular sleeping pattern, the mother may still be woken up in the night by a vigorous kick. Appetite is still more than normal. Exercise helps to reduce uncomfortable symptoms like back pain.

The last three months

Month 7 – the baby weighs about two and a half pounds in the beginning of this month and is viable to be born, though still very premature. Finger prints are set and all organs are more or less fully formed. Fingernails form to cover the finger tips. By the end of the month, the weight doubles and the shape of the baby may be felt through the abdomen. The movements of the baby decrease due to its large size, but it can still kick.

The mother may be off balance more often due to the increase in weight. She may feel false contractions called 'Braxton Hicks'. These should be brought to the doctor's notice if they are more than five within an hour. The breasts and abdomen may develop stretch marks and may start itching. Massage may help to provide some relief.


Month 8 - the baby is fully formed now and is only undergoing cosmetic changes. The lanugo begins to reduce and the baby changes position to head down, ready to be born. If the baby does not change position, then there may be difficulty during birth. The baby in a position with legs down is called a breach baby.

The mother may feel the urge to urinate frequently. There may be trouble breathing at times when the baby pushes upwards. She may tire easily and may need to rest for longer periods.

Month 9 – the baby is in a perfect condition to be born. The lungs are able to sustain breathing on their own. Fat layers will regulate the baby's body temperature when she is born. Her immune system is also geared up to fight against infections.

The mother is also psychologically ready to go into labour. The difficulty in breathing may ease due to the baby's movement downwards. However, urination may increase due to the increased pressure on the bladder. The mother may have to rest very often, and she should not push herself too hard.