L4: Preterm Labor & Prematurity Flashcards
Classification of fetuses & neonates according to GA
Classification of fetuses & neonates according to GA
- Preterm
Classification of fetuses & neonates according to GA
- Term
GA from 37 week up to 42 weeks
Classification of fetuses & neonates according to GA
- Post-term
GA > completed 42 weeks.
Classification of fetuses according to fetal weight in relation to GA
Classification of fetuses according to fetal weight in relation to GA
- SGA
- Fetal weight < 10th percentile for GA
- Fetal weight ≥ 2 SD below mean for its GA
(SGA fetuses include IUGR or constitutionally small but healthy fetus)
Classification of fetuses according to fetal weight in relation to GA
- AGA
Fetal weight ( ) 10th & 90th percentile for GA
Classification of fetuses according to fetal weight in relation to GA
- LGA
- Fetal weight > 90th percentile for GA
- Fetal weight ≥ 2 SD above mean for its GA.
Classification of neonates according to birth weight
Classification of neonates according to birth weight
- NBW
Neonates with birth weight > 2500 gm.
Classification of neonates according to birth weight
- LBW
- Neonates with birth weight ≤ 2500 gm regardless GA (LBW infants include preterm & growth retarded infants).
Classification of neonates according to birth weight
- VLBW
- Neonates with birth weight < 1500 gm regardless GA
Def of Preterm labor (premature labor)
Onset of labor after fetal viability & before completed 37wk gestation
Def of Prematurity
- Baby needs artificial aids to maintain life (needs incubation) due to deficiency of different body functions to face extrauterine life.
Incidence of Prematurity
7% of all deliveries.
Etiology & RF for Prematurity
Etiology & RF for Prematurity
- Maternal Factors
Etiology & RF for Prematurity
- fetal Factors
1) Fetal anomalies
2) multiple infections as TORCH
3) IUFD.
Etiology & RF for Prematurity
- obstetric Compications
1) Polyhydramnios, PPROM
2) Chorioamnionitis
3) placenta previa, placental abruption
4) pregnancy on top of IUD.
Etiology & RF for Prematurity
- Iatrogenic Factors
1) Premature induction of labor
2) ECV
3) amniocentesis or surgery.
Etiology & RF for Prematurity
- Idiopathic
In 50% of cases
Etiology & RF for Prematurity
- Commonest Cause
Idiopathic
Importance of Prematurity
Complications of Prematurity
- Long term
- Short term
Complications of Prematurity
- Long-term
- ↑↑ incidence of underdevelopment.
- ↑↑ incidence neurological & intellectual abnormalities later in life.
Complications of Prematurity
- short Term
- Respiratory
- Brain
- Blood
- Metabolic
- Others
Short term Complications of Prematurity
- Respiratory
Respiratory Complications of Prematurity
- incidence
Asphyxia accounts for majority of neonatal deaths.
Respiratory Complications of Prematurity
- Causes
Brain Complications of Prematurity
- Incidence
> 10% of prematures
Brain Complications of Prematurity
- Causes
- Hypoprothrombinemia.
- Immature vascular bed in germinal matrix prior to 35 weeks gestation.
- Softness of skull allows rapid & dangerous moulding.
Blood Complications of Prematurity
- Increased Bilirubin
- liver is unable to conjugate bilirubin from blood sufficiently d2 enzymatic immaturity
Blood Complications of Prematurity
- Anemia
- Due to poor iron stores & slow synthesis of Hb molecule
Metabolic Complications of Prematurity
Metabolic Complications of Prematurity
- Causes of hypothermia
Metabolic Complications of Prematurity
- Causes of hypoglycemia
Due to poor glycogen stores
Metabolic Complications of Prematurity
- Causes of hypocalcemia
Manifested by clonus, tremors or convulsions
Metabolic Complications of Prematurity
- Kidney Immaturity
Limited ability to excrete solutes in urine
Metabolic Complications of Prematurity
- malnutrition
- Develops easily due to poor suckling & immature
digestive & metabolic processes.
Metabolic Complications of Prematurity
- Decreased Resistance to infections
- Due to poor passive immunity (which is usually acquired from mother near term).
Dx of Preterm Labor
- Prediction
- Manifestations of threatened preterm labor
- Criteria to document preterm labor
Dx of Preterm Labor
- Prediction
Dx of Preterm Labor
- Manifestations
Dx of Preterm Labor
- Criteria
Dx of Prematurity
- Before delivery
- After delivery (Features of prematurity at birth)
Dx of Prematurity
- Before Delivery
Tests for determination of fetal maturity
Dx of Prematurity
- After Delivery
Prevention of Preterm Labor
- General
- Rest
- Cervical Cerclage
- Prophylactic tocolytic
Prevention of Preterm Labor
- general Measures
Prevention of Preterm Labor
- rest
In high risk cases as in:
- cervical incompetence, multifetal pregnancy.
- previous preterm labor, PPROM or after uterine manipulation
Prevention of Preterm Labor
- cervical Cerclage
Done when indicated as in:
- cervical incompetence, uterine anomalies
- multifetal pregnancy or previous preterm labor
Prevention of Preterm Labor
- tocolytics
Not recommended
Managment of Preterm Labor
- Bed Rest
- Sedatives & narcotics
- Tocolytics
- Corticosteroides
- managment of Delivery
- Neonatal Care
Managment of Preterm Labor
- Sedatives & Narcotics
As barbiturates, diazepam & pethidine:
▪ these agents depress preterm infant when administrated to mother near time of delivery
Managment of Preterm Labor
- Bed Rest
Preferably in Lt lateral position to improve uterine blood flow.
Managment of Preterm Labor
- Tocolytics
Types of Tocolytics
- Short term
- Long term
Def of Tocolytics
Tocolytics are drugs that inhibit uterine contractions.
Types of Tocolytics
- Short term
Indicated to:
- Delay labor 2-3 days till achieving max. effect of steroids.
- Prevent preterm labor after abdominal or cervical
operations or uterine manipulation.
Tocolytics
- If pregnancy is ( ) 34 & 37 weeks
- Decision of tocolysis depends on quality of care available for premature infants & estimated fetal weight
Types of Tocolytics
- Long term
Not effective(oral):
- As they stop uterine contractions temporarily but rarely prevent preterm birth
CI of Tocolytics
Tocolytics
- In cases of PPROM with immature fetus
- Some contraindicate tocolysis in all cases (for fear of chorioamnionitis) while others recommend giving short term tocolysis + prophylactic antibiotics + corticosteroids (to enhance lung maturity) then TOP.
Tocolytics
- Drugs Used
- β-agonists
- Magnesium sulfate (MgSO4)
- PG synthetase inhibitors (anti-PGs)
- Ca++ channel blockers (Nifedepine).
- Oxytocin antagonists (atosiban)
- Progesterone(17 α-Hydroxyprogesterone caproate)
- Others
B-Agonists in prematurity
- Examples
Ritodrine HCL (Yutopar) or Hexoprenaline sulfate (Gynipral)
B-Agonists in prematurity
- Action
inhibition of uterine activity.
B-Agonists in prematurity
- Adminstration
B-Agonists in prematurity
- SE
- Tachycardia, hypotension (due to VD) & arrhythmias.
- Pulmonary edema (specially when given e steroids).
- Hypokalemia, hyperglycemia & lactic acidosis.
MgSO4 in prematurity
- Action
Competes with Ca++ for cellular entry.
MgSO4 in prematurity
- Use
The best for diabetic patients
MgSO4 in prematurity
- Dose
- 4-6 gm slowly IV over 15-20 minutes then 2 gm/hr by IV drips for 12-24 hours.
MgSO4 in prematurity
- SE
See preeclampsia.
PG synthetase inhibitors (anti-PGs) in Prematurity
- exaamples
Indomethacin
PG synthetase inhibitors (anti-PGs) in Prematurity
- Action
PG synthetase inhibitors (anti-PGs) in Prematurity
- SE
Maternal:
▪ Thrombocytopenia & GIT disturbances (peptic ulcers).
Fetal:
▪ Premature closure of ductus arteriosus, pulmonary HTN, necrotizing enterocolitis & ICH.
Drugs in Prematurity
- CCBs
Nifedepine
Drugs in Prematurity
- Oxytocin Antagonsits (Atosiban)
Very effective e minimal side effects.
Drugs in Prematurity
- Progesterone(17 α-Hydroxyprogesterone caproate)
Has some value in preventing onset of preterm labor but it is ineffective once labor is established (the drug of choice is)
Drugs in Prematurity
- Others
Diazoxide, ethanol & halothane (anesthetic).
Managment of Preterm Labor
- Corticosteroids
Corticosteroids in Managment of Preterm Labor
- Role
Accelerates lung maturity & ↓↓ incidence of RDS.
Corticosteroids in Managment of Preterm Labor
- Preparations
Dexamethasone or betamethasone (better).
Corticosteroids in Managment of Preterm Labor
- Dose
12 mg/ 12 hrs for 2 doses.
Corticosteroids in Managment of Preterm Labor
- Efficacy
- Peak effect is reached after 48 hours & lasts for 1 week.
- Best effect is when given before 30 weeks & least effect is when given after 34 weeks
Corticosteroids in Managment of Preterm Labor
- SE
- Chorioamnionitis, early neonatal sepsis, neonatal death & delayed brain development
Management of delivery (conduct of preterm labor)
- Place
- In well equipped hospital with availability of neonatal intensive care & neonatologist efficient in resuscitative techniques present at delivery room
Management of delivery (conduct of preterm labor)
- Methods
Management of delivery (conduct of preterm labor)
- Vaginal
Vaginal Delivery of Preterm Labor
- During 1st stage
Vaginal Delivery of Preterm Labor
- During 2nd Stage
Important precautions:
- Generous episiotomy once head reaches perineum.
- Outlet forceps is the only type of forceps allowable.
- Ventouse is contraindicated.
- No vigorous manipulations
Vaginal Delivery of Preterm Labor
- during 3rd stage
As normal labor.
CS Delivery of Preterm Labor
Neonatal Managmnet of Pretem Labor