NORMAL AND ABNORMAL LABOUR.777777777777777777777pptx

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1. Physiology & Management of Normal labour By : DR.DAVID BREWEN CONTEH

2. Overview Physiological changes in pregnancy Definition of labour Stages of labour Mechanism of labour Management 5/29/2024 2

3. HORMONAL CHANGES: Pituitary gland: The anterior pituitary enlarges due to an increase in prolactin secreting cells ( lactotrophs ). Prolactin level increases up to 150 ng /ml at term to ensure lactation. Physiological changes in pregnancy 5/29/2024 3

4. Thyroid gland. Gland activity increases as evidenced by the increase in: basal metabolic rate (BMR) by about 30%, thyroxine -binding globulin, total T3 (tri- iodothyronine ) and T4 ( thyroxine ), protein bound iodine (PBI). TSH, free T3 and T4. Parathyroid glands: increase in size and activity to regulate the increased calcium metabolism. Physiological changes in pregnancy 5/29/2024 4

5. Adrenal glands: Incr. mineralocorticoids (aldosterone) and glucocorticoids (cortisol). Progesterone is synthesized by the corpus luteum until 35 days post- conception and mainly by the placenta thereafter. It decreases smooth muscle excitability (gut, ureters, uterus) and raises body temperature. • Oestrogens , mainly oestradiol (90%), increase breast and nipple growth and pigmentation of the areolar. 5/29/2024 5

6. • Human placental lactogen ( hPL ), also called chorionic growth hormone or human somatomammotropin , is lactogenic and has some growth- stimulating activity. It promotes growth and insulin secretion, but decreases insulin's peripheral effect, liberating maternal fatty acids (hence sparing maternal glucose use), lactalbumin , and lactoglobulin production. 5/29/2024 6

7. CARDIOVASCULAR SYSTEM Heart Position: As the diaphragm is elevated progressively during pregnancy the apex is displaced upwards and to the left so that it lies in the 4th intercostal space outside the midclavicular line. Rate: The resting pulse rate increases by 10-15 beats per minute during pregnancy. 5/29/2024 7

8. CARDIOVASCULAR SYSTEM Cardiac output: increases mainly by increased stroke volume rather than increased HR reaching a maximum of 40% above the non-pregnant level at 20 weeks to be maintained till term. Arteries : ABP usually declines during the second trimester due to peripheral vasodilatation caused by oestrogens and prostaglandins. The posture of the pregnant woman affects ABP 5/29/2024 8

9. Supine hypotensive syndrome may develop in some women late in pregnancy in supine position. This is due to compression of the IVC by the large pregnant uterus resulting in decrease VR, decrease CO and BP that fainting may occur. Veins: Varicosities in the lower limbs and vulva may occur due to: back pressure from the compressed IVC by the pregnant uterus, relaxation of the smooth muscles in the wall of the veins by progesterone. 5/29/2024 9

10. RESPIRATORY SYSTEM Dysponea may occur due to : increase sensitivity of the respiratory center to CO2 possibly due to high progesterone level, elevation of the diaphragm by the pregnant uterus. 5/29/2024 10

11. GI system Decreased oesophageal sphincteric tone is responsible for the reflux oesophagitis (heartburn) that occurs in pregnancy. Gastric mobility is low and gastric secretion is reduced resulting in delayed gastric emptying. Gut motility is generally reduced resulting in constipation. 5/29/2024 11

12. Changes in the uterus The non-pregnant uterus weighs 100g. It undergoes a 10-fold increase in weight to weigh 1000g at term. Muscle hypertrophy occurs up to 20 weeks with stretching after that. 5/29/2024 12

13. Changes in the vagina High oestrogen levels stimulate glycogen synthesis and deposition, and the action of lactobacilli on glycogen in vaginal cells produces lactic acid, which in turn lowers the vaginal pH to keep the vagina relatively free from any bacterial pathogens. 5/29/2024 13

14. Skin changes Pigmentations in linear nigra , nipple, and areola or as chloasma (brown patches of pigmentation seen especially on the face) are seen in pregnancy. Palmar erythema, spider naevi , and striae are also common. They are probably related to the effect of increased production of adrenocortical hormones in pregnancy as well as to the actual stress in the skin folds associated with expansion of the abdomen. 5/29/2024 14

15. Renal function changes Renal blood flow increases by 30-50% in the first trimester and remains elevated throughout pregnancy. Effective renal plasma flow and glomerular filtration rate (GFR) increase. Creatinine and urea production remain the same and plasma levels therefore fall during pregnancy. Uric acid clearance increases from 12 to 20 mmol /mL with a consequent reduction in plasma uric acid levels 5/29/2024 15

16. Definition of labour The process by which the fetus is delivered after the 28 th week of gestation Prior to that- delivery of the fetus is termed: miscarriage 5/29/2024 16

17. Definition of labour 2 The diagnosis is made when: Painful uterine contractions accompanied by dilatation and effacement of the cervix 5/29/2024 17

18. Definition of labour 2 Other features of labour: Rupture of chorioamniotic membranes Descent of presenting part through birth canal Birth of baby Delivery of placenta and membranes 5/29/2024 18

19. The stages of labour First Starts with the onset of true labour pain and ends with full dilatation of the cervix (latent 0-4cm, active 4-10cm) It takes about 10-14 hours in primigravida and about 6-8 hours in multipara 5/29/2024 19

20. The stages of labour Second It is the stage of expulsion of the foetus . Begins with full cervical dilatation and ends with the delivery of the foetus . Its duration is about 1 hour in primigravida and ½ hour in multipara. Third Delivery of fetus to delivery of placenta Its duration is about 10-20 minutes in both primi and multipara . 5/29/2024 20

21. First stage The 1 st stage is divided into 2 phases: LATENT Cervix fully effaces and dilates up to 4cm ACTIVE Cervix dilates from 4cm to 10cm (“fully”) 5/29/2024 21

22. Engagement of the fetal head “ The passage of the maximal diameter of the presenting part beyond the pelvic inlet” Primparous - by 37 weeks Multiparous - by onset of labour NB/ In Afro-Caribbean women, engagement may only occur at the onset of labour or during labour even in primips 5/29/2024 22

23. Use the palm width of the 5 fingers of your hand to assess engagement A head that is 2/5 palpable is engaged. Breech presentation can be mistaken for deeply engaged head. 5/29/2024 23

24. Mechanism of labour The normal process of movement of the head in labour for a normal vertex presentation involves the following sequence. Descent -with increased flexion as the head enters the cavity. The sagittal suture lies in the transverse diameter of the brim. 5/29/2024 24

25. Mechanism of labour Internal rotation occurs at the level of the ischial spines due to the grooved gutter of the levator ani muscles. Flexion produces a small diameter of presentation changing to the suboccipito-bragmatic diameter from the occipito -frontal diameter. Distension of the perineum with crowning is followed by extension of the head as it comes out of the vulva. 5/29/2024 25

26. Mechanism of labour…. Restitution The head rotates back for the occiput to be in line with the spine. External rotation . The shoulders rotate when they reach the levators until the bi-acromial diameter is anteroposterior . Accordingly, the head externally rotates by the same amount. 5/29/2024 26

27. Mechanism of labour…. Delivery of the posterior shoulder occurs by lateral flexion of the trunk anteriorly. Delivery of the anterior shoulder occurs by lateral flexion of the trunk posteriorly. Delivery of the buttocks and legs follows the delivery of body. 5/29/2024 27

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29. MANAGEMENT OF NORMAL LABOUR A ) Antenatal Preparation: Maternal education: about the physiology of labour and symptoms of impending labour . Breathing exercise: adapt the mother to breathing during labour to guard against respiratory alkalosis caused by hyperventilation . 5/29/2024 29

30. Complete obstetric history and examination Active procedures: Evacuation of the rectum by enema to; Evacuation of the bladder: ask the patient to micturate every 2-3 hours or catheterize Preparation of the vulva Nutrition: When labour is established no oral feeding is allowed , but sips of water. 5/29/2024 30

31. Posture: Patient is allowed to walk during the early first stage particularly with intact membranes. Analgesia: Pethidine 100 mg IM, trilene inhalation, epidural anaesthesia are the most common use. tramadol PATOGRAPH 5/29/2024 31

32. ABNORMAL LABOUR Prolonged labour is prolongation of the first stage of labour a condition mostly common in primiparae . Prolongation of the second stage is referred to as a delay in labour Progress in labour is judged by a. dilatation of the cervix 0-10cm b. descent of fetal head

33. Additional assessment in the first stage a. condition of the mother-pulse, Temp, BP b. condition of the fetus by auscultation of FHR at regular interval c. looking for meconium in liquor or by cardiotocography and fetal scalp blood pH. d. size of caput and extent of moulding indicating a tight fit

34. Partogram The portion measuring or plotting cervical dilatation (cm) against time (h) is called cervimetric graph ( cervicogram ). This is to focus attention in recognition and classification of prolonged labour It is usually started when labour becomes established at the time when amniotomy is done

35. The first stage is divided into latent and active phase latent- --0-4cm can take 6hrs active 4cm to 10cm and is just under 1cm dilatation per hour, also takes 6hrs, that is equivalent to 12 hrs that is acceptable normal duration of first stage of labour in primigravida . Multiparae not that long.

36. Types of prolonged labour 3 types: a. prolonged latent phase lasting for more than 6hrs b. primary dysfunctional labour : is when uterine activity is either inert or incoordinate from the start of the active phase C. secondary arrest of labour : is the rate of cervical dilatation normal at first, but slows down.

37. Prolongation of first stage 1:3 primi 1:8 multi In both prolonged labour is associated with a higher 10—16 fold C/S rate and roughly 4 fold increase of low APGAR score ( 6 or less) Prolonged labour is regarded as HR condition requiring the best hospital facilities and specialist skills

38. Causes CPD This diagnosis is made whenever the presenting fetal head to be too big for the birth canal that it has to pass through. The most important causes of CPD 1. Fetal Malposition , Malformation e.g hydrocephalus Macrosomia or large baby

39. 2. Maternal contracted pelvis a combination of both 1 and 2. 3. Abnormalities abnormalities causing prolonged labour in the absence of CPD a. fetal malpresentation ( brow, shoulder, face, or breech)

40. b. maternal abnormalities Stenosis or scarring of the cervix Pelvic Tumors. Septae or stenosis of the vagina Primary uterine dysfunction or inertia

41. END OF TODAY’S LECTURES