presentation on physiological changes during pregnancy.

1. -Anju Bista
-MSc nursing

2.  Pregnancy is very crucial, during pregnancy there is
progressive anatomical, physiological and
psychological changes occur in genital organs
including all systems of body. It is phenomena of
maternal adaptation towards changes in the body with
increasing demand of growing fetus

4. Genital organs:-
vulva:-
 vulva becomes oedematous and more vascular;
superficial varicosities may specially in multi – parae.
libia minora are pigmented and hypertrophied.

5.  Vaginal walls becomes hypertrophied ,oedematous
and more vascular.increased blood supply the venous
plexus surrounding the walls gives the bluish
coloration of mucosa(jacquemier’s sign).
 Pulsation of the uterine arteries feels through the
lateral fornices called osiander’s sign.
 The length of the anterior vagina wall is increased.

6.  The secretion becomes copious, thin and curdy white
due to marked exfoliated cells and bacteria.
 The ph becomes more acidic(3.5- 6) due to more
conversion of glycogen into lactic acid by the
lactobacillus acidophilus.

7.  There is enormous growth of the uterus during
pregnancy .after conception ,the uterus develops to
provide a nutritive and protective environment in
which the fetus will develop and growth.
 The uterus which in non pregnant state weight about
60 gm, with a cavity of 5- 10 ml and measures about
7.5 in length, at term ,weights 900-1000gm and
measures 35cm length.

8.  The capacity is increased by 500 to 1000 times.
Changes occur in all the part of the uterus body
,isthmus and cervix.

9.  There is increase in growth and enlargement of the
body of the uterus. The uterine enlargement is not a
symmetrical one.
 The fundus enlarges more than the body.
The enlargement of the uterus is affected by the following
factors:
 Changes in muscles
 Hypertrophy and hyperplasia.
 Stretching.
 Uterine ligaments show hypertrophy.

10.  Dextro-rotation:- the uterus is tilted and twisted to
the right in 80% of case.
 Lower uterine segment (LUS) the LUS is formed
from the isthmus formed from the 4th month to reach
10 cm at full term.

11.  The deciduas is a name given to the endometrium
during pregnancy ; progesterone and estrogen
initially produces by corpous luteum causes the
deciduas to become thicker and richer and more
vascular at the fundus and in the upper body of
uterus.
 The decidua provides a glycogen rich environment
for the bastocyst until the trophoblast cells begins to
form the placenta.
 When placenta is formed; it is able to produce its own
hormone.

12.  Estrogen is responsible for the growth of uterine
muscle.
 Increased in size of the muscle fibers is known as
hypertrophy and increase in their number is referred
to as hyperplasia.

13.  The uterus is able to stretch in this way because
progesterone encourages relaxation of smooth muscle.
After 16 weeks of gestation, uterus begins to generate
small wave of contraction known as Braxton hick’s
contraction which is painless although some women
experience pain.

14.  It is a layer of peritoneum. It does not
totally cover uterus.it allows for the
unrestricted growth of uterum.

15.  There is structural and functional change in the
isthmus during pregnancy. During 1st trimester ,
isthmus hypertrophies and elongates to about 3 times
its original length. With advancing pregnancy beyond
12 weeks, it progressively unfolds from above,
downward until it is incorporated into the uterine
cavity
 It’s become softer.

17.  The cervix becomes soft and secretes more mucus. Its
color changes from pink to bluish due to more
vascularity.There is hypertrophy and hyperplasia of
the elastic and connective tissues.
 The cervix undergoes a marked softening which is
referred to as the Goodell's sign."It begins at the
margin of the external os and then spread upwards.

18.  It serves to seal the uterus and to protect the fetus and
fetal membranes from infection. The mucus plug is
expelled at the end of the pregnancy. This may occur
at the onset of labor or precede labor by a few days.
When the mucus is blood-tinged, it is referred to as a
"bloody show’’.
 Additional changes and softening of the cervix occur
prior to the beginning of labor.

19.  It is placed almost vertical by the side of the uterus.
At term,its attachment to the uterus is placed at the
lower end of the upper 1/3rd,because of the marked
growth of the fundus.

20.  Ovary looks bright orange, later on becomes yellow
and, finally pale.
 Regression occurs following decline in the secretion
of human chorionic gonadotropin (hCG) from the
placenta.
 The follicle-stimulating hormone (FSH) ceases its
activity due to the increased levels of estrogen and
progesterone secreted by the ovaries and corpus
luteum. The FSH prevents ovulation and
menstruation.

21.  The corpus luteum produces progesterone which
helps maintain the lining of the endometrium in early
pregnancy
 It functions until about the 10th to 12th week of
pregnancy when the placenta is capable of producing
adequate amounts of progesterone and estrogen. It
slowly decreases in size and function after the 10th to
12th week

22.  The changes in the breast are best evident in a primi
gravida.
 In multipara who has once lactated , the changes are
not clearly defined.
 During pregnancy , the breast changes in both size
and appearance.

23.  The increases in size is due to the effects of estrogen
and progesterone.
 Estrogen stimulate the growth of mammary ductal
tissue, progesterone promotes the growth of lobes
,lobules and alveoli.
 Fullness, tingling and heaviness of the breast begin
in the early weeks of gestation in response to
increased level of estrogen and progesterone.

25.  Blood volume: The blood volume starts to increase
from about 6th week;expands rapidly thereafter to
maximum 40-50% above the non pregnant level at
30-32 weeks.
 Plasma volume: total plasma volume increases by
1250ml.
 RBC: it is increased to the extent of 20-30%,ie by
350ml.

26.  Hemoglobin : it increases by 18-20%,ie by 85 gm.
 Neutrophilic leukocytosis occurs to the extent of 10-
15000/cu mm and even to 20,000/cu mm in labour .
 Platelets level decrease up to 15% than in non-
pregnant state.

27.  Even though the total Hb mass increases during
pregnancy, there is apparent fall in total hb
concentration .At term, the fall is about 2 gm% from
the non pregnant value.

28. Non pregnant Pregnancy near term chan
ge
Blood volume 4000 5500 1500
Plasma volume 2500 3750 1250
Redcell volume 1400 1750 350
Hb 475 560 85

30.  Due to elevation of the diaphragm consequent to the
enlarged uterus, the heart is pushed upwards and
outwards with slight rotation to left.

31.  The cardiac output starts to increase from 5th week of pregnancy,
reaches its peak 40-50 % at about 30-34 weeks.
 Cardiac output is lowest in sitting or supine position and highest
in left or left lateral or knee chest position
 Cardiac output increases further during labour (+50%) and
immediately following delivery(+70%) over the pre-labour
values
 Cardiac output returns to pre-labour values by
One hour following the delivery and to pre-pregnant value
level by another 4 week time.

33. The increase in cardiac output is caused by:
 Increased blood volume.
 To meet the additional oxygen required due to
increased metabolic activities during pregnancy.
 The increase in cardiac output is chiefly affected by
increase in stroke volume and pulse rate.

34.  Systemic vascular resistance (SVR) decreases due to
the smooth muscle relaxing effect of progesterone,
NO, prostaglandins.
 In-spite of large increase in cardiac ouput, maternal
B.P decreases due to decrease in SVR.
 There is overall decrease in diastolic blolod pressure
(DBP) and Mean Arterial Pressure (MAP) by 5-10
mm ofHg.

35.  Femoral venous pressure is markedly raised specially
in later months. It is due to the pressure exerted by
the gravid uterus on the common iliac veins, more on
the right side due to the dextro-rotation of the uterus.

36. Non-
pregnant
Pregnant change
Cardiac output(co)
( litre/min )
4.5 6.26 +40%
Stroke volume(ml) 65 75 +27%
Heart rate (/min) 70 85 +17%
Venous pressure 8-10cm H2o 20cmH2o +100%
Systemic vascular
resistance
-21%

37.  Uterine blood flow is increased from 50ml/min in non
pregnant state to about 750 ml(near term).
 The increase is due to the combined effect of utero-
placental and feto-placental vasodilatation.
 Renal blood flow (normal 800 ml) increases by 400 ml/min
at 16th week and remains at this level till term.
 The blood flow through the skin and mucus membrane
reaches a maximum of 500ml/min by 36th week.

38.  With the enlargement of uterus, especially in later
months, there is elevation of the diaphragm(4cm) and
breathing becomes diaphragmatic.

39.  Mucosa of the upper respiratory tract shows
hyperaemia and congestion .A state of hyper ventilation
occurs during pregnancy leading to increase in tidal
volume.
 It is probably due to the progesterone acting on the
respiratory centre and also to increase in sensitivity of
the centre to carbondioxide. The women feels shortness
of breath.

40. NON
PREGNANT
PREGNANCY
NEAR TERM
CHANGE
Respiration rate 15 15 unaffected
Vital capacity 3200 3300 Almost unaffected
Tidal volume 475 675 +40%
Residual volume 965 765 -20%
Total lung
capacity
500 4750 -5%

42.  Striking anatomical and physiological changes are
seen in the urinary system comprising of the kidneys
,ureters and the urinary bladder with the enlargement
of the uterus.

44.  During pregnancy , each kidney increases in length
by 1-1.5cm, with a concomitant increase in weight.
 The renal pelvis is dilated.
 The ureters are dilated above the brim of the bony
pelvis.
 The ureters also elongate, widen, and become more
curved.
 Thus there is an increase in urinary stasis, this may
lead to infection.

45.  The absolute cause of hydro nephrosis and
hydro ureter in pregnancy is unknown, there
may be several contributing factors:
 Elevated progesterone levels may contribute to
hypotonia of the smooth muscle in the ureter.
 The ovarian vein complex in the suspensory ligament
of the ovary may enlarge enough to compress the ureter
at the brim of the bony pelvis, thus causing dilatation
above that level.

46.  The glomerular filtration rate(GFR) increases during
pregnancy by about 50% .
 The renal plasma flow rate increases by as much as
25-50%.
 Even though the GFR increased dramatically during
pregnancy, the volume of the urine passed each day is
not increased.
 With the increase in GFR, there is an increase in
endogenous clearance of creatinine.

47.  Increased levels of urinary glucose also contribute to
increased susceptibility of pregnant women to urinary
tract infection.
 Proteinuria changes little during pregnancy and if
more than 500mg/24hour is lost, a disease process
should be suspected.

48.  Levels of the enzyme renin, which is produced in
kidney, increase early in the first trimester, and
continue to rise until term.

49.  After the 4th month of pregnancy the bladder
trigone(base of bladder) is lifted and there is
thickening of its intraureteric margin owing to the
enlarging uterus, hyperemia of all the pelvic organs
and hyperplasia of the muscles and connective tissue.
 Bladder pressure increases and may result in reduced
bladder capacity.

50.  The muscles of the internal sphincter relax which,
along with pressure from the pregnant uterus on the
bladder causes a significant number of women to
experience some degree of stress incontinence
 Urgency of micturition and urge incontinence also
increases in pregnancy, partly because of the effects
of progesterone on the detrusor muscles.
 These all usually resolve during the puerperium.

52.  During pregnancy, nutritional requirements, including
those for vitamins and minerals, are increased, and
several maternal alterations occur to meet this
demand.
 The mother`s appetite usually increases, so that food
intake is greater.
 Some women have a decreased appetite or experience
nausea and vomiting. These symptoms may be
related to relative levels of human chorionic
gonadotrophin(hCG).

53.  Salivation may seem to increase due to swallowing
difficulty associated with nausea ,and if the pH of the
oral cavity decreases, tooth decay may occur.
 Due to the effect of estrogen, gum becomes
congested and spongy and may lead to bleed on touch
and gingivitis.

54.  Transit time of food throughout the gastrointestinal
tract may be so much slower that more water than
normal is reabsorbed, leading to constipation.
 Gastric production of hydrochloric acid is variable and
sometimes exaggerated, especially during the first
trimester. More commonly, gastric acidity is reduced.

55.  Gastric production of mucus may be increased.
 Esophageal peristalses is decreased, accompanied by
gastric reflux because of the slower emptying time
and dilatation or relaxation of the cardiac sphincter.
 Gastric reflux is more prevalent in later pregnancy
owing to elevation of the stomach by the enlarged
uterus.

56.  Gallbladder function is also altered during pregnancy
because of the hypotonia of the smooth muscle wall.
 Emptying time is slowed and often incomplete.
 Bile can become thick, and bile stasis may lead to
gallstone formation.

57.  There are no apparent morphologic changes in the
liver during normal pregnancy, but there are
functional alterations.
 Serum alkaline phosphatase activity can double,
probably because of increased placental alkaline
phosphatase isoenzymes.
 Thus, a decrease in the albumin/globulin ratio occurs
normally in pregnancy.

58.  The female endocrine system consists of the pituitary,
the pineal body, the thyroid, the adrenal and the thymus
glands, along with the pancreas and the ovaries.
 All of them undergo changes during pregnancy in order
to prepare the mother’s body to effectively meet the
challenges associated with pregnancy, childbirth and
breastfeeding

59.  Some of the most significant changes occur in the
pituitary and thyroid glands to meet the nutritional
needs of the baby in the uterus, restricting reproductive
organs and passing on genetic information.

60.  Morphological changes: During normal
pregnancy,the pituitary increases in weight by 30-
50% and is enlarged to about twice its normal due to
the hyperplasia of acidophilic prolactin secreting
cells.
 Physiological changes: Posterior pituitary: Near the
end of term, the posterior pituitary will begin to
secrete oxytocin that was produced in the
hypothalamus and stored there. It will serve to initiate
labor.

61.  Anterior pituitary: At birth, the anterior pituitary will
begin to secrete prolactin. It is increased 10 times.
This stimulates the production of breast milk.
 Growth hormone level is elevated due to
syncytiotrophoblast of the placenta.
 ADH and TSH remains unchanged.

62.  Morphological changes:Hyperplasia of the thyroid gland
occurs and slight generalized enlargement of the gland,
however pregnant women remain euthyroid.
 Physiological changes:- Maternal serum iodine levels fall
due to increased renal loss and transplacental shift to the
fetus.
 TSH remains normal.total T4 and T3 increases but free T4
and T3 levels remains unchanged.
 Calcitonin secretions increases by 20%.

63.  Morphological changes: There is slight enlargement
of the adrenal cortex.
 Physiological changes: There is significant increase
in the serum levels of aldosterone,
deoxycorticosterone(DOC), cortico steroid binding
globulin (CBG),cortisol and free cortisol.

64.  Morphological changes: Parathyroid hyperplasia
occur.
 Physiological changes: The concentration of PTH
doesn’t change during pregnancy.
 PTH doesn’t cross the placenta but the calcium ions
do cross along the concentration gradient.

65.  During pregnancy, there occur hyperinsulininsm
particularly during third trimester but there are
several anti-insulin factors and tissue insulin
resistance which modify the action of insulin during
pregnancy which results in gestational diabetes.

66.  During these adaptations various changes occur that
has impact on the skeletal system, which can develop
variety of problems such as back pain, separation of
the pelvic bones, transient osteoporosis, and
tendonitis , strain in the axial skeleton and pelvis.

68.  Exaggerated lordosis of the lower back, forward flexion
of the neck, and downward movement of the shoulders
typically occur to compensate for the enlarged uterus
and change in center of gravity.
 There is widening and increased mobility of the
sacroiliac joints and pubic symphysis in preparation for
the fetus' passage through the birth canal.

70.  In normal pregnancy, variable amount of weight gain
is a constant phenomenon. Inearly weeks, the patient
may lose weight because of nausea or vomiting.
 During subsequent months, the weight gain is
progressive until the last 1 or 2 weeks, when the
weight remains static. The total weight gain during
the course of a singleton pregnancy for a healthy
woman averages 11 kg (24 lb).
 This has been distributed to 1 kg in first trimester and
5 kg each in second and third trimester.

71. The total weight gain at term is distributed
approximately as follows:
Reproductive weight gain: 6 kg Net maternal weight gain – 6kg
Fetus – 3.3kg, placenta- 0.6kg
and liquor-0.8kg.
Uterus : 0.9 kg and breast -0.4
kg .
Accumulation of fat and
protein – 3.5 kg
Increased in blood volume-
1.3kg.
Increased in extracellular fluid -
1.2kg.

72.  Pigmentation : the distribution of pigmentary
changes is selective.
 Face: its is an extreme form of pigmentation around
the cheek, forehead and around the eyes.
 Abdomen:
 Linea nigra- brownish black pigmentation.
 Stria gravidum.
 Sweat glands will be active ,more body secreation.

73.  Compression of pelvic nerve or vascular stasis caused
by enlargement of the uterus may result in sensory
changes in the legs.
 Edema involving the peripheral nerve may result in
carpal tunnel syndrome.

74.  Forthcoming parenthood causes psychological
changes in mother ,physical stress, hormonal
changes, coping with changing body shape and yet
going about in life and performing daily living
attending to the need of the family and children all
together may affect the emotional equilibrium of the
would be mother.
 The formost psychological changes that can affect
the pregnant lady are mood swings. Being angry and
unreasonable , feeling good and depressed
successively, being tensed and changing body shape
and hormone level.

75. Some other psychological changes are:
 Mood swings.
 Moodiness irritability ,pregnancy can bring a
roller roster of emotions.
 Fear.
 Forgetfulness.
 Weepiness.

76.  Marshall, J & raynor ,M.Myles textbook for
midwives.17th edi.(2014).churchill livingstone.
 Dutta, DC.textbook of obstetrics .9th edi.new central
book agency.pvt.ltd.