W7 starred: prenatal adaptations & maternal changes in pregnancy

Adaptations During Pregnancy & Preventative Care

When is the embryonic period?

beginning of 3rd week to end of 8th week after conception

What are the 3 layers developed in the embryonic disc?

• ectoderm

• mesoderm

• endoderm

What happens at the end of the embryonic period?

All major organ systems are in place

What are teratogens? What happens when they’re exposed in the embryonic period?

substances or agents that can cause birth defects (major structural and functional damage to the developing organs)

What are some physical examples of teratogens?

• ionizing radiation (ie; x-rays)

• hyperthermia (ie; hot tubs, sauna, high fever)

What are some chemical teratogens?

• prescription meds (chemo, thalidomide (sedative), isotretinoin (acne med), valproate (anticonvulsant- seizures, bipolar))

• recreational drugs / cigs / alcohol

• environmental chemicals (ie; lead, mercury, pesticides)

What are some infectious agents teratogens?

• rubella virus

• herpes simplex virus

• syphilis

What are some metabolic conditions teratogens?

• malnutrition

• diabetes

• thyroid disorders

Gestational age (GA) is what?

• how you date a pregnancy

• describes how far along it is from LMP (last menstrual period)

What is quickening?

can feel fetal movement

What is brown fat?

• type of adipose tissue that helps maintain body temp (when you get too cold)

• prominent in late fetal & newborn stages

What is lanugo?

fine, soft hair typically seen covering body and limbs of late fetus / newborn

What is vernix caseosa?

• white, creamy substance that develops on the skin of the fetus in the 3rd trimester

• protects newborn

• facilitates extra uterine adaptation of skin the first postnatal week if not washed away after birth

What is pulmonary surfactant?

• lipoprotein complex that lines the alveoli of the lungs

• decreases surface tension to promote lung expansion after birth and prevents lung atelectasis (collapse)

Major functions of the placenta

1. produces hormones critical for maintaining pregnancy (estrogen, progesterone, hCG)

2. transports substances between maternal & fetal circulation

   a. acts as respiratory organ for gas exchange

3. metabolizes & synthesizes agents necessary for transferring gas & nutrients & removing waste products

4. provides an immunological barrier between maternal & fetal systems

How much does the placenta weight at birth?

1/6 weight of fetus at nirth

Is there mixing of maternal & fetal blood?

No; maternal and fetal blood do not mix

The placenta is in contact with what of the pregnant person

uterine wall

What is the placenta composed of?

• chorion

• amnion

• umbilical cord

Where does the exchange of the maternal & fetal substance happen?

in the intervillous space

What are the 3 placental hormones?

• hCG

• Estrogen

• Progesterone

What does hCG do?

• rapidly increases

• stimulates corpus luteum to produce estrogen & progesterone

• this is what causes you to have positive pregnancy

Which hormone is responsible for causing a positive pregnancy tst?

HCG

What does estrogen do?

• stimulates uterine growth

• increases blood supply to uterine vessels

• helps in developing ductal system in breasts for lactation

• associated with; hyperpigmentation, vascular changes in skin, increased activity of salivary glands, hyperemia (++ blood flow) of gums and mucus membranes

What does progesterone do?

• maintain endometrial layer for implantation of fertilized egg

• stimulates lobes of breasts for lactation

• relaxes smooth muscle of uterus (for growth and quiescence?)

• produced by corpus luteum, then by placenta

The umbilical cord has how many arteries and veins?

2 arteries, 1 vein (AVA)

In the fetus, the artery(s)/vein(s) carries deoxygenated blood away from the fetal heart to the placenta

arteries (2 arteries)

In the fetus, the artery(s)/vein(s) carries oxygenated blood & nutrients from the placenta to the fetal heart

1 vein

The umbilical arteries carry _____________

a. oxygenated blood to the placenta

b. deoxygenated blood to the placenta

c. maternal immunity to the placenta

d. nutrient rich blood to the placenta

b. deoxygenated blood to the placenta

The umbilical vein carries _____________

a. oxygenated blood to the fetal heart

b. deoxygenated blood to the placenta

a. oxygenated blood to the placenta

d. nutrient rich blood to the placenta

a. oxygenated blood to the fetal heart

A new parent is distressed by the “thick white substance” covering their newborn because it “looks gross”. What action by the nurse is most appropriate?

a. Scrub it all off and bathe the baby right away.

b. Reassure them that it will go away

c. Report the findings to the provider

d. Explain that vernix cassenas protects the fetal skin from amniotic fluid in the uterus

d. Explain that vernix cassenas protects the fetal skin from amniotic fluid in the uterus

What are maternal cardiovascular system changes during pregnancy?

• decreased systemic vascular resistance (progesterone relaxes smooth muscle) (blood vessel are wider - vasodilation)

  • lower BP

• blood volume increases ~45%

• increase cardiac output (heart pumping more blood) ~50%

• heart rate increases 15-20 bpm

• heart is deviated up and left (pushed by expanding uterus

• hypercoagulable (more likely to clot)

What are maternal respiratory system changes during pregnancy?

• increase in oxygen use

• pressure on diaphragm (from growing uterus)

  • this limits lung expansion/capacity

• slight hyperventilation

  • RR is unchanged, breath is deeper

What role do estrogen and progesterone play in the respiratory system of a pregnant person?

Estrogen: increases vascularity of mucous membranes

Progesterone:

• decreases airway resistance (relaxes smooth muscle)

• raises sensitivity of CO2 in the respiratory center

• increases awareness of need to breathe

What are the endocrine system changes in the pregnant person?

Estrogen:

• increases vascularity

• relaxes pelvic ligaments

• decreases maternal insulin sensitivity (more insulin resistance)

Progesterone

• relaxes smooth muscle

• suppresses FSH/LH (to prevent ovulation)

• decreases uterine contractility

• decreases maternal insulin sensitivity (more insulin resistance)

hCG

• maintains corpus luteum production of estrogen & progesterone until placenta takes over their production

hPL (human placental lactogen)

• decreases maternal metabolism of glucose (so higher blood sugar)

• growth hormone

What are GI changes in a pregnant person? not starred

• slowed emptying of stomach

• decrease of GI tone & motility (constipation)

• heartburn (pyrosis)

• hyperemia in mouth (due to increased estrogen)

  • ptyalism (more saliva)

• increased absorption in large & small intestine

What are maternal urinary system changes in pregnancy? not starred

• increases urinary frequency

• increase GFR (kidneys filtering more blood)

• hypertrophy (larger) bladder walls

• increase risk of UTI (cause of less effective urine emptying?)

• ureters are longer

What are maternal integumentary (skin) changes in pregnancy? not starred

• hyperpigmentation (cause of ++estrogen & progesterone)

• hair growth rapid, hair loss slower

• increased circulation (++sweat & sebaceous glands) —> acne

Linea nigra (not starred)

dark vertical line that appears on stomach during pregnancy

Chloasma or melasma (not starred)

darker skin patches

Striae gravidarum

stretch marks