PREVENTION OF BIRTH DEFECTS
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Transcript PREVENTION OF BIRTH DEFECTS
PREVENTION OF DISORDERS
OF CHILDREN BEFORE BIRTH
Prevention of Disorders of
Children Before Birth
PRIMARY PREVENTION - preventing the
development of the problem
Secondary prevention - preventing the
problem from causing disease, removing the
cause
Tertiary prevention - preventing the
problem from progressing and causing
disability
Prevention of Disorders of
Children Before Birth
Primary Prevention
• The plumber, the grocer, the politician, the
doctor
• Maternal Nutrition
• Maternal Immunization
• Avoidance of environmental teratogens
• Maternal Disease Management
• Pre-implantation diagnosis
Prevention of Disorders of
Children Before Birth
Secondary prevention
• Pregnancy interruption after prenatal diagnosis
• Inutero medical management of maternal
disorders
• Inutero surgical management
Prevention of Disorders of
Children Before Birth
Tertiary prevention
• identification of inborn errors of metabolism
• management of medical disorders
• surgical management of birth defects
Primary Prevention
Maternal nutrition
• Folic Acid 400 micrograms per day
• neural tube defects 1965 Hibbard and Smithells
• Northern China 6 per 1000 live births with NTD
• Berry et al. NEJM 341:1485, 1999
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130,142 women who took folic acid
117,689 women who did not take folic acid
1/1000 NTD affected in the North with folic acid
4.8/1000 NTD affected in the North without folic acid
0.6/1000 NTD affected in the South with folic acid
1/1000 NTD affected in the South without folic acid
Primary Prevention
Maternal Nutrition
• Folic Acid
• Reduction in non syndromic cleft lip/palate more
controversial
• Reduction in cardiovascular malformations
especially outflow tract malformations
• Decreased incidence of urinary tract abnormality
• Decreased risk of imperforate anus in China RR .59
• adult benefits - cardiovascular, cancer, Alzheimers
Primary Prevention
Maternal Nutrition
• Iodine - requirement of >20 microgram per day
to prevent maternal iodine deficiency and
cretinism in the fetus. 100-200 microgram/day
recommended for supplementation
• Zinc - 15 mg/day suggested daily requirement important in neural development
Primary Prevention
Maternal Immunization - prevention of
primary infection during pregnancy
• Rubella - cataracts, deafness, pulmonary
stenosis, learning handicaps
• Varicella - 1st trimester contractures, skin scars,
limb reduction, mental retardation, seizures
• Mumps - congenital deafness
Primary Prevention
Avoidance of teratogens
• Drugs - cocaine, alcohol, tobacco, toluene
• Medications - accutane, seizure medications,
ACE inhibitors, coumadin, aminopterin,
methotrexate, penicillamine, misoprostol,
thalidomide
• Viruses - cytomegalovirus, parvo B19, HIV
• Syphilis, toxoplasmosis, malaria
• Ionizing radiation, lead (tofu protective),
organic methylmercury, PCBs
Primary Prevention
Maternal Disease Management
• Diabetes Mellitus - establish control prior to
pregnancy as well as during the pregnancy
• with preconceptural care 2% birth defects risk,
lowered with addition of folic acid
• without preconceptual care 6-7% birth defects
risk
• Risk for single and multiple malformations and
overgrowth with cardiomyopathy
Primary Prevention
• Phenylketonuria - fetal brain and heart defects
maternal diet to keep phenylalanine level below
20 mg/dL
• Hypothyroidism - fetal brain development
iodine supplementation in endemic areas (RDA
175 micrograms in preg.), synthroid treatment
for hypothyroidism
• Hypertension - Chronic hypertension, PIH,
pre-eclampsia, eclampsia: may reflect placental
disease
Primary Prevention
Pre-implantation Diagnosis expensive and highly sophisticated
Single cell DNA amplification with
PCR and diagnostic testing of
specific gene
Karyotype
Implantation of blastocysts found to
be unaffected
Secondary Prevention
Diagnose maternal disorders and treat
Maternal triple marker screening for
detection of neural tube defects, abdominal
wall defects, nephrosis, Tri 21, Tri 18
Ultrasound for structural abnormalities
Amniocentesis to confirm chromosomal,
DNA diagnosable, or metabolic conditions
Termination or management
Secondary Prevention
Test for maternal infections and treat with
antibiotics, antiviral, antimalarial agents
Monitor for preterm labor and use
corticosteroids for pulmonary maturation
when premature delivery imminent
Secondary Prevention
Maternal autoimmune disorders identify
and treat
Rh isoimmunization
Platelet isoimmunization
Antiphospholipid antibody
Graves Disease
Myasthenia Gravis
Secondary Prevention
• Maternal Rh Isoimmunization
Prevention by identifying couples at
risk and using Rhogam post delivery.
For sensitized women, amniocentesis
to monitor the fetus and transfuse when
appropriate
Secondary Prevention
Maternal Platelet Isoimmunization
recognition after a prior affected infant
Mother lack antigen, father is either
homozygous or heterozygous for the
antigen
Fetus is antigen positive -> inutero
thrombocytopenia and bleeding
Rx - maternal IVIG, ? Fetal IVIG
Secondary Prevention
Antiphospholipid antibodies Anticardiolipin/ lupus anticoagulant
Maternal history of recurrent fetal loss
aspirin and heparin (in women with a
history of repeated fetal loss)increase in
preterm birth and IUGR
Secondary Prevention
Graves Disease
Thyrotoxicosis in the mother
treatment of mother with PTU 1-5% of infants -> hypothyroidism
Transfer of thyroid stimulating
immunoglobulin to the fetus - >
neonatal thyrotoxicosis -rx Lugol’s
and beta blocker
Secondary Prevention
Maternal Myasthenia Gravis
IgG against nicotinic acetylcholine
receptors
rare joint contractures in the fetus or
neonatal myasthenia 2-4 weeks
Avoid magnesium sulfate
Follow mother post delivery
Secondary Prevention
Maternal Serum Screening
AFP - open body defects = neural tube
defects, gastroschisis, limb-body
wall - offer ultrasound and amnio
• Estriol and HCG along with AFP for risk for
Down syndrome and trisomy 18 if increased
risk option for ultrasound and amniocentesis
• Low estriol also for cholesterol metabolism
defects and steroid sulfatase deficiency
Secondary Prevention - surgical
management
Renal Obstruction - catheter placement
Hydrothorax -laparoscopic catheter
placement
Inutero surgery for cystic adenomatoid
malformation
Ligation or cautery of placental shunts in
monozygotic twins
Cesarean section for maternal herpes
Tertiary Prevention
Identification and management of medical
disorders
• Physical Examination - minor and major
malformations - further studies as appropriate
• Screening for inborn errors of metabolism,
thyroid function
• Audiology testing/vision screening
• vitamin k at birth, immunizations after birth
Tertiary Prevention
Newborn screening
• Galactosemia - avoidance of galactose formulas
• amino/organic acid disorders - appropriate
metabolic management - formulas, carnitine,
vitamins when responsive, betaine
• hypothyroidism - synthroid
• others - fatty acid oxidation defects - frequent
feeds, avoid fasting
Tertiary Prevention
Surgical management of birth defects
• Neural Tube defects - repair of defect,
ventricular shunting
• Cleft lip/palate - repair of cleft, management of
middle ear disease
• Congenital Heart defects - medical
management until surgery is available
• Recognition of lethal disorders for which
aggressive care is inappropriate
First Steps
IDENTIFY THE AREAS OF NEED ESTABLISH REGISTRIES
MATERNAL IMMUNIZATION
PRENATAL VITAMINS PRIOR TO
CONCEPTION (by 8 weeks it has
happened)
PRENATAL CARE OF MEDICAL
PROBLEMS
Section 2
Maintenance of Health Through Good
Nutrition
Objectives
State the effect inadequate nutrition has on
an infant
Identify the ingredients used in infant
formulas
Describe when and how foods are
introduced into the baby’s diet
Describe inborn errors of metabolism and
their dietary treatment
Nutritional Requirements of the
Infant
During the first year, the normal child needs
about 100 kcal per kilogram of body weight
each day.
Infants up to 6 months of age should have
2.2 g of protein per kg of weight each day;
age 6-12 months should have 1.56 g of
protein per kg of weight each day.
Nutritional Requirements of the
Infant
Iron-fortified cereal is usually started at
about 6 months.
A vitamin K supplement is routinely given
shortly after birth.
Infants should not be given an excess of
vitamin A or D.
Breastfeeding
Provides infant with temporary immunity to
many infectious diseases.
It is economical, nutritionally adequate, and
sterile.
Breastfeeding
Easily digested
Breastfed infants grow more rapidly during
the first few months of life than formula-fed
babies and have fewer infections.
Breastfeeding
Breast should be offered every 2 hours in
the first few weeks.
The infant should nurse 10-15min on each
breast.
Growth spurts occur at about 10 days, 2
weeks, 6 weeks, and 3 months; infant may
nurse more frequently.
Breastfeeding
Indications of adequate nutrition include:
• The infant has six or more wet diapers per day.
• The infant has normal growth.
• The infant has one or two mustard-colored
bowel movements per day.
• The breast becomes soft during nursing.
Bottle Feeding
The infant should be cuddled and held in an
upright position.
He should be burped.
Formulas are developed so that they are
similar to human milk in nutrient and kcal
values.
Synthetic milk made from soybeans may be
used for sensitive or allergic infants.
Burping a Baby
Bottle Feeding
Sterile water must be used to mix formula.
Infants under one year should not be given
cow’s milk.
Consistent temperature should be used.
Infants should not be put to bed with bottle.
Supplementary Foods
Limit diet to breast milk or formula until the
age of 4 to 6 months.
Cow’s milk should be avoided until after
one year of age.
Solid foods should not be introduced before
4 to 6 months of age and should be done
gradually.
Supplementary Foods
The typical order of introduction begins
with cereal, usually iron-fortified rice, then
oat, wheat, and mixed cereals.
Cooked and pureed vegetables follow, then
cooked and pureed fruits, egg yolk, and
finally, finely ground meats.
Supplementary Foods
Between 6 and 12 months, toast, zwieback,
teething biscuits, custards, puddings, and
ice cream can be added.
Honey should never be given to an infant
because it could be contaminated with
Clostridium botulinum bacteria.
Supplementary Foods
When the infant learns to drink from a cup,
juice can be introduced.
Juice should never be given from a bottle
because babies will fill up on it and not get
enough calories from other sources.
Supplementary Foods
Pasteurized apple juice is usually given
first.
It is recommended that only 4 oz. of 100%
juice products be given because they are
nutrient-dense.
Indications for Readiness for
Solid Foods
Ability to pull food into the mouth rather
than pushing the tongue and food out of the
mouth.
Willingness to participate in the process.
Ability to sit up without support.
Indications for Readiness for
Solid Foods
Having head and neck control.
The need for additional nutrients.
Drinking more than 32 ounces of formula or
nursing 8 to 10 times in 24 hours.
Special Nutritional Needs
Premature infants
Cystic Fibrosis
Failure to thrive
Metabolic Disorders
• Galactosemia
• Phenylketonuria
• Maple Syrup Urine Disease
Premature Infants
An infant born before 37 weeks gestation.
The sucking reflex is not developed until 34
weeks gestation. Infants born earlier will
require total parenteral nutrition, tube
feedings, or bolus feedings.
Premature Infants
Other concerns include: low birth weight,
underdeveloped lungs, immature GI tracts,
inadequate bone mineralization, and lack of
fat reserves.
Many special formulas are available.
Cystic Fibrosis
An inherited disease
Decreased production of digestive enzymes
Malabsorption of fat
Recommendation: 35-40% of diet should
be from fat
Cystic Fibrosis
Digestive enzyme is taken in pill form.
There is a water-soluble form of fat-soluble
vitamins that can be administered if normal
levels cannot be maintained with the use of
fat-soluble vitamins.
Nighttime tube feedings may be indicated.
Failure to Thrive
Determined by plotting the height and
weight of the infant on the growth chart.
May be caused by poverty, congenital
abnormalities, AIDS, lack of bonding, child
abuse, or neglect.
The first six months are the most crucial for
brain development.
Galactosemia
A condition in which there is a lack of the
liver enzyme transferase.
Transferase normally converts galactose to
glucose.
The amount of galactose in the blood
becomes toxic.
Galactosemia
Diarrhea, vomiting, edema, and abnormal
liver function
Cataracts may develop, galactosuria occurs,
and mental retardation develops.
Diet therapy: exclusion of anything
containing milk from any mammal;
nutritional supplements of calcium, vitamin
D, and riboflavin.
Phenylketonuria (PKU)
Lack the liver enzyme phenylalanine
hydroxylase, which is necessary for the
metabolism of the amino acid
phenylalanine.
Infants are normal at birth, but if untreated
become hyperactive, suffer seizures, and
become mentally retarded between 6 to 18
months.
Phenylketonuria (PKU)
Diet Therapy: commercial formula
“Lofenalac”, regular blood tests, synthetic
milk for older children, avoidance of
phenylalanine.
Hospitals routinely screen newborns for
PKU.
Maple Syrup Urine Disease
(MSUD)
Congenital defect resulting in the inability
to metabolize three amino acids: leucine,
isoleucine, and valine.
Named for the odor of the urine of clients
with the condition.
Maple Syrup Urine Disease
(MSUD)
Hypoglycemia, apathy, and convulsions
occur and if not treated promptly, will result
in death.
Diet therapy: extremely restricted amounts
of the three amino acids; a special formula
and low protein diet is used; diet therapy
necessary throughout life.
Women, Infants, and Children
(WIC)
A federally funded
program that provides
monthly food packages of infant formula or
milk, cereal, eggs, cheese, peanut butter, and
juice for a mother who is breastfeeding.
Conclusion
Babies must have adequate diets so that
their physical and mental development are
not impaired.
Breastfeeding is nature’s way of feeding an
infant.
Formula feeding is also acceptable.
Some infants have special nutritional needs.