Understanding Physiologic Changes During Pregnancy

1. Physiologic changes of pregnancy . DINA AKEEL

2. AIMS • TO GAIN AN UNDERSTANDING OF THE PHYSIOLOGICAL CHANGES THAT OCCUR DURING PREGNANCY

4. Organ systems • Cardiovascular system • Pulmonary system • Genital tract • Urinary system • Endocrine system • Gastrointestinal Tract • Skin

5. CHANGES ARE DUE TO • ALTERATIONS IN • HORMONAL PRODUCTION • CIRCULATION • METABOLISM

6. HORMONES OESTROGEN • Produced in corpus luteum • Produced by placenta after 12 weeks • Responsible for growth particularly of uterus and breasts

7. progesterone • Produced in corpus luteum and then the placenta • Relaxes smooth muscle • Inhibits uterine contractions until uterus is prepared for labour • Regulates storage of body fat

8. Maternal changes - anatomical and physiological • Cardiovascular changes • increase in SV • increase in cardiac output • increase in HR at given work load • increase in blood volume (mostly during latter half of pregnancy) • Uterus may compress large blood vessels reducing venous return

9. Circulatory System

10. Supine hypotension related to Venal cava syndrome This leads to dizziness, air hunger, nausea

11. Total body water • Increases 6-8 L • Increases by 40 % • Normal body water • 2/3 intracellular • 1/3 extracellular • ¾ interstitial • ¼ intravasular • 2/3 increase is extravascular

12. Respiratory system • Mechanical • diaphragm • Consumption • Increase in needed oxygen • Stimulation • Progesterone stimulation

14. Physiologic changes - RESPIRATORY SYSTEM increase respiratory rate increased oxygen consumption common are nasal stuffiness, nosebleeds due to Increased vascular swelling to nose

15. Respiratory • Consumption • O2 consumption Increases 15-20 % • 50 % of this increase is required by the uterus • Despite increase in oxygen requirements, with the increase in Cardiac Output and increase in alveolar ventilation oxygen consumption exceeds the requirements. • .

16. Physiologic changes - GASTROINTESTINAL Digestive system slow due to progesterone Nausea and vomiting Ptyalism: increase salivation Heartburn Hemorrhoids Prolonged gallbladder emptying time may lead to gall stones Bile salt buildup may lead to itching.

17. Gastrointestinal Tract • Displacement of the stomach and intestines • Appendix can be displaced to reach the right flank • Gastric emptying and intestinal transit times are delayed secondary to hormonal and mechanical factors • Vascular swelling of the gums • Hemorrhoids due to elevated pressure in veins

19. Physiologic changes - METABOLISM BMR increases by 20-25 % during pregnancy Recommended weight gain – 25-35 lb Overweight – 15-25 lb Underweight – 25-35 lb Need for increased iron, calcium, fat, and protein

20. Genital Tract • Increased vascularity and hyperemia • Vagina • Perineum • Vulva • Increased secretions • Characteristic violet color of the vagina • Chadwick’s sign • Increased length to the vaginal wall • Hypertrophy of the papillae of the vaginal mucosa

21. Changes in the cervix • Length remains the same • Increase in width • Softening after third month due to oestrogen • Increased vascularity • Increased cervical mucosa • Increased glandular function

22. uterus grows to 30x23x20 at termweight increases to 900gmshypertrophy.. Oestrogen causes cells to increase until 20 weeks gestationHyperplasia:- number of cells increase under the influence of oestrogen.

23. Relative Uterus Size During Pregnancy Figure 28.15

24. PLASMA VOLUME Increases from 10th week of pregnancy variable related to parity, fetal weight and number Reaches maximum level approx 50% above non-pregnant levels at 32-34 weeks then maintained

25. 50% rise in plasma volume • 20% rise in red cell mass • Heamodilution: Physiological anaemia • Most apparent at 32-34 weeks

26. RENAL SYSTEM • DILATION OF THE RENAL VESSELS • DUE THE EFFECTS OF PROGESTERONE • INCREASED RENAL BLOOD FLOW • GFR INCREASES BY 60% IN EARLY PREGNANCY

27. Urinary Changes • Kidneys grow and filter more blood as the blood volume increases • Become more susceptible to bladder and kidney infections • Bladder becomes compressed causing frequent urination and incontinence

28. Physiologic changes - URINARY TRACT Increased glomerular filtration rate Frequency Infection : Smooth muscle of bladder relaxes/stasis Wajed Hatamleh RN, MSN, PhD.

29. WATER, WATER, WATER Hydration is a major concern during maternal exercise. • Provide a ready source of water • Encourage frequent water breaks

30. Skin changes • Chloasma or melasma gravidarum • Striae • Linea nigra

31. Skin Changes • Stretch marks • Dark pigmented line on there abdomen which is called Linea Nigra • Pigment changes on their face and neck • Small blood vessels in the face, neck and upper chest • MOST OF THESE RESOLVE AFTER PREGNANCY

32. Melasma

33. Melasma

34. Melasma • Also known as the mask of pregnancy • More common in dark skin people • More pronounced in the summer • Fades a few months after delivery • Repeated pregnancy can intensify • Can occur in normal non-pregnant women with harmless hormonal imbalances or women on OCPs or depo

35. Striae

36. Striae • Reddish slightly depressed • Breasts, thighs, and abdomen • In future pregnancies they appear as glistening, silver lines

37. Linea nigra