Preterm and Postterm Flashcards
neonates who are born too small
Low birthweight
neonates born too early
preterm or premature birth
weight of LOW birthweight
1500-2500g
weight of VERY LOW birthweight
500-1500g
weight of EXTREMELY LOW birthweight
500-1000g
classification of:
- small for gestational age (SGA)
- large for gestational age (LGA)
- appropriate for gestational age (AGA)
SIZE
classification of:
- preterm (early, late)
- term (early, late)
- postterm
AOG
Birthweight BELOW the 10th percentile for gestational age
small-for-gestational age (SGA)/
fetal growth restriction/
intrauterine growth restriction (IUGR)
IUGR: fetus inside the mother
SGA: fetus already delivered
Birthweight ABOVE the 90th percentile for gestational age
large-for-gestational age (LGA)
weight between the 10th and 90th percentiles
Appropriate-for-gestational age(AGA)
born before 37 completed weeks
preterm/ premature birth
> 42 weeks
postterm
37-42 weeks
term
39- 40 6/7 weeks
Late term
37-38 6/7 weeks
Early term
34-36 weeks
Late preterm
<33 6/7 weeks
Early preterm
causes of preterm birth
- spontaneous preterm labor
- PPROM
- multifetal pregnancy
contributing factors of preterm birth
- pregnancy factors
- lifestyle factors
- genetic factors
- periodontal disease
- interval between pregnancies
- prior preterm birth
- infection
4 major causes of spontaneous preterm labor
- uterine distention
- maternal-fetal stress
- premature cervical changes
- infections
TRUE/FALSE
2 examples of uterine distention are multifetal pregnancy and hydramnios
TRUE
examples of uterine distention
- multifetal pregnancy
- hydramnios
leads to premature loss of uterine quiescence due to the release of:
- CAP
- GRP
- stretch induced potassium channel TREK-1
- maternal release of corticotropin release hormone and estrogen
Uterine distention
Early uterine distention releases maternal CRH and estrogen which enhances the expression of myometrial _________.
CAP (contractions associated protein)
levels of __________ are INCREASED with stretch to promote myometrial contractility
GRP (gastrin releasing peptides)
This can inhibit uterine contractility
GRP antagonists
this is UPREGULATED during gestation and DOWNREGULATED in labor
stretch induced potassium channel- TREK 1
Upregulated- gestation
downregulated- labor
these 2 hormones can further enhance the expression of myometrial CAP genes
corticotropin releasing hormone (CRH)
estrogen
true/false
increase cortisol and estrogen can lead to loss of uterine quiescence
TRUE
INCREASE cortisol and estrogen can lead to loss of uterine quiescence
true/false
one potential mechanism for stress-induced preterm labor is PREMATURE DEACTIVATION of the placenta-adrenal endocrine axis
FALSE
one potential mechanism for stress-induced preterm labor is PREMATURE ACTIVATION of the placenta-adrenal endocrine axis
Activation of WHAT AXIS yields rising maternal serum levels of placental derived corticotropin-releasing hormone (CRH)
Plancenta-adrenal endocrine axis
- Activation of this axis yields rising maternal serum levels of placental derived corticotropin-releasing hormone (CRH)
This hormone raises adult and fetal steroid hormone production and promotes early loss of uterine quiescence
Placental derived CRH
True/false
early rise in serum estriol concentrations is noted in women with subsequent preterm labor
TRUE
stretch-induced potassium channel
TREK-1
true/false
premature labor onset precedes premature cervical remodeling
false
premature cervical remodeling precedes premature labor onset
Cervical dysfunction
Cervical dysfunction of either of these parts is the underlying cause
cervical dysfunction of either the EPITHELIA or STROMAL EXTRACELLULAR MATRIX is the underlying cause.
Mechanical competence of the cervix can be reduced
Cervical dysfunction
genetic mutations in components of collagen and elastic fibers or protein required for their assembly
Cervical dysfunction
genetic mutations in components of collagen and elastic fibers or protein required for their assembly- example of reduced mechanical competence of the cervix
genetic mutations in components of collagen and elastic fibers or protein required for their assembly are risk factors for what conditions
- cervical insufficiency
- PPROM
- preterm birth
Source/ mode of transmission of intrauterine infection
- TRANSPLACENTAL TRANSFER of maternal systemic infection
- RETROGRADE FLOW of infection into peritoneal cavity via fallopian tubes
- ASCENDING INFECTION with bacteria from vagina and cervix
most common entry route of Intrauterine infection
Ascending infection
true/false
This anatomical arrangement provides passageway for microorganisms: the lower pole of the fetal membrane– Decidual Junction is contiguous with the Cervical Canal Orifice
TRUE
This anatomical arrangement provides passageway for microorganisms: the lower pole of the fetal membrane– Decidual Junction is contiguous with the Cervical Canal Orifice
the ascending microorganisms colonize these parts where they may enter the AMNIOTIC SAC
the ascending microorganisms colonize the CERVIX, DECIDUA, and possible the MEMBRANES where they may enter the AMNIOTIC SAC
Category of infection:
bacterial vaginosis
Category I
!!! REMEMBER: BDAF !!! Bacterial vaginosis- category I Decidual infection- category II Amniotic infection- category III Fetal systemic infection- category IV
Category of infection:
decidual infection
Category II
!!! REMEMBER: BDAF !!! Bacterial vaginosis- category I Decidual infection- category II Amniotic infection- category III Fetal systemic infection- category IV
Category of infection:
amniotic infection
Category III
!!! REMEMBER: BDAF !!! Bacterial vaginosis- category I Decidual infection- category II Amniotic infection- category III Fetal systemic infection- category IV
Category of infection:
Fetal systemic infection
Category IV
!!! REMEMBER: BDAF !!! Bacterial vaginosis- category I Decidual infection- category II Amniotic infection- category III Fetal systemic infection- category IV
Microbes associated with preterm birth
Gardnerella vaginalis
Fusobacterium spp.
Mycoplasma hominid
Ureaplasma urealyticum
Spontaneous rupture of membranes before 37 completed weeks or before labor onset
PPROM
Major predisposing events of PPROM
- intrauterine infection
- oxidative stress-induced DNA damage
- premature cellular senescence
Associated risk factors of PPROM
- lower socio-economic status
- BMI of <19.8
- nutritional deficiencies
- cigarrette smoking
what is the BMI that is considered a risk factor of PPROM
BMI: <19.8
pathophysiology of PROM
increased apoptosis markers in amnion will lead to _____
increased apoptosis markers in amnion will lead to CELL DEATH
pathophysiology of PROM
increased proteases will lead to _________
increased proteases will lead to WEAK AMNION
most important risk factor of preterm birth
prior preterm birth
gum inflammation due to anaerobic microorganism
Periodontal disease
True/false
antibiotic prophylaxis is recommended to prevent preterm birth in women with preterm labor and intact membranes
FALSE
normal hydrogen peroxide-producing lactobacillus predominant vaginal floral is replaced by anaerobes
Bacerial vaginosis
etiology/microbes of bacterial vaginosis
- Gardnerella vaginalis
- Mobiluncus species
- Mycoplasma hominis
Vaginal pH of bacterial vaginosis
> 4.5
vaginal discharge of bacterial vaginosis
homogenous; amine odor when mixed with KOH
vaginal epithelial cells heavily coated with bacilli “clue cells”
Bacterial vaginosis
Gram staining of bacterial vaginosis
show few white cells along w/ mixed flora as compared with the normal predominance of lactobacilli
scoring used for gram staining in bacterial vaginosis
nugent score
bacterial vaginosis is clinically assessed by _______
bacterial vaginosis is clinically assessed by AMSEL CRITERIA
management of bacterial vaginosis
Metronidazole 500 mg BID for 7 days
etiology of Periodontitis
- Fusobacterium nucleatum
- Capnocytophaga spp.
Management of Periodontitis
- teeth cleaning and polish,
- deep root scaling and planning,
- plus metronidazole
regular contractions before 37 weeks associated with cervical discharge
Preterm Labor
-regular contractions before 37 weeks associated with cervical discharge
Symptoms that are empirically associated with impending preterm birth:
- contractions with pelvic pressure
- menstrual-like cramps
- watery vaginal discharge
- lower back pain
Cervical changes in preterm labor
- asymptomatic cervical dilatation after midpregnancy
true/false
prenatal cervical examinations in asymptomatic women are neither beneficial nor harmful
TRUE
glycoprotein produced by:
- hepatocytes
- fibroblasts
- endothelial cells
- fetal amnion cells
fetal Fibronectin (fFn)
high concentrations in Maternal blood and amniotic fluid
fetal Fibronectin (fFn)
function as:
- INTERCELLULAR ADHESION during implantation
- maintenance of PLACENTAL ADHERENCE to uterine decidua
fetal Fibronectin (fFn)
true or false
fetal Fibronectin (fFn) is detected in cervico-vaginal secretions before membrane rupture was possible marker for preterm labor.
TRUE
fetal Fibronectin (fFn) is detected in cervico-vaginal secretions before membrane rupture was possible marker for preterm labor.
value of POSITIVE fetal Fibronectin (fFn)
> 50ng/mL
Positive fetal Fibronectin (fFn) as early as ________ is a powerful indicator of subsequent preterm birth
18-22 wks
true/false
value of cervical length to predict preterm birth is ONLY for high-risk women
TRUE
value of cervical length to predict preterm birth is ONLY for high-risk women
true/false
Routine cervical UTZ has NO ROLE in screening of normal risk pregnant women
TRUE
Routine cervical UTZ has NO ROLE in screening of normal risk pregnant women
mean cervical length at 24 weeks AOG
35mm
women with previous preterm birth should undergo cervical length UTZ at what AOG?
between 16-24 wks AOG
length of shortened cervix
<25mm
true/false
shortened cervix (<25mm) is NOT correlated with another subsequent preterm birth before <35 wks
FALSE
shortened cervix (<25mm) is correlated with another subsequent preterm birth before <35 wks
done emergently when cervical incompetence is recognized in women with threatened preterm labor
Rescue cerclage
Consider cerclage with these following conditions
- singleton pregnancy
- prior spontaneous preterm birth <34 wks
- cervical length: <25mm
- AOG: <24 wks
a history of vaginal leakage of fluid
PPROM
Sterile speculum examination: (+) gross vaginal pooling of amniotic fluid, clear fluid from the cervical canal
PPROM
used for the confirmation of PPROM
Ultrasound
- to assess the amniotic fluid
- identify the presenting part
- estimate gestational age
pH testing of PPROM
alkaline= 7.1-7.2
Conditions that gives a false positive result for the diagnosis of PPROM
false positive results:
- semen
- blood
- antiseptic
- bacterial vaginosis
Management for PPROM
<24 wks
(E/I, S, A, T)
E/I= Expectant management/ Induction of labor S= Single corticosteroid course A= Antimicrobials T= Tocolotyics (no consensus)
Management for PPROM
24-31 wks
(E,S,A, T + G,M)
E= expectant management S= single corticosteroid course A= Antimicrobials T= Tocolotyics (no consensus) M=Magnesium sulfate (neuroprotection) G= Group B streptococcal prophylaxis
Management for PPROM
32-33 wks
(E,S,A + G)
E= expectant management S= single corticosteroid course A= Antimicrobials G= Group B streptococcal prophylaxis
Management for PPROM
>34 wks
(I,G,S)
I= Induction of labor/ planned delivery
G= Group B steptoccoccal prophylaxis
S=single corticosteroid course (up to 36 6/7 wks)
given to the patient to prevent cerebral palsy for neonates
Magnesium sulfate
- given at 24- 31 wks to women at risk of imminent preterm delivery
- 6g bolus over 2-30 mins followed by infusion of 2g/hr for at least 12 hours.
- threatened preterm delivery from 24th-27 6/7 wks.
Used to detect infection for preterm labor with INTACT membranes
Amniocentesis
-not routinely recommended
true/false
Antimicrobials is recommended if will be used solely to prevent preterm labor
FALSE
Antimicrobials is NOT recommended if will be used solely to prevent preterm labor. It is used for ONLY for infection treatment
currently recommended prophylaxis to preterm labor with intact membrane ONLY within RESEARCH protocols
cervical pessaries (arabin pessary)
reasonable management for women facing poor pregnancy prognosis due to cervical dilatation (painless) at mid-gestation
Emergency or rescue cerclage
with appropriate counseling
This agents do not markedly prolong gestation but may delay delivery in women for up to 48 hours
tocolytic agents
may allow transport to an obstetrical center with higher level neonatal care
tocolysis to treat preterm labor
permit time for a course of corticosteroid therapy
tocolysis to treat preterm labor
6 Classification of Tocolysis
- Beta adrenergic receptor agonist
- Magnesium sulfate
- Prostaglandin inhibitors
- Ca++ channel blockers
- Atosiban
- Nitric Oxide donors
reduce intracellular ionized calcium levels and prevent activation of myometrial contractile proteins
Beta adrenergic receptor agonist
Ritodine, Terbutaline, Isoxuprine
Beta adrenergic receptor agonist
side effects of Beta adrenergic receptor agonist
- pulmonary edema
- volume overload
- arrhythmia
- myocardial ischemia
in a sufficiently high concentrations, it can alter myometrial contractility (indirect tocolytic)
Magnesium sulfate
may inhibit labor
Calcium antagonist
dosage of magnesium sulfate
4g IV loading dose followed by a continuous infusion of 2g/hr
this tocolytic agent is ineffective and potentially harmful.
Prolonged use: fetal bone thinning and fractures
Magnesium sulfate
has a dual role of tocolytic effect + neuroprotective
Magnesium sulfate
MOA: inhibits prostaglandin syntheses or by blocking their action on target organs
Prostaglandin inhibitors
indomethacin
Prostaglandin inhibitors
has a side effect of Patent Ductus Arteriosus
Prostaglandin inhibitors
Side effects: (PONI)
- Patent ductus arteriosus
- Oligohydramnios
- Necrotizing enterocolitis
- Intraventricular hgg.
act to inhibit calcium entry through the cell membrane channels thus decreasing uterine contractility
Calcium channel blockers
one of the primary drugs used for tocolysis
Calcium channel blockers
Nifedipine
Calcium channel blockers
the combination of these 2 drugs for tocolysis is potentially dangerous
Nifedipine + MgSO4
Nifedipine enhances the neuromuscular blocking effect of Mg++, which can interfere with PULMONARY AND CARDIAC FUNCTION
Nona-peptide oxytocin analogue
Atosiban
- Nona-peptide oxytocin analogue is an oxytocin receptor antagonist (ORA)
competitive antagonist of oxytocin-induced contractions
Atosiban
only drug formulated for preterm labor
Atosiban
true/false
Atosiban is the true tocolytic agent while other drugs promoting tocolysis is just their side effect
TRUE
not effective and causes MATERNAL HYPOTENSION
Nitric Oxide donors
Nitroglycerine
Nitric Oxide donors
Nifedipine
Calcium channel blockers
Ritodine, Terbutaline, Isoxuprine
Beta adrenergic receptor agonist
indomethacin
Prostaglandin inhibitors
Atosiban
Nona-peptide oxytocin analogue
drug used for lung maturation
corticosteroids
corticosteroids used for the management of preterm labor with intact membranes
Bethamethasone (12mg every 24 hrs x 2 doses)
Dexamethasone (6mg every 12 hrs x 4 doses)
RESCUE DOSE: single course of corticosteroid given to women whose prior course was administered at least 7 days previously and who are <34 wks AOG
what is the management?
Patient admitted at 30 wks and you gave her steroids as a management. Patient came back after a week and labored at 31 wks.
give rescue dose of corticosteroids
although frequently prescribed, this management is rarely indicated
Bed rest
done if the cause of preterm labor with intact membrane is due to cervical incompetence
Emergency or rescue cerclage
true/false
Parenteral beta antagonist prevent preterm birth for at least 48 hrs facilitating maternal transport and giving steroids
False
Parenteral beta AGONISTS prevent preterm birth for at least 48 hrs facilitating maternal transport and giving steroids
Management of preterm labor with intact membranes
- Amniocentesis (detect infection)
- Corticosteroids (lung maturation)
- MgSO4 (prevent cerebral palsy in neonates)
- Antimicrobials (infection treatment)
- Bed Rest
- Cervical Pessaries (for research only)
- Emergency or rescue cerclage
- Tocolysis (treat preterm labor)
fetal tachycardia especially with ruptured membranes is suggestive of _______
SEPSIS
- fetal tachycardia especially with ruptured membranes
ACOG recommends these drugs to prevent neonatal group B streptococcal infection for women in preterm labor
Penicillin G or Ampicillin IV every 4-6 hours until delivery for women in preterm labor
True/false
preterm newborns have germinal matrix bleeding that can extend to more serious intraventricular hgg.
TRUE
preterm newborns have germinal matrix bleeding that can extend to more serious intraventricular hgg.
Cesarean delivery to obviate trauma from labor
and vaginal delivery to prevent these complications has not been validated
True/false
Some evidence supports that intrapartum ALKALEMIA may intensify some of the neonatal complications usually attributed to preterm delivery
FALSE
Some evidence supports that intrapartum ACIDEMIA may intensify some of the neonatal complications usually attributed to preterm delivery
newborn with recognizable clinical features indicating a pathologically prolonged pregnancy
Postmature
True/false
Postmature is reserved for a specific clinical fetal syndrome
TRUE
preferred expression for an extended pregnancy
Postterm or Prolonged pregnancy
postdates- should be an abandoned term to call postterm pregnancy, because the real issue in many postterm pregnancies is “post-what dates?”
42 complete wks (294 days) or more from the first day of LMP
Postterm
Difference of postmature and postterm/prolonged pregnancy
Postterm/prolonged pregnancy: pertains to the AOG
Postmature: fetal features of post-maturity
True/false
In postterm pregnancy, the baby will either be growth-restricted or macrocosmic
TRUE
In postterm pregnancy, the baby will either be GROWTH-RESTRICTED or MACROSCOMIC
Maternal/Perinatal
Adverse _________ outcomes associated with postterm are the ff:
- fetal macrosomia
- oligohydramnios
- preeclampsia
- CS: dystocia, fetal jeopardy
- shoulder dystocia
- postpartum hgg.
- perineal lacerations
Adverse MATERNAL outcomes associated with postterm:
- fetal macrosomia
- oligohydramnios
- preeclampsia
- CS: dystocia, fetal jeopardy
- shoulder dystocia
- postpartum hgg.
- perineal lacerations
Maternal/Perinatal
Adverse _________ outcomes associated with postterm are the ff:
- stillbirth
- post-maturity syndrome
- NICU admission
- meconium aspiration
- neonatal convulsions
- hypoxic-ischemic encephalopathy
- birth injuries
- childhood obesity
Adverse PERINATAL outcomes associated with postterm
- stillbirth
- post-maturity syndrome
- NICU admission
- meconium aspiration
- neonatal convulsions
- hypoxic-ischemic encephalopathy
- birth injuries
- childhood obesity
wrinkled patchy peeling skin
Post-maturity syndrome
long thin body, wasting
Post-maturity syndrome
open eyed, alert
Post-maturity syndrome
appears old and worried
Post-maturity syndrome
long nails
Post-maturity syndrome
true/false
Placental Dysfunction: the concept that post-maturity stems from placental insufficiency has persisted despite an absence of morphological or significant quantitative findings of placental degeneration
TRUE
Placental Dysfunction: the concept that post-maturity stems from placental insufficiency has persisted despite an absence of
morphological or significant quantitative findings of
placental degeneration
Consequence of cord compression associated with oligohydramnios
- Antepartum fetal jeopardy
- Intrapartum fetal distress
Management for one or more prolonged decelerations on CTG
emergency CS
In Fetal distress/ Oligohydramnios, findings are consistent with ___________ as the proximate cause of the non-reassuring tracings
Fetal distress/ Oligohydramnios:
Findings are consistent with CORD OCCLUSION as the proximate cause of the non-reassuring tracings
Meconium released into an already reduced amnionic fluid volume results in thick, viscous meconium
Meconium Aspiration Syndrome
True/False
STILLBIRTHS were LESS common among growth-restricted infants who were delivered at 42 weeks or beyond
False
STILLBIRTHS were MORE common among growth-restricted infants who were delivered at 42 weeks or beyond
True/False
1/3 of the postterm stillbirths were growth restricted
TRUE
1/3 of the postterm stillbirths were growth restricted
Complications of Postterm
- Oligohydramnios
- Macrosomia
- Medical and obstetrical complications (hypertension, diabetes, prior CS)
AFI of Oligohydramnios
<5cm
Although growth velocity SLOWS at 37 weeks, most fetuses continue to gain weight leading to ____
Macrosomia
TRUE/FALSE
Pregnancy should not be allowed to continue past 37 weeks
FALSE
Pregnancy should not be allowed to continue past 42 weeks
bishop score of unfavorable/undilated cervix
Bishop score of <7
2-fold higher CS rate for “dystocia”
ACOG concluded that ___________ gel can be used safely in postterm pregnancies→dilate
ACOG concluded that PROSTAGLANDIN GEL (PGE2 and PGE1) can be used safely in postterm pregnancies→dilate
Cervical length of ______ determined by TVS was predictive of successful induction
Cervical length of 3cm OR LESS determined by TVS was predictive of successful induction
Decreased the frequency of postterm pregnancy
Sweeping or stripping of the membranes
True/false
Stripping did not modify the risk for cesarean delivery, and maternal and neonatal infections were not increased
TRUE
Stripping did not modify the risk for cesarean delivery, and maternal and neonatal infections were not increased
Important in predicting successful postterm pregnancy induction
Station of the vertex
if station is TOO HIGH, induction may NOT be successful
TRUE/FALSE
Antepartum interventions are indicated in cases of postterm pregnancies
TRUE
Antepartum interventions are indicated in cases of postterm pregnancies
41 wks w/ FAVORABLE cervix (soft, effaced, anterior in position)
Induce labor
41 wks w/ UNFAVORABLE cervix
Antepartum fetal testing
42 wks, whether cervix is favorable or not
Labor is generally induced
41 0/7 wks, uncomplicated
Consider:
- fetal surveillance
- membrane sweeping
- labor induction
41 0/7 wks, complicated (Hypertension, Oligohydramnios, Decreased fetal movement)
Labor induction
42 0/7- 42 6/7 wks
Labor induction
True/False
Usage of labor induction methods (Prostaglandins, etc.) will depend on AOG
True
Usage of labor induction methods (Prostaglandins, etc.) will depend on AOG
this test is done prior to induction
Contraction stress test
if (-): start induction
if (+): CS
Aids in identification of thick meconium stain
Amniotomy
- Aids in identification of thick meconium stain
- aspiration may cause severe fetal pulmonary dysfunction and neonatal death
Further reduction in fluid volume following amniotomy can enhance the possibility of _________
Further reduction in fluid volume following amniotomy can enhance the possibility of CORD COMPRESSION
Can provide more precise data concerning FHR and uterine contractions after membrane rupture
placement of scalp electrode and intrauterine pressure catheter
management when CPD is suspected or uterine dysfunction evident and has thick meconium staining
CS delivery