⏰ Preterm Labor
Before 37 weeks. What stops it, what matures the lungs, and the two drugs with very different jobs.
🧬 What counts
Regular contractions with cervical change before 37 weeks. Contractions alone are not preterm labor — the cervix has to be changing.
| Risk factor | Note |
|---|---|
| Previous preterm birth | The strongest single predictor |
| Infection | UTI, bacterial vaginosis, chorioamnionitis |
| Multiple gestation | Overdistension |
| Short cervix, previous cervical surgery | Measured on ultrasound |
| Smoking, substance use, poor nutrition | Modifiable |
| Preeclampsia, polyhydramnios, PROM |
Untreated urinary tract infection is a preventable cause. That is why every pregnant woman with dysuria gets treated promptly, and why asymptomatic bacteriuria is screened for and treated in pregnancy but not otherwise.
👀 Warning signs to teach
Teach every pregnant woman to report:
- Regular contractions — more than 4–6 an hour before 37 weeks
- Low, dull backache that comes and goes
- Pelvic pressure — “the baby feels like it is pushing down”
- Change in vaginal discharge — more, watery, or bloody
- Menstrual-like cramping; abdominal tightening
- Any gush or trickle of fluid
Women often dismiss backache and pressure as normal pregnancy discomfort. Teaching them the difference is what gets them in early enough for steroids to work.
🩺 The two drugs, and why they differ
One buys time. The other uses it.
| Tocolytics | Corticosteroids | |
|---|---|---|
| Purpose | Delay birth for about 48 hours | Mature the fetal lungs |
| Examples | Nifedipine, indomethacin, terbutaline | Betamethasone, dexamethasone |
| Why 48 hours? | That is how long the steroids need to work. The tocolytic exists to create the window | |
💉 Magnesium sulfate here does something different
In preterm labor before about 32 weeks, magnesium is given for fetal neuroprotection — it reduces the risk of cerebral palsy.
Same drug, same monitoring (reflexes first, respirations, urine output, calcium gluconate at the bedside) — but a different purpose from its use in preeclampsia, where it prevents seizures.
🚨 When NOT to stop labor
Tocolysis is contraindicated when continuing the pregnancy is more dangerous than delivering:
- Chorioamnionitis or any intrauterine infection
- Severe preeclampsia or eclampsia
- Fetal distress or fetal death
- Significant hemorrhage, abruption
- Cervix already advanced
If there is infection, delivery is the treatment. Stopping labor would keep the baby in an infected uterus.
✅ Nursing care
- Left lateral position; bed rest as ordered
- Hydration — dehydration itself can trigger contractions
- Continuous fetal and contraction monitoring
- Look for the cause: urinalysis, vaginal swabs, temperature
- Emotional support — fear for the baby is the dominant experience
- Involve neonatal team early; tour the NICU if there is time
🎯 NCLEX traps
- Tocolytics buy 48 hours so steroids can work — that is the whole logic
- Betamethasone matures the lungs, it does not stop labor
- Magnesium here is neuroprotection, not seizure prevention
- Infection = deliver, do not tocolyse
- Treat UTIs promptly — a preventable cause