Maternal Changes with Pregnancy Pregnancy is a period of adaptation for : • The needs of the fetus • Meeting the stress of pregnancy and labour THE GE NI T AL CHANGES (A) The whole uterus Size - 1 increase from 7.5 x 5 x 2.5 cm in nonpregnant states to 35 x 25 x 20 cm at term i.e. the volume increase 1000 time Weight - 2 increases from 50 gm in nonpregnant state to 1000 gm at term Shape -3 pyriform in the nonpregnant state , becomes globular at 8th week , then pyriform by 16th week till term . Position - 4 with ascent from the pelvis , the uterus usually undergoes rotation with tilting to the right (dextrorotation) due to the presence of the rectosegmoid colon on the left side. 5 - Consistency : becomes progressively softer due to : i - Increased vascularity ii - Presence of amniotic fluid Contractility -6 from the first trimester onwards , the uterus undergoes irregular painless contractions (Braxton Hicks contractions) . They may cause some discomfort late in pregnancy and may account for false labour pain . 7- Capacity increases from 4 ml in non-pregnant state to 4000 ml at term (B) Myometrial changes 1 - Hypertrophy (estrogen effect) rather than hyperplasia (progesterone effect) till 14th week, then the fetus exerts a direct stretch 2 - Formation of the lower uterine segment (L.U.S.) from the isthmus and lower half inch of the body Formation of lower uterine segment After 12 weeks, the isthmus (0.5cm) starts to expand gradually to form the lower uterine segment which measures 10 cm in length at term Upper Uterine Segment • Peritoneum: Firmly-attached • Myometrium: 3 layers; outer longitudinal, middle oblique and inner circular. • The middle layer forms 8-shaped fibers around the blood vessels to control postpartum hemorrhage Upper Uterine Segment • Decidua: Well-developed • Membranes: Firmly-attached • Activity: Active, contracts, retracts and becomes thicker during labour. Lower Uterine Segment • Peritoneum: Loosely- attached • Myometrium : 2 layers; outer longitudinal and inner circular. Lower Uterine Segment • Decidua: Poorly-developed • Membranes: Loosely- attached. • Activity: Passive, dilates, stretches and becomes thinner during labour The junction between the upper uterine segment (U.U.S.) which is thick and the lower uterine segment which is thin is called the physiologic contraction ring at the level of the symphysis pubis (not seen or felt) (C) Uterine blood vessels 1 - Uterine artery lumen: is doubled and its blood flow increases 5 times 2 - Myometrial and decidual arteries (spiral arteries) undergo fibrinoid degeneration due to 2 waves of trophoblastic migration , so they become dilated to be the uteroplacental arteries • Uterine blood flow increases progressively and reaches about 500 ml / minute at term (D) Changes in the cervix : 1 - It becomes hypertrophied , soft and bluish in colour due to oedema and increased vascularity. 2 - Soon after conception , a thick cervical secretion obstructs the cervical canal forming a mucous plug . 3 - The endocervical epithelium proliferates and or everted forming cervical ectopy (previously called erosion) (E) Changes in fallopian tubes and ligaments (round and broad): Inactive , elongated , marked increase in vascularity There may be broad ligament varicose veins (F) Changes in the vagina : The vagina becomes soft , warm , moist with increased secretion and violet in colour (Chadwick's sign) due to increased vascularity (G) Changes in the vulva : • It becomes soft, violet in colour • Oedema and varicosities may develop (H) Changes in the ovaries 1 - Both ovaries are enlarged due to increased vascularity and oedema particularly the ovary which conatins the corpus luteum . (H) Changes in the ovaries 2 - Corpus luteum continues to grow till 7 - 8 weeks , then it stops growing , It becomes inactive and starts degeneration at 12 weeks (degeneration is completed after labour) Corpus luteum secretes 1.estrogen , 2.progesterone, 3.relaxin hormones (H) Changes in the ovaries 3 - Ovulation ceases during pregnancy due to pituitary inhibition by the high levels of oestrogen and progesterone • Relaxin is a protein hormone. • Its exact role in pregnancy is unknown. • It may induce softness and effacement of the cervix. II - Haematological Changes (A) Blood volume The total blood volume increases steadily from early pregnancy to reach a maximum of 35-45 % above the non-pregnant level at 32 week . - Plasma volume : Increases from 2600 ml by ± 45 % (1250 in the 1st pregnancy) and 1500 ml in subsequent pregnancies - Red blood cell mass : • Increases from 1400 ml (nonpregnant) by 33 % (± 450 ml) due to increased production resulting from erythropoeitin or action of hCG or HPL . • The increase is steady till full term. The increase in plasma volume is more than the increase in red blood cell mass (Hb mass) resulting in haemodilution (physiologic anemia) However, the minimal Hb. accepted is 10-11 gm% Values of increased blood volume 1 - Meets increased demands for uterus , baby .... etc . 2 - Protects against supine hypotension syndrome . 3 - Protects against fluid loss in labour . Increased blood volume more than the increase in red cell mass , leads to decreased blood viscosity which leads to decrease in peripheral resistance (B) Blood indices 1 - Decreased Hb % and RBCs % : • Erythrocytes decrease from 4.5 million / mm3 to 3.7 million / mm3 (due to the relative increase in plasma volume more than red cell mass) . Erythrocytes contents from 2,3- DPG increases which competes for 02 binding sites in the Hb molecule , thus releasing more 02 to the fetus . Hb concentrations falls from 14 gm / dl To 12 gm / dl. 2 - M.C.H.C : no change 3 - M.C.V. : , or no change (depending on the availability of Fe). 4- Fragility of R.B.Cs: . 5 - Reticulocytes : mild 6 - E.S.R : from 12 to 50 mm / hour 7 – Fibrinogen: from 200 - 400 mg / dl to 400 - 600 mg / dl. 8 - White blood cells: (from 7.000 / mm3 to 10.500 / mm3 during pregnancy and up to 16.000 / mm3 during labour : - PNL & its enzymes . - Lymphocytes : no change . 9 - Platelets: or 10-Total plasma proteins : slightly (mainly albumin) resulting in osmotic pressure. (C) Coagulation system • Platelets or . (controversial). • Fibrinogen doubled to 600 mg % • Factor VIII tripled . • Factor VII & factor X are doubled • Factor XI & factor XIII slight • Fibrinolytic activity . • Therefore pregnancy is a hypercoagulative state . • All these changes are reversed after labour with RBCs production (not destruction)& the excess Fe is stored . Ill - Cardiovascular system changes (A) Changes in the 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. Pulse rate : - The resting pulse rate increases by 8 beats / min. (8 weeks) and 16 beats / min. (full term). -Some episodes of ectopic beats - Water hummer pulse . Heart sounds • The first heart sound become louder before midpregnancy and splitting of this sound may occur due to earlier closer of the mitral than the tricuspid valve • The intensity of the second heart sound may increase. Heart sounds • The third sound becomes louder before mid-pregnancy and persists as such till one week post partum. • The fourth sound may be detectable by phonocardiography. Murmurs Systolic functional murmurs develop in most of women, usually early systolic, but mid systolic murmurs may occur and heard over the left sternal edge, they are thought to be due to functional tricuspid regurgitation ECG CHANGES • The main features of ECG may be attributed to the changes in the position of the heart. • The axis undergoes left shift by 15 - 28°. • The QRS complexes become of low voltage, and T wave becomes flattened. (B) Haemodynamic changes 1 - Cardiac output (C.O.P.) Cardiac output: increases mainly by increased stroke volume rather than increased heart rate reaching a maximum of 40% above the non-pregnant level at 20 weeks to be maintained till term. Cardiac output Distribution : • 400 ml to the uterus , • 300 ml to the kidneys , • 300 ml to skin , • 300 ml to GIT , breast & heart • Values : Distributes extra 02 • During labour : C.O.P. increases more particularly during the second stage due to pain , uterine contractions , and expulsive efforts pushing the blood into the general circulation • Postpartum : the increased C.O.P. is maintained for up to 4 days and then declines rapidly 2 - Arterial blood pressure Although C.O.P. incease , yet A.B.P. is decreased in midtrimester to increase again in 3rd trimester This is due to: i - Decreased Peripheral resistance : (mainly affect diastolic B.P.) due to : vasodilatation + increase metabolism + arteriovenous shunt at placenta . ii - Supine hypotension : may develop in some women in late pregnancy while lying supine due to compression on the I.V.C. by the large pregnant uterus , resulting in decreased venous return C.O.P. and low B.P. to the extent that fainting may occur iii - Decreased sensitivity of blood vessels to angiotensin II which is vasoconstrictor Vena Cava Syndrome • The posture of the pregnant woman affects arterial blood pressure. • Typically, it is highest when she is sitting, lowest when lying in the lateral recumbent position and intermediate when supine. Peripheral Vasodilatation Peripheral Vasodilatation blood flow to the skin, particularly in the hands and feet generally giving the pregnant women a feeling of warmth Peripheral Vasodilatation Increases the congestion of nasal mucosa leading to a common complaint of nasal obstruction and bleeding (epistaxis). 3 - Venous pressure Increased venous pressure in the lower limbs due to : 1. Back pressure from the compressed I.V.C. by the pregnant uterus . 2.Mechanical pressure of the uterus on pelvic veins . 3.Increased venous return from internal iliac veins --> increase pressure in external iliac veins . Increased venous pressure in the lower limbs Predisposes to : Oedema , varicose veins and piles Oedema and varicose veins in the lower limbs & vulva are due to i - Venous pressure . ii - Relaxation of the smooth muscles in the wall of the veins by progesterone iii - Osmotic pressure in blood . iv - Capillary permeability (due to progesterone and aldosterone). v - Interstitial pressure (Na retention). Varicose Veins treatments 1. avoid long periods of standing and encourage active exercise. 2. avoid constricting clothes. 3. keep the legs elevated while sitting and during sleep. 4. use of elastic stockings. These should be removed at night and applied with leg elevated before getting out of bed in the morning (empty veins). 5. stretch panties may be necessary for vulval varicosities. IV - Respiratory system (A) Anatomically: The enlarged uterus displaces the diaphragm up to ± 4 cm . This result in : 1. The diaphragmatic mobility is reduced and respiration becomes mainly thoracic . 2. Widen the subcostal angle and increases the transverse diameter of the chest. Respiratory functions The respiratory rate does not increase during pregnancy from its normal rate of 14 - 15 / minute. Overbreathing (deep respiration) occurs due to the effect of excess progesterone Shortness of breath (the need to breath becomes a conscious one) and dyspnea are common complaint of the pregnant women which may be due to unfamiliarity with low C02 tension in the alveolar capillaries. The vital capacity 1.The inspiratory capacity (Tidal volume + inspiratory volume) is decreased in late pregnancy 2.The expiratory reserve volume (maximum amount of air which can be expired after normal expiration) is reduced 3.The residual volume is reduced . The reduction in: 1.The inspiratory capacity 2.The expiratory reserve volume 3.The residual volume is not significant . 4.The tidal volume : (amount of gas inspired or expired in each respiration) rises throughout pregnancy by about 40 % . Hyperventilation is due to increased tidal volume not respiratory rate V - Urinary system (A) Kidney and kidney function tests • Renal blood flow and glomerular filtration rate increases by 50 % . This leads to increased excretion • Therefore: 1. There is serum creatinine (due to creatinine cleareance) ,the same for uric acid. 2. blood urea . 3. kidney excretion of glucose due to filtration load and renal threshold leading to renal glucosuria Therefore , in interpretating the results of kidney function test you should take into consideration that the highest normal values in pregnancy = the lowest normal values in non- pregnant state (B) Ureters Dilatation of the ureters and renal pelvis due to : i - Relaxation of the ureters by the effect of progesterone . ii - Pressure against the pelvic brim by the uterus particularly on the right side due to dextroposed uterus and dilatation of the right ovarian vessels (C) Bladder and urethra • Frequency of micturition in early pregnancy due to : i - Pressure on the bladder by the enlarged uterus . ii - Congestion of the bladder muscosa . • Urinary stress incontinence may develop for the first time during pregnancy (due to decreased intraurethral pressure and decreased length of the urethra) and spontaneously relieved later on VI - Gastrointestinal tract & liver 1 - Gingivitis : There is increased vascularity and tendency for bleeding as well as hypertrophy of the interdental papillae • The gums may become hyperemic and soft and may bleed when mildly traumatized, as with a tooth brush. • Epulis of pregnancy may develop. Treated by dental hygiene and cryosurgery for severe cases. cases 2 - Ptyalism: • It is excessive salivation which is more common in association with oral sepsis . • It is due to failure to swallow saliva and not due to increase in amount. • Smoking is stopped and anticholinergic drugs may help. 3 - Nausea and vomiting Nausea (morning sickness) and vomiting (emesis gravidarum) occur in early months 4 - Appetite changes (longing or craving) • The pregnant woman dislikes some foods and odours while desires others • Reduced sensitivity of the taste buds during pregnancy creates the desire for markedly sweet, sour , or salt foods . (pica) Deviation may be so extreme to the extent of eating blackboard chalk , coal or mud 5 - Indigestion and flatulence This is probably due to : i - Decreased gastric acidity caused by regurgitation of alkaline secretion from the intestine to the stomach . ii - Decreased gastric motility (progesterone effect). 6 - Heart burn Due to reflux of acidic gastric contents to the oesophagus The treatment includes : (a) small frequent meals to prevent overdistension of the stomach ,The evening meal should be taken at least 3 hours before going to bed (b) avoid fatty foods, chocolate, and smoking, as these relax the lower esophageal sphincter. (c) the bed should be raised at the head (15-20 cm), and an extra pillow is used. (d) Antacid Preparations containing aluminium hydroxide are favoured. 7 - Constipation due to : i - Reduced motility of large intestine (progesterone effect). ii - Increased water reabsorption from large intestine (aldosterone effect). 7 - Constipation iii - Pressure on the pelvic colon by the pregnant uterus. iv - Sedentary life during pregnancy . It is treated by (a) evacuation of the bowel at the same time each day (bowel training) (b) diet rich in fiber in the form of vegetables, fruits, and bran (c) milk and avoid dehydration by increasing fluid intake. (d) minimize coffee and tea as they are diuretics and cause dehydration. (e) increase physical activity and avoid sedentary life. (f) a mild laxative may be needed. Liquid paraffin is better avoided as it prevents absorption of fat soluble vitamins. In some women iron supplementation may be the cause 8 - Gall stones More tendency to stone formation due to atony and delayed emptying of the gall bladder 9 - Haemorroids due to : i - Mechanical pressure on the pelvic veins. ii - Laxity of the walls of the veins by progesterone iii - Constipation. 10 - Appendix Is displaced upwards and laterally (pain and tenderness due to appendicitis is higher than in nonpregnant state) Appendix Liver i - Decreased albumin and increased globulin resulting in decreased A/G ratio ii - Increased heat labile serum alkaline phosphatase . Therefore both A/G ratio and heat labile alkaline phosphatase are not reliable as liver function tests during pregnancy VII - Metabolic changes (A) Weight gain The average weight gain in pregnancy is 10 - 12 kg The increase occurs mainly in the second and third trimester at a rate of 350 - 400 gm/ week Out of the 11 kg weight gain 6 kg is composed of maternal tissues (breast, fat, blood and uterine tissues), and 5 kg of fetal tissue , placenta and amniotic fluid Maternal Tissues Increases during weeks of Pregnancy 1600 1400 1200 1000 Uterus 800 Mammary Gland 600 Plasma Volume 400 200 0 10 wk 20 wk 30 wk 40 wk King JC. Am J Clin Nutr 71 (5(S));2000. Products of Conception Increases during weeks of Pregnancy 3500 3000 2500 2000 Fetus 1500 Placenta Amniotic Fluid 1000 500 0 10 wk 20 wk 30 wk 40 wk King JC. Am J Clin Nutr 71 (5(S));2000. Out of the 11 kg :weight gain ,kg are water 7 kg fat and 3 kg protein 1 )B) Water metabolism There is tendency to water retention secondary to sodium retention (C) Protein metabolism There is tendency for nitrogen retention (+ ve nitrogen balance) for fetal and maternal tissue formation (D) Carbohydrate metabolism Pregnancy is potentially diabetogenic - Alimentary glucosuria may occur in early pregnancy . - Renal glucosuria may occur in the middle of pregnancy . (E) Fat metabolism There is increase of plasma lipids with tendency to acidosis (HPL action) (F) Mineral metabolism There is increased demand for iron , calcium , phosphate and magnesium VIII - Musculoskeletal changes (a) Increased mobility of pelvic joints due to softening of the joints and ligaments caused by progesterone and relaxin (b) Flattening of feets . (c) Progressive lordosis leading to lordotic gait & backache ( by high heals). (d) Pendulous abdomen in multigravida resulting in many complications Backache • The majority of pregnant women complain of low backache which increases as pregnancy advances. • It is due to increased lumbar lordosis to counter- balance the forward growth of the uterus • This puts strain on ligaments and muscles leading to pain. • Strain of sacroiliac joint is relatively common. • Progesterone causes softening and relaxation of ligaments. Backache is treated by: (a) more periods of rest. (b) use of maternity corset. (c) local heat in the form of hot water bag or infrared lamp (d) analgesics given systemically or as local creams, Paracetamol is the drug of choice, Non-steroidal anti- inflammatory drugs as indomethacin may be given (e) physiotherapy may be needed. Orthopaedic consultation is indicated if pain is severe, or radiates to the legs, and in the presence of neurological signs Leg cramps • These are common in the second half of pregnancy particularly at night. • The exact cause is unknown. It may be related to shift of blood away from the muscle, i.e., ischaemic cramp, or it may be tetanic cramp caused by lack of calcium, or increased phosphorous, or both • Treated by taking calcium tablets, and reducing the intake of phosphorous-containing substances as milk, meat, and cheese. • Vitamin B complex may be tried. • Leg massage and hyperextension of foot help during the attack. Round ligament strain • Pain is felt along the round ligament and in the groin. • Pain unilateral and left-sided, (dextroflexion ). • It is due to stretching of the nerve fibres in the round ligaments. IX - Endocrine system 1 - Anterior pituitary i - Increase in size more than increase in vascularity This renders anterior pituitary liable for ischaemia ii - Pregnancy cell (modified chromophobe) appears due to increased hCG . iii - Prolactin level increases up to 150 ng /ml at term to ensure lactation . 2 - Posterior pituitary Does not hypertrophy , but increase its oxytocin secretion near term 3 - Thyroid gland There is diffuse slight enlargement of the gland Gland activity is as evidenced by normal free T4 (although total T4 ) due to thyroid binding globulin (TBG) , BMR 20 % , total T3 , protein bound iodine and TSH 4 - Parathyroid gland Hypertrophy due to increased demand for Calcium 5 - Suprarenal gland Hypertrophy particularly the cortex resulting in increased glucocorticoids (cortisone) and increased mineralocorticoids (aldosterone) 6 - Insulin increased mainly due to HPL (anti - insulin hormone) 7 -Ovaries corpus luteum of pregnancy functions till 8-12 wks. when its function is taken by the placenta XI - Skin changes 1 - Persistance of basal body temperature (BBT) elevation beyond the expected day of menstruation (due to increased progesterone). 2 - Spider telangiectasis & palmar erythema due to increased estrogen or cutaneous vasodilatation 3 - Cutaneous vasodilatation (hyperaemia) leads to : i - Masks pallor due to anaemia with or without palmar erythema . ii - Glandular activities (sweat & sebaceous glands). iii - Sensation of heat and nasal congestion 4 - Pigmentation due to increased estrogen or melanocyte stimulating hormone or ACTH • In the face = chloasma graviderom = mask of pregnancy a butterfly pigmentation on the cheeks and nose . It usually disappears few months after labour . •In abdomen: Linea Nigra= pigmentation in midline below the umbilicus Linea nigra Stria gravidarum pigmentation in the lower abdomen , flanks , inner thighs , buttocks & breast and increase as pregnancy advances It starts bluish (stria rubra) , then becomes pale to become white (stria albicans) after delivery , which persists (primigravida has stria rubra only ,while multigravida has both S.R and S.A) It It may be due to mechanical stretching or increased glucocorticoids which results in rupture of the elastic fibres in the dermis and exposure of the vascular subcutaneous tissues 5 - Secretions increase in sweat and sebaceous glands activity (B) Breast signs • Diagnostic in primigravida and may persist after delivery . • In multigravida it may be due to the previous pregnancies . • They may occur with any hyperestrogen , so they are not diagnostic for pregnancy i - First month : increased size & vascularity (dilated veins) , mastodynia may be present which ranges from tingling to frank pain due to hormonal responses of the mammary ducts and alveolar system ii - Second month : increased pigmentation of the nipple & areola and prominence of Montgomery tubercles (nonpigmented nodules around the primary areola (12 - 20) Montgomery tubercles They were thought to be enlarged sebaceous glands, but recently they are found to be the lips of orifices of peripheral active lacteal ducts Breast changes iii - Third month : secretion of colostrum (thick yellowish fluid) which can be expressed from the nipple iv - Fourth month : a pigmented area appears around the primary areola called the secondary areola Lower limbs signs i - Edema : bilateral and pitting ii - Varicose veins XII. Neurologic System • Sensory changes from compression of nerves • Tension headaches • Carpal tunnel syndrome due to edema • Numbness and tingling related to postural changes 1. Headache It is relatively common, and attributed to intracranial vasodilatation caused by oestrogen and progesterone 1. Headache • It is most troublesome in the second trimester, but may persist throughout pregnancy. • However, headache may be due to lack of sleep, or overwork. • An analgesic is prescribed. prescribed 2. Fainting It results from lowering of blood pressure due to vasodilatation which occur in pregnancy 3. Insomnia During pregnancy some women are sleepy and depressed, others may be irritable and suffer insomnia 4.Carpal tunnel syndrome Caused by compression of the median nerve as it passes through its fibrous tunnel at the wrist, as a result of fluid retention and oedema in pregnancy There is tingling, numbness and burning sensation affecting the radial side of the hand • Treatment: includes reassurance, use of a wrist splint, diuretics, non steroidal anti-inflammatory drugs, and local injection of hydrocortisone in the tunnel below the fibrous roof (retinaculum) Operation is rarely needed during pregnancy by incising the retinaculum to relieve compression Other compression neuropathies affect the lateral cutaneous nerve of the thigh , obturator and peroneal nerves LEUCORRHOEA The normal vaginal discharge increases during pregnancy because of excess oestrogen and may form a complaint However, a pathological discharge, e.g., monilial infections which is common in pregnancy must be excluded. 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"Maternal Changes with Pregnancy"