Physiological Changes in Pregnancy😍

Physiological Changes in Pregnancy

• Pregnancy : Progesterone dependent condition.
• ↑E & ↑P (In pregnancy) ↓FSH, ↓LH.
• Suspension of ovulation.
• Responsible for maintenance of pregnancy.
• Decidualization of endometrium.
• ↓PVR → Smooth muscle relaxation.
• Prevents preterm labor.

Estrogen dependent changes in pregnancy :

1. Skin changes : Chloasma.

2. Salt & water retention (↑Blood volume).

3. Obstetric cholestasis.

4. ↑ TBG (Thyroid binding globulin).

For onset of labor

1. Estrogen level ↑↑

2. Oxytocin receptors ↑↑ (Not level)

3. Functional withdrawal of progesterone.

Leg cramps for a pregnant woman

• Extend knee and dorsiflex foot → Relieves

Melasma

• Melasma → Most common pigmentary disorder → photoexposed areas → Sun exposure, Pregnancy (chloasma), OCP use, Hypothyroidism → Always hyperpigmented macules → Sunscreen is a must → Topical depigmenting agents → Triple combination cream (Hydroquinone (depigmenting),Tretinoin (exfoliating),Mild steroid )→ Kligman's formula → Oral Tranexamic acid → Q-switched Nd:YAG

• Classical predisposing factors:
• Sun exposure.
• Pregnancy (chloasma).
• OCP use.
• Hypothyroidism.

• ESTROGEN

• Most common pigmentary disorder.

• Typically in photoexposed areas.

Pathogenesis:

• Melanocytes become 
• hyperactive
• larger
• more dendritic
• produce more melanin

Presentation

• Always hyperpigmented macules.

• Asymptomatic.

Types (based on site):

• Centrofacial.

• Malar.

• Mandibular.

Types (based on depth of pigmentation):

Types	Appearance
Epidermal melasma	Mainly epidermal.
Dermal melasma	Mainly dermal, appears bluish.
Mixed melasma	Both epidermal and dermal.

Diagnosis/Differentiation:

• Wood's lamp.

Treatment:

• Sunscreen is a must

• Topical depigmenting agents:
• Hydroquinone.
• Kojic acid.
• Arbutin.
• Glycolic acid.

• Triple combination cream:
• Kligman's formula.
• Combines:
• Hydroquinone (depigmenting).
• Tretinoin (exfoliating).
• Mild steroid (hydrocortisone, for inflammation).

Oral treatment:

• Tranexamic acid (also topical).

Peels:

• Glycolic acid, lactic acid, others.

Lasers:

• Mostly Q-switched Nd:YAG or other pigmentary lasers.

Pyogenic Granuloma

• Misnomer: 
• Not associated with pus/bacteria (pyogenic); 
• does not show granulomas.

• Other Names:
• Granuloma Gravidarum (partially correct, seen in pregnancy); 
• Pregnancy Tumor (most accurate).

• Clinical: Seen in pregnant ladies (reddish lesion).
• Oral cavity or fingertips.

• Microscopy: Known as Lobular Capillary Hemangioma (LCH).
• Tiny capillaries arranged in lobules/groups.

Hematological Changes in Pregnancy

Parameters ↑

1. Blood volume 
• D/t estrogen & aldosterone

2. Plasma volume (40%).
• d/t estrogen
• Estrogen ↑ → RAAS ↑ → ↑ Aldosterone

3. RBC volume (20%).

4. Hb mass

5. Reticulocyte count.

6. Plasma protein mass (g).

7. Globulin ↑↑
• ↑ TBG, sex hormone binding globulin
• Total T3, T4 ↑↑
• FT3, FT4 same

8. Clotting factors (Excluding 11 & 13).

9. WBC count (15,000 - 25,000) : Mostly neutrophils.

10. Hyperinsulinemia
• d/t HPL
• Cause: Insulin Resistance
• Fasting Hypoglycemia
• Postprandial Hyperglycemia
• Fetal growth
• D/t Fetal Insulin / IGF
• Not d/t Maternal Insulin / GH
• Insulin do not cross Placenta
• Normal Newborn
• Fetal Hyperglycemia
• Stimulates Insulin → Fetal growth
• In Newborn of Diabetic mother
• Maternal hyperglycemia → ↑↑↑ Fetal insulin → Macrosomia
• Fetal Hypoglycemia

Parameters ↓

1. Hematocrit/PCV : D/t hemodilution.

2. Hb concentration (g/dL).

3. Plasma protein concentration (g/dL).

4. Albumin.

5. A : G ratio = 1 : 1.
1. (normal: 1.7:1)

6. Factor 11, 13.

7. Fibrinolytic activity.

8. Protein C & S.

9. Antithrombin.

10. Platelet count : Benign gestational thrombocytopenia.

11. Eosinophils.

Parameters Unchanged

1. Bleeding time.

2. Clotting time.

3. APTT.

4. FT3, FT4 same

Note :

1. Size of spleen : ↑ by 50%.

2. Size of pituitary : ↑ by 125-135% (Anterior > Posterior).

3. BMR : ↑ by 10-20%.

↑ESR in pregnancy

• D/t fibrinogen

Renal and Respiratory Changes in Pregnancy

Renal Changes in Pregnancy

• Size of kidney: Increases by 1 cm

• Renal blood flow: Increases

• GFR: Increases

• Serum urea: Decreases

• Serum uric acid: Decreases

• Serum creatinine: Decreases

Asymptomatic Bacteriuria (ASB)

• Presence of ≥10^5/mL in urine without any UTI symptoms

• m/c organism: E.coli

• Urine R/M (+ culture if risk factors present) to be done in every trimester to monitor ASB

Diagnosis:

• clean catch urine:
• No. of samples required: 2 consecutive
• Minimum CFU/mL: ≥10^5 of same bacteria species

• Catheterized urine:
• No. of samples required: single
• Minimum CFU/mL: 100

• Suprapubic aspirate:
• Minimum CFU/mL: any growth of microorganisms in culture

• CFU: Colony forming units

• Risk factors: Sickle cell anemia, diabetes

• Complications: Pyelonephritis > Preterm labour ??

• Rx: Nitrofurantoin

Respiratory Changes

• Transverse diameter of chest: Increases by 2 cm

• Diaphragm pushed: Increases by 4 cm

• Chest circumference: Increases by 6 cm

Unchanged parameters:

• IRV: Inspiratory Reserve Volume

• RR: Respiratory Rate

• VC: Vital Capacity

• COMPLIANCE

• Mnemonic: IRV

Thyroid Physiological Changes

• Thyroid gland increases

• Goitre is pathological

Thyroid profile:

• Thyroid binding globulin ↑↑

• Total T3, T4 increases
• hCG similar to α subunit of TSH stimulates thyroid gland
• So in first trimester → TSH will be low
• Rest of pregnancy → TSH normal range is 0.1-2.5 mu/L

• Free T3, T4 are normal

Thyroid Disorders

• Hyperthyroidism
• m/c cause: Graves disease
• Overall DOC: Propylthiouracil (PTU)
• DOC in 1st trimester: PTU
• DOC in 2nd and 3rd trimester:
• Methimazole
• Carbimazole
• Caution with Methimazole/Carbimazole in 1st trimester due to risk of aplasia cutis

• Hypothyroidism
• m/c cause: Hashimoto's thyroiditis
• If hypothyroid patient conceives: increase dose of thyroxine

• Thyroid storm DOC:
• PTU
• Propranolol for symptomatic management

• Note:
• Iodine requirement in pregnancy: 250 mcg/day
• In pregnancy, size of pituitary gland increases by 125%, spleen by 50%

Cardiovascular Changes & Heart Disease in Pregnancy

Normal Findings in Pregnancy :

• Heart sounds :
• S1 : Loud & prominent splitting.
• S2 : Normal.
• S3 : Easily heard.

• Murmurs :
• Ejection Systolic Murmur (ESM) <3/6 grade.
• Continuous murmur (Mammary murmur)
• NOT PANSYSTOLIC MURMUR

• Chest X-ray : 
• Mild apparent cardiomegaly (d/t diaphragm pushing the heart up and out)

• ECG : 
• Left axis deviation
• VPC
• APC
• Mild ST T changes in Inferior Leads

• All pressures except femoral pressure decreases

• Progesterone > Estrogen
• Make blood vessels resistant to Vasopressors
• Progesterone → Smooth muscle relaxant

Remain constant

1. JVP

2. LVEF

Note : Symptoms normal in pregnancy

1. Dyspnea on exertion.

2. Easy fatiguability.

3. ↓ Exercise tolerance.

4. Peripheral dependent edema.

HEART DISEASE IN PREGNANCY

• M/c heart disease in pregnancy : Mitral stenosis.

• M/c CHD in pregnancy : ASD.

• Heart disease with maximum maternal mortality : Eisenmenger syndrome.

Indicators of Heart Disease in Pregnancy :

• ↑JVP.

• S2 : Loud + prominent splitting.

• S4.

• Chest X-ray : Marked cardiomegaly.

• Murmurs :
• ESM ≥3/6 grade.
• Diastolic murmur (Normally found in 20%).

• Symptoms : Chest pain, hemoptysis, PND, orthopnea.

• Signs : Clubbing, cyanosis.

Supine Hypovolemia Syndrome:

• Gravid uterus leads to decreased venous return → decreased cardiac output, decreased BP, and fetal distress.

• Management: Lie on left lateral position.

Cardiac Output in Pregnancy

• Starts to increase at 5 weeks.

• Maximum CO : 28-32 weeks.

Maximum chance of heart failure : 

• Immediate postpartum >

• 2nd stage of labor >

• Late 1st stage of labor >

• 28-32 wks.

• Normalizes within 10 days post delivery.

Management :

• Mandatory pain relief.

• Restrict IV fluid : 75 mL/hour.

• Semi-recumbent position.

• AMTSL :
• Inj. oxytocin used.
• C/I : Inj. methyl ergometrine 
• D/t tetanic uterine contractions → Blood re enters circulation from uterus → Precipitates heart failure
• Twin, cardiac d/s, Rh
• Mnemonic: Methyl kidathath are? → Rich people, tension people, cardiac patients, twins ne

• Vaginal Delivery :
• Preferred mode of delivery.
• Induction of labor : Not C/I.
• Prophylactic use of forceps > Vacuum :
• Shortens 2nd stage of labor.

• Indications for C-section :
1. Patient on warfarin.
2. Aortic lesions :
1. ↑Risk of aortic dissection with vaginal delivery.
• Aortic aneurysm.
• Aortic regurgitation.
• In Marfan’s syndrome with aortic involvement
• Coarctation of aorta.
• No aortic stenosis → MTP

Prognosis :

• Overall better prognosis : Congenital > Acquired heart disease.

Mitral Stenosis in Pregnancy

• 1st symptom : Exertional dyspnea.

Management of Symptomatic Patients :

• Conservative
• Limit physical exercise.
• ↓ Salt intake.
• β antagonist : ↓HR.

• Surgical
• Balloon mitral valvotomy (Best done in T2).
• Note : Valve replacement is C/I in pregnancy.

C/I for Pregnancy :

• WHO Class IV Pregnancy (Indications for MTP in heart disease) :
1. Pulmonary HTN : 1˚, 2˚(Eisenmenger).
2. Severe MS.
3. Severe AS.
4. LVEF <35%.
5. Marfan syndrome with aortic involvement.
6. Coarctation of aorta.
7. NYHA Class 3/4.
8. Residual defects
1. Peripartum cardiomyopathy.
2. Fontan surgery (Left hypoplastic heart).

PERIPARTUM CARDIOMYOPATHY

• Criteria :
• No prior heart disease.
• Heart failure anytime b/w last month of pregnancy up to 5 months after delivery.

• Risk Factors :
• ↑Age.
• Multifetal pregnancy.
• Pre-eclampsia.
• Some role for prolactin

• Management : Heart failure Mx + Bromocriptine

• Echocardiography (IOC) :
• ↓ LVEF : Diagnostic criteria
• <45%
• Dilatation of Lt. ventricle.
• No diastolic failure
• Left ventricular end diastolic dimension > 2.7 cm/m2

Anticoagulants in Pregnancy

• For bioprosthetic valves : Aspirin.

• For mechanical valves : Anticoagulant + Aspirin.

DOC per POG:

Warfarin in Pregnancy

• Only indication : 
• Mechanical valve replacement.

• Teratogenicity
• T1 : Chondrodysplasia in fetus.
• T3 : Intracranial hemorrhage in newborn.

Note

• Only indication for UFH →
• To temporarily bridge LMWH/ warfarin

• Previous h/o DVT and in all other cases
• DOC ► LMWH (Enoxaparin/Dalteparin).

Warfarin → Fetal Warfarin Syndrome

• Disala syndrome
• Chondrodysplasia
• Stippled epiphysis
• Nasal hypoplasia
• CNS: Corpus callosum agenesis, microcephaly
• Cataract

• Mnemonic: War (Warfarin) nu poya Michel (Microcephaly) and salar (Disala Syndrome) nu idi kitti mookilum (Nasal hypoplasia) bone (Stipled epiphysis) ilum cartilage (Chondrodysplasia) ilum and killed his cat (Cataract)