At the moment of fertilisation, many amazing things happen – all of your baby’s physical characteristics are determined, including gender, hair colour, and eye colour. The single fertilised cell begins to divide rapidly, and a watertight sac called the amniotic sac forms around it, gradually filling with fluid, to help cushion your baby for the nine-month journey towards birth.
Month 1: The placenta and umbilical cord begin to develop, to transfer nutrients from you to your baby and to remove wastes from the baby. A very basic face starts to form, with large dark circles for eyes and the earliest signs of a mouth, lower jaw, and throat. By the end of the first month, along with an extended tailbone that makes it look like a tadpole, your baby will have eyes, still partially covered by eyelid folds, buds that will become arms and legs, the beginnings of lungs and a digestive tract, and a tiny ‘heart’ tube which beats sixty-five times a minute. Your baby is around 2mm long – smaller than a grain of rice.
Month 2: Your baby’s heart, neural tube, arms and legs, liver and other major organs begin to form. By the sixth week the heart is beating and visible on ultrasound. Facial features continue to develop, with each ear beginning as a tiny fold of skin at the side of the head, and fingers, toes, and eyes are forming more distinctly. By the end of this month your baby is called a foetus rather than an embryo and is about 2.5cm long.
Month 3: By now, your baby’s arms, hands, fingers, feet, and toes are fully developed; fingernails and toenails are growing and the external ears are formed. The earliest stages of teeth are appearing. Your baby’s reproductive organs develop, though it’s generally not yet possible to distinguish gender on ultrasound, and he or she can open and close fists and mouth. By the end of the third month your baby is fully formed, with all organs and extremities present, and is around 10cm long.
Month 4: Your baby will be moving and active now, though you may not be aware of movement for another month or so. Fingers and toes are well defined, teeth and bones become denser, and eyelids, eyebrows, eyelashes, nails, and hair are formed. Reproductive organs and genitalia are fully developed, and your doctor will be able to tell on ultrasound whether your baby is a boy or a girl. By now your baby is about 14cm long, and can suck his or her thumb, yawn, and stretch.
Month 5: Your baby’s shoulders, back, and temples are covered by a soft fine hair called lanugo which protects him or her and will usually be shed a week or so after birth; a white lanolin-like covering called vernix forms to protect the skin. Eyelashes and eyebrows are developing, and fingerprints and footprints are fully formed – ears are also fully formed, and your baby may be able to hear you now. He or she is around 18cm long.
Month 6: Your baby has developed a hand-grip reflex and a startle reflex. His or her immune system is maturing and beginning to create antibodies; eyelids begin to part and the eyes to open; and the baby responds to sounds by moving or by an increased pulse-rate. You may notice jerking movements when he or she hiccups! Skin is reddish in colour and wrinkled, and still translucent enough for veins to be visible through it. By the end of this month your baby will be about 26cm long.
Month 7: Your baby changes position frequently and responds to sound, light, and pain. Hearing is fully developed and eyes are open. He or she has taste buds, is able to cry, and will be very active though could be running out of space in which to move much! Body fat is increasing, and bones are fully developed. The baby is now around 33cm long.
Month 8: Preparing for life outside the womb, your baby continues to grow and mature, developing reserves of body fat. He or she sleeps most of the time now and has periods of REM sleep. The brain develops dramatically during the eighth month, most internal systems are well developed, but the lungs are not yet fully mature. By the end of the month your baby could be approaching 40cm in length.
Month 9: Now your baby is actually preparing for birth by shedding most of the lanugo and vernix, and he or she may spend a lot of time resting. Reflexes are coordinated, and the baby can blink, turn his or her head, grasp firmly with fingers and toes, and open and close his or her eyes. Lungs are almost fully developed and your baby will be around 50cm “tall.”
Most babies are born within two weeks before and two weeks after the due date, but scientists still don’t know precisely what triggers the start of labour – other than the fact that your baby is now ready and eager to enter the world!
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Pregnancy and pigmentation
Natural cures for those pregnancy pains
The importance of being a mother
Treatments to avoid when pregnant