1. Prenatal & Postnatal Nutrition
Chapter 17
Prenatal & Postnatal Nutrition

2. Nutrition for the Life Cycle
Nutritional needs change at each stage of the life cycle.
Pregnancy (Prenatal)
Infancy (Postnatal)
Early and middle childhood
Adolescence
Adulthood
Senior adulthood

3. Pregnancy ( Prenatal)

4. CHANGES IN THE BODY DURING PREGNANCY
Life begin with single cell.
Over the course of 40 weeks this cell grows and develops into a fully formed human baby.
Prenatal growth and development are carefully orchestrated processed that require adequate supplies of all the essential nutrients.
After fertilization, single cell divides rapidly to form a ball of cells.
The cells than begin to differentiate and move to form body structures.
During these early development , these cells obtains the nutrients from the fluid around it

5. CHANGES IN THE BODY DURING PREGNANCY
About a week after fertilization the developing embryo begin to settle with the lining of the uterus
By two weeks implantation is complete and it is now an EMBRYO.
The embryonic stage of development last until 8th week after fertilization.
During embryonic stage, the cell differentiate to form multitude of specializes cell types—
Embryo is about 3 inches at this stage and has beating heart.
The early embryo gets its nourishment by breaking down the lining of the uterus.
After about 5 weeks Placenta takes over the role of nourishment.

6. CHANGES IN THE BODY DURING PREGNANCY
From 9 weeks on the developing offspring is a fetus.
Length of the fetus grow from 3 cm to 50cm
Fetal period usually end after 40week
Weight of healthy baby is usually between 6.5 to 9 pounds at birth
A woman’s body typically experiences following change during pregnancy?
increase in breathing rate
increase in fluid volume
shifts to primarily using fat as fuel source
increase in metabolic rate

7. CHANGES IN THE BODY DURING PREGNANCY
Important Terms
Small for gestational age: Infant who born on time but have failed to grow
Preterm or premature: born before 37 weeks of gestation
Whether born too soon or too small, low-birth-weight infants and very-low-birth-weight infants are at increased risk for illness and early death
Health risks associated with a small-for-gestational-age infant (SGA)
infant mortality.
stillbirth.
increased risk for hypertension as an adult.
increased risk for diabetes as an adult.

8. Pregnancy: The Impact of Nutrition on the Future
The woman who is pregnant, or who soon will be, must understand that her nutrition is critical to the health of her future child throughout life
Before a woman becomes pregnant, she must establish eating habits that will optimally nourish both the growing fetus and herself
She must be well nourished at the outset because early in pregnancy the embryo undergoes rapid and significant developmental changes that depend on good nutrition
The nutrient demands of pregnancy are extraordinary

9. Preparing for Pregnancy
Uterus
The muscular organ within which the infant develops before birth
Placenta
The organ of pregnancy in which maternal and fetal blood circulate in close proximity and exchange nutrients and oxygen (flowing into the fetus) and wastes (picked up by the mother’s blood)
Maternal and fetal blood vessels are intertwined
The two bloods never mix
The barrier between them is notably thin

10. Preparing for Pregnancy
The mother’s nutrition before pregnancy determines whether her uterus will be able to support the growth of a healthy placenta during the first month of gestation
The only way nutrients can reach the developing fetus is through the placenta, the special organ that grows inside the uterus to support new life.
If the mother’s nutrient stores are inadequate during the period when her body is developing the placenta, then the placenta will never form and function properly
As a consequence, no matter how well the mother eats later, her fetus will not receive optimal nourishment, and a low birthweight baby with all of the associated risks is likely

11. Preparing for Pregnancy
If a girl is born with low birth weight, she may be ill equipped, even as an adult, to store sufficient nutrients, and she may be unable to grow an adequate placenta or bear healthy full-term infants
A woman’s poor nutrition during her early pregnancy could affect her grandchildren as well as her child

12. Preparing for Pregnancy
Infants born of malnourished mothers are more likely to:
become ill
have birth defects, and
suffer retarded mental or physical development.
Malnutrition in the prenatal and postnatal periods also affects learning ability and behavior.

13. Preparing for Pregnancy
Pre-pregnancy Weight
Before pregnancy, all women, but underweight women in particular, should strive for appropriate body weights
A woman who starts out underweight and who fails to gain sufficiently during pregnancy is very likely to bear a baby with dangerously low birth weigh.
Infant birth weight is the most potent single indicator of an infant’s future health

14. Low-birth weight
Weight of less than 5.5 pounds at birth
Used as a predictor of probable health problems in the newborn and as a probable indicator of poor nutrition status of the mother before and/or during pregnancy
40 times more likely to die in the first year of life than a normal-weight baby

15. Preparing for Pregnancy
Not all cases of low birthweight reflect poor nutrition
Heredity,
disease conditions
smoking, and
drug (including alcohol) use during pregnancy all contribute
Even with optimal nutrition and health during pregnancy, some women give birth to small infants for unknown reasons

16. Infant Birth Weight Main factors that influence birth weight
The duration of the pregnancy
The weight status of the mother before conception
The amount of weight gained during pregnancy
Whether the mother smoked during pregnancy

17. Preparing for Pregnancy
Low birthweight is associated with
Lower adult IQ and other brain impairments
Short stature
Educational disadvantages
Nutrient deficiency coupled with low birthweight is the underlying cause of more than half of all deaths worldwide of children under 5 years of age

18. Pregnancy First trimester is 0 to 13 weeks.
Trimester: one-third of the normal duration of pregnancy.
First trimester is 0 to 13 weeks.
Second trimester is 13 to 26 weeks.
Third trimester is 26 to 40 weeks.

19. NUTRIENTS REQUIREMENT IN PREGNENCY

20. Nutritional Needs During Pregnancy
New cells are laid down at a tremendous pace as the fetus grows and develops
The number of the mother’s red blood cells must rise because her blood volume increases
A function requiring more cell division and therefore more vitamins, adequate minerals, energy and good quality protein.

21. Pregnancy Need for Nutrients
Nutrients deserving special attention during pregnancy include
15% more total calories
50% more of some nutrients
Protein, folate, zinc, iodine, and iron
Consuming inadequate nutrients or excess amounts can put the baby at risk for birth defects and other anomalies, especially during critical periods
protein to 25g or 50% higher
Folate – 50% higher
iron– 50% higher
zinc, and
calcium, as well as
vitamins which known to be toxic in excess amounts.

22. Follow advice of doctor or midwife Focus on supplements such as
Iron
Only universally recommended supplement
Prenatal multivitamin/mineral supplements
For inadequate diet or high-risk pregnancies
Vegans should consider additional vitamin D, iron, and vitamin B12

23. Important Nutrients During Pregnancy
Protein
DRI recommendation for pregnancy is higher than for non pregnant women by grams/day
Most women in the U.S. need not add protein-rich foods to their diets
They already exceed the recommended protein intake for pregnancy

24. Important Nutrients During Pregnancy
Folate
Development of new cells DNA
Women in US between 15 to 45 years of age, even if not pregnant, need 400 mcg/day
because it is very difficult to get adequate amounts of folate or folic acid from a typical American diet
During pregnancy women need 600 mcg/day
Folate deficiency leads to
Birth defects, fetal growth problems, autism, neural tube defects
In 1998 U.S. FDA began requiring grain fortification
it is critical for women to ensure they are receiving adequate amounts of folate or folic acid prior to pregnancy

25. Nutritional Needs During Pregnancy
Folate
Plays an important role in preventing neural tube defects – BUT THAT HAPPENS BEFORE WOMAN KNOWS SHE IS PREGNENT
The early weeks of pregnancy are critical periods for the formation and closure of the neural tube that will later develop to form the brain and spinal cord
By the time a woman suspects she is pregnant, usually around the sixth week of pregnancy, the embryo’s neural tube has normally closed

26. Important Nutrients During Pregnancy
Vitamin A
Need 770 mcg/day during pregnancy
Not exceed the UL of 3,000 mcg/day
Stop taking medications that contain vitamin A
Too little can lead to developmental problems
Too much can lead to birth defects; this is not associated with beta-carotene
Toxic level can cause birth defects, such as facial and heart deformities

27. Important Nutrients During Pregnancy
Iron
Deficiency is the most common nutrient deficiency in pregnancy
Need 27 mg/day during pregnancy
Most woman consume just over half this amount
Supplements of 30 mg/day recommended during the second and third trimesters
Without enough, mothers risk iron-deficiency anemia and babies with low birth weight

28. Important Nutrients During Pregnancy
Calcium
1,000 mg/day – requirement does not increase but right amount become very important during pregnancy
Vitamin D
600 IU/day
Iodine
220 mcg/day
Omega-3 fatty acids
No official recommendations

29. Pregnancy Need for Nutrients
Although nutrient needs are much higher than usual, energy needs are not.
An average increase of only about 17% of maintenance calories is recommended to support the metabolic demands of pregnancy and fetal development.

30. Nutritional Needs During Pregnancy
Fat
The high nutrient requirements of pregnancy leave little room in the diet for excess energy from added purified fats such as oil, margarine, and butter
The essential fatty acids are particularly important to the growth and development of the fetus
The brain is composed mainly of lipid material and depends heavily on long-chain omega-3 and omega-6 fatty acids for its growth, function, and structure

31. Pregnancy Need for Nutrients
Energy, Carbohydrate, Protein, and Fat
Energy needs vary with the progression of pregnancy
First trimester
No additional needs
Second trimester
An additional 350 daily calories
Third trimester
An additional 450 daily calories

32. Nutritional Needs During Pregnancy
The bacteria, listeria, can contaminate foods and cause premature birth, miscarriage, stillbirth, or severe illness in the newborn.
Pregnant women need to avoid unpasteurized cheese, such as brie or blue cheese to decrease their risk of contracting listeriosis.

33. Nutritional Needs During Pregnancy
Iron
During pregnancy, the body avidly conserves iron
Menstruation ceases and absorption of iron increases up to threefold
Despite these conservation measures, iron stores dwindle because the developing fetus draws heavily on its mother’s iron store up to a supply sufficient to carry it through the first three to six months of life

34. MATERNAL WEIGHT GAIN
Normal Weight Gain & Adequate Nutrition Support The Health Of The Mother & The Fetus

36. MATERNAL WEIGHT GAIN

37. MATERNAL WEIGHT GAIN Obese women have increased risk of:
Low weight gain is associated with increase risk of Low-Birth Weight
Excessive Weight Gain Increase the Risk of :
Complication during labor
Postpartum Obesity
Obese women have increased risk of:
HYPRTENSION
GESTSTIONAL DIABETES

38. MATERNAL WEIGHT GAIN
First trimester weight gain should be only 3 to 4 lbs
Followed by about a pound per week
If Weight gain is higher in early pregnancy, mother should not try to diet in the last weeks
DIETING IS NOT RECOMMENDED DURING PREGNANCY

39. MATERNAL WEIGHT GAIN

41. MATERNAL WEIGHT GAIN About 10 lbs of the weight lost at delivery
About 3 to 5 lbs. loss in first week
Remainder is generally lost within a few months because:
Blood volume return to normal
Loses fluids she accumulate

42. Teratogen.
Any chemical, biological, or physical agent that causes a birth defect is called a teratogen.
Each organ system develops at a different time and rate, each has a critical period.
During Critical Period exposure to a teratogen is most likely to disrupt development and cause irreversible damage.
Severe damage can result in miscarriage.

43. Practices to Avoid During Pregnancy
Optimal pregnancy outcome is influenced by maternal nutrient intake but also affected by:
EXCESS CAFFEINE
ALCOHOL
TOBACCO
LOW CALORIE DIET
MEGA DOSES OF CERTAIN VITAMINS
DRUGS

44. Practices to Avoid During Pregnancy
Low-carbohydrate or low-calorie diets that cause
Ketosis.
That can cause CONGENITAL DEFORMITIES
Can deprive the fetus's brain of needed glucose

45. Practices to Avoid During Pregnancy
Smoking restricts blood supply to the fetus
There by limit supply of Oxygen & Nutrient to Fetus and stunts growth, thus increase Risk of:
PREMATURE DELIVERY
LOW BIRTH WEIGHT
RETARDED DEVELOPMENT AND
SPONTANEOUS ABORTION
SUDDEN INFANT DEATH SYNDROME (SIDS)
Smoking is responsible for 20-30% of all low-birth weight deliveries in the United States.

46. Practices to Avoid During Pregnancy
SUDDEN INFANT DEATH SYNDROM (SIDS)
HAS BEEN LINKED TO SMOKING DURING PREGNANCY & SECOND HAND SMOKE

47. Practices to Avoid During Pregnancy
ALCOHOL
Consumption affect fetal development. Even 1 or 2 drinks can cause
THE MOST SEVERE IMPACT OF MATERNAL DRINKING IS LIKELY TO OCCUR IN THE FIRST MONTH OF PREGNANCY
BEFORE THE WOMEN IS SURE SHE IS PREGNANT.
ALCOHOL IS THE LEADING CAUSE OF MENTAL RETARDATION IN U.S
IT OCCUR IN APPROXIMATELY 2 TO 3 PER 1000 LIVE BIRTHS IN U.S

48. Practices to Avoid During Pregnancy
Fetal Alcohol Syndrome (FAS): the cluster of symptoms seen in an infant or child whose mother consumed excess alcohol during pregnancy. Those include:
RETARDED GROWTH
IMPAIRED DEVELOPMENT OF THE CENTRAL NERVOUS SYSTEM
MENTAL & PHYSICAL RETARDATION
FACIAL MALFORMATION
Fetal alcohol effect (FAE): A lesser condition that causes learning impairment and other more subtle abnormalities in infants exposed to alcohol during pregnancy.

49. FAS

50. Alcohol
Not all babies who are exposed to alcohol while in the uterus have FAS, but many have some alcohol-related problems.
Alcohol-related neurodevelopmental disorders (ARND) are functional or mental impairments linked to prenatal alcohol exposure, and
Alcohol-related birth defects (ARBD) are malformations in the skeleton or major organ systems.
These conditions are less severe than FAS but occur about three times more often.

51. Practices to Avoid During Pregnancy
EVIDENCE SHOW THAT EVEN ONE DRINK MAY BE TOO MUCH FOR PREGNANT WOMAN, THAT LED THE AMERICAN ACADEMY OF PEDIATRICS TO TAKE THE POSITION THAT:
WOMAN SHOULD STOP DRINKING AS SOON AS THEY PLAN TO BECOME PREGNANT.

52. Practices to Avoid During Pregnancy
DRUGS
DRUGS AND MEDICATION TAKEN DURING PREGNANCY CAN ALSO CAUSE BIRTH DEFECT.
Avoid taking all drugs and herbal supplements except for physician-advised medicine.

53. Practices to Avoid During Pregnancy
Avoid lead exposure:
Avoid ceramic and leaded crystal ware.
Reduce exposure to mercury:
Avoid large ocean fish such as shark, swordfish, king mackerel and tilefish.
Pregnant women can safely eat 12 ounces of cooked fish including canned fish, shellfish, and smaller ocean or farm-raised fish.

54. CAFFEINE
When consumed in excess, coffee and other caffeine-containing beverages have been associated with increased risks of miscarriage or low birth weight.
It is recommended that pregnant women avoid consuming more than 200 mg of caffeine per day
1 cup of Coffee, drip mg
1 cup of Coffee, brewed mg

55. Common Nutrition-Related Problems of Pregnancy
Morning Sickness
Pica
Constipation
Cravings
Pregnancy-induced hypertension (PIH)
Gestation diabetes

56. Common Nutrition-Related Problems of Pregnancy
Morning sickness seems unavoidable
Certain strategies may reduce the problem, such as eating:
SODA CRACKERS
HARD CANDIES
DRY STARCHY FOOD
EAT SMALL FREQUENT MEALS AS SOON AS FEEL HUNGRY

57. Pica:
the craving of nonfood items such as clay, ice, and laundry starch. Pica does not appear to be limited to any particular geographic area, race, sex, culture, or social status.
Hypertension
TRANSIENT HYPERTENSION OF PREGNANCY USUALLY DEVELOPS DURING SECOND HALF OF PREGNANCY, IT IS
USUALLY MILD FORM
NO ADVERSE EFFECTS
BLOOD PRESSURE BACK TO NORMAL AFTER BIRTH
PREELAMPSIA
ECLAMPSIA

58. Common Nutrition-Related Problems of Pregnancy
Preeclampsia: a condition characterized by
hypertension,
fluid retention (Generalized edema)
Sudden Large Weight Gain and
WARNING SIGNS OF PREECLAMPSIA
Sever & Constant Headache
Sudden weight Gain (1lb/day)
Swelling of Face, Hand & Feet
Dizziness & Blurred vision

59. Common Nutrition-Related Problems of Pregnancy
Eclampsia: a severe extension of preeclampsia characterized by :
Convulsions that may lead to
Coma
PREGNANCY-INDUCED HYPERTENSION (PIH) CAN CAUSE:
RETARDED FETAL GROWTH
THE PLACENTA TOSEPARATE FROM THE UTRUS RESULT IN
STILL BIRTH

60. Common Nutrition-Related Problems of Pregnancy
Gestational diabetes: the appearance of abnormal glucose tolerance during pregnancy, with a return to normal following pregnancy.
Abnormal blood glucose level occur in second half of pregnancy
Return back after birth, mostly
However sometimes may develop TYPE II Diabetes.

61. INFANTS BORN TO WOMEN WITH DIABETES ARE AT GREATER RISK FOR:
PREMATURE BIRTH
CONGENTAL DEFECTS
EXCESSIVELY HIGH BIRTH WEIGHT AND
RESPIRATORY DISTRESS SYNDROME

62. Adolescent Pregnancy
More than 700,000 teenagers become pregnant in the United States each year.
One out of every eight babies is born to a teenager.
More than a tenth of these mothers are under age 15.
Pregnancy places adolescent girls, who are already at risk for nutrition problems, at even greater risk because of the increased energy and nutrient demands of pregnancy.

63. Adolescent Pregnancy
MEDICAL & NUTRITIONAL RISKS ARE PARTICULARLY HIGH WHEN TEENAGERS IS 15 YEAR OF AGE OR YOUNGER:
HIGH RATE OF HYPERTENSION
IRON DEFICIENY
PREMATURE BIRTHS
STILLBIRTHS
LOW-BIRTHWEIGHT
PROLONG LABOR

64. Adolescent Pregnancy
To support the needs of both Mother and Infant, teenagers are encouraged to gain UPPER LIMIT of weight gain.
Those who gain between 30 to 35 lbs during pregnancy may have lower risk.

65. Pregnancy After Age 35
Older women are more likely to already have one or more medical conditions
They have a higher incidence of low-birth-weight infants.
Their infants are more likely to have chromosomal abnormalities, especially Down syndrome
An interval of less than 18 months between pregnancies increases the risk of delivering a small-for-gestational age infant

66. POSTNATAL NUTRITION

67. Nutrition of the Breastfeeding Mother
Adequate nutrition of the mother makes a highly significant contribution to successful lactation.
A nursing mother produces 30 ounces of milk a day, on the average, with wide variations possible.
Lactation creates increased energy need because of milk production
The American Academy of Pediatrics recommends
Breast-feeding exclusively through age of 6months
Continue breast-feeding until 1 year or beyond, while introducing solid foods at 6 months

68. Breast Milk Benefits FOR THE INFANT FOR THE MOTHER Reduce rick of:
-Obesity
-Ear Infections
-Gestrointestinal infactions
-Sudden infants death syndroms
-Severe respiratory track infections
-Celiac disease & food allergies
-Type 1 & type 2 disease
-Inflammatory bowel disease
Improved
-Brain development
-Immune response
Reduced risk of:
Breast Cancer
Ovarian Cancer
Type 2 diabetes
More rapid return to pre-pregnancy body weight

69. LACTATION Alveoli are the milk producing glands in the breast
Lactation involves both the synthesis of milk components and
the movement of those components through the milk ducts to the nipple.
Milk production and let-down are triggered by hormones that are released in response to an infant's suckling.
The pituitary hormone prolactin stimulates milk production
the more the infant suckles, the more milk is produced
Let-down is caused by oxytocin, another pituitary hormone.
Alveoli are the milk producing glands in the breast

70. Postnatal Nutrition
BABY GROW FAST DURING THE FIRST YEAR OF LIFE THAN EVER AGAIN.
FIRST 4 TO 6 MONTHS WEIGHT DOUBLE
END OF THE FIRST YEAR - TRIPLE ITS BIRTH WEIGHT
ADEQUATE NUTRITION IS CRITICAL THIS RAPID RATE OF GROWTH
FIRST YEAR IS THE MOST IMPORTANT YESR OF A PERSON’S LIFE

71. Nutrition of the Breastfeeding Mother
Breastfeeding has both emotional and physical health advantages.
Colostrum (co-LAHS-trum): a milklike secretion from the breast, rich in protective factors, present during the first day or so after delivery and before milk appears.
Bifidus factor (BIFF-id-us): a factor in colostrum and breast milk that favors the growth in the infant’s intestinal tract of the “friendly” bacteria Lactobacillus bifidus so that other, less desirable intestinal inhabitants will not flourish.
Lactoferrin (lak-toe-FERR-in): a factor in breast milk that binds and helps absorb iron and keeps it from supporting the growth of the infant’s intestinal bacteria.

72. Nutrition of the Breastfeeding Mother
PERIOD OF LACTATION IS THE NATURAL TIME FOR WOMEN TO LOSE EXTRA BODY FAT.
Beginning 1 month after birth, most lactating women lose 0.5 to 1 kg (1 to 2 lbs)/month during breastfeeding.
Breast milk is tailor made to meet the nutrient needs of the young infant.
With the exception of vitamin D, its vitamin contents are ample.
The American Academy of Pediatrics recommends that infants receive breast milk for the first twelve months of life.
Exclusively breastfeeding your infant is the best way to provide your baby with unique immune protection against ear, gastrointestinal, and sever lower respiratory tract infections

73. A breastfeeding mom may decrease her risk of
Breast cancer.
Ovarian cancer.
Colon cancer.
Exclusively breastfed infants may need supplementation with vitamin D.
Newborn infants are typically given an inoculation of Vitamin K at birth, as their sterile colons do not yet have the bacteria to make this nutrient.

74. Nutrition of the Breastfeeding Mother
BREAST MILK ALSO CONTAIN:
SEVERAL ENZYMES
SEVERAL HORMONS
LIPIDS THAT HELP TO PROTECT AGAIST INFEATION
OFFER CARBOHYDRATE
OMEGA 6 FATTY ACIDS
EASILY DIGESTABLE PROTEIN
Ca, P & Mg PRESENT IN ADEQUATE AMOUNT
LOW IN SODIUM
Exclusively breastfed infants may be at risk for iron deficiency if they do not have adequate stores, and/or if they were born prematurely

75. Formula feeding can have benefit such as:
mom need not to worry about taking medications that are contraindicated with breastfeeding.
no concerns over the amount of nutrition the baby is consuming.
alleviates any concerns regarding discomfort with breastfeeding
But formula does not provides immune properties

76. Milk for the Infant: Breastfeeding
Feeding Formula
Infant formulas are manufactured with the approximate nutrient composition of breast milk.
The parents can see that the baby is getting enough milk during feedings.
The mother can offer similar closeness, warmth, and stimulation during feedings as the breastfeeding mother does.
Other family members can get close to the baby and develop a warm relationship in feeding sessions.
However, it cannot provide all that protections that mother’s milk can provide.

77. Formula Feeding Designed for infants
Nutritious addition to or replacement for breast milk
Lacks antibodies and other components in breast milk
Is expensive
Should not be diluted
Consult physician to select appropriate formula

78. Milk for the Infant
RAPID GROWTH AND METABOLISM DEMAND ADEQUATE SUPPLY OF ALL NUTRIENTS
SOLD FOOD MAY BE GIVEN AFTER 6 MONTHS
EARLY INTRODUCTION OF SOLID FOOD CAN DEVELOP ALLERGIES
Newborn
Vitamin K injection at birth
0 to 6 months of age
Exclusively breast-fed or formula-fed
Vitamin D supplements of 400 IU
6 to 12 months of age
Introduce solid foods
Continue breast-feeding or formula-feeding

79. Beginning solid foods too early may result in
Signs that a baby is ready to start eating solid food include:
being able to hold the head up,
sitting up in a high chair, and
the disappearance or diminishment of the tongue thrusting reflex
Beginning solid foods too early may result in
increased risk for childhood obesity.
increased risk of food allergies.
having an upset stomach.
choking, if child is not able to hold their head up.

80. Nutrition for the Growing Child

83. Introducing Solid Foods

84. Healthy Infants Nutrition-Related Problems of Infancy
Iron deficiency remains a prevalent nutritional problem in infancy.
It has declined in recent years in large part because of the increasing use of iron-fortified formulas.
Food allergies are common and genetics is probably the most significant factor affecting an infant’s susceptibility to food allergies.
At-risk infants can be identified by means of careful skin testing and by a family history.
To detect food allergies, new foods should be introduced one at a time.