2.01 - Physiology of Pregnancy Flashcards

Question

Describe the affect of pregnancy on the cardiovascular system.

Answer 1

Increased progesterone decreases systemic vascular resistance, decreasing diastolic blood pressure. In response, cardiac output increases by about 40%. Pregnancy activates RAAS, leading to an increase in sodium levels and water retention. Therefore, total blood volume increases.

Answer 2

Growth of the foetus causes upward displacement of the diaphragm, however due to increase in transverse and AP diameters of the thorax, total lung volume is unchanged. Increased progesterone increases respiratory drive, resulting in hyperventilation (respiratory alkalosis).

Answer 3

Upward displacement of the stomach due to foetus growth increases intra-gastric pressure, predisposing the mother to GOR and n+v. Increased progesterone causes smooth muscle relaxation to decrease gut motility. This allows more time for nutrient absorption, but can also lead to constipation.

Answer 4

Increased cardiac output during pregnancy increases renal plasma flow, so GFR increases by 50-60%. The levels of urea and creatinine are lower. Increased progesterone relaxes the ureter and muscles of the bladder, which can cause urinary stasis > UTIs > pyelonephritis.

Answer 5

Increased risk of thromboembolic disease due to: - increased fibrinogen - increased clotting factors - decrease in fibrinolysis - increase progesterone (venous stasis) Note warfarin is teratogenic so LMWH heparin is given to pregnant women if required.

Answer 6

Plasma volume increases significantly, more than red cell mass. This results in dilutional anaemia.

Answer 7

Usually, there is an increase in insulin resistance during pregnancy. This can be counteracted by increasing insulin production. In gestational diabetes, the compensatory rise in insulin levels does not occur, resulting in higher blood sugar levels.

Answer 8

- increased age - high BMI before pregnancy - FHx T2DM - smoking

Answer 9

- fasting plasma glucose >5.6mmol/L - two-hour plasma glucose >7.8mmol/L

Answer 10

Conservative management includes changing diet and physical activity levels. Insulin or metformin can be given when lifestyle measures do not help.

Answer 11

- macrosomia (causing complications during birth) - intrauterine growth retardation

Answer 12

Significant hypertrophy of the ductular-lobular-alveolar system, with differentiation to allow milk production capacity. There is little milk secretion due to a high progesterone:oestrogen ratio, which favours growth rather than secretion.

Answer 13

A high progesterone:oestrogen ratio during pregnancy favours the development of alveoli, but not secretion. When the placenta is delivered, progesterone falls and breast milk begins to form within 24-48 hours. Prolactin stimulation is promoted by suckling, increasing milk production.

Answer 14

In response to suckling, oxytocin is released from the posterior pituitary gland. This causes contraction of ducts and squeezes milk out of the breast.

Answer 15

Suckling - as soon as suckling stops, milk production will cease gradually.

Answer 16

- meets all baby's nutritional needs - breast milk protects baby from infection - breast milk is available whenever needed - breastfeeding can build a strong emotional bond between mother and baby

Answer 17

Breastfeeding lowers risk of: - breast cancer - ovarian cancer - osteoporosis - cardiovascular disease - obesity

Answer 18

The first six months of baby's life, after which breast milk can be given alongside solid foods. Breast milk adapts as the baby grows to meet the changing needs.

Answer 19

Throughout the third trimester, involuntary contractions of uterine smooth muscle beings to occur. They are thought to be a form of 'practice' contraction, but are not regarded as part of labour.

Answer 20

Softening of the cervix before labour in response to oestrogen, relaxin and prostaglandins, allowing the cervix to dilate. Ripening involves: - reduction in collagen - increase in glycosaminoglycans - increase is hyaluronic acid - reduced aggregation of collagen fibres

Answer 21

At ~36 weeks gestation, oestrogen levels increase the number of oxytocin receptors in the myometrium. Pulsatile release of oxytocin causes contractions. As contractions occur, there is a positive feedback loop that results in further release of oxytocin. This allows for stronger and more frequent contractions (Ferguson reflex).

Answer 22

When regular, painful contractions lead to dilatation of the cervix.

Answer 23

The first stage of labour results in the creation of the birth canal, lasting from the beginning of labour until the cervix is fully dilated (~10cm). Contractions occur every 2-3 minutes and foetal membranes rupture if not already.

Answer 24

The period of time between the cervix being fully dilated, and the foetus being expelled. Approx. 40 mins in nulliparous and 20 mins in multiparous women. Passive stage - lasts until the head of the foetus reaches the pelvic floor. Active stage - pressure of foetal head of the pelvic floor brings the desire to push. Myometrial contractions are forceful and frequent under the influence of prostaglandins and oxytocin, which helps with expulsion of the foetus.

Answer 25

The period of time between delivery of the baby until delivery of the placenta. Uterine muscle continues to contract until the placenta and the membranes have been delivered.

Answer 26

By week 42

Answer 27

The process of starting labour artificially. Approximately 1 in 5 pregnancies will require an induction.

Answer 28

40+0 to 40+14 The aim is to avoid the risks of foetal compromise and stillbirth associated with prolonged gestation.

Answer 29

- prolonged gestation (>40 weeks) - fetal growth restriction - premature rupture of membranes - maternal health problems (e.g. hypertension, pre-eclampsia, diabetes) - intrauterine fetal death

Answer 30

a) delay IOL unless obstetric factors indicate otherwise b) timing of IOL depends on risks vs benefits of delaying pregnancy further c) offer IOL, or offer expectant management for a maximum of 24 hours

Answer 31

- cephalopelvic disproportion - vasa praevia - cord prolapse - transverse lie - active primary genital herpes - previous classical Caesarean section

Answer 32

- breech presentation - triplet - >2 previous low transverse Caesarean sections

Answer 33

- vaginal prostaglandins (most common) - amniotomy - membrane sweep

Answer 34

Prostaglandins ripen the cervix, and help stimulate contraction of the uterus. They are the mainstay of induction for labour (NICE, 2008).

Answer 35

Artificial rupture of the membranes using an amnihook. This releases prostaglandins in an attempt to expedite labour. It is only performed where the cervix has been deemed as ripe, and vaginal prostaglandins are contraindicated.

Answer 36

Offered at 40-41 weeks gestation, used as an adjunct to IOL. Insertion of a gloved finger through the cervix and rotating against the fetal membranes, helping to release natural prostaglandins to initiate labour.

Answer 37

Bishop Score ≥ 7 suggests cervix is 'ripe' and so induction of labour is possible. <4 suggests labour is unlikely to progress naturally and vaginal prostaglandins are required.

Answer 38

a) vaginal prostaglandins b) Caesarean section

Answer 39

Cardiotocography (CTG) or Intermittent auscultation

Answer 40

- failure of induction - uterine hyperstimulation - cord prolapse - infection - pain - uterine rupture

Answer 41

Uncomplicated pregnancies, involving 10 appointments over the course of a pregnancy for nulliparous women, and 7 if it is a second pregnancy.

Answer 42

If classes as higher risk including multiple pregnancy and maternal health problems. Consists of all the midwifery appointments PLUS joint clinics to cover mental health, haematology issues, diabetes etc.

Answer 43

- epilepsy - previous baby with neural tube defects - BMI ≥ 35kg/m2 - T1DM / T2DM - sickle cell disease - Crohn's disease

Answer 44

Folic acid (5mg) taken for three months before pregnancy, and up to the first 12 weeks. Offer all women Vitamin D (10mcg) to reduce the risk of rickets.

Answer 45

The first appointment covering education on lifestyle, nutrition and aspects of physical and mental health. - measure BMI - blood pressure - urine dipstick - FBC - blood group - antibodies and RhD status - screen for Thalassaemias and Sickle cell - offer screening for HIV, HepB and syphilis

Answer 46

If RhD-ve woman, administer at: - sensitising events (amniocentesis, antepartum bleed, abdominal trauma) - routinely offer prophylaxis at 28 and 34 weeks

Answer 47

Kleihauer-Betke test

Answer 48

Measure symphysis fundal height (SFH) at each antenatal appointment after 24 weeks. If there are concerns, send for an ultrasound assessment.

Answer 49

- multiple pregnancy - BMI >35 - large or multiple fibroids Abdominal palpation is unlikely to be accurate in these instances.

Answer 50

Avoid raw meat, fish, eggs, unpasteurised milk or cheese, pate and shellfish. Wash fruit and vegetables.

Answer 51

Strenuous exercise is a risk factor for small for gestational age babies. Encourage exercise at the same level as pre-pregnancy if this was not vigorous, or advise to start a gentle regular programme. Advise to avoid contact or high risk sorts, and scuba diving.

Answer 52

Encourage smoking cessation and counsel about risks. Limited evidence exists on nicotine replacement therapy but can be prescribed if the mother wishes.

Answer 53

High use may result in foetal alcohol syndrome. To avoid the risk, the advice is to exclude completely.

Answer 54

Cocaine particularly associated with adverse complications (e.g. spontaneous abortion, placental abruption, growth restriction). Refer patients for early intervention for good outcomes. Interventions can include: - CBT - couples therapy - talking therapy If people are addicted to opiates such as heroin and are struggling to quit, refer to the methadone programme.

Answer 55

Increased risk of VTE during pregnancy. Recommend compression stockings and check with individual airlines on gestation limits. Advise patients even if they are low risk for VTE to be active daily and keep well hydrated to reduce the risk of VTE.

Answer 56

- reduced foetal movements - nausea and vomiting - heartburn - constipation

Answer 57

Advise to immediately contact maternity services if there is concern about a baby's movement. There should be no change to the pattern or number of movements after 28 weeks gestation.

Answer 58

Normally starts between the 4th and 7th week, and should settle by week 20. Suggest ginger and acupuncture, progressing to antiemetics if severe. If prolonged and severe, consider treatment for hyperemesis gravidarum.

Answer 59

Alleviate by sitting up after meals, reducing fat and spice and eating smaller portions. Can suggest Gaviscon or omeprazole in severe cases.

Answer 60

Encourage increased fibre and oral fluids. Suggest bran or wheat fibre supplements.

Answer 61

- substance misuse (alcohol and drugs) - teenage pregnancy - asylum seekers, recent migrants, refugees or those with a language barrier - victims of domestic abuseA

Answer 62

- risk of maternal death >4x in Black women compared to white women. - stillbirth rates >2x in Black women compared to white women. - stillbirth rates ~2x for women living in most deprived areas compared with least deprived areas

2.01 - Physiology of Pregnancy Flashcards

(87 cards)