Fetal Development & Maternal Adaptation During Pregnancy

Goal Gestational

37- 42 weeks

Preterm

< 37 weeks gestation

Early Term

37- 38/6 weeks

Full Term

39 - 40/6 weeks

Late Term

41- 41/6 weeks

Postterm

>42 weeks

Antepartum

prior labor or childbirth

Intrapartum

onset of labor through the delivery of the placenta

Postpartum

after birth and until return of reproductive organs to normal nonpregnant state takes about 6 weeks

Gestation

process of carrying fetus/embryo in the uterus

Abortion

loss prior to 20 weeks gestation

Stillborn

fetal death occurring at 20 weeks or later

Gravida

The total number of times someone has been pregnant

Parity

The number of times a woman has given birth after 20 weeks

Nulligravida

a woman who has never been pregnant

Primigravida

a woman who is pregnant for the very first time

Multigravida

a women who has been pregnant 2 of more times (pregnancy count)

Nullipara

a woman who has never given birth

Primipara

a woman who has given birth to her first child or who has delivery a baby that reach gestational age

Multipara

a women who has given birth 2 or more time (delivery count)

what does TPAL stand for

term births, pregnancies, abortions, living

Embryonic Stage

implantation to end of 8th week post conception

fetal stage

beginning of 9th week post conception to birth

quality of ova and sperm can cause

issues with genetic code can cause miscarriage, anomalies, chromosomal, genetic problems

extra chromosomes trisomy 21 missing monosomy x-turner’s syndrome

Intrauterine Environment

if unsuitable may have spontaneous abortion

Teratogens

agents that can cause development of abnormal structures (drug, chemical, viruses, alcohol, stress)

Teratogens chemical medications that should be avoided during pregnancy

Actuate, Lithium, Coumadin, Phenytoin

If a pregnant woman gets Rubella what could happen to the baby

deafness, cardiac anomalies, miscarriage

If a pregnant woman gets Cytomegalovirus what could happen to the baby

40% transmission rate, microcephaly, hearing and cognitive impairment

If a pregnant woman gets syphilis what could happen to the baby

check and treat during prenatal care could cause blindness, deafness, issues with MSK, liver, spleen

If a pregnant woman gets Toxoplasmosis what could happen to the baby

teach avoid raw/rare meat and cat litter, blindness, cognitive impairment

If a pregnant woman gets Zika what could happen to the baby

microcephaly and cognitive impairment

Chorion

is the outermost layer embryonic membranes layer finger like projections called chorionic villi which assist in attaching and implanting into uterus which then give way to the placenta

Amnuion

the embryonic membranes fuses with chorion to become amniotic sac thin inner protective membrane contains the embryo and amniotic fluid

Amniotic Fluids

Constantly formed and reabsorbed, fetus swallows and urinates it

at term what is the correct amount of amniotic fluids

700-1000mL

Polyhdramnios

>2000mL caused by GI problems/anomalies

Oligohydramnios

<500 mL caused by renal anomalies, poor placental perfusion

what are some functions of amniotic Fluids

shields against pressure and provides cushion, helps control temperature, allows for symmetrical growth and development, MSK development, protects against cord compression, keep membranes from adhering to fetal parts

placenta

one layer of cells between maternal/fetal circulation, provides for metabolic and nutrient exchange, many things mother ingests will cross the placenta, endocrine glands (produces hormones for pregnancy)

HCG

endocrine gland produced by the placenta present in serum 7-10 days after fertilization, urine at missed menses, HCG stays high until placenta is fully functioning and producing its own estrogen and progesterone

Estrogen

endocrine gland produced by the placenta, growth in uterus, breast, increased vascularity, increased vasodilation

Progesterone

endocrine gland produced by the placenta, essential for pregnancy, development of endometrium for implantation, decreases contractility of uterus

Prolactin

endocrine gland produced by the placenta important role in lactation

Human placental lactogen

endocrine gland produced by the placenta that stimulates changes in maternal metabolism, can cause insulin resistance leading to gestational DM

Relaxin

endocrine gland produced by the placenta softens ligaments and cartilage in skeletal system, quiets the myometrium

Umbilical cord

connects embryo/fetus to placenta, contains 1 large vein (carries oxygenated blood) and 2 small arteries (carries deoxygenated blood), insertion of cord should be center of the placenta check for nuchal cord or knots

what is Wharton’s jelly

connective tissue around vessels

fetal circulation

placenta to umbilical vein (oxygenated blood) if it goes left goes to the liver if it goes right it goes to the ductus venosus to the foramen ovale to ductus arteries to the second umbilical arteries (unoxygenated) to pulmonary pressure high to systemic pressures low

fetal maturation 8-10 weeks

FHR with doppler

fetal maturation 20 weeks

quickening (earlier for multiple)

fetal maturation 22 weeks

earliest point to viability production of surfactant

fetal maturation 28 weeks

more developed respiratory system

fetal maturation 32 weeks

sucking reflex

fetal maturation 36 weeks

survival with little support

Lung maturation

approximately 22 weeks surfactant is starting to be produced, the further into the gestation more surfactant is produced, surfactant is mixture of fats and proteins that reduces surface tension and coats the alveoli prevents them from sticking together

Presumptive Signs

mostly subjective

Probable Signs

objective

Positive Signs

can be explained only by pregnancy

examples of presumptive signs

amenorrhea, N/V, breast tenderness/changes, fatigue, reported weight gain, increased urinary frequency, quickening

examples of probable signs

uterine changes hegar sign, cervical changes chadwick Goodell sign, positive pregnancy test, balllottement, enlarging abdomen, fetal outline felt by examiner

positive signs of pregnancy

fetal visualization, fetal heart tones, fetal movement detected/palpated by examiner

hCG human chorionic gonadotropin

7-10 days after conception

serum hCG blood

high accuracy

urine hCG home pregnancy tests

use first void in the morning, if test is done at time of misses period and negative, repeat the test in one week if still no period, follow up with provide if positive or negative with no period

physiological changes of uterus and ovaries

ovulation and menes cease during pregnancy, 12 weeks slightly the symphysis pubis into the abdomen, McDonald’s rule fundal height

whats the McDonald’s Rule

Fundal height, level of umbilicus by about 20 weeks which is about 1 cm per week, fundal height correlates with gestational age 32 weeks = 32 cm

physiologic changes

quickening, ballottement, Braxton hicks, lightening

when can quickening occur

16-20 weeks

when can ballottement occur

16-18 weeks

when can Braxton Hicks occur

about 20 weeks

when can lightning occur

38-40 weeks fundal height decreases as fetus descends into pelvis for birth

physiologic changes in cervix

Chadwick’s sign, Goodell’s sign mucus plug, increased friability, ripening last 4 weeks of gestation

Chadwick’s sign

bluish coloring

Goodell’s Sign

softening of cervix

physiological changes in vag

pH changes more alkaline at risk for vaginitis, glycogen rich more vulnerable to candidiasis (yeast), leukorrhea increased clear/white slippery vaginal discharge

physiological changes in breast

enlargement causing heaviness, fullness and tenderness, nipple and areola become larger and darker

Physiological changes in integumentary

striae gravidarum, Chloasma/Melasma, linea nigra

where can striae gravidarum happen

breasts, abdomen, buttocks, thighs

what is Chloasma/Melasma

mask of pregnancy looks almost like a bunch of freckles

linea nigra

dark line right down the middle of the stomach through the umbilicus

cardiovascular changes

slight increase in HR, systolic murmur, S3 By 32 weeks there is a 10-15 bpm increase from baseline

Physiologic anemia

due to hemodilution, Hgb 12-16; Hct 38-47, elevated clotting factors- hypercoagulable state if Hgb is less than 11 will typically start iron supplement

Vena Cava Syndrome

supine hypotension

physiological changes in respiratory

Oxygen demands increase, slight increase in RR, third trimester: larger uterus pushes diaphragm upward putting pressure on lungs can cause some shortness of air and decreased lung capacity

physiological changes in GI

N/V, Constipation, heartburn, food aversions or cravings, PICA

physiological changes in Renal

Increased GFR, urine output remains same, increased urinary frequency

physiological changes in MSK

relaxin, increased mobility of pelvic joints may cause pain, lordosis, change in center of gravity/balance, diastasis recti

physiological changes in Endocrine/Metabolic

Increased BMR, increased need for calories/protein/carbs/water, placenta acts as an endocrine gland producing hCG, estrogen, progesterone, human placental lactogen etc

what is the normal weight gain during pregnancy

25-30lb about 3.5-5lb in the first trimester and about 1lb pre week in the 2nd and 3rd trimester

Nutritional need for energy

Additional 340 kcal 2nd trimester and 450 kcal 3rd trimester

Nutritional need for fluids

8-10 glasses per day and 4-6 of those should be water

Nutritional need for protein

element basic to growth

Nutritional need for calcium

Bone and teeth formation of developing fetus, Milk, nuts, legumes, dark green leafy vegetables

Nutritional needs for water soluble vitamins

folic acid (folate) 400/600mcg reduce neural tube defects eat fortified grains/cereals/breads, leafy vegetables, dried peas/beans, seeds, orange juice

Pyridoxine (B6) helps with N/V

Vitamin C (ascorbic acid) enhances absorption of iron

Nutritional needs for iron

often added in the 2nd and 3rd trimrdtrtd

pregnancy issues alcohol

do not consume

pregnancy issues caffeine

try to avoid, no more than 200mg daily, excessive amounts can contribute to infertility, spontaneous abortion, IUGR

Pregnancy issues fish and mercury levels

no shark, swordfish, tuna, king mackerel, tile fish

pregnancy issues listeriosis

no hot dogs, lunch meat, deli meat, soft cheeses such as brie and feta, no unpasteurized milk/dairy