Pretem Labor
Ramzy Nakad, MD
Preterm Birth
• Definition: Birth that occurs prior to
completion of 37 weeks of gestation.
• Preterm birth is the leading cause of neonatal
mortality and the most common reason for
antenatal hospitalization .
• In the United States, approximately 12% of all
live births occur before term, and preterm
labor preceded approximately 50% of these
preterm births.
Preterm Birth
• Account for approximately 70% of neonatal
deaths and 36% of infant deaths as well as 25–
50% of cases of long-term neurologic
impairment in children.
• Estimated annual cost of preterm birth in the
United States to be $26.2 billion or more than
$51,000 per premature infant.
Preterm Birth
• Classified into two main categories.
• Spontaneous: Approximately 40-50% are due
to spontaneous preterm labor with intact
membranes and 25-40% due to preterm
premature rupture of the membranes.
• Indicated: Deliberate intervention for variety
of maternal or obstetric indications 20-30%.
Preterm Labor
• Definition: Cervical change before 37 weeks of
gestation due to regular contractions.
• Causes ?!?!?!?!
Pretem Labor:
• Risk Factors
Multifetal gestation
Prior preterm birth
Preterm uterine contractions
Premature rupture of membranes
Pretem Labor:
• Risk Factors
Behavioral
. Low maternal pre-pregnancy weight
. Smoking
. Substance abuse
. Short inter-pregnancy interval
Pretem Labor:
• Risk Factors:
Vaginal bleeding
Urinary tract infections
Genital tract infections
Periodontal disease
Prediction of Preterm Labor
• Recognize the signs and symptoms:
. Menstrual-like cramps
. Low, dull backache
. Abdominal/ Pelvic pressure
. Increase or change in vaginal discharge.
Prediction of Preterm Labor
• Cervical change:
• Short cervix detected by ultrasound has the most value
with people that are high risk patients (had a previous
preterm delivery or have an anatomic defect of the
crevix).
• Early dilation and effacement of the crevix
Prediction of Preterm Labor
• Other modalities that showed no benefit in
improving outcomes of pregnancy in
asymptomatic women:
– FFN
– Bacterial vaginosis
– Home uterine contraction monitoring
Prevention of Preterm Labor
• Historically nonpharmacologic interventions
such as bed rest, abstention from intercourse
and hydration were recommended; Evidence
for the effectiveness of these interventions is
lacking, and adverse effects have been
reported.
Prevention of Preterm Labor
• There are currently no uniformly effective
interventions toprevent preterm labor ,
regardless of risk factors.
Prevention of Preterm Labor
• Treatments that have been proved to affect
outcome
- 17OH caproate progesterone for patients
with history of preterm delivery.
- Progesterone for short cervix
- Antenatal corticosteroids
Betamethasone or Dexamethasone
- Targeted use of magnesium sulfate for fetal
neuroprotection.
Evaluation of a Patient With Suspected
Preterm Labor
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History & Physical
Place patient on the external monitor
Ultrasound
Cervical evaluation
- if PPROM use sterile speculum exam
• Collect cultures including GBS, GC and
perform a wet mount to rule out BV.
Management of Patients with Preterm
Labor
• Purpose in treating preterm labor is to delay
delivery if possible until fetal maturity is
attained.
• Corticosteroids up until 34 weeks.
• Tocolysis: Stopping contractions.
• Magnesuim Sulfate for neuroprotection up
until 32 weeks.
• Possible amniocentesis if infection is
suspected.
Contraindications to Tocolysis
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Intrauterine fetal demise
Lethal fetal anomaly
Nonreassuring fetal status
Severe preeclampsia or eclampsia
Maternal bleeding with hemodynamic instability
Chorioamnionitis
Preterm premature rupture of membranes*
Maternal contraindications to tocolysis (agent
specific)
Premature Rupture of Membranes
• PROM is the rupture of the chorioamniotic
membrane before the onset of labor; happens
with about 8% of term pregnancies.
Preterm PROM
• PPROM, defined as PROM that occurs before
37 weeks of gestation, associated with 30% of
preterm deliveries.
• Major complication is intrauterine infection.
• Consequences of PPROM depend on
gestational age.
• <22 weeks associated with incomplete
alveolar development.
PROM; Etiology
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Infections
Smoking; two fold increase
Short cervix
Previous preterm labor
Polyhydramnios
Multiple gestations
Threatened abortion
Chorioamnionitis
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Fever > or = 100.5
Fundal tenderness
Tachycardia ( maternal and fetal)
Treatment is antibiotics and prompt delivery
ROM diagnosis
• Nitrazine test, amniotic fluid PH is above 7.1
turns blue
• Fern test
• Pooling
• Ultrasound?role
• Carmine dye
Evaluation and management
• History and Physical exam
• Sterile speculum exam, collect vaginal
cultures. GC-C, GBS.
• Ultrasound