The period from conception to birth. After the egg is
fertilized by a sperm and then implanted in the lining
of the uterus, it develops into the placenta and
embryo, and later into a fetus. Pregnancy usually
lasts 40 weeks, beginning from the first day of the
woman's last menstrual period, and is divided into
three trimesters, each lasting three months.
Changes in the uterus:
• By 12th week, uterus rises out of pelvic
cavity and becomes upright.
• By 16th week it is midway between
umbilicus and symphysis pubis.
By 20th week it is just below the umbilicus.
By 24th week at the umbilicus.
By 30th week midway between umbilicus
After 38 weeks lightening occurs and fetus
sinks down and fundus can be palpated
below the level of xiphisternum.
Changes in decidua:
• Decidua is the name given to the
endometrium during pregnancy.
• Estrogen and progesterone
produced by corpus luteum,
causes the decidua to
More vascular at the fundus and
in the upper body of the uterus.
Changes in myometrium:
It is made up of smooth muscle
fibres.The muscle fibers grow up to
15-20 times their non-pregnant
length. Hypertrophy and
hyperplasia of muscles occurs due
to estrogen and progesterone
weighs 750-1000gm & capacity of
uterus increases from 50ml -5 liters.
in fallopian tubes:
The fallopian tubes
on either side are
more stretched out in
pregnancy and is
much more vascular.
Changes in the cervix:
The cervix remains
tightly closed during
The mucous secreted
by endo cervical cells
become thicker and
more viscous during
Changes in the
changes in muscle
epithelial layer of
The muscle layer
capacity of vagina
Changes in the ovaries:
Due to increased
progesterone there is
decrease in level of FSH
and LH resulting in
inhibition of maturation
and release of graffian
follicles resulting in
The heart muscle
particularly the left
enlargement of heart.
The growing uterus
pushing the heart
upwards and to the
The stroke volume increases from 65ml/beat-75ml/beat.
Pulse rate increases from 75beats/min-85beats/min.
Cardiac output increases from 5litre/min-7litre/min.
Venous pressure increases from 8-10cmH2O-20cmH2O
Blood viscosity decreases from 4.7-3.8 .
Blood volume increases from 4000ml-5500ml.
Plasma volume increases from 2500ml-3750ml.
Red cell volume increases from 1400ml-1650ml.
Hematocrit value decreases from 38% to 32%.
Clotting factor level increases in 7th, 8th, 9th, 10th
WBC increases changes to 15000cells/mm3 in 2nd
and 3rd trimester.
30-50% blood flow increase in kidneys.
The anterior and posterior diameter of
chest increases to 2cm.
Displacement of diaphragm by 4cm.
The respiratory rate rises to 18-20 .
Inspiratory capacity increases.
Expiratory volume decreases to 7-11litres
in later weeks.
Tidal volume is increased to 40%.
Residual volume is decreased.
Co2 tension is 27-32mmHg.
O2 consumption increases from 15-20%.
Co2 production is increased.
Gums become edematous, soft and
spongy and can bleed with a
There is increase in salivation
known as ptylism.
At 4-8 weeks women complains of
nausea and vomiting, known as
Decreased peristaltic movements
resulting in constipation.
Gall bladder increases in size and
empties more slowly during
The bladder capacity is more
Relaxation of soft tissue.
Frequency of urination is
more in 1st and 3rd trimester.
Renal blood flow increases by
70-80% by 2nd trimester.
Plasma levels of urea, uric
acid and creatinine fall
Glucose excretion increases
Human chorionic somatomamotrophin
hormone increases – it has an anti-insulin
HCG hormone level also increases. Beta
in blood give confirmatory diagnosis of
AT 3-4 weeks Prickling/tingling sensation of mammary gland.
At 6 weeks Enlargement of breasts
Mastodynia-pain in the breast.
At 8 weeks Bluish veins visible over the mammary gland.
At 8-12 weeks Montgomery tubercle; 15-20 over each mammary gland.
At 16 weeks Secondary areola
Expression of colostrum
1.What are the changes occurring in
2.Explain the maternal weight gain
3.What is osiander sign?
4.Enumerate goodell’s sign.
Jacob Annamma;A Comprehensive Textbook Of Midwifery And Gynecological Nursing;jaypee publishers;page no.-
C.S Dawn;Textbook of obstetrics and neonatology;aarthi dawn publishers;page no.321
Myles;a textbook for Midwives;Elsevier publishers;page no:-653