fetal growth & development Flashcards
1
Q
gestational age is dated from ?
A
the first day of the LMP
precedes conception, which occurs approx. 2 wks later
2
Q
gestation takes approximately how many days? months? weeks?
A
280 days
10 “lunar” months
40 weeks
3
Q
Nagle’s rule
A
LMP+ 7 days - 3 months= EDD
4
Q
what takes place the 1st 2 weeks of pregnancy?
A
ovulation
fertilization- formation of zygote
formation of blastocyst- hCG production
implantation
5
Q
what happens during implantation?
A
embryonic laminar develop
2 flat layers of cells
the first of 3 germ layers
6
Q
when does the embryonic period begin?
A
beginning of 3rd week
7
Q
trilaminar disc in embryonic period 3rd wk) is what?
A
3 germ layers
8
Q
ectoderm
A
skin of genitalia
part of anal canal
nervous system
9
Q
mesoderm
A
gonads
ureters
uterus, part of vagina
10
Q
endoderm
A
GIT, epithelium
urinary bladder, anorectal canal
male urethra, prostate gland
female urethra, vaginal epithelium, vestibule
11
Q
disc becomes cylindrical in the 4th week, what does it look like/ form
A
“salamander look”
buds of arms, ears, legs & facial/neck structures
12
Q
development during week five?
A
brain development
head looks big
eyes begin
13
Q
development during week six?
A
nose
mouth
palate
14
Q
development during week seven
A
neck established
distinctly human form
15
Q
development during week eight
A
end of embryonic period
fetus begins
has male/female characteristics
16
Q
by the end of 1st trimester, fetus can do what?
A
make respiratory movements urinate swallow move limbs squint frown open mouth
17
Q
folate acid deficiency can result in what?
A
neural tube defects- spina bifida, cleft lip
18
Q
what can fetus do beginning week 14
A
sucking motion
19
Q
when do you generally begin to feel the baby move?
A
18 weeks
20
Q
quickening
A
first fetal movements
21
Q
3rd trimester, weeks 28-40
A
this is where the baby grows in size & fine tunes the organ systems- nervous system has control over organ function
22
Q
non-stress test
A
look at a baby’s heart rate that corresponds to the babies movement…fetal well being in utero
23
Q
normal growth reflects what?
A
the interaction of the fetus’ genetically predetermined growth potential & it’s modulation by the health of the fetus, placenta & mother
24
Q
3 phases of growth & development
A
cellular hyperplasia (1st 16 weeks) concomitant hyperplasia & hypertrophy (wks 16-32) cellular hypertrophy (32 weeks- term)
25
evaluating fetal growth
establish GA as early as possible- using hx, LMP, early ULS
monitor wt gain
measure fundal ht at each visit
serial ULS PRN
26
fundus rises....by_______weeks it is still a pelvic organ
12 weeks
27
size>date discrepancy
```
inaccurate dating
LGA
multiple gestation
polyhydramnios
molar pregnancy (1st tri)
uterine anomaly (fibroid)
congenital anomaly
```
28
size < dating discrepancy
```
inaccurate dating
intrauterine growth restriction (IUGR)
oligohydramnios (having little fluid)
congenital anomaly
chronic maternal dz
viral infxn
```
29
large for gestational age (LGA)
birth wt>95th percentile
| usually >4000g (8lbs 13 oz)
30
risk factors for LGA
large mother
GDM
post-date
h/o large babies
31
complications of LGA
cephalopelvic disproportion
postpartum hemorrhage
stillbirth
neonatal complications
32
cephalopelvic disproportion (CPA)-
- labor dystocia/prolonged labor
- shoulder dystocia
- maternal soft tissue damage
- increased c/s
33
shoulder dystocia
head is pushed out of but shoulder is impinged & all the blood rushes to the babies head
have ~ 4min to get baby out before it dies from hemorrhage
34
neonatal complications d/t LGA
low apgar
hypoglycemia
hematologic abnormalities
35
hypoglycemia can cause?
seizures
| inability to regulate body temp
36
mngt of LGA
- screen for GDM
- ULS to r/o polyhydramnios, molar -pregnancy, fibroids
- serial ULS to monitor growth
- anticipate cephalopelvic disproportion (CPD) & sequelae, shoulder dystocia, postpartum hemorrhage
- offer delivery @ 39 wks if possible macrosomia
- offer elective c/s
- alert peds at delivery
37
prognosis of LGA
- risk of subsequent LGA baby
- increased risk of DM eventually in CH
- neonatal complications & sequelae
- increased risk of neoplasia in CH
38
IUGR
-impaired/restricted intrauterine growth
-significant b/c there is an inverse relationship bet. fetal/neonatal wt % & perinatal mortality
not be confused w/ SGA
39
SGA
neonatal dx of size below the 10th %
| usualy genetic or d/t inadequate nutrition
40
risk factors of IUGR
```
poor nutrition/wt gain
vascular dz/HTN
renal dz
infxn
genetic abnormality
multiple gestation
placental problems
pregestational diabetic (Type I)
drug use/smoking/EtOH
hypoxemia/ anemia
late onset prenatal care
low socioeconomic status
prothrombic d/o's
ART
```
41
symmetrical IUGR
the whole baby is smaller
| compromised growth in length, head circumference & wt
42
asymmetrical IUGR
decreased length & wt, but nml head circumference
| aka head sparing
43
complications of IUGR
increased risk of fetal distress
meconium staining
increased perinatal morbidity & mortality
44
Dx of IUGR
careful menstrual/medical/OB hx
accurate dating/ early sono
monitor for adequate wt gain
carefully eval fundal ht changes (watch for "progressive" growth, <2cm in 4wks suspicious)
2 sonos 4 wks apart to confirm (esp head & abdominal circumference, AFI check to r/o oligohydramnios)
45
management of IUGR
```
limit activity/ bedrest
nutrition
cessation of smoking
fetal surveillance (repeat sonos q 4-6 wks, NST's weekly, BPP's prn, amniocentesis for lung maturity
delivery of compromised fetus
```
46
birth defects
a major birth defect is one of medical, surgical or cosmetic significance
47
some causes of birth defects
```
genetic/ environmental factors
maternal age
illness
drug use
physical features of uterine environment
```
48
genetic causes of birth defects
```
single gene d/or (15-20%)
chromosomal abnormalities (5%)
```
49
environmental exposures & birth defects
```
maternal illness
substance use
infxn
drugs
chemicals
radiation
hyperthermia
mechanical/physical constraints
```
50
genetic d/o's general info
>90% do not survive to term
multiple organ systems tend to be involved
longevity & fertility of these individuals tend to be reduced
chromosomal abnormalities
single gene d/o's
non-mendellian patterns of inheritance
51
chromosomal abnormalities
affect 1:200 newborn infants
| nondisjunction, unequal recombination, inversions, deletions/suplications, translocations
52
single gene d/o's
autosomal dominant/recessive
| x-linked
53
non-mendellian patterns of inheritance
```
unstable DNA
fragile X syndrome
imprinting
mitochondrial inheritance
etc
```
54
maternal illness
pregestational DM
phenylketonuria
androgen producing tumors
autoimmune dz's
55
pregestational diabetes
2-3 fold increase in congenital anomalies (esp heart dz, spina bifida)
abnormal fetal growth
newborn hypoglycemia
stillbirth
56
newborn hypoglycemia
cyanosis
poor eating
seizures
damage to brain cells
57
phenylketonuria
can be minimized by dietary ctrl
microcephaly
MR
congenital heart dz
58
androgen producing tumors
virilization of female fetuses
59
autoimmune dz's
same or different toxicity to fetus
| tx of mother does not always reduce effects on fetus
60
teratogenic infections
CMV (cytomegalovirus)- can cause seizure, MR, etc
Parvovirus (aka 5th dz)
rubella (eye lesion, heart, CNS, etc)
toxoplasmosis (uncooked meat, cat feces)
varicella (13-20 wks= highest risk; last 10 days)
herpes
syphilis
61
teratogens
radiation
meds
EtoH, tobacco, recreational drugs
62
meds that are teratogenic
```
ACE inhibitors, chloramphenicol
warfarin/coumadin/anticoags
DES, toluene, iodides, lithium
accutane/isoretinoin, tetracycline
thalidomide, valproate, lead, rubella vaccine, anticonvulsants, antineoplastics, SSRIs
```
63
Avoid what in pregnancy
ibuprofen
ASA
sulfa drugs @ term
trimethoprim
64
alcohol in pregnancy
no amt considered safe
binge drinking worse than spread out
-no exact dose-response relationship bet amt & damage caused
65
alcoho + other factors that may effect outcome
maternal age
hih parity
being AA or Native American
genetics
66
exposure risk factors
```
low economic status
smoking
unmarried
unemployed
illicit drug use
h/o sexual/physical abuse
h/o incarceration
family member who drinks heavily
socially transient
psychologic stress/mental health d/o
```
67
fetal alcohol spectrum d/o (FASD)
describes the broad range of adverse sequelae
- no effect, nml
- fetal alcohol effects (FAE)
- alcohol related birth defects (ARBD)
- fetal alcohol syndrome (FAS)
68
Fetal alcohol syndrome (FAS)
most severe
affects 1-2 ounces daily
chronic alcohol consumption
69
what is the most important modifiable risk factor in pregnancy?
tobacco use
70
pathophys of tobacco use in pregnancy
impaired fetal oxygen delivery
CO exposure
direct damage to fetal genetic material
direct toxicity from >2500 subst. in cigs
directly impair LU develop.
sympathetic activation leading to accelerated HR & reduction in fetal breathing mvnt
genetics
71
impaired fetal ozygen delivery
placentas of smokers show structural changes that may contribute to abnormal gas exchange
72
carbon monoxide exposure
carboxyhemoglobin clears slowly from fetal circulation & diminshes tissue oxygenation
73
adverse effects of tobacco
```
infertility (maternal)
low birth wt
miscarriage
stillbirth
preterm premature rupture of membranes
placental abruption/previa
preterm delivery
congenital malformations
postnatal morbidity
preeclampsia
```
74
opiate exposure risks that are the same for pregnant & nonpregnant women
infxn
psychological stress
violence
75
S&S of high-risk chemical abuse
```
late prenatal care
multiple missed appts
impaired school/work performance
past OB h/o SAB, IUGR, premature birth, placental abruption, stillbirth, precipitous delivery
CH w/ neuro-developmental problems
h/o drug/EtoH problems
```
76
OB complications w/ opiate use
```
preeclampsia
3rd trimester bleeding
malpresentation
nonreassuring fetal status
meconium passage
low birth wt
perinatal mortality
puerperal morbidity
```
77
neonatal outcomes in opiate use
```
premature birth
neonatal opiate withdrawal
postnatal growth deficiency
microcephaly
neurobehavioral deficits
SIDS
```
78
cocaine use in pregnancy
related to dose:stage of pregnancy
dcreased birth wt, length, HC
increased risk prematurity, placental abruption, SAB, fetal death
readily crosses placenta
79
what is the major mechanism of fetal & placental damage is?
vasoconstriction
80
possible teratogenic effects of cocain
intestinal atresia
brain anomalies
cognitive development
*possibilities!
81
how long is cocaine detectable in neonatal urine, meconium, & hair
urine: tests + w/in 2 days of delivery, excreted w/in 12-24 hrs
meconium: + for 3 days
hair: + for months
82
what is the MC illicit substance taken during pregnancy?
marijuana
83
impact of marijuana?
unknown
not significantly related to growth measures, prematurity, congenital anomalies
*CH of heavy users had smaller HC at all ages
84
methamphetamine
neurotoxic agent that damages ending of brain cells containing dopamine
3.5x's more likely to be SGA
85
mgnt of pregnant substance users
```
screen all for EtOH & substance use
counsel regarding risks
behavioral/pharmacotherapy for addiction
multidisciplinary approach
test for STIs & tx
frequent visits to monitor status of both
ULS to get GA, baseline for growth
fetal surveillance if complications evident
inform peds of possible neonatal w/d
```
86
discourage what in women who continue to take illicit drugs?
breastfeeding
