Preterm Labor
Audace NIYIGENAIntern in Gynecology & Obstetrics
In Butare University Teaching HospitalSupervised by
Dr Ntwali NDIZEYE
ObjectivesDefine preterm laborDiscuss epidemiologyReview risk factorsDiagnosis Review complicationDiscuss Management
Case studyM.E 19y Admitted on 19th Jan. 2013Transferred from Nyanza DH
Nifedipine 20mg bidDexametasone 12mg 2times
SymptomsPeriodic pelvic pain and back pain for 2 daysNo bleeding, no fluid gush
G.O G1P0Lmp 12th Jull. 2012 GA 27W2D
Case study cntMhx:
No hx of STINo diseases on pregnancyNo asthmaticHIV negNo alcoholNo tobaccoNo trauma
Low socio economic status
Case study cntP/E
HEENT: no pallor, no oedema, no jaundiceChest: good symmetric chest expansion, lung
clear, S1 & S2 well audible without added sound
Abdomen & pelvic: Gravid uterus FH: 24cm Bcf: 148b/m Cephalic presentation 2 contractions/10m Cervix dilatation 4cm Effacement 100% Engagement 1/5
Diagnosis: Preterm labor
Case study cntSpontaneous rupture of membrane at 13h15’14h45’
Eutocic delivery of preterm babyAPGAR 3, weight:900grTransferred in neonatology (but died in the
evening)
Define preterm labor
Term pregnancy - 37 to 42 weeks gestationPreterm pregnancy 24 to 37 weeks gestationPreterm labor is occurrence of uterine
contractions between 24 to 37 weeks of gestation( amenorrhea)
Preterm labor is the presence of contractions of sufficient strength and frequency to effect progressive effacement and dilation of the cervix between 20 and 37 weeks' gestation (WHO)
Gynecology and obstetrics clinical protocols & treatment guidelines
Epidemiology
Preterm Birth 12 % of deliveries/yr are preterm71.2% 34-36 weeks13% 32-33 weeks10% 28-31 weeks6% <28 weeks
Preterm BirthSpontaneous preterm labor 30-50%Multiple gestation 10-30%PPROM 5-40%Preeclampsia/eclampsia 12%Antepartum bleeding 6-9%Fetal growth restriction 2-4%Other 8-9%
Survival in Premature Infants23 wks – 17%24 wks – 39%25 wks – 50%26 wks – 80%27 wks – 90%28-31 wks – 90 to 95%32-33 wks – 95%34-36 wks – approaches
term survival ratesSources: march of Dimes, Quint Boenker Preemie Survival Foundation
Review risk factors
Risk Factors for PTDPrevious PTBMultiple gestationIncreased uterine size
(Polyhydramnios, twins)
Uterine abnormalities Maternal InfectionsPlacental pathologyMaternal traumaSmoking (Substance
abuse)
Maternal age extremes
AnemiaLow BMI < 20cervical
incompetencySevere stressorsShort inter-
pregnancy interval
Diagnosis
Signs and SymptomsPelvic and Back painUterine contractionsCervix dilatation and effacement
Investigations FBCVaginal swab for lab analysisUrine analysisMaternal and fetal screening for infectionsObstetric Ultrasound
Review complication
Complications of PrematurityRDSIVHFeeding
difficulties/NECApneaPDAInfectionJaundiceHypothermiaNeurobehavioralROPAnemia
Management
Goals of Treatment of PTLHalt contractions temporary by
tocolysingAllow 48 hr+ for steroids to be givenAllow for transport to delivery
location with NICU capability
SteroidsReduce incidence of RDS, IVH, NEC, sepsis,
and mortality by about 50%Dexamethasone 6 mg IM 12 hr x 4 (cervix
dilatation < 4cm)Dexamethasone 12mg IM 12 hr x 2 ( cervix
dilatation > 4 cm) (Gynecology and obstetrics clinical protocols & treatment guidelines)
TocolysisBeta agonists ( terbutaline, salbutamol)Magnesium sulfateIndomethacinAtosibanNifedipine
TocolysisRisk/benefit ratio of various treatments
Beta agonists (salbutamol, terbutaline)Tachycardia, hypotension, tremor, palpitations, chest
discomfort, hypokalemia, hyperglycemiaMagnesium sulfate
Nausea, flushing, fatigue, diaphoresis, loss of DTRs, respiratory depression, cardiac arrest
IndomethacinMaternal GI SE, premature closure of ductus,
oligohydramniosAtosiban
Possible increase in fetal/neonatal morbidity/mortality; not available in US
CAUTION we should avoid combining tocolytics (Green-top guideline no:1b feb 2011)
TocolysisNifedipine
Low costOralLow incidence of side effects (hypotension, dizziness,
flushing)
Often considered first lineDose:
20mg start dose and 10-20 mg 3 to 4 times daily
Total ≥ 60mg appears to be associated with increase of 3 to 4 fold the bad event of headache and hypotension
Caution: be careful when use in multiple pregnancy, rupture of membrane, sepsis, diabet mellitus and cardiac disease.
(Source: the royal Australian and new Zealand college of obstetrics and gynecology C-obs 15)
Management after TocolysisIf maternal and fetal conditions are stable,
can be managed at homeAvoid excessive physical activity; most
advocate pelvic restContinued tocolytics have not shown definite
benefit
Prevention of PTBReduce/eliminate risk factors, if possibleNot proven to be effective: bedrest, home
uterine monitoring, prophylactic tocolytics, prophylactic antibiotics, abstinence
To retain Preterm labor is the presence of sufficient
uterine contractions to effect progressive cervix changes between 20 and 37 weeks' of gestation
Various strategies that have been used to prevent or treat preterm labor, haven't proven effective.
Tocolysis should be considered only for 2 days- for corticosteroids action,gain time for transfer to a tertiary center .
ReferencesUpToDate19.3 2009 offlinemarch of Dimes, Quint Boenker Preemie
Survival FoundationGynecology and obstetrics clinical protocols
& treatment guidelines Sept.2012the royal Australian and new Zealand college
of obstetrics and gynecology C-obs 15Green-top guideline no:1b Feb.2011
Thanks
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