Anatomy and Physiology of Pregnancy Lecture Iryna Kuziv, MD, PhD Pregnancy is a normal physiologic process . . . . . . not a disease!

Probable signs of pregnancy (observed by examiner): Bluish or purplish coloration of the vaginal mucosa and cervix (Chadwick’s sign-a dark blue to purplish-red congested appearance of the vaginal mucosa ) Palpation of Braxton-Hicks contractions Outlining the fetus manually Endocrine tests of pregnancy

Positive signs of pregnancy (noted by examiner, confirm pregnancy) Identification of the fetal heart beat separately and distinctly from that of the mother (10-12 w) Perception of fetal movements by the examiner (18-20 w) Visualization of pregnancy on ultrasound Fetal recognition on X-ray

Uterus Non Pregnant Uterus Pregnant Uterus Muscular Structure Almost Solid Relatively thin – walled (≤ 1.5 cm) Weight ≈ 70 gm Approx. 1100 gm by the end of pregnancy Volume ≤ 10 ml ≈ 5 L by the end of pregnancy

Mechanism Of Uterine Enlargement Stretching & marked hypertrophy of muscle cells. Considerable increase in elastic tissue Accumulation of fibrous tissue, particularly in the external muscle layer.

Uterine size, shape & position First few weeks, original peer shaped organ As pregnancy advances, corpus & fundus assumes a more globular form. By 12 weeks, the uterus becomes almost spherical . Subsequently, uterus increases rapidly in length than in width & assumes an ovoid shape. With ascent of uterus from pelvis, it usually undergoes Dextrorotation (caused by the rectosigmoid colon on the left side)

Breast changes

Breast Breast: tenderness, fullness, tingling enlargement, nipple and areola hyperpigmentation, Montgomery’s tubercles, colostrum (16 w)

Integumentary System Darcening of nipples, areola, axillae, vulva Facial melasma=chloasma Linea Nigra Striae gravidarum Palmar erythema (Caucasian, African-American)

Stria gravidarum

Butterfly pigmentation

Pigmentation: It is due to suprarenal changes, it usually begins to appear after the 4th month. The pigmentation may appear anywhere but the commonest sites are: 1. Linea nigra: which is a line of pigmentation between the umbilicus and the symphysis pubis. 2. Increased pigmentation of the nipple as primary areola and appearance of the secondary areola.

Vascular Vascular spider Minute, red elevations on the skin common on the face, neck, upper chest, and arms, with radicles branching out from a central lesion. The condition is often designated as nevus, angioma, or telangiectasia. Palmar erythema . The two conditions are of no clinical significance and disappear in most women shortly after pregnancy (estrogen)

Musculoskeletal System Change in posture Waddling walk Back Pain Slight relaxation and increased mobility of the pelvic joints Diastasis recti abdominis

Uterine Sizing Uterine enlargement 12 weeks – At Symphysis 16 weeks – Midway between symphysis and umbilicus 20 weeks – At the umbilicus 36 weeks - Near xyphoid process

Uterine Sizing

Accuracy of Dating by Ultrasound Gestational Age weeks) Ultrasound Measurements Range of Accuracy < 8 Sac size + 10 days 8-12 CRL + 7 days 12-15 CRL, BPD + 14 days 15-20 BPD, HC, FL, AC 20-28 + 2 weeks > 28 + 3 weeks

Medical/Surgical History Serious illnesses Hospitalizations Surgery Drug allergies or unusual reactions Meds since LMP

Family History Maternal Maternal or Paternal Diabetes CAD Pre-eclampsia Preterm delivery Cancers (breast, ovarian, colon) Depression, bipolarity Twins Anesthesia reactions Maternal or Paternal Birth defects Mental retardation Bleeding disorders Chromosomal abnormalities (e.g. Down Syndrome)

Vital Signs Elevated BP suggests the presence of preeclampsia. Elevated BP may be defined as a persistently greater than 140 systolic or 90 diastolic. Usually, if one is elevated, both are elevated. Elevated temperature suggests the possible presence of infection. Many pregnant women normally have oral temperatures of as much as 99+. These mild elevations can also be an early sign of infection. While a pregnant pulse of up to 100 BPM or greater may be normal, rapid pulse may also indicate hypovolemia. Temperature Blood pressure Respirations Radial pulse

Additional Measurements Height Weight BMI (Body mass index ) BMI Categories: Underweight = <18.5 Normal weight = 18.5-24.9 Overweight = 25-29.9 Obesity = BMI of 30 or greater

Bones and Joints of the Pelvis

The Diagonal Conjugate The obstetric conjugate extends from the middle of the sacral promontory to the posterior superior margin of the pubic symphysis. This is the most important diameter of the pelvic inlet. The diagonal conjugate extends from the subpubic angle to the middle of the sacral promontory and can be measured clinically to estimate the obstetric conjugate.

The Ischial Spines The transverse diameter, between the ischial spines, is a measurement of the dimensions of the pelvic cavity

The Pelvic Outlet Subpubic arch Bituberous (transverse) diameter Inferior pubic rami

The First Prenatal Visit: Counseling What to expect during the course of prenatal care Risk factors encountered Nutrition Exercise Work Sexual activity Travel, seat belts Smoking cessation Avoidance of drugs and alcohol Warning signs Where to go or call in case of problems Prenatal vitamins

Leopold's Maneuvers - are used to determine the orientation of the fetus through abdominal palpation. 1. Using two hands and compressing the maternal abdomen, a sense of fetal direction is obtained (vertical or transverse). .

2. The sides of the uterus are palpated to determine the position of the fetal back and small parts.

3. The presenting part (head or butt) is palpated above the symphysis and degree of engagement determined

4. The fetal occipital prominence is determined.

Measuring Fundal Height

Auscultating Fetal Heart Tones