Physiology of Pregnancy Year 2 (2024-25) PDF

Physiology of Pregnancy Year 2 Charlotte Illsley [email protected] PSQ C505 Learning objectives By the end of this session, you should be able to: Describe the physiological changes to the body during pregnancy Describe the change...

Physiology of Pregnancy Year 2 Charlotte Illsley [email protected] PSQ C505 Learning objectives By the end of this session, you should be able to: Describe the physiological changes to the body during pregnancy Describe the changes to the oral cavity during pregnancy Introduce the possibility that common oral diseases may impact on outcomes from pregnancy This teaching session refers mainly to maternal health, embryonic development covered in your embryology sessions. Foetal changes in SDL Pregnancy A time over which a foetus develops to maturity inside a woman's womb or uterus. Begins when trophoblast implants into the endometrium, leading to the production of a number of hormones that support and establish the developing foetus Usually lasts about 40 weeks (270 days), or just over 9 months, as measured from the last menstrual period to delivery. Divided into three segments of pregnancy, called trimesters Pregnancy overview Most physiological systems change Basal metabolic rate Cardiac output Blood volume Oxygen utilisation Ventilation Renal tubule reabsorption GFR Changes in maternal physiology Weight gain mother Average foetus Extra-embryonic fluid Uterus Breasts Body fluid Fat accumulation Exaggerated lumbar lordosis Symphysis pubis diastasis & back pain  First trimester symptoms Foetus most at risk for development of abnormalities 80% miscarriages occur in first trimester (affects 10-15% pregnancies) Morning sickness -mostly during first trimester, 5lbs Gastric reflux / heartburn (pyrosis); -progesterone inhibits motilin, leading to decreased gastric emptying -growing foetus displaces stomach increasing gastric pressure Urinary system Increased urination (polyuria) -increased blood volume/flow through the kidney (increased GFR60-70%) -downward pressure of enlarging foetus on the bladder -decreased muscle tone (hypotonia) due to progesterone Cardiovascular System Haematological -blood volume Increased blood volume, 20-100% above pre- pregnancy levels RBC mass increased by 110%, WBC mass increased by 150% Varicose veins and haemorrhoids caused by the placenta inhibiting venous return Growth of uterus in third trimester may compress on vena cava when patient supine -tilt onto left side in dental chair Aorto-Caval Compression  Cardiovascular System Haematological –blood pressure Slight decrease in blood pressure, peaks in second trimester Increased cardiac output (increase in heart rate and stroke volume) Decrease in maternal systemic vascular resistance (vasodilation); involving the renin-angiotensin-aldosterone system and vascular remodelling Recommended reading: Sanghaviand Rutherford Circulation. 2014;130:1003–1008 https://www.ahajournals.org/doi/full/10.1161/circulationaha.114.009029  Respiratory System In the third trimester, respiratory minute volume increases compensating for increased oxygen demand (15%) by the foetus Respiratory mucosa swell in responses to increased blood flow, leading to nasal congestion and nose bleeds  Respiratory System Diaphragm also moves upwards 4-5 cm, decreasing functional residual capacity; feeling of breathlessness Suggested reading: LoMauroA, AlivertiA. Respiratory physiology of pregnancy: Physiology masterclass. Breathe (Sheff). 2015 Dec;11(4):297-301. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818213/ Integumentary system Increased skin elasticity, but if too fast collagen and elastic rupture, leading to stretch marks Increased pigmentation of the skin, due to increased melanocyte stimulating hormone (MSH) during pregnancy; responsible for protection again UV a and appetite -areolar -lineaniagra - line on abdomen -other areas, e.g. face Musculoskeletal system Relaxin, causes ligament laxity and softening of connective tissue throughout the body, including pelvic floor, ligaments supporting hips Changes in weight and realignment of spinal curvature posture affect way of walking (waddle), back pain not uncommon Immune system Considerable immunological adaptation occurs during pregnancy Some parts of immune system are enhanced while others are suppressed; maybe time dependent - immunological clock. Higher risk of sepsis during pregnancy; increased 12% Placenta also forms an immunological barrier between the mother and the foetus, so the foetus is not rejected as foreign; immune tolerance https://doi.org/10.3389/fimmu.2020.575197 Pregnancy complication -pre-eclampsia Affects pregnant women during second trimester up to 6 weeks after delivery, but exact cause unknown High blood pressure (>140/90mmHg) and protein in the urine, with retracted blood flow to the placenta Risk factors include obesity, maternal age, family history Symptoms headaches, blurred vision, oedema (swelling to hands, face and feet) and pain below the ribs. Careful monitoring required, sometimes admission to hospital for early delivery Left undiagnosed and untreated, poor outcomes for mother and or foetus -eclampticfits (seizures), organ failure, stroke, stillbirth and death (2ndleading cause) Labour Foetus descends into pelvic cavity Cervix dilates, effacement (softening, thinning) False labour, practice contraction e.g. Braxton Hicks Labour -Cervical dilation -up to 10 cm required -Bloody show; blood coloured mucous plug lost -Waters breaking, due to rupture of the amnion and loss of amniotic fluids -Contraction and increasingly shorter intervals Lactation Mostly associated with mammals Changes in the breast tissue first initiated by hormones, including oestrogen and progesterone Milk production then involves prolactin and oxytocin Oxytocin release by suckling -bonding and pleasure Changes to the oral cavity during pregnancy Changes within individual dental tissues Teeth Oral mucosa Salivary tissues Others  Gum hypertrophy  Incidence gingivitis  Tissue perfusion  risk of bleeding Recommended reading, including dental management (useful if you see a pregnant patient): Naseemet al, 2016 https://www.sciencedirect.com/science/article/pii/S2352003515000404  Oral soft tissues and pregnancy -gingivitis Sore gums common during pregnancy Gingivitis is the host immune response to plaque Immune response exaggerated during pregnancy; pregnancy induced gingivitis -common Pregnancy granulomas further tissue proliferation due to increased oestrogen and progesterone in combination with bacteria stimulating a host responses, possible role of decrease Vit C Erythematous, smooth and lobulated Located on the gingiva Grow rapidly Treat via improved oral hygiene Do not remove as will return Recede after delivery Salivary glands and pregnancy Branching or tubular-acinar glands occurs similar to that in the breasts, in response to oestrogen Early in pregnancy increased salivation, also associated with nausea As pregnancy progresses hormonal changes in oestrogen cause saliva production to decrease Xerostomia can contribute to dental caries and halitosis Oral hard tissues and pregnancy At increased risk of caries due to changes in behaviours, such as eating habits(cravings) At increased risk of dental erosion due to vomiting A mothers teeth are already formed, a baby cannot ‘take calcium from teeth’, even if maternal calcium levels were low Slight reduction in salivary flow, slight increase in salivary acidity, and decrease in salivary bicarbonate (reduced buffering captivity of saliva) but not correlated with increased caries Oral disease and pregnancy outcomes Complex bi-directional relationship between oral and systemic conditions, including pregnancy complications Periodontitis associated with adverse effects on the foetus Inflammatory markers (i.e. IL-6,IL-8and PGE2) found in the amniotic fluid of child bearing women with periodontal disease (Naseem et al., 2016) High levels of progesterone and oestrogen during pregnancy may temporarily loosen tissue leading to increased tooth mobility, but usually only clinical symptoms if existing periodontal disease Increased cariogenic bacteria (dental caries) in the mother associated with increased dental caries in the infant (Xio et al., 2019) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6554051/ But cariogenic bacteria not associated with adverse pregnancy outcomes (Cho et al., 2020) https://www.nature.com/articles/s41598-020-62306-2 Ide, M. & Linden, G. J. (2014) Periodontitis, cardiovascular disease and pregnancy outcome – focal infection revisited? BDJ, 217, 467-474. Díaz-Guzmán LM, Castellanos-Suárez JI. Lesions of the oral mucosa and periodontal disease behavior in pregnant patients. Med Oral Patol Oral Cir Bucal 2004; 9: 430–437. Oral disease and pre-clampsia (research led) Read this paper, answer these questions https://journals.sagepub.com/doi/full/10.1177/2380084417731097 What is the estimated increase in risk for pre-eclampsia if the mother has periodontal disease? ………………………………………………………………………………………………………………….. What two outcomes is a baby at risk of if the mother has periodontal disease? ……………………………………………………………………………………………………………………. THINK! What you know about periodontal disease and oral hygiene interventions. Why do you think the pregnancy outcomes don’t always improve with interventions to improve oral hygiene during pregnancy? ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… ………………………………………………………………………………………………………………………… Summary –pregnancy systems changes Required reading –use the reading list/E books Essential physiology for dental students Ali K. https://ebookcentral.proquest.com/lib/plymouth/reader.action?docID=5612956 Pg 186-189 Physiology at a Glance Jeremy P. T. Ward and Roger W. A. Linden https://ebookcentral.proquest.com/lib/plymouth/detail.action?docID=4816495 Chap 7 Endocrinology and reproduction Pg 122-125 Basic reading, to include fertilization, parturition and lactation, not covered in detail here Scully's Handbook of Medical Problems in Dentistry Scully C. https://ebookcentral.proquest.com/lib/plymouth/detail.action?docID=5184636 Chap 4 Age and gender; pregnancy Pg 54-61 Basic reading, to include pregnancy complications and dental implications not covered in detail here Learning objectives By the end of this session, you should be able to: Describe the physiological changes to the body during pregnancy Describe the changes to the oral cavity during pregnancy Introduce the possibility that common oral diseases may impact on outcomes from pregnancy This teaching session refers mainly to maternal health, embryonic development covered in your embryology sessions