Preterm Labor Flashcards
What is preterm birth
After 20wks and before 37 completed
Upon which does the mortality and morbidity depend on in preterm labor
Gestational age
What are the risk factors for preterm labor
1- prev 2- poor placenta implantation 3- iatrogenic (pre-eclampsia\IUGR\thrombo) 4- ART (AVF) 5- maternal (advanced age, disease, obesity) 6- multiple gestations 7- rupture of membrane 8- APH & cervical incompetency 9- stress
What is early pre-term
<32 weeks
What is the most common factor for preterm
Unkown
What is the most known common factor for preterm
infection
Name infection that is associated w\preterm
BV
How does infection affecting the cervicx cause preterm labor
Disrupt the fetal membrane > release FFN and preterm labor
What is a placental cause of preterm labor
- abnornal trophoblast invasion
- progestrone dysregulation
How does stress induce preterm labor
Cortisol and catecholamine
How does uterine stretch cause preterm labor and where do we commonly see it
Cause failure of parathyroid related protein PTrP
We see it in: multiple gestation, polyhydraminos & macrosomia
What is the role of PTrP?
Keeping the myometrium muscles relaxed
What are the most common causes of preterm labor (spont, or, induced)
Spontanous
Name iatrogenic causes of preterm birth
Placenta previa or abruptio, fetal growth restriction, multiple gestation, pre-eclampsia
How to predict the chance of preterm labor
Fibronectin test
What does the fibronectin test indicate
Labor could happen within 7 days
What is the diagnostic criteria for preterm labor
- uterine contraction (4 per 20\8 per 60)
- cervical changes (80% effaced or 2cm dilated)
What is the investigation that you’d like to do for patients undergoing preterm labor
CTG, US, HVS, baseline investigation + cervical assessment
What is the initial management that you’d like to do for these patients with preterm labor
1- Bed rest, hydration
2- antibiotics
3- steroid (+- tocolytics)
Is bed rest actually affective in preterm labor
Yes 20% the contraction will stop
What are the AB that are usually given in preterm labor
Ab for 48 hours
What is the role of steroids in preterm
Induce lung maturity
Why do we give tocolytics in preterm labor
1- give time for transfer
2- give time for steroid to work
(Postpone labor for 48 hours)
What are the uterine tocolytic agents used in preterm labor
PCOS NO bleeding
- PGs
- Cyclooxygenase (indomethacin)
- Sulfate
- Nifedipine
- oxytocin antagonist
What is the maximum side effect for the
- mother
- fetal
- B-blocker (tribtualine)
- indomethacin
What is the most commonly used tocolytic
Nefidipine
What tocolytic medication should be avoided\indicatedfor cardiac patients
avoided: Nefidepine
Indicated: atopan
What is the role of magnesium sulfate
Lung maturation, prevent eclampsia, neuroprotection
What is the maternal complication in preterm
- Retained plcacenta
- need of c\s
What is the risk on fetus for preterm
RDS, patent ductus, retinopathy, hypoglycemia and thermia, anemia
What medication stimulate the closuer of ductus arteriosus
Indomethacin
What is the definition of premature rupture of membrane?
Spontanous rupture of membrane (amniorrhexis)before onest of labor
- preterm premature: before 37 weeks
What are the causes for premature rupture of membrane
- unknown
- vaginal\cervical infection
- abn membrane physiology (apoptosis 2ndary to oxidative stress)
- cervical insufficiency
- nutritional def.
How to diagnose PROM
1- hx of vaginal loss of fluid
2- amniotic fluid in vagina
3- speculum + US
What are the tests for sterile examination to diagnose PROM
Pooling - ferning - nitrazine - amnisure
What is pooling test?
Leakage by vision
What is fening test
Swab from posterior vernix
What is nitrazine test?
PH test, if alkaline this is either sperm or leaking of amniotic fluid
What is amnisure
Alpha-microglobulin-1
What are the US findings if there’s PROM?
AFI<5cm
What are the ddx for PROM
Urinary incontience, leucorrhea (discharge) - loss of mucus plus - vaginal infection or secretion
What is the property of the amniotic sac and fluid
Sac: mechanical protection against infection
Fluid: bacteriocidal effect
Is intact membranes an absolute barrier to infection?
No, there’s hematogenous spread of infections
What is the workup for PROM
Same as preterm labor except add th amniotic sample for culture & sensitivity
How to treat PROM
Same as PTL
When to deliver patient with PROM and when to provide medications
According to GA
- > or equal to 36
- <36
What if there’s PROM with no contraction >or equal to 36
- Induction of labor within 6-12hrs
- if no evidence of infection & cervix isn’t favorable > in 24hrs
What is the management of PPROM <36
- if stable, no contraction & infection: expectant until lung maturation.
- antibiotics
- look for chorioaminitis
How to diagnose chorioaminitis?
- Temp>= 38 w\no infection
- fetal tachycardia
- uterine tenderness & irritability on CTG
- leukocytosis
What is the Ab used in PPROM?
IV erythromycin 48hrs then PO 5x
When is it applicable to manage these patients as outpatient
- no infection
- normal AFI
- well educated
- vertex presentation
- closed cervix
- home instructions
What are the home instructions to give to patients with PPROM
1- no coital activity or PA
2- monitor temp because PROM=infection
3- weekly hospital visit\CTG\ growth
What if there’s chorioaminitis in PROM?
Immidiate delivery is indicated
Is it recommended to give tocolysis to patients with chorioaminitis?
Not recommended
