Detailed Report on Human Reproduction: Hormones, Pregnancy, and Birth

This report provides a comprehensive overview of human reproduction, starting with the roles of various hormones like hCG, hPL, estrogen, and progesterone in maintaining pregnancy. It details the process of fertilization and the significant physiological changes that occur in women during pregnancy, including uterine and vaginal adaptations, changes in posture, and alterations in blood volume. The report then describes the stages of fetal development within the womb, highlighting the importance of the placenta in providing nutrition and mediating waste. Finally, it outlines the events of birth, including the three stages of labor and the changes necessary for the baby's survival, such as maintaining body temperature and initiating breastfeeding. The report is supported by several references to books, journals and online resources.

Reproduction

Table of Contents
INTRODUCTION...........................................................................................................................1
TASKS.............................................................................................................................................1
1.3 Role of hormones in maintaining pregnancy, initiating birth and lactation..........................1
1.4 Fertilisation and key changes which happen in the women during pregnancy.....................1
1.5 Development of foetus in the womb and importance of the placenta...................................3
1.6 Events of birth and the changes which must occur for the baby to survive..........................4
CONCLUSION ...............................................................................................................................5
REFERENCES................................................................................................................................6

INTRODUCTION
Reproduction can be simply defined as a biological process through which new organism
is produced from their parents (Speakman and Garratt, 2014). There are generally two kinds of
reproduction that is sexual and asexual reproduction. The present report is explaining the
functions of hormones in every stage of pregnancy and different events of birth have also been
highlighted.
TASKS
1.3 Role of hormones in maintaining pregnancy, initiating birth and lactation
Several hormones are there that play significant roles at the time of pregnancy. Important
one among them are as follows:
 Human Chorionic Gonadotropin (hcG): This is one of the hormones that is formed at
the time of gestation. Its level is found in the urine and parental blood that increases
dramatically during the first week of pregnancy. This also causes feeling of vomiting and
sickness.
 Human placental lactogen (hPL): This hormone is also named as human chorionic
somatomammotropin that is secreted by placenta. This gives nourishment for the foetus
and activate milk glands in the breasts (Levine and et. al., 2011).
 Estrogen: This is having the responsibility to develop female sexual characteristics. It is
generally formed in ovaries and is also made by placenta in order to maintain a healthy
pregnancy.
 Progesterone: This is secreted by ovaries and is of vascular structure while maternity.
Due to this, uterine line get thickened in the anticipation of positioning of a fertilised
ovum.
 Oestrogen: This type of hormone is responsible for tenderness and expansion of breast. It
is secreted throughout the period of pregnancy and aids in regulating progesterone levels.
Apart from this, it also modifies or prepares the womb for infant and mammary gland for
feeding.
1.4 Fertilisation and key changes which happen in the women during pregnancy
Fertilisation can be simply referred as a moment when an egg and a sperm have a fusion.
During this time, genes from father and mother also joins and a new life is formed as a result.
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After the fertilisation of ovum and sperm, certain changes start occurring in females as the stage
of pregnancy gets started from here. The major changes that is seen in women during pregnancy
are stated below:
 After fertilisation, Uterus provides a nutritious and safe environment whereby foetus
would grow up and develop. Its size gets increased so that kid can be fit into it. The
tissues of uterus continuously grow for the first 20 weeks and in turn, its weight increases
from fifty to one thousand grams.
 Vagina gets more elastic in nature in the end of gestation period so that baby can easily
come out from that.
 The whole posture of a pregnant woman alters as the infant gets bigger. The shape of her
abdomen changes from flat to very convex (Kofman, 2012). The weightiness of placenta ,
the large uterus, the amniotic fluid and the fetus along with the increased status of her
back, puts larger stress on the muscles and bones of females.
 A pregnant woman feel weaknesses and puke during these weeks. So, some weight loss
might occurs during first week of pregnancy. But after that she also gain specific amount
of weight. She will gain about 8 – 12 kg in total.
 The size of heart might also increases due to an increment in its work.
 There is increment of number of blood cells and this is around 18 % during gestation
period and plasma as well in the circulation (Modi , 2015).
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(Source : Modi , 2015)
1.5 Development of foetus in the womb and importance of the placenta
The stage of development of foetus is described below :
 An egg begins segmenting into numerous of cells after 1 day of fertilisation. It lies in
fallopian tube for around 3 days. This fertilised egg is named as Blastocyte and it keeps
on dividing as it passes slowly via that tube to the uterus.
 After that it get connected to endometrium and this procedure is known as implantation.
The next stage in development is the embryo inside amniotic sac. This stage is defined
by the creation of interior and exterior body structures (Development of the Foetus,
2005). Most of the organs started to develop after 21 days of fertilisation and after that
spinal cord and brain starts developing.
 At 56 days of gestation, placenta starts developing. It forms small hairs like projections
that is prolonged to the wall of uterus and after 12 weeks of maternity the fetus covers
whole uterus. At the end of around 24 weeks there is probability of survival of fetus
outside the uterus.
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Illustration 1: Ovulation and Fertilization in Women

Placenta plays an important role as it provides nutrition to the fetus. It act as mediator of
nutrients as well as metabolism wastes across the barrier isolating fetal and maternal
compartments (Guerra, 2011).
(Source : Development of the Foetus, 2005)
1.6 Events of birth and the changes which must occur for the baby to survive
Birth events can be simply defined as the sequence of activity by which an infant and the
placenta are removed from uterus at child birth. This procedure normally starts spontaneously
about 280 days after sexual practice with onset of labour. There are certain events of birth which
is listed below :
 First stage : It starts from the oncoming of actual labor and lasts until the uterine cervix
is entirely expanded to 10 cm (El Hajj and Haaf, 2013).
 Second stage : It remains continued after the cervix is dilated to 10 cm until the birth of
baby.
 Third stage : At this stage delivery of placenta occurs.
Some of the modifications must be done in order to survive the kid that are as follows :
 A baby should provided as much amount of heat as it gets out of the womb.
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Illustration 2: Development of the Foetus

 Breast feeding should be provided to him regularly when he feels hungry.
CONCLUSION
From the above based report, it can be concluded that pregnancy is very big process and
it takes around 9 months to produce a new organism. So many hormonal changes are seen during
this period. In addition to this, weight or body structure of a female also get altered week to week
during the maternity period.
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REFERENCES
Books and Journals
El Hajj, N. and Haaf, T., 2013. Epigenetic disturbances in in vitro cultured gametes and
embryos: implications for human assisted reproduction. Fertility and sterility. 99(3).
pp.632-641.
Guerra, P.A., 2011. Evaluating the life‐history trade‐off between dispersal capability and
reproduction in wing dimorphic insects: a meta‐analysis. Biological Reviews. 86(4).
pp.813-835.
Kofman, E., 2012. Rethinking care through social reproduction: Articulating circuits of
migration. Social Politics. 19(1). pp.142-162.
Levine, A. J., and et. al., 2011. The p53 family: guardians of maternal reproduction. Nature
reviews Molecular cell biology. 12(4). pp.259-265.
Lim, D. and et. al., 2012. Oxidative stress‐related PMK‐1 P38 MAPK activation as a mechanism
for toxicity of silver nanoparticles to reproduction in the nematode Caenorhabditis
elegans. Environmental Toxicology and Chemistry. 31(3). pp.585-592.
Liu, X. and et. al., 2013. Effects of TDCPP or TPP on gene transcriptions and hormones of HPG
axis, and their consequences on reproduction in adult zebrafish (Danio rerio). Aquatic
toxicology. 134. pp.104-111.
Speakman, J. R. and Garratt, M., 2014. Oxidative stress as a cost of reproduction: Beyond the
simplistic trade‐off model. Bioessays. 36(1). pp.93-106.
Online
Modi. 2015. [Online]. Available through :
<http://jayeshmodi1986.blogspot.in/2015/12/ovulation-and-fertilization-in-
women.html>.
Development of the Foetus. 2005. [Online]. Available through :
<https://moodle.beverleyhigh.net/mod/resource/view.php?id=6154>.
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