PHYSIOLOGICAL CHANGES DURING PREGNANCY

1. PREPARED BY :
JAYDIP NINAMA
PHYSIOLOSICAL CHANGES DURING PREGNANCY

4. REPRODUCTIVE SYSTEM
a) Vulva : becomes vascular
and hypertrophied, pigmented
and varicose veins appear in
some.

5. b) Vagina
 It becomes vascular and hypertrophied, looks
bluish, felt soft.
 Increased blood supply of the venous plexus
surrounding the walls gives the bluish
colouration of the mucosa(Jacquemier’s sign)
 Vaginal secretion, increases in amount and is
acidic (3.5-6) due to the production of lactic
acid.

6. c) Cervix : remains 2.5 cm long
throughout pregnancy, but the
hygroscopic properties of
oestrogen cause it to increase in
width.
 Oestrogen increases cervical
vascularity and if viewed through
a speculum the cervix looks
purple

7. Softening of the cervix (Goodell’s
sign
Cervical mucosa undergo
hypertrophy and hyperplasia and
occupies inner half of cervix.
A mucus plug called “operculum” is
formed between the maternal and
external os .

8. INTERNAL OS
VASCULARITY
INCREASES
MUCUS PLUG
HYPERTROPHY OF
ENDOCERVIX
CERVIX
EXTERNAL OS

9. d) Uterus:
Gravid uterus gradually enlarges from 50 gm
muscular organ to 900 gm at term pregnancy.
 Non-pregnant state measures about 7.5 cm in
length, 5 cm in breadth and 2.5 cm in thickness.
 Length becomes 30 cm; breadth 22.5 cm and
thickness 20 cm.
 Uterine wall forms a sac containing amniotic
fluid and foetus

10.  The perimetrium is the outermost layer
of the uterus. It does not totally cover the
uterus.
 The myometrium or muscle coat
surrounds the lower uterine segment
and cervix during labour.
 The muscle layer is involved in the
contraction necessary to expel the foetus
at the end of the pregnancy

11. Arrangement of the muscle fibres
1)Outer longitudinal – follows a hood like arrangement
over the fundus.
2) Inner circular – It is scanty and have sphincter like
arrangement around the tubal orifices and internal os
3) Intermediate – It is the thickest and strongest layer
arranged in criss-cross fashion through which the blood
vessels run.
Apposition of two double curve muscle fibres give the
figure of ‘8’ form, it called as living ligature.

12. The outer longitudinal layer of
muscle fibres contract and retract
during labour causing upper
segment to thicken.
 The thickened upper segment acts
as a piston to force the foetus into
the receptive, passive lower segment.

13. Changes in Uterine Shape
 Non pregnant - pyriform shape is maintained in early
months.
 Becomes globular at 12 weeks.
 As the uterus enlarge, the shape once more becomes
pyriform or ovoid by 28 weeks
 Changes to spherical beyond 36th week

14. Position
 Normal anteverted positions exaggerated up
to 8 weeks
 The enlarged uterus may lie on the bladder
 Afterwards, it becomes erect, the long axis of
the uterus conforms more is a tendency of
ante version
 Primigravidae with good tone of the
abdominal muscles, it is held firmly against
the maternal spine.

15. Cont..
Contractions (Braxton-Hicks) : Irregular,
infrequent, spasmodic and painless without
any effect on dilatation of the cervix.
Endometrium : structural and secretory
activity of the endometrium

16. e) Isthmus:
 During the first trimester isthmus
hypertrophies and elongates to about 3
times its original length
 Becomes softer

17. ISTHMUS
CERVIX
8 WEEKS
INTERNAL
OS 12
WEEKS
EXTERNAL
OS
LOWER
UTERINE
SEGMENT
16 WEEKS

18. f) Fallopian tube:
 Total length is increased
 Tube becomes congested
 Muscles undergo hypertrophy

19. f) Ovaries :
Ovulation ceases throughout pregnancy.
Corpus luteum of usual menstrual cycle
persists and enlarges to 2.5 cm till 8th
week due to the changes in the fertilized
ovum (trophoblast) and helps in
producing hormones.

20. f) Ovaries :
 Ovulation ceases throughout pregnancy.
 Corpus luteum of usual menstrual cycle persists
and enlarges to 2.5 cm till 8th week due to the
changes in the fertilized ovum (trophoblast)
 Hormones-oestrogen and progesterone secreted
by the corpus luteum maintain the environment
for the growing ovum
 Control the formation and maintenance of
decidua of pregnancy
 Inhibit ripening of the follicles

21. g) Breasts : under the stimulation of
estrogen and progesterone the breasts
increase in size, nodularity and
sensitivity throughout pregnancy with
increased vascularitis .
 Total weight becomes 0.4 kg volume.
Enlargement is due to alveolar
proliferation and deposition of fat.
 Sebaceous glands (5-15) become
hypertrophied and are called
Montgomery’s tubercles

22. Areola becomes dark pigmented, which is
primary areola,
and a second zone of pigmentation
appears around the primary areola in
second trimester, which is secondary
areola.
 Secretion (colostrum) can be squeezed out
of the breast at about 12th week

25. CUTANEOUS CHANGES
Face (chloasma gravidarum or pregnancy mask)
an extreme form of pigmentation around the cheek,
forehead and around the eyes

26. ABDOMEN
 Linea nigra : a brownish black pigmented area in the
midline stretching from the xiphisternum to the
symphysis pubis
 Straie graviderum :slightly depressed linear marks
with varying length and breadth found in pregnancy

28. CHANGES IN OTHER
SYSTEMS OF THE BODY

29. CARDIOVASCULAR SYSTEM
 Heart works more during pregnancy.
 increase in the cardiac volume by 10%
 no change in E.C.G.
WHAT IS RELATION
BETWEEN CARDIAC
OUTPUT AND HEART
RATE ?

30.  Cardiac output increases by 15-30% due
to increased heart rate and increase
stroke volume.
 Pulse rate near term increases by 10 per
minute.
 Platelet count shows slight decrease due
to increased concentration .

31.  Blood Pressure and Blood volume
 Blood pressure remains within normal limits
 due to pressure of gravid uterus on pelvic
veins Venous pressure– Femoral venous
pressure rises from 10 cm water to 30 cm
water.
 Blood volume increases from 3rd month and
reaches a peak of 25% rise at 32 weeks.
 The red cell volume increases by 200 ml,
plasma volume increases to 1000 ml .

32. RESPIRATORY SYSTEM
 increased inspiration so the increased
oxygen intake results in improved oxygen
supply to the foetus.
 increased expiration, more carbondioxide is
expelled, there is low maternal
carbondioxide leading to easy transfer of
CO2 from foetus to mother’s blood.
 breathing difficulty which is relieved after
lightening.

33. DIGESTIVE SYSTEM
WHICH IS COMMON GI
PROBLEM /
COMPLAINT OF
WOMAN DURING
PREGNANCY ?

34.  regurgitation of stomach juice and
heart burn
 slow emptying of stomach
 constipation.
 Gums become spongy and vascular and
may bleed during brushing in many
women.

35. NERVOUS SYSTEM
 Slumpliness is common and mood changes
occur in many.
 Pregnancy is one of the periods in a woman’s
life when there seems to be lowering of the
ability to cope with emotional experiences in
life.
 Even the cases where the coming of the baby
is welcome a mild degree of depression or
irritability may be evident during the early
months.

36. URINARY SYSTEM
 Frequency of micturition
 Stress incontinence
 Due to dilatation of uterus and renal pelvis
during early pregnancy which continues till
mid-pregnancy there is a tendency for
urinary stasis and these favours infection.
 Glomerular filtration rate (GFR ) increases
by 50% early in pregnancy, increasing
creatinine clearance. Serum creatinine and
urea will fall by about 25%.

37.  Increased GFR also increases filtered
sodium. Aldosterone levels rise by 2-3
times to reabsorb the filtered sodium.
 Increased GFR and impaired tubular
reabsorption of glucose produce
glucosuria in approximately 15% of
normal pregnancies.
 Proteinuria is abnormal in pregnancy.

38. LOCOMOTOR SYSTEM
 Due to Lordisis of pregnancy and
relaxation of joints under the influences
of relaxin hormone backache is
common.
 Leg cramps occur due to pressure on
sacral and lumbar plexus.
 Gait becomes waddling.

40. ENDOCRINE SYSTEM
 Gonadotrophine:
 FSH, LH are inhibited by placental
steroids. Prolactin rises throughout
pregnancy.
 Protein hormones, HCG appears in
blood and urine from 8th day of
fertilisation, and reaches a peak at 9th-
10th week, thereafter drops rapidly and
remains at a plateau for the rest of
pregnancy.

41.  HCG values are increased in presence of
multiple pregnancies.
 Oestrogen and progesterone levels increase
and continue to be secreted from the
placenta during the last 6 months of
pregnancy.
 Progesterone is produced by all steroid-
forming glands including ovaries, testes and
adrenal. It acts as an immediate or precursor
for other hormones.

42.  During pregnancy, progesterone is
secreted by corpus luteum up to six
weeks of pregnancy.
 Thereafter, the placenta takes over the
function of progesterone production up
to term.

43.  Prolactin: During pregnancy,
prolactin values rise to about 100
mg/ml due to maternal pituitary
activity.
 The decidual lining of the uterus
contributes to amniotic fluid content of
prolactin.

44.  Oestriol: Oestriol levels reach 25-30
mg/day.
 Extremely low Oestrol denotes foetal
death or anencephaly.
 High circulating oestrol values are
associated with multiple pregnancies or
Rh isoimmunisation.
 A normal oestrol level signifies foetal
well being.

45.  HPL (Human Placental
Lactogen): HPL levels vary directly
according to placental mass. Therefore
HPL levels are higher in multiple
pregnancy.
 Secretion of oxytocin (stimulates
uterine contraction)

46.  Thyroid activity is increased – In
normal pregnancy thyroid gland
increases in size by about 13 % due to
hyperplasia and increased vascularity.
 There is normaly an increased uptake
of iodine during pregnancy , which may
be due to compensate for renal
clearance of iodine leading to a reduced
level of plasma iodine.

47. MUSCULOSKELETAL SYSTEM
 The body's posture changes as the
pregnancy progresses.
 The pelvis tilts and the back arches to help
keep balance.
 Poor posture occurs naturally from the
stretching of the woman's abdominal
muscles as the fetus grows. These muscles
are less able to contract and keep the lower
back in proper alignment.

48.  The pregnant woman has a different pattern
of gait. The step lengthens as the pregnancy
progresses, due to weight gain and changes
in posture..
 The influences of increased hormones such
as estrogen and relaxin initiate the
remodeling of soft tissues, cartilage and
ligaments.

49.  Increased ligamental laxity caused by
increased levels of relaxin contribute to back
pain and pubic symphysis dysfunction.
 Shift in posture with exaggerated lumbar
lordosis leading to the typical gait of late
pregnancy.

50. HEMATOLOGY
 During pregnancy the plasma volume
increases by 50% and the red blood cell
volume increases only by 20-30%.
 Consequently, the hematocrit decreases on
lab value; this is not a true decrease in
hematocrit, however, but rather due to the
dilution.

51.  A pregnant woman will also become
hypercoagulable , leading to increased risk
for developing blood clots and embolisms,
due to increased liver production of
coagulation factors, mainly fibrinogen and
factor VIII (this hypercoagulable state along
with the decreased ambulation causes an
increased risk of both DVT and PE).

52. DVT

53. DVT

54. DVT

55.  Women are at highest risk for developing
clots during the weeks following labor.
 Clots usually develop in the left leg or the
left iliac venous system.
 The left side is most afflicted because the left
iliac vein is crossed by the right iliac artery.
 The increased flow in the right iliac artery
after birth compresses the left iliac vein
leading to an increased risk for thrombosis
(clotting) which is exacerbated by the
aforementioned lack of ambulation
following delivery .

56. Edema , or swelling, of the feet is
common during pregnancy, partly
because the enlarging uterus
compresses veins and lymphatic
drainage from the legs.

57. Edema

58. Ankle odema

59. Edema

60. WEIGHT GAIN
HOW MUCH WEIGHT GAIN
OCCUR DURING
PREGNANCY AND OF WHAT
?

61.  Average weight gain during pregnancy
is about 10 kilogram in the
pregnant Indian woman of average
built .
 And can be accounted for the weight of
foetus, placenta, amniotic fluid,
increase in weight of breasts and
uterus, increase in blood value, extra
cellular fluid and fat.

62. There is a wide range of normality
in weight gain and many factors
influence it which include
 maternal edema ,
maternal metabolic rate ,
 dietary intake ,
vomiting and
diarrhea etc.

63.  Poor weight gain is due to
 nausea, vomiting,
 indigestion,
 underweight woman
 Inadequate food,
 overwork,
 maternal illness,
 intra-uterine growth retardation
 foetal death

64. Excessive weight gain is due to
overeating,
excess water intake,
oedema,
large foetus,
multiple pregnancy and
overweight of woman.

65. Reproductive weight gain
Fetus – 3.3 kg ,
Placenta – 0.6 kg ,
 Liquor – 0.8 kg ,
Uterus – 0.9 kg ,
 Breast – 0.4 kg

66. Net maternal weight gain :
Increase blood volume – 1.3 kg ,
 Increase in extracellular fluid -
1.2 kg ,
Accumulation of fat and protein
– 3.5 kg

67. GENERAL METABOLISM
 The basal metabolic rate increases by 15-
20%.during the later half of pregnancy in
response to the demands of the growth fetus
and maternal tissues and so energy
requirement is higher.
WHAT IS DAILY
ENERGY
REQUIREMENT
OF PREGNANT
WOMAN ?

68.  In women with normal BMIs,
 energy requirement does not increase
significantly during the first trimester,
 increases by about 350 Kcal/day in the
second trimester
 and 500 Kcal/day in the third.

69.  About 40% of women develop physiological
ankle oedema during the last 12 weeks of
pregnancy which disappears with rest and is
rarely present in the morning.
 However, oedema in pregnancy should
never be considered physiological until all
pathological causes have been ruled out.

70. ANY
QUESTION
??????