PRETERM LABOR Flashcards
Sub-categories of preterm birth, based on gestational age
- Extremely preterm : less than 28 weeks
- Very Preterm : 28-32 weeks
- Moderate to late preterm : 32-36 6/7 weeks
Refers to <37 weeks AOG but more than 20 completed weeks
Preterm
37-41 weeks AOG
Term
Sub-categories of term birth, based on gestational age:
- Early term (37-38 6/7 weeks)
- Full term (39-40 6/7 weeks)
- Late term (41-41 6/7 weeks)
- Post term (42 & onwards)
Defined as regular contractions resulting to cervical effacement & dilation that occurs before 37 completed weeks but after 20 completed weeks.
Preterm Labor
Risk Factors / Causes
- History of Premature birth
- Smoking & Drug Use
- Short interpregnancy interval
- Previous surgeries involving the cervix
- Congenital abnormalities of the uterus
- Cervical insuffiency
- Infections
- Maternal stress
- Dehydration
- Uterine distention
- Maternal factors
- Placental issues
Strongest risk factor for preterm labor
History of Premature birth
Why is smoking & drug use a risk factor
Vasoconstriction 🡪 decrease uterine / placental perfusion 🡪placental insufficiency
How does infections become a risk factor or a cause for preterm labor
Microbial invasion 🡪 causes inflammation on uterine muscles/weakening of amniotic sac 🡪 triggers release of prostaglandins 🡪 uterine contractions
2 reasons how dehydration is a risk factor / cause?
- Can lead to oligohydramnios 🡪 uterine irritation / fetal stress 🡪 contractions
- Can stimulate release of ADH to retain water 🡪 ADH has similar chemical structure as oxytocin 🡪 mistaken as oxytocin 🡪uterine contractions
How is maternal stress a risk factor / cause
oxytocin levels are high under stressful conditions 🡪 uterine contractions
How uterine distention can lead to premature labor
Excessive uterine stretch can send signals that the uterus is of adequate size & that fetus is already “term” 🡪uterine contractions
Predictors of Preterm Labor
1) Measurement of cervical length via UTZ
2) Fetal Fibronectin test
Cervical length that is a good predictor that woman can go into preterm labor
< 2-2.5 cm
Used to rule out preterm labor -In normal conditions, fFn is found at very low levels in cervico-vaginal secretions
Fetal Fibronectin test
Is a protein that is believed to help keep the amniotic sac “glued” to the lining of the uterus.
Fetal fibronectin
Elevated levels of fibronectin indicates preterm labor by how much.
greater than or equal to 50 ng/mL
A Positive fFN test means?
indicates that the “glue” has been disrupted and the woman is at increased risk of premature birth.
Signs of Preterm Labor
- Pelvic pressure & backache
- Regular uterine contractions
- Abdominal pain or cramps
- Vaginal spotting / light bleeding
- Cervical mucus discharge
- Leaking amniotic fluid from vagina
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of consistency.
- Cervical Mucus Discharge : Thick, sticky or stretchy
- Leaking Amniotic Fluid: Watery, thin, continuous
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of color
- Cervical Mucus Discharge : White, clear, yellowish (may have blood streaks)
- Leaking Amniotic Fluid: Clear, pale yellow
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of odor
- Cervical Mucus Discharge : no strong odor
- Leaking Amniotic Fluid: sweet-smelling
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of amount
- Cervical Mucus Discharge : small amounts
- Leaking Amniotic Fluid: continuous trickle or sudden gush
Differentiating Cervical Mucus Discharge & Amniotic Fluid
Difference between cervical mucus discharge & leaking amniotic fluid in terms of significant
- Cervical Mucus Discharge : normal or early sign of labor
- Leaking Amniotic Fluid: Possible water breaking (PROM/PPROM)