Parturition, is also called childbirth.
This is the process of giving birth during labour. This occurs 15 days of
planned due date. (MedicineNet.com,
2016). During the first stage of labour,
the cervix becomes thinner (effacement) and stretches (dilation) as the baby’s
head  descend and engage with the pelvis.
This takes 4-8 hours, in in a woman who is having her second or first baby. (NHS.Choice,
2018).

 The first stage consist of three phases: the Latent
Phase, the uterus starts to tighten regularly with the Braxton Hicks
contractions, are irregular and do not usually hurt, it occurs at
least every 10 minutes with lasting 20 seconds.The
contractions cause the cervix to widen and begin to open, till it reaches 3cm
dilatation. The active phase, is from 3cm full cervical dilatation (10cm),
contractions becomes more frequent and stronger. The cervix dilate at rate of
1cm or hour faster and last between 2-6 hours. And the Transition stage of
labour, is intense and It is characterised by frequent strong contraction occur
every 2-3 minutes. (NHS.Choice, 2018)

The Second stage of
labour is from the time of full dilatation of the cervix until the baby is delivered. It consist of 2 initial part, a passive
(descent) phase; where the baby’s head moves down through the mother’s vagina.
Followed by an active phase, where the mother feels the desire to push.
The pushing involves contracting the abdominal muscles in time with each
uterine contraction and takes average of 20-40minutes and delivers the baby.During the
third stage of labour, the umbilical cord is
clamped and cut by the midwife/doctor. The remains shrinks up in  few days to form the belly button.The suckling
of the nuzzling at the breast by the baby, help gives the body oxytocin
hormone. This help contract the womb and push out the placenta and reduces the
amount of blood loss. (NHS.Choice, 2018)

Birth hormones acts as chemical messengers. These hormones help co-ordinates the process of labour, which is the
expulsion of the foetus from the mother’s uterus. (MedicineNet.com, 2016).High levels
of progesterone prevent
uterine contractions while the baby is still developing. Therefore,
progesterone is decrease so that labour can occur.
If it is inhibited, that means the smooth muscles of the uterus can begin to
contract. This process is initiated by the baby. (MedicineNet.com, 2016).

The rise in stress hormones
triggers a rise in the steroid hormone estriol. It is a form of oestrogen that stops the synthesis of
progesterone by the placenta and prepares the smooth muscles of the uterus
for labour. The mother’s pituitary gland secretes oxytocin when the baby is
fully developed and ready for labour. This hormone stimulates contractions. The
baby’s adrenal glands send a signal to start labour. (Google.com, 2018). The
baby’s lungs secrete an enzyme when they are fully developed. This causes
prostaglandins to be released into the mother’s system. The release of
prostaglandins helps initiate labour and, along with another hormone
called relaxin, relaxes the
muscles of the cervix. This is important because the cervix must be relaxed, if
it is to stretch (or dilate) enough to allow the baby to pass through. (Google.com, 2018).

The body produces
calming and pain-relieving hormones called beta-endorphin
or catecholamine. This is
also known as the fight or flight hormones. High levels
of this hormone causes the oxytocin level to reduce and cause contractions to
slow down. Low levels of
endorphins can cause labour to be excessively painful and difficult to accept. Prolactin
is known as the mothering hormone. It increases during labour. It plays a role
in helping the new-born healthy development, and change to life outside the
womb. Low levels of prolactin may cause Poor transition of the baby at the time
of labour.    (Google.com, 2018).

During foetal
circulation, Blood
enters the right atrium, the chamber on the upper right side of the heart. When
the blood enters the right atrium, most of it flows through the foramen ovale
into the left atrium. Blood then passes into the left ventricle (lower chamber
of the heart) and then to the aorta, (the large artery coming from the heart).
From the aorta, blood is sent to the heart muscle itself in addition to the brain.
(Natalie, 2017). After
circulating there, the blood returns to the right atrium of the heart through
the superior vena cava. About two thirds of the blood will pass through the
foramen ovale, but the remaining one third will pass into the right ventricle,
toward the lungs. (Natalie, 2017)

In
the foetus, the placenta does the work of breathing instead of the lungs. As a
result, only a small amount of the blood continues on to the lungs. Most of
this blood is bypassed from the lungs through the ductus arteriosus to the
aorta. Most of the circulation to the lower body is supplied by blood passing
through the ductus arteriosus. (Natalie, 2017). With the first breaths of life, the lungs
begin to expand. As the lungs expand, the alveoli in the lungs are cleared of
fluid. An increase in the baby’s blood pressure and a significant reduction in
the pulmonary pressures reduces the need for the ductus arteriosus to shunt
blood. These changes promote the closure of the shunt. (Natalie, 2017)

These
changes increase the pressure in the left atrium of the heart, which decrease
the pressure in the right atrium. The shift in pressure stimulates the foramen
ovale to close. The closure of the ductus arteriosus becomes ligamentum
arteriosum and foramen ovale completes the transition of foetal circulation to
new-born circulation. (Natalie, 2017)

Hormonal
control of lactations occurs through lactation, this  process is under endocrine control. The two
main hormones involved are prolactin and oxytocin. Prolactin is a hormone that
stimulates mammary gland development which stimulates milk production called
lactogenesis, the functional change of the breasts to secrete milk. (Harmsen, 1995)

During
pregnancy, the body prepares for lactation by stimulating the growth and
development of branching lactiferous ducts and alveoli lined with
milk-secreting lactocytes. (Faye, 2010). At the end of the 6 months, the
mammary glands become fully developed, and the gland cells begin to produce a
secretion known as colostrum. (Faye, 2010). These functions are related to the
actions of several hormones that involved prolactin. Following the first two or
three days of childbirth, mammary gland secretion of breast milk suckling
triggers and Stimulated physical receptors that stimulate the release of
oxytocin from the posterior lobe of the pituitary gland. Oxytocin causes
contraction of the myoepithelial cells in the walls of the lactiferous ducts to
squeeze milk from alveoli and milk is ejected. (Faye, 2010)Galactopoiesis starts around 9 days after birth, it
is the maintenance of milk secretion controlled by hormones called Prolactin.
It levels
are high at night. The more milk  is removed from the breast, is the more
prolactin is secreted. (Harmsen,1995)

Colostrum is the first early milk produced
since about 14 weeks of pregnancy. It is thick, sticky and yellowish and is particularly rich in immunoglobulin,
antimicrobial peptides (lactoferrin and lacto peroxidase) and other bioactive
molecule, including growth factors which are important for nutrition, growth
and development of newborn infants and also for passive immunity.Colostrum has nutrient
profile highly different from mature milk. It contains macronutrient like
proteins, Carbohydrate, fats and micronutrients like vitamins (A and K) and minerals. (Harmsen, 1995)

Milk
is produced in the first postpartum days and contains more protein, less fat
than breast milk. Many of the proteins are antibodies that help infant fight
bad infections until its own immune system develops. (Stephan,1990). Mature milk contains
water, fat, carbohydrates, protein,
vitamins and minerals, amino acids,
enzymes, and white blood cells called macrophages. Milk will change from
colostrum to mature breast milk, which is more diluted and greater in volume. When breastfeeding is
initiated, breast milk changes from foremilk, high in water and
lactose, to hind milk, high in fat and calories. (Harmsen, 1995).

Mothers who are either not able to produce milk or have
conditions that prevent them from breastfeeding can access milk through donor
banks. These facilities collect extra breast milk from lactating mothers and
process it for distribution to infants in need. While Bovine colostrum is
available for human consumption as an over-the-counter supplement in capsule
form. (AFO, 2011).