Chapter 15: Preterm Labor Flashcards
What is preterm?
Preterm =
Common preterm complications
Common complications: Respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, sepsis, neurologic impairment, and seizures
Longterm morbidities of preterm
Long term morbidities: Bronchopulmonary dysplasia and cerebral palsy
What percent of kids are premature?
The 11-12% of babies born prematurely account for 75% of all perinatal mortality and 50% of longterm neurologic impairment in children in the United States
What causes preterm?
Absolute number one cause is multifetal gestation, followed by history of preterm birth
What steps do we follow to deal with preterm labor
a) Get preterm labor patients to the hospital.
b) Use corticosteroids to reduce incidence of respiratory distress syndrome
c) Use tocolytics to slow down contractions for 48 hours to allow corticosteroids to take effect
d) Magnesium sulfate administration prior to pre-term labor to decrease incidence of cerebral palsy
e) Prophylaxis against GBS
Symptoms of preterm labor
Menstrual like cramps, low-dull backache, abdominal pressure, pelvic pressure, abdominal cramping with possible diarrhea, change or increase in vaginal discharge, painless uterine contractions
Can we detect preterm labor potential?
Cervical length - As the cervix gets smaller, you get closer to labor, and if this happens sooner, you’ll give birth early. Use transvaginal ultrasound in those you suspect with risk factors for pre-term delivery to detect cervical length. Early effacement and dilation are obvious indicators.
Can we prevent preterm?
Prevention: Can’t prevent this.
However, some voodoo: High risk women for preterm who have had preterms in the past: Weekly intramuscular injections of 17-a-hydroxyprogesterone caproate starting at 16 - 20 weeks until 36 weeks appears to reduce spontaneous pre-term. Vaginal progesterone supplementation in women with an US-determined shortened cervical length has also shown some benefit
What exam should we do to assess preterm?
Preterm Evaluation: Remember that doing a blind digital exam is bad, as you don’t know what you’re hitting and you could increase infection in the setting of PROM. So use the tocodynamometer to see contractions and then move to speculum exam before the digital exam.
Labs for preterm?
Lab tests: UTIs can increase uterine contractions so obtain UA and urine Cx along with the vaginal/rectal cultures for GBS
US use for preterm?
US: Placenta abruption (not visible on US really as the blood behind the fetus looks similar to the placenta) and placenta previa are possible causes of pre-term labor, so keep this in mind with US, as well as monitoring for amniotic fluid levels to make sure ROM has not spontaneously occurred)
Amniocentesis for preterm?
Amniocentesis: Chorioamnionitis is associated with pre-term labor so make sure to assess intra-amniotic conditions if suspected, looking for lactate dehydrogenase (increased), WBCs (increased), bacteria (presence) and glucose (decreased)
Evidence of infection means you go to labor immediately. Don’t dick around with tocolytics.
Two things to think about with management of pre-term labor:
- The only point here is to delay if possible.
- Tocolytics: Try one for preterm labor and change/add as needed. In the past magnesium was used a lot but we seem to be switching to nifedipine since there is growing evidence that magnesium sulfate isn’t as effective as a tocolytic agent, even though it is being shown as neuroprotective.
How do Ca Channel blockers work in pre-term and who can’t we give them to?
Ca Channel blockers (nifedipine): Prevents calcium entry into muscle cells so this is contraindicated in hypotension or preload-dependent cardiac lesions like aortic insufficiency.
