Prenatal Care and Normal Pregnancy Flashcards
What is Apgar score?
a method to quickly summarize the health of newborn children
When is the test generally done?
at one and five minutes after birth and may be repeated later if the score is and remains low
How is Apgar scored?
- activity (2=active movement)
- pulse (2=>100)
- grimace (2 =pulls away, sneeze)
- appearance (2= pink)
- respiration (2=crying)
What is a good Apgar score?
score >6 is good
When Apgar score means resuscitation?
score of 4 necessitates resuscitation
What are the characteristics of fetal size?
- fetal head most critical; cephalopelvic disproportion - labor dystocia (difficult/obstructed)
- marcosomina (birth weight >90th percentile for gestational age/> 4500 g) associated with shoulder dystocia (fetal shoulder unable to pass below maternal pubic symphysis), birth injuries
What are the characteristics of fetal attitude?
relationship of fetal parts to one another
-full flexion (chin on chest; rounded back with flexed arms, legs); smallest diameter of head (suboccipitobregmatic diameter) presents at pelvic inlet
What are the characteristics of fetal ile?
relationship of fetal cephalocaudal axis (spinal column) to maternal cephalocaudal axis
- longitudinal (ideal): fetal spine lies along lateral
- transverse: fetal spine perpendicular to maternal
- oblique: fetus at slight angle
What is fetal presentation?
fetal/presenting part enters pelvic inlet first
What are the characteristics of cephalic position?
head first
- vertex (most common): optimal for easy delivery; head completely flexed onto chest = occiput (part of fetal skull covered by occipital bone) is presenting
- brow: fetal head partially extended; sinciput (part of fetal skull covered by frontal bone, anterior fontanelle to orbital ridge) presenting part
- face: fetal head hyperextended; fetal face from forehead to chin presenting part
What are the characteristics of breech position?
head up; bottom, feet, knees present first
- frank breech: hips flexed, knees extended, bottom presents
- complete breech: hips, knees flexed, bottom presents
- incomplete breech: one/both hips not completely flexed, feet present
- shoulder: transverse lie,; shoulders present first
What are the characteristics of breech presentation?
a breech birth happens when a baby is born bottom first instead of head first
- around 3-5% of pregnancy women at term (37-40 weeks pregnant) will have a breech baby
- prevalence decreases with increasing gestational age
- 25% of fetuses under 28 weeks are breech
- 7 to 16% are breech at 32 weeks
- 3 to 4% are breech at term
- a breech presentation may be frank, complete, or incomplete
- the diagnosis of breech presentation is based on physical examination, with ultrasound confirmation, if the diagnosis is uncertain
What is the tx of breech presentation?
external cephalic version at or near term, followed by a trial of vaginal delivery if the version is successful and planned cesarean delivery if breech presentation persists
What is multiple gestations?
the overall incidence in the US is 3%
-twins occur in 1 out of every 80 births
What does monozygotic mean?
identical
-multiple (typically two) fetuses produced by splitting of a single zygote
What does dizygotic mean?
fraternal
-multiple (typically two) fetuses produced by two zygotes
What does polyzygotic mean?
multiple fetuses produced by two or more zygotes
What is the dx of multiple gestations?
often diagnosed at first screening ultrasound other clues include
- fundal height is usually greater than dates
- extra fetal heart tones
- elevated maternal alpha-fetoprotein (AFP)
What is the tx of multiple gestations?
prenatal visits should occur more frequently to monitor and prevent maternal complications
- the most common complication is spontaneous abortion an preterm birth
- other problems occur with greater frequency are preeclampsia and anemia
- mange of diet, surveillance of fetal growth and cervical length
- delivery by induction for vaginal route or c-section (common) try to deliver at >34 weeks
What are the characteristics of labor (parturition)?
uterine contractions = cervical changes = delivery of baby, placenta
- begins at term (37-42 weeks of gestation)
- duration of three stages varies with gravity (nulliparas typically longer than multiparae)
What are the characteristics of cervical changes?
- remodeling of cervix by enzymatic collagen dissolution, increase water content = softening, increased distensibility
- cervical softening = explosion of mucus plug = “bloody show” (pink-tinged mucus)
- spontaneous rupture of amniotic membranes (ROM)
What are the characteristics of false labor?
AKA Braxton-Hicks contractions
- true labor: regular, increase in frequency, duration, intensity; produce cervical changes (e.g. dilation/opening, effacement/getting thinner); pain begins in lower back, radiates to abdomen, not relieved by ambulation
- false labor: irregular, intermittent contractions, no cervical changes, pain in abdomen, walking may decrease pain
What is the first stage of labor?
onset of labor to fully dilated (10 cm)
What are the characteristics of early/latent labor?
- 8 to 12 hours
- mild contractions every 5 to 30 minutes
- duration 30 seconds each
- gradually increase in frequency, intensity, duration
- cervical dilation 0-3 cm
- effacement 0-30%
- spontaneous ROM
What are the characteristics of the active phase of labor?
- 3-5 hours
- contractions every 3 to 5 minutes
- duration >1 minute
- cervical dilation 3-7 cm
- effacement 80%
- progressive fetal descent
What are the characteristics of the transition phase?
- 30 minutes to 2 hours
- intense contractions every 1.5-2 minutes
- duration 60-90 seconds
- cervical dilation 7 to 10 cm
- effacement 100%
What is the second stage of labor?
fully dilated to the birth of the infant
- AKA pushing stage
- begins with full dilation
- navigation through maternal pelvis dilated by 2 Ps: power, passenger, passage
What are the characteristics of power?
-frequency, duration, intensity of uterine contractions
-physiology of contractions
-stimulation of uterine myometrium
-alpha-receptors stimulate uterine contractions
-numerous oxytocin receptors, mostly on uterine fundus
-contraction steps:
wave begins in fundus, proceeds downward to rest of uterus - muscle shortened in response to stimulus - increment (build up) - acme (peak) - decrement (gradual letting up) - relaxation - fetal descent, cervical effacement, dilation - amount of pressure exerted by uterine contractions (intrauterine pressure) measured in millimeters of mercury (mmHg)
What are the characteristics of passenger?
Fetal size:
- fetal head most critical; cephalopelvic disproportion - labor dystocia (difficult/obstructed)
- macrosomia (birth weight >90th percentile for gestational age/>4500 g) associated with shoulder dystocia (fetal shoulder unable to pass below maternal pubic symphysis), birth injuries
- fetal attitude: relationship of fetal parts to one another
- full flexion (chin on chest; rounded back with flexed arms, legs); smallest diameter of head (suboccipitobregmatic diameter) presents at pelvic inlet
- fetal Iie: relationship of fetal cephalocaudal axis (spinal column) to maternal cephalocaudal axis
- longitudinal (ideal: fetal spine lies along maternal
- transverse: fetal spine perpendicular to maternal
- oblique: fetus at slight angle
- fetal presentation: fetal/presenting part enters pelvic inlet first
- cephalic: head first
- vertex (most common): optimal for easy delivery; head completely flexed onto chest - occiput (part of fetal skull covered by occipital bone) is presenting
- brow: fetal head partially extended; sinciput (part of skull covered by frontal bone. anterior fontanelle to orbital ridge) presenting part
- face: fetal head hyperextended; fetal face from forehead to chin presenting part
- breech: head up, bottom, feet, knees present first
- frank breech: hips flexed, knees extended, bottom presents
- complete breech: hips, knees flexed, bottom presents
- incomplete breech: one/both hips not completely flexed; feet present
- shoulder: transverse Iie; shoulders present first
What are the characteristics of passage?
- route through bony pelvis
- size, type of pelvis
- gynecoid: rounded pelvic inlet, midpelvis, outlet capacity adequate; optimal vaginal delivery
- android: heart-shaped pelvic inlet, decrease midpelvis diameters, outlet capacity; associated with labor dystocia
- anthropoid: oval-shaped pelvic inlet, midpelvis diameters, outlet capacity adequate, favorable for vaginal delivery
- platypelloid: oval-shaped pelvic inlet, decreased midpelvis diameters, outlet capacity adequate, not favorable for vaginal delivery
- Cardinal Movements (mechanisms of labor)
- descent: presenting part reaches pelvic inlet (engagement) before onset of labor = degree of descent (fetal station), relationship of presenting part to maternal ischial spine = fetus moves from pelvic inlet (-5 station) down to ischial spines (0 station) to pelvic outlet (+4 station) to crowning at vaginal opening (+5 nation)
- flexion: fetal chin presses against chest, head meets resistance from pelvic floor
- internal rotation: fetal shoulders internally routes 45 degrees, widest part of shoulders in line with widest part of pelvic inlet
- extension: fetal head passes under symphysis pubic (+4 station), moves (+5 station), emerges from vagina
- restitution (external rotation): head externally rotates as shoulders pass through pelvic outlet, under symphysis pubis, turns to align with back
- expulsion: anterior shoulder slips under symphysis pubis, followed by posterior shoulder, rest of the body, marks end of second stage
What are the characteristics of the third stage of labor?
delivery of infant to delivery of the placenta
-delivery of placenta, umbilical cord, fetal membranes, uterus contracts firmly, placenta begins to separate from uterine wall
What is the fourth stage os labor?
physiological adaptation to blood loss, initiation of uterine involution
What is the monitoring during labor?
- heart rate and the pattern is an indicator of infant well-being
- normal heart rate in newborn is 120-160 beats per minute
- consistent decelerations after a contraction can indicate fetal distress
- external fetal monitor - on the maternal abdomen
- internal fetal monitor - electrode attached to the infants head
What is accelerations of fetal heart rate?
increased of baseline 15 bpm for 15 seconds = response to fetal movement = reassuring
What are early decelerations of fetal heart rate?
mirror images of contractions = fetal head compression = benign
What are variable decelerations of fetal heart rate?
rapid FHR drop with a return to baseline with variable shape = cord compression = benign if mild or moderate = worrisome if severe
What are late decelerations of fetal heart rate?
FHR drop at the end of the contraction = uteroplacental insufficiency = always worrisome
What is the physiology of the uterus during pregnancy?
- increase size, capacity due to hypertrophy, hyperplasia, mechanical stretching
- 20 times larger
- increase strength, distensibility, contractile proteins, number of mitochondria
- increase volume capacity (10 mL to 5 L)
- softening of uterine isthmus (Hegar’s sign)
What is the physiology of the cervix during pregnancy?
- formation of mucus plug, seals endocervical canal
- increase vascularity - purplish-blue color
- mild softening due to edema, hyperplasia (Goodell’s sign); increase softening in third trimester
What is the physiology of the placenta during pregnancy?
- develops where embryo attaches to uterine wall
- expands to cover 50% internal uterine surface
- functions as maternal-fetal organ for metabolic, nutrient exchange
- secretes estrogen progesterone, relaxin, hCG
What is the physiology of the vagina during pregnancy?
- increase vascularity - bluish-purple color
- loosening of connective tissue - increase distensibility
- leukorrhea
- pH of 3.5 to 6.0 - protects against bacterial infections
What is the physiology of breast during pregnancy?
- increase size, weight, nodularity, blood flow, vascular prominence
- areola, nipples are a darker pigmentation due to increase melanocyte activity
- increase activity of Montgomery’s tubercles (sebaceous glands)
- progesterone increase alveolar-lobular development; prevents milk production during pregnancy (inhibits prolactin)
- estrogen increase growth of lactiferous ducts
- secretion of colostrum begins week 16
What is the physiology of cardiovascular during pregnancy?
- mild hypertrophy
- S2, S3 more easily auscultated, split exaggerated
- heart displaced upward, forward, slightly to left
- increase heart rate by 15-20 beats/minute
- stroke volume increase 30%, cardiac output (CO) increase 30-50% (by term); decrease blood pressure (BP) despite increased CO due to progesterone-induced vasodilation; BP = CO x systemic vascular resistance (SVR)
- supine hypotensive syndrome caused by gravid uterus pressing on inferior vena cava (left lateral recumbent position optimal for CO, uterine perfusion)
- gravid uterus elevated pressure veins draining legs, pelvic organs = slowed venous return, dependent edema, varicose veins, hemorrhoid
What is the physiology of hematologic during pregnancy?
- increased blood volume ( approx. 150 mL)
- related to sodium, water retention due to changes is osmoregulation, secretion of vasopressin by anterior pituitary, renin-angiotensin-aldosterone system (RAAS)
- increase total red blood cell (RBC) volume (30%) with iron supplementation
- increase volume, oxygen-carrying capacity needed for increased basal metabolic rate (BMR), needs of uterine-placental unit (offsets blood loss at delivery)
- plasma > RBC volume = hemodilution, decrease hematocrit (physiologic anemia)
- increase white blood cells (WBC) count (approx. 5,000 to 12,000/mm3)
- increase clotting factors (fibrin, fibrinogen): hyper coagulable state of pregnancy
What is the physiology of respiratory during pregnancy?
- increase oxygen consumption, subcostal angle, anteroposterior diameter, tidal volume (30-50%), minute ventilatory volume, minute oxygen uptake
- gravid uterus places upward pressure on diaphragm - elevates approx. 4 cm
- hyperventilation - mild respiratory alkalosis (renal compensation - maternal blood pH 7.40 -7.45)
- nasal congestion, epistaxis due to estrogen - induced edema
What is the physiology of gastrointestinal during pregnancy?
- gums bleed easily due to estrogen-induced hyperemia, friability
- progesterone-induced smooth muscle relaxation, delayed gastric emptying, decrease peristalsis = nausea, vomiting (AKA “morning sickness”); constipation; heartburn (pyrosis), esophageal reflux, intrahepatic cholestasis of pregnancy due to decrease gallbladder emptying time = increase risk of cholelithiasis
- increase saliva production (ptyalism)
What is the physiology of urinary and renal during pregnancy?
Bladder
- first trimester: gravid uterus presses on bladder = urinary frequency, nocturne, stress incontinence
- second trimester: uterus occupies abdominal space - decrease urinary frequency
- third trimester: presenting part descends into pelvic - urinary frequency, nocturne, stress incontinence
- increase glomerular filtration rate (GFR)
- 40-50% by second trimester, increase urinary output (25%)
- increase size of kidneys (1-1.5 cm)
- dilation of urinary collecting system - physiologic hydronephrosis
- urinalysis
- glycosuria (due to increase glucose lead), increase protein excretion (due to altered proximal tubule function + increase GFR)
What is the physiology of integumentary during pregnancy?
- hyperpigmentation (due to estrogen, increase melanocyte activity) = melisma (chloasma) brownish “mask of pregnancy”, linea nigra formation on abdomen; darkening of
- nipples, areolae, vulva
- increase cutaneous blood flow - increase heat dissipation - increase pregnancy “glow”
- decrease connective tissue strength secondary to increase adrenal steroid levels - increase stretch marks (striae gravidarum) in breasts, abdomen, thighs, inguinal area
- estrogen-induced vascular permeability - spider nevi, angiomas, palmar erythema
What is the physiology of musculoskeletal during pregnancy?
- abdominal distention + shift in center of gravity = lordosis
- enlarging uterus = separation of abdominal rectus muscles (diastasic recti)
- increase progesterone, relaxin = increase joint mobility, “waddling” gait
- widening of symphysis pubis
- facilitates accommodation of fetus into pelvis
- high bone turnover, remodeling
What is the physiology of endocrine during pregnancy?
- increase size of pituitary gland, mostly due to proliferation of lactotroph cells
- increase intrasellar pressure - increase risk of postpartum infraction (Sheehan syndrome) in setting of postpartum hemorrhage
- increase parathyroid hormone (meets calcium need of developing fetal skeleton)
- physiologic hypercortisolism
- increase need of estrogen, cortisol - increase glucocorticoids from adrenal glands = supports fetal somatic, reproductive growth
- “diabetogenic state” of pregnancy
- increase need for glucose, insulin production - hypertrophy, hyperplasia of pancreatic beta cells
- decrease thyroid-stimulation hormone (TSH); thyroid gland enlarges; increase total T3, T4
- reproductive hormones
- hCG from placenta, estrogen, progesterone corpus luteum (first, second trimesters), placenta (second, third trimesters)
- suppressed FSH, LH due to feedback from estrogen, progesterone, inhibin
- decrease oxytocin levels throughout pregnancy - increase labor onset - increase second stage of labor
What are the nutritional needs during pregnancy?
- recommendation of additional 300kcal/day, weight gain of 25-35 pounds (11.5-16 kg)
- 11 lb (5 kg): placenta, amniotic fluid, fetus
- 2 lb. (0.9 kg): uterus
- 4 lb (1.8 kg): increase blood volume
- 3 lb. (1.4 kg): breast tissue
- 5-10 lb (2.3-4.5 kg): maternal reserves
- 600 mcg folic acid/day - RBC synthesis, placental/fetal growth, decrease risk of neural tube defects
- 1,000 - 1,300 mg calcium/day supports pregnancy, lactation
- 60 G protein daily supports tissue growth
- 27 mg iron/day supports increase RBCs
What percentage of pregnancies are unplanned?
50%
What is the recommended prenatal care schedule?
consists of the following:
- monthly visits to healthcare professional for weeks 4-28 of pregnancy
- visits twice monthly from 28 to 36 weeks
- weekly after week 36 (delivery at week 38-40)
What are the recommendations for use of dietary supplements in pregnancy?
- all pregnant women should receive a prenatal vitamin
- folic acid supplementation (0.4 - 0.8 mg) prior to conception; 4 mg for secondary prevention
- calcium: 1,000 to 1,300 mg/day; supplement may be beneficial for women with high risk for gestational hypertension or communities with low dietary calcium intake
- iron: screen for anemia (Hgb/Hct) and treat if necessary, recommend 30 mg/day of iron in pregnant women
- Vitamin A: pregnant women industrialized countries should limit to <5,000 IU/day
- Vitamin D: consider supplementation in women with limited exposure to sunlight
What should be done at prenatal visits?
- a full physical exam should be performed at the 1st prenatal appointment
- weight: total weight gain range (lb) should be 25-35 lb, except in obese women, for whom weight gain should be <15 lb
- ACOG defines hypertension as BP >140 mmHg systolic or >90 mmHg diastolic
- monitor BP especially closely in patients with chronic hypertension (predating pregnancy), preeclampsia/eclampsia, or gestational hypertension
- UA for glucose and protein; 24-hour protein excretion is the gold standard but not practical
- fundal height
- fetal heart rate: usually audible by 12 weeks’ GA with a Doppler instrument
- fetal position by abdominal palpation at 36 weeks
- pelvic/cervical exam if indicated
What is advanced maternal age?
35
-each mother should be offered testing for genetic abnormalities
How can expectant date of confinement by calculated?
Naegele’s Rule
- when was the first day of bleeding? = 1st day of the last menstrual period
- 1’st day of menstrual period + 7 days - 3 months + 1 year
When should an initial OB visit be?
6 weeks after LMP
What does each visit assess?
- fetal heart tones, blood pressure, fundal height, fetal movement and urinalysis
- ultrasound should be able to detect fetal heart activity 1-2 weeks after 1st missed cycle (around 5-6 weeks)
What is a triple screen?
AFP, HCG, Estriol
What is quad screen?
AFP, HCG, Estriol, Inhibin A
When is chorionic villus sampling done?
between 10-12 weeks (end of first trimester)
When is an amniocentesis done?
between 15-18 weeks (beginning of second trimester) - especially for women over age 35 in the high-risk group
When is the 75 g 2-hour oral glucose tolerance test done?
26-28 weeks
When is Group B strep test done?
between 35-37
Where is the uterus at 12 weeks?
at pubic symphysis
Where is the uterus at 16 weeks?
midway from symphysis to umbilicus
Where is the uterus at 20 weeks?
at umbilicus
When is the uterus at 20-36 weeks?
height (in cm) above pubic symphysis correlates with weeks of gestation
When and what are the first trimester screening?
11-14 weeks
- ultrasound for nuchal translucency
- PAPP-A and hCG
- increase levels are seen in chromosomal abnormalities
- low levels of PAPP-A can be associated with Down’s syndrome
When and what is cell free fetal DNA?
~10 weeks
- analyze fetal DNA in maternal blood
- screens for trisomies 13, 18, and 21
- positive test results should be followed by CVS or amniocentesis
When and what is Chorionic villus sampling (CVS)?
11-14 weeks
-collect placental tissue to test for chromosomal and genetic abnormalities
When and what is quadruple screen?
16-18 weeks
- AFP, hCG, estriol, inhibin
- increase AFP = neural tube or abdominal wall defects
- increase hCG and inhabit and decrease AFP and estriol = down syndrome
- decrease AFP, hCG, and estriol = Edwards syndrome
When and what is an amniocentesis?
15-20 weeks
-collect amniotic fluid to diagnosis chromosomal abnormalities
When and what is the glucose challenge test?
24-28 weeks
- 1 hour glucose challenge test
- if abnormal followed by glucose tolerance test
When and what is group B strep test?
35-37 weeks
-swab the lower genital tract fro colonization by GBS
What are the symptoms of pregnancy?
- amenorrhea
- increase urine frequency
- breast engorgement
- treat with breastfeeding/pumping or cold compress
- nausea
- bluish discoloration of vagina, vulva, and cervix due to vascular contestation (Chadwick’s sign)
- softening of cervix
What are the characteristics of urine pregnancy test (UPT)?
- detects hCG or B subunit
- sensitive to 1-2 weeks
What are the characteristics of ultrasound?
most accurate method to detect fetal size
- gestational sac - 5 weeks
- fetal image detected at 6-7 weeks
- cardiac activity at 8 weeks
How often are prenatal visits during the first trimester and what you do evaluate?
visit every 4 weeks Evaluate -weight gain/loss -BP -pedal edema -fundal height -urine dip glycosuria and proteinuria -trace glucose is normal due to increase GFR -trace protein is not normal and should be evaluated
What are the characteristics of Cell-free fetal DNA?
- non-invasive
- very sensitive/specific
- can order at 10 weeks or greater
- can confirm with CVS or amniocentesis
What are the characteristics of Chorionic villus sampling (CVS)?
a procedure where small samples of placenta are acquired in order to perform a prenatal genetic analysis (e.g. DNA analysis and cytogenetics)
-CVS is typically performed between 10 and 13 weeks of gestation
What are the indications of CVS?
- maternal age 35 years or older
- prior child had a genetic disorder (cystic fibrosis) and chromosomal abnormalities (Down syndrome)
- parents are carriers of a genetic disorder
- first trimester ultrasound examination suggests a congenital anomaly
- abnormal aneuploidy screening result
What are the risk of doing a CVS testing?
- maternal alloimmunicatidn (relative contraindication)
- vertical transmission of infection (HIV)
What are the complications of CVS testing?
- miscarriage
- amniotic fluid leakage
What is done at 15-18 week visit?
- offer triple marker screen (hCG, estriol, AFP)
- used to detect neural tube defects or trisomies
What is done at 16-20 week visit?
amniocentesis if >35 years old or history indicates
What is done at 17 week visit?
document movement
What is done at 24 week visit?
glucose screening
What is done at 25-28 weeks visit?
repeat Hct
What are the routine third trimester tests?
- urinalysis
- blood glucose
What are preterm labor symptoms?
- vaginal bleeding
- contractions
- rupture of membranes
What is done at 28-30 week visit?
-give RhoGAM if indicated
What is done at 28-32 week visit?
mothers with pre-gestational diabetes should undergo twice weekly non stress testing until delivery
What is done at 35-37 week visit?
screen for Streptococcus agalactiae (group b strep)
What is done at 36-40 week visit?
cervical chlamydia and gonorrhea cultures if indicated
