Lectures 2/3: Anatomy and Physiology of Pregnancy

Gravida

Person who is pregnant

Gravidity

Pregnancy is called

Nulligradiva

Person who has neve been pregnant

Primigravida

Person who is pregnant for the first time

Multigravida

Person who has had two or more pregnancies

Parity

Number of pregnancies in which fetus (or fetuses) have reached 20 weeks gestation. NOT number of fetuses.

Nullipara

Person who has not completed a pregnancy with fetus(es) beyond 20 weeks gestation

Primipara

Person who has completed one pregnancy with fetus(es) reaching 20 weeks gestation

Multipara

Person who has completed two or more pregnancies with 20+ weeks gestation

20 weeks

Theorectically, what is the age of viability?

Viability

Capacity to live outside the uterus

22-25 weeks

How many weeks gestation is there a higher chance of surviving

Preterm

Pregnancy that has reached 20 weeks of gestation but before 36 weeks

Miscarriage

Pregnancy that has not lasted to 20 weeks

Term

Pregnancy from the beginning of week 37 to the end of 40 weeks plus six days of gestation

Early term

Pregnancy between 37 weeks and 38 weeks +six days

Full term

Pregnancy between 39th week and 40 weeks +six days

Late term

Pregnancy during 41st week of pregnancy

post term

Pregnancy after 42 weeks. Will not see unless someone has had no pretanal care or their dates are wrong.

Gravidity (# of pregnancies)

Term (# of term births, 37 weeks or more)

Preterm (# of preterm births between 20 weeks and 36 weeks+ 6 days)

Abortions (therapeutic or spontaneous)

Living children (# of live births)

What does GTPAL mean:

Human chorionic gonadotrophin (hCG)

Biomedical marker that can be measured in blood and urine.

8-10 days after fertilization.

When does hCG quickly rise?

At about 9-10 weeks gestation, then drops a bit and stays steady for the remainder of the pregnancy.

When does hCG peak?

Early morning urine samples/

What urine samples have the highest amount of hCG?

1. Medications

2. Test is done to early and hCG is too low

3. Not collecting the specimen properly (human erro

What are some reasons for a false negative reading on home pregnacy teset? [3]

Could indicate miscarriage or abnormality in pregnancy gestation (ex: chromosomal abnormality)

What could cause low levels of hCG for gestational age in pregnancy? [2]

1. multiples fetuses

2. Gestational trophoblastic disease (molar pregnancy)

What could high levels of hCG for gestational age in pregnancy?

Gestational trophoblastic disease (or molar pregnancy)

When an egg is fertilized that has no genetic information. It develops into liquid filled sacs and grows very rapidly. hCG levels are high and uterus is very large for gestational age. Considered malignant

Requires chemotherapy. They will do a dilate the cervix, remove products of the condition.

Patients are recommended to not get pregnant for one full year and to monitor hCG levels very closely as they come down.

Treatment for molar pregancy/ gestational trophoblastic disease [2]

Enzyme-like immunosorbent assay (ELISA)

The most popular method of testing pregnancy. The basis of most over-the-counter home pregnancy tests.

Presumptive signs

Subjective signs of pregnancy. Patient starts to notice changes and feels different

Probable signs

Objective signs of pregnancy. Urine test shows a positive sign.

Positive signs

Actually seeing an outline of the fetus via ultrasound to confirm pregnancy.

Ballottement

Feeling the presenting part of the fetus. Pushing up into the vagina and feeling baby come back down

Mucous plug

Seals off the cervix so nothing can get up through the uterus and closes it off the infection.

Fundus

Top of the uterus. Measuring the height from the top of pubic symphysis to the top of this for gestational age.

TO take weight off of the vena cava that is supplying blood to the uterus and placenta.

Why does a towel go under the hip when measuring the height of the fundus?

amenorrhea

Presumptive sign of pregnancy where patient misses their period. But this can also be due to stress, overexercising, being sick, early menopause, endocrine problems, and malnutrition

3-4 weeks. They feel full, different. But this could also mean that period is starting soon

When do breast changes occur?

Quickening

Presumptive sign where patient can feel baby moving. Could also be peristalsis or gas

16-20 weeks

When is quickening felt?

Goodell sign

Part of the cervix that goes to vagina is softening. Can also be caused before period

Chadwick sign

Changes in colour to the vagina and vulva, usually 6-8 weeks. Can also be caused by pelvic congestion, increased blood flow

Hagar sign

Softening of the narrowing of the uterus. Can also be due to pelvic congestion.

Braxton hicks

Baby is stretching the walls of the uterus. These are painless contractions that don’t do anything other than contract the walls. Feel belly getting really tight, but does not dilate the cerix. Felt at about 16 weeks.

Fetal heartrate can be heard around 17-19 weeks with a doctone or fetoscope

When can fetal heartrate be heard?

700-1000mL

How much amniotic fluid is there in a healthy pregnancy?

Amniotic fluid

Fluid that helps maintain the fetus’s body temperature, cushions the fetus, helps with musculoskeletal deelopment, and acts as a barrier to infections. Baby drinks and pees it out.

Oligohydramnios

Pregnancy has less than 300mL of amniotic fluid. Could be because baby’s kidneys are not functioning, problems with the placenta (not enough blood flow), or premature rupturing (leaking fluid)

Polyhdramnios

Pregnancy that has more than 2000mL of amniotic fluid. Could be due to swallowing issues, twins, or a maternal condition (ex: diabetes)

40 weeks

In primagravida, when should baby drop/engage?

Sometimes not until labour starts, because the abdominal muscle that pushes baby into position has stretched

In multigravida, when does baby engage?

Don’t want to be hunched over or arched. Can cause problems later on

Why should pregnant patients be aware of posture?

Montgomery tubules

Sebaceous glands that secrete moisturizing fluid to prepare nipple and areola for breastfeeding

Colostrum

First milk produced. Has a laxative effect.

Patients may need a bigger cup size and a more supportive bra. Breast pads have to be cotton, not nylon or plastic to reduce risk of bacterial growth. Bras should be washed in hot water to kill bacteria.

Breast pads must be what in pregnancy?

30-50%

How much does cardiac output increase up to 32 weeks?

20%

After 32 weeks, cardiac output is increased by how much?

10-15 bpm

How much does heart rate increase in pregnancy?

May increase or decrease, there is a slight change. slight decrease towards the end

How does systolic BP change in pregnancy?

Slight decrease mid pregnancy (24-32 weeks)

How does diastolic BP change in pregnancy?

1500mL

How much will blood volume increase in pregnancy?

There is an increase in clotting due to a rise in clotting factors. THis happens because there is more blood and greater risk of bleeding.

How are clotting factors affected during pregnancy?

1. increase in clotting factors

2. Decrease in fibrolynic activity (dissolving clots)

Mechanisms that activate during pregnancy and post partum that prevent bleeding

More risk of clots after surgery. Normally given heparin (blood thinner) and lovenox (low-molecular heparin) for a short period of time to stop clots developing.

Why are c-sections more at risk of blood clots? What are they given to prevent?

DVT

What is important to check for in pregnancy/post partum relating to clotting factors?

BMR increases. Reflects increased oxygen demands of the uterus, palcenta, and fetus.

Pregnancy on basal metabolic rate:

10-20% over pre-pregnancy levels, ut will return to normal 5-6 days post partum.

By third trimester, BMR will increase by how much?

To get rid of the excess energy and heat from increase in BMR

Why do post partum women have excessive perspiration?

Need to add tissue mass (breast, uterus). Need oxyge to help with that. Also need to supply it to fetus and to eliminate fetal CO2

Why does BMR increase in pregnancy?

Allows ligaments of the ribs to expand and relax more, allowing for increased chest expansion and increase oxygen (especially to eliminate fetal CO2). It may not go back to per-pregnant size.

Increased estrogen levels causes what to the ribs?

Tidal volume

Amount of air that moves in and out of the lungs with each respiration cycle.

Increases 30-40%

What happens to tidal volume in pregnancy?

Vital capacity

Greatest volume of air that you can expel after taking a deep breath. Does not change during pregnancy.

Goes up

What happens to inspiration capacity in pregnancy?

Goes down. Not able to expel as much air.

What happens to expiratory volume during pregnancy?

A larger volume of urine is held. Urine flow rate is shorter.

Increased estrogen and progesterone causes what to volume of urine that can e held in pelvis and ureters?

Urine flow rate is slower, there is stagnation of urine.

Why are pregnant women at risk of UTIs?

Concentrated. there is a bit of glucose and more nutrients. patients are encouraged to drink water to keep teh flow moving.

Pregnant urine is typically more what?

The bladder mucosa is more vascular and susceptible to bleeding. Because it is compressed by enlarged uterus

Why does urinary frequency increase in pregnancy?

Kidneys are able to excrete water more efficiently. The kidneys are getting rid of more water and patients may feel excess thirst.

What happens to urine in early pregnancy, related to fluid-electrolyte balance?

Fluid may pool in the legs means swelling caused by standing, walking, and being on feet for long periods of time.

What may happen to fluid in body in later pregnancy?

Physiological edema

Pooling of fluid in the legs that goes away if legs are raised. This is normal

Pathological edema.

When swelling in legs does not go away when legs are raised. Is associated with hypertensive diseases of pregnancy and is not considered normal.

After birth. Otherwise this is abnrmal.

When might patients see a trace of protein in blood?

Gestational diabetes.

High levels of glucose in the urine could be a sign of what?

Melanotropin

Hormone secreted by the anterior pituitary that increases in pregnancy. Has an affect on the color of the skin

Chloasma

“mask of pregnancy”. Darkened area on the face that tends to fade post partum, and get darker with sunexposure. Can reappear with birth control or another pregnancy

Linea nigra

Little line from the top of symphysis pubis to umilibus and beyond. Grows the same rate of the fundus.

Striae gravidarum

Stretch marks due to separation ofthe underlying connective tissue.

Angiomas

Vascular spider nevi. Little veins that come to the surface of the skin. Blueish in colour, when you touch them they don’t blanch out.

Palmar erythema

Red blotches on the palms of the hands due to an increase in estrogen levels

polymorphic eruption of pregnancy (PEP) or pruritic urticarial papules and plaques of pregnancy (PUPPP).

Women are develop uncomfortable itching. Associated with increased weight gain, multiple gestation, increased blood pressure, and hormones. Often need to hold until 37 weeks and induce because it is so uncomfortable.

Relaxin

Hormone secreted that helps the joints to move very lightly to accomodate for birth. All joints are just a little bit more flexible.

Diastasis recti

When abdominla muscles lose tone and may separate along the midline, and abdominal contents protrude midline.

Rectus abdominus

Outermost layer of abdominal muscles

Uterus compresses nerves

Decreased sensation in the legs during pregnancy is caused by what?