Maternal adaptation to pregnancy

Question 1

What is the age of foetal vitality?

Answer 1

24 weeks

Question 2

What are the different classifications of delivery based on the time of gestation when the women delivers?

Answer 2

Below 24 weeks is a (late) miscarraige
Between 24 weeks and 32 weeks is Extreme Premature term
Between 32-37 weeks in pre term
Between 37 to 41 is full term
Later than 41 weeks is an extended gestation and labour is foten induced.

Question 3

What hormonal changes in women help maintain pregnancy?

Answer 3

Corpus luteum - secretes oestrogen and progesterone after ovulation to thicken and maintain the uterus lining
Human Chorionic Gonadtrophin - hCG, mainly produced by the trophoblast cells of the placenta or blastocyst, smaller amounts from the pituitary glands and liver.
Placenta formation - around 50 to 60 days after the last period, secrete oestrogen and progesterone to maintain the pregnancy.

Question 4

What is the role of hCG in pregnancy?

Answer 4

Produced in early pregnancy by the blastocyst and the trophoblast. - main role is in the first trimester of pregnancy.
Binds to lutenising hCG receptors
Causes the corpus luteum to secrete progesterone
Myometrial smooth muscle cells to promote myometrial quiescence (relaxation)
Increased blood vessel formation by increasing VEGF levels
Causes decidualisation of the stromal cells in the endometrium ( prepares for implantation)

Question 5

Describe the changes that occur in the uterus during pregnancy.

Answer 5

Thickening of the uterine wall
Grows out of the pelvic inlet and cavity, becomes an abdominal organ rather than a pelvic organ.
Increases in weight and size, changes from a pear shape to an ovoid shape as pregnancy progresses.
Increased size and number of blood vessels
Lower uterine segment forms between 32 and 34 weeks gestation
Braxton Hicks contractions from the first trimester
Muscle fibres increase in lenght and widen
Ligaments soften and thicken - under oestrogen.

Question 6

What is meant by the upper and lower uterine segment?

Answer 6

The upper segment is also called the corpus segment, it tends to be thicker walled. This regions is active and shortened in compression.
The lower segment is also called the isthmus, it tends to be thinner and can distend and stretch during pregnancy. This region is passive and streched in contractions.
Segments are developed at 3 months.

Question 7

What are Braxton Hicks contractions?

Answer 7

Braxton Hickes contractions are when the womb contracts and relaxes.
They are normally felt in the second or third trimester.
They are uncomfortable, but not painful, they happen infrequently, lessen then disappear and typically last less than 30 seconds.
Unlike contractions they will not dilate the cervix or cause effacement, they do increase tone of the uterine muscles in preparation for labour.
Are uncoordinated

Question 8

What are some physiological changes that occur to the cervix during pregnancy?

Answer 8

Changes form a firm structure to an elastic tissue.
Appears a darker or purply colour as oestrogen increases vascularity
Oestrogen, Progesterone, relaxin and prostaglandin levels change
Operculum forms.

Question 9

What is the affect of different hormones on the cervix?

Answer 9

Oestrogen - increased in pregnancy, then decrease rapidly right before the end of pregnancy. Thins the cervical mucus ready for labour.
Progesterone - maintain cervical closure.
prostaglandins - relax the cervix
Relaxin - softens and widens the cervix

Question 10

What do homeotic genes do?

Answer 10

Regulate the development of anatomical structures in eukaryotes (patterning)

Question 11

What is the operculum?

Answer 11

A mucous plug that seal the opening of the cervix during pregnancy to protect the growing baby.
Occurs when oestrogen rises

Question 12

What are some of the physiological changes in the cardiovascular system during pregnancy?

Answer 12

Cardiac output increases by 40% at term
Uterine blood flow takes up 10% of output at term
Heart rate increase by 10-15bpm
Plasma volume increased by 50%
Decrease in BP

Question 13

What are some maternal risks due to maternal cardiovascular changes during pregnancy?

Answer 13

Risk of compression of the IVC from 20 weeks gestation.
Anemia - as decrease in hb is lower than decrease in plasma volume resulting in a lower hematocrit
Decreased oxygen reserves
Potential for huge hemorrhage due to increase blood volume
Increased demand on the heart.

Question 14

What are some of the changes to the maternal respiratory system during pregnancy?

Answer 14

Increase in breathing rate and effort (15-17bpm)
Oxygen consumption increased by 20%
Decrease in vital capacity due to pressure from the uterus on the diagphram
Arterial pCO2 reduced and increase pO2 as ventilates more regularly.

Question 15

What are some health concerns regarding a pregnant mothers respiratory system?

Answer 15

Significant acidosis more likley
Hypoxia will happen faster
- as used up and produced faster - nothing to do with change in pO2 before event
Difficult to intubate.

Question 16

What changes are the endocrine system responsible for in pregnant women?

Answer 16

Changes the levels of pituitary and placental hormones including porgesteron and oestrogen
Maintain pregnancy by relaxing smooth muscle
Deposits fat subcutaneous tissue on the back and abdomen
Encourages enlargment and vascularisation of the uterus and breasts
Relaxes the pelvic ligaments and joints
Controls the onset and strength of uterine contractions

Question 17

What causes nasea and vommitting during pregnancy?

Answer 17

Decreased HCL and pepsin secretion, progesterone slows contraction of smooth muscle so slower digestion
Detection of increased pregnancy hormones such as hCG by chemical trigger zone in the vommitting centre.
CHECK ANSWER

Question 18

What is oxytocin?

Answer 18

A natural hormone that stimulates uterine contractions in childbirth and lactation after childbirth.
Secreted by the pituitary gland.

Question 19

What is partuition?

Answer 19

The process of childbirth

Question 20

What are some of the effects on the gastrointestinal system during pregnancy?

Answer 20

Delayed gastric emptying, increases the acidity of stomach contents. (despite HCl and pepsin secretion decreasing)
Progesterone causes relaxation of upper oesophageal spihnicter, increasisns the risk of reflux and regurgitation
Nause and vommiting starts at 4-8 weeks and lasts till 14-16 weeks gestation
Hypermesis Gravidarum (severe dehydration)

Question 21

What is hyperemesis gravidarum?

Answer 21

An extreme form of nasuea and vommitting during sickness, affects 3% of pregnany women with morning sickness.
Requires urgent medical attention, if unable to keep fluids and liquids down quickly become dehydrated. May also suffer weight loss and malnutrition of the growing foetus
‘Dry’ hyperemesis gravidarum is when the person feels nausea’s but is not sick, however the strong nausea is enough to prevent food and liquid intake.

Question 22

What are the affects of pregnancy on the maternal urinary system?

Answer 22

Increases frequency of micturition
In 1st trimester this is ude to pressure of the uterus on the bladder.
In late pregnancy this is due to engagement of the fetal head
Increased risk of urinary tract infections
increased risk of stress incontinence
Urinary bladder displacement increasing risk of injury/infection.

Question 23

What is stress incontinence?

Answer 23

When physcial movement of activity, such as coughing or heavy lifting puts pressure on your bladder causing you to leak urine.

Question 24

What are the impacts of pregnancy on the maternal muscoulskeletal system?

Answer 24

Hypermobility of joints due to progesterone release
Symphysis Pubis Dysfunction
Change in centre of gravity
Back ache - over arch lumbar spine to compromise for weight of baby
Change in fair - compromise for weight of baby.

Question 25

What is symphysis pubis dysfunction?

Answer 25

When the pubic symphysis allows for more movement than normal, due to weekening of pelvic ligaments. Additional movement causes pain. Pain increases with physical activity, often resolves after pregnancy has ended Occurs in 30% of women.

Question 26

What are the changes to the abdominal region during pregnancy? What three key landmarks note the movement of the uterus?

Answer 26

The gravid uterus (pregnancy or containing something) becomes an abdominal organ. At 12 weeks the fundus is palpable above the subic symphysis >22 weeks it is palpable above the umbilicus >36 weeks it is palpable at the xiphoid process.

Question 27

What changes occur in the breast during pregnancy?

Answer 27

Enlarge due to hormal changes and increased blood flow. Areala and nipple darken in colour Colostrum may be present during the third trimester Heightened sensitivity.

Question 28

What is colostrum?

Answer 28

The first milk produced by mammary glands during pregnancy, production may start in late trimester 3 and lasts for a few days (4 days) after birth. Is thicker and more yellow in appearance. Is high in protein, vitamines, minerals and immunoglobulins. is low in fat and sugar so it is easy to digest.

Question 29

What are the different stages of breast milk?

Answer 29

Colostrum - late third trimester until 4 days after birth Transitiona milk - 4 days after birth till two weeks post birth Mature milk - from two weeks until stop breast feeding

Question 30

What are some of the emotional changes that occur during pregnancy?

Answer 30

Mood swings Changed body imafe Depression Fearfulness Increased sensitivity Indecisiveness Altered libido

Question 31

What skin changes may occur during pregnancy?

Answer 31

Linea nigra - pigmented line normally extenededing from belly button vertically Stritae gravidarum - stretch marks, darker during pregnancy, become thinner and whiter after birth. Chloasma Gracidarum - butterfly mask

Question 32

What is the linea nigra during pregnancy?

Answer 32

Becomes noticeable often in the 2nd trimester, rising levels of progesterone and oestrogen stimulate melanocytes, this darkens the fibours region called the linea alba. Linea nigra runs vertically from above and below the belly button

Question 33

What causes stretch marks during pregnancy?

Answer 33

Dermis is stretched and broken. Degree of stretch marks in dependent on the size of the uterus and the elastic content of the skin. Increased cortisol weakens the elastic of the skin Affect 80% of women.

Question 34

What causes the butterfly mask of pregnancy?

Answer 34

Increased oestrogen and progesterone causes increased activation of melanocytes. Melanocytes are also activated by sunlight, which is more common on the face. Causes increased melanin production on the cheeks and nose resulting in the pigmented butterfly mask.

Question 35

What causes mood swings during and after pregnancy?

Answer 35

Increased levels of oestrogen - increase levels of serotonin and serotonin receptors in the brain, negative feedback to decrease seratonin production Progesterone - natural antidepressant. After birth - post partum depression, due to sharp drop and oestrogen adn progesterone, hypothyroidism

Question 36

What causes fatigue in pregnancy?

Answer 36

Linked with thyroid function - decreased T3 and T4 production, less energy intake from food. !st trimester symptoms replicate hypothyroidism Progesterone - increase levels of GABA, increased tiredness.

Question 37

What is PICA during pregnancy?

Answer 37

PICA is extreme cravings, in which a person craves substances that are non-food or have no nutritional values such as paper or coal. Often due to nutritional deficits during pregnancy, changes in hormones affecting smell, changes in taste buds meaning they crave things with stronger taste.

Question 38

What are some common physical changes during pregnancy?

Answer 38

Odema to hands anf feet Leg cramp Nail and hair changes Increased vaginal secretions/discharge Weight gain Heartburn Ptyalism - overproduction of saliva/reduced swalloeing of saliva Constipation Varicosities

Question 39

Whatare varicosities? How are they caused by pregnancy?

Answer 39

Swollen and enlarged veins Compression of the IVC reduces drainage from the legs, increased blood volume during pregnancy exerts extra strain on blood vessel walls.