Download Low birth weight

Low Birth Weight
Bongkot Chakornbandit, MD.
OB-GYN, HPC 10 Ubon Ratchathani
เป้ าหมายงานอนามัยแม่และเด็กใน
แผนพัฒนาสาธารณสุข ฉบับที่ 11 (2555-60)
• อัตราส่ วนการตายของมารดา < 18:100,000 การเกิดมีชีพ
• การติดเชือ้ HIV ในหญิงตัง้ ครรภ์ < 1 %
• หญิงตัง้ ครรภ์ มีภาวะโลหิตจางจากการขาดธาตุเหล็ก < 10 %
• การขาดออกซิเจนในทารกแรกเกิด ไม่ เกิน 30:1000 การเกิดมี
ชีพ
• ทารกแรกเกิดนา้ หนักน้ อยกว่ า 2500 g < 7 %
สถานการณ์ LBW ภาพรวมเขตสุขภาพที่ 10
ปี งบประมาณ 2555-2558
UNICEF global databases, 2014
Low birth weight
…
problem of growth
Fetal growth
• 3 phases
• < 16 wks. : hyperplasia
• 16 – 32 wks.: cellular hyperplasia &
hypertrophy
• > 32 wks. : cellular hypertrophy
• Fetal weight gain
• 15 wks. : 5 g/day
• 24 wks. : 15 – 20 g/day
• 34 wks. : 30 – 35 g/day
• Fetal development
• Maternal provision of substrate
• Placental transfer
• Fetal genome
Birth weight
• Vary with ethnicity, geographic region, genetic
• Neonatal size
• Small for gestational age (SGA)
• Appropriate for gestational age (AGA)
• Large for gestational age (LGA)
SGA
• Small for gestational age (SGA)
• Neonatal weight < 10th percentile for their GA
• Constitutional small
• Congenital anomaly
• Fetal (intrauterine) growth restriction (FGR / IUGR)
• Symmetrical IUGR (type I)
• Asymmetrical IUGR (type II)
•
Battaglia FC, Lubchenco LO. A practical classification of newborn infants by weight and gestational age.
J Pediatr. 1967;71(2):159-63.
Definition
• WHO
• Birth weight < 2,500 g
(5.5 pound)
• Die > 20 X
• Both preterm birth / IUGR
• increase neonatal
morbidity & mortality
• Inhibited growth &
cognitive development
• Chronic disease later in
life
Factors for small infant
• Same GA
• Girls < boys
• Firstborn infants < subsequent infants
• Multiple pregnancy < singleton
• Prepregnancy
• Mother’s own fetal growth
• Diet from birth to pregnancy
• Body composition at conception
• Smaller babies
• Short stature
• Living at high altitudes
• Young women (teenage pregnancy)
• Pregnancy
• Mother’s nutrition & diet
• Lifestyle (e.g., alcohol, tobacco or drug abuse)
• Other exposures (e.g., malaria, HIV or syphilis)
• Complications (e.g., hypertension)
• Duration of pregnancy
• Social
• Deprived socio-economic conditions
• Chronic poor nutrition and health problems
• Physically demanding work during pregnancy
Low birth weight
Timing
problem
Growth
problem
Preterm
birth
FGR
Preterm birth
Preterm birth
• Labor < 37 complete week
•
•
•
•
Late PTB
Moderate PTB
Very PTB
Extremely PTB
: GA
: GA
: GA
: GA
> 34
32-34
28 – 32
< 28
wk.
wk.
wk.
wk.
•
•
•
•
40 – 45 %
Preterm labor
30 – 35 %
PPROM
30 – 35 %
Medically indicated
Multifetal gestation
Cause of PTB
•
•
•
•
•
•
•
Previous preterm birth
Serious maternal disease
Infection
Uterine problems / overdistension
Cervical problem
Placental abnormality
Other factors : smoking, drug abuse,
teenage pregnancy, malnutrition, anemia
Prediction
• Cervical length (CL)
• Fetal fibronectin (fFN)
• Other
• Risk scoring system
• Cervical dilatation
• Home uterine-activity monitoring
Prediction
• Cervical length (CL)
• Fetal fibronectin (fFN)
• Other
• Risk scoring system
• Cervical dilatation
• Home uterine-activity monitoring
Cervical length (CL)
• TVS
• 16-24 wk./ early 3rd trimester
• High risk for preterm
• CL < 2 cm.
• CL < 2.5 cm. with Hx PTB
• CL > 3 cm.  low risk for PTB
• Fetal fibronectin (fFN)
• Glycoprotein in cervicovaginal secretion
• Intercellular adhesion to uterine desidual
• > 50 ng/ml  high risk for PTB
• Contamination by maternal blood & AF
Prevention
•
•
•
•
•
•
Identify high risk for preterm birth
Reduction teenage pregnancy
Avoid risk factors
Diminish correctable cause
Treat infection
Progesterone
• 17-hydroxyprogesterone caproate 250 mg. IM
weekly (GA 16-36 wk.)
• Micronized progesterone Vg capsule 100 - 200
mg nightly (GA 24-36 wk.)
• Cervical cerclage
Management
•
•
•
•
•
Stop labor / Tocolysis
Corticosteroid (GA < 32 – 34 wk.)
Antibiotic (PPROM)
Intrauterine transfer
Intrapartum & neonatal care
Growth restriction
IUGR
• Fetal weight < 10th percentile for their gestational
age
• 25 – 60% (SGA < 10th) no pathologically growth
restrict (consider ethnic, parity, wt. & ht.)
• Other definition : wt. < 5th percentile.
•
Gynecologists ACoOa. ACOG Practice bulletin no. 134: fetal growth restriction. Obstet Gynecol.
2013;121(5):1122-33.
Risk factor & Etiology
Maternal effect
• Increase cesarean section rate
• Child rearing problem
• Mental effect
Fetal effect
•
•
•
•
•
•
•
•
Hypoglycemia
Hypocalcemia
Polycythemia
Hyperbilirubinemia
Meconium aspiration syndrome
Sepsis / infection
Asphyxia
Perinatal death
Long term sequelae
• Increase risk for
• Cardiac structural change & dysfunction
• Coronary heart disease
• Artherosclerosis
• Type II DM
• Hypertension
• Chronic kidney disease
Diagnosis
• Risk scoring system
• PE
• Body weight
• Fundal height
• Ultrasound
Maternal body weight
Prepregnancy
BMI
(kg/m2)
Category
Total Weight
Gain
Weight Gain
in 2nd & 3rd
Trimesters
(kg/wk)
< 18.5
underweight
12.5 – 18 kg
0.45 – 0.6
18.5-24.9
Normal weight
11.5 - 16 kg
0.36 – 0.45
25-29.9
Overweight
7 - 11.5 kg
0.22 – 0.3
> 30
Obesity
5 - 9 kg
0.18 - 0.27
• Uterine fundal height
• Simple
• Safe
• Inexpensive
• Accurate screening method
• Jimenez,et al. : GA 20-34 wks.  GA + 2-3 cm.
• Sensitivity < 35%, Specificity > 90%
Ultrasound
• Estimated fetal weight
• < 10th percentile
• AC (Abdominal circumference)
• < -2SD
• HC/AC ratio
• < -2SD
• Amniotic fluid index
• Placental grading
• Doppler velocimetry
• Brain sparing effect (MCA)
• End-diastolic velocity in umbilical artery
• Serial ultrasound follow growth velocity
Umbilical artery Doppler study
Prevention
• Depend on cause of IUGR
• Pre-gestational status
• Nutritional status
• Antenatal care / problems
• Placental abnormality
Pre-gestational status
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Improve BMI / pre-pregnancy maternal weight
Improve nutrition in reproductive age group
Prevention of teenage pregnancy
Cessation of drug use
Control underlying disease (DM, HT, CRF, APS)
Prevention anemia
Infection screening & Tx
Nutritional status
• Awareness case
• Age < 16 yr.
• Low socioeconomic status
• G 3 within 2 yr.
• Eating limitation
• Smoking / drinking / drug use
• Low BMI (< 18 kg/m2)
• Anemia
• Weight gain in 2nd & 3rd trimester < 1 kg/mo. (2
lb/mo.)
• Calories
• additional 300 kcal/d
• Total 2400-2700 kcal/d in normal weight
• Total pregnancy need 80,000 kcal
• Protein
• 60 -70 g/d
• Carbohydrate
• 175 g/d
• Iron
• 7 mg/d (GI absorb 10%)
• Total pregnancy need 1,000 mg.
Antenatal care / problem
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•
•
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Risk identification
Rest
Control pregnancy complication ; PIH, anemia
US if suspected
Intrauterine growth restriction
• Awareness in high risk case
• Carefully ANC
• Ultrasound for structural anomaly screening &
fetal growth evaluation (32-34 wk. / suspicious
case)
• Early detection
• Antenatal surveillance
• Timing delivery & decrease neonatal adverse
outcome