chapter 5 nutrition during pregnancy: conditions and interventions nutrition through the life cycle...

Chapter 5 Nutrition During Pregnancy:Conditions and Interventions

Nutrition Through the Life Cycle Judith E. Brown

Key Nutrition Concept #1

• Some complications of pregnancy are related to women’s nutritional status.


• Nutritional interventions for a number of complications of pregnancy can benefit maternal and infant health outcomes.


• Nutritional interventions during pregnancy should be based on scientific evidence that supports their safety, effectiveness, and affordability.

Introduction

• Health conditions impacting pregnancy & interventions are covered to include:– Hypertensive disorders of pregnancy

– Preexisting & gestational diabetes

– Obesity

– Multifetal pregnancies

– HIV/AIDS

– Eating disorders

– Fetal alcohol spectrum

– Adolescent pregnancy

Obesity and Pregnancy

• Obesity associated with higher rates of gestational diabetes and hypertensive disorders– Associated with unfavorable metabolic changes:

blood glucose levels C-reactive protein levels blood levels of insulin & insulin resistance blood pressure• High Total-LDL cholesterol & Triglycerides• Low HDL cholesterol

Obesity and Infant Outcomes

• Obesity associated with higher rates of– Stillbirth– Large for gestational newborns– Cesarean-section delivery– May increase risk of child becoming

overweight or having Type 2 diabetes later in life

Nutritional Recommendations and Interventions for Obesity in

Pregnancy• Meet nutrient needs

• Consume a variety of basic foods

• Participate in physical activity

• Maintain appropriate rates of weight gain

Pregnancy After Bariatric Surgery

• Bariatric surgery for weight loss has increased• Weight rapidly lost due to

– Limited food intake– Fat malabsorption – Dumping syndrome

• Deficiencies of many nutrient stores– Thiamine, Vitamins D, B12 and Folate– Iron and calcium

Nutrition Care Post-Bariatric Surgery and Pregnancy

• Nutrient deficiencies vary depending on type of bariatric surgery performed

• Nutrition care includes:– Assessment of dietary intake– Supplement use– Nutrient biomarker status– Weight gain– Physical activity– Gastrointestinal symptoms

Hypertensive Disorders of Pregnancy

• Hypertension (HTN) is defined as blood pressure ≥140 mm Hg systolic or ≥90 mm Hg diastolic blood pressure– Affects 6 to 10% of pregnancies– Contributes to stillbirths, fetal & newborn deaths, &

other adverse conditions

• “Pregnancy-induced hypertension” is being replaced with “hypertensive disorders of pregnancy”

Hypertensive Disorders of Pregnancy

Hypertensive Disorders of Pregnancy, Oxidative Stress, and

Nutrition• HTN in pregnancy is related to:

– Inflammation– Oxidative stress – Damage to the endothelium (cells lining the inside of

blood vessels)

• Consequences of endothelial dysfunction:– Impaired blood flow– Increased tendency to clot– Plaque formation

Ways to Reduce Oxidative Stress

• Regular intake colorful fruits and vegetables, dried beans and whole-grain products

• Adequate intake of vitamin D, & omega-3 fatty acids

• Ample physical activity– Weight loss if overweight (not recommended

during pregnancy) See Table 5.3.

Chronic Hypertension

• HTN present before pregnancy or diagnosed <20 weeks

• Estimated incidence is 1 to 5%

• More common in:

– African American, obese, >35 years of age, or history of HTN with previous pregnancy

• Blood pressure ≥ 160/110 mm Hg associated with increased risk of:

– Fetal death, preterm delivery, & fetal growth retardation

Nutritional Interventions for Women with Chronic

Hypertension in Pregnancy– Intervention should aim to achieve adequate &

balanced diets for pregnancy– Weight gain is same as for other pregnant

women– If salt-sensitive, Na restriction required for

blood pressure control without too little that could impair fetal growth

Gestational Hypertension

– Hypertension diagnosed for first time after 20 weeks of pregnancy

– No proteinuria

– Tend to be overweight or obese with excess central body fat

Preeclampsia-Eclampsia

– A pregnancy-specific syndrome occurring >20 weeks gestation accompanied by proteinuria

• Proteinuria—urinary excretion of ≥0.3 gram protein in 24-hour urine sample (or >30 mg/dL protein or ≥2 on dipstick reading)

• Eclampsia—occurrence of seizures not attributed to other causes

Characteristics of Preeclampsia-Eclampsia

• Oxidative stress, inflammation, & endothelial dysfunction

• Blood vessel spasms & constriction

• Increased blood pressure

• Adverse maternal immune system responses to the placenta

• Platelet aggregation & blood coagulation due to deficits in prostacyclin relative to thromboxane

• Insulin resistance

• Elevated blood levels of triglycerides, free fatty acids and cholesterol


• Signs and symptoms of preeclampsia range from mild to severe

• Health consequences also range from mild to severe

• Cause is unknown – appears to originate from:– Abnormal implantation & vascularization of

placenta with poor blood flow.

Diabetes in Pregnancy

• Diabetes: a leading complication in pregnancy• Forms of diabetes include:

– Type 1 diabetes—Results from destruction of insulin-producing cells of pancreas

– Type 2 diabetes—Due to body’s inability to use insulin normally, or produce enough insulin

– Gestational—CHO intolerance with 1st onset during pregnancy

Gestational Diabetes

• See in about 7.5% of pregnant women (and increasing with obesity)

• Women who develop gestational diabetes appear to be predisposed to insulin resistance & type 2 diabetes

• Associated with increased levels of blood glucose, triglycerides, fatty acids, & blood pressure

Potential Consequences of Gestational Diabetes

• Elevated glucose from mother – risk of adverse outcomes.

– Spontaneous abortion, stillbirth, neonatal death

– Congenital anomalies insulin glucose uptake & triglyceride

formation in fetus

• Fetal changes likelihood later in life:

– Insulin resistance and/or Type 2 diabetes

– High blood pressure

– Obesity

Adverse Outcomes Associated with

Gestational Diabetes

Risk Factors for Gestational Diabetes

• Linked to multiple inherited predisposition

• Environmental triggers such as:– Excess body fat– Low physical activity levels

Risk Factors for Gestational Diabetes

Diagnosis of Gestational Diabetes

• Glucose screening recommended for women at high risk

• Risk factors are listed below:– Marked obesity– Diabetes in a parent or sibling– History of glucose intolerance– Previous macrosomic infant– Current glucosuria

Glucose Screening

• First screen is a 50-g oral glucose challenge test • If elevated, 3-hour, 100-g oral glucose tolerance test

(OGTT) is given• Gestational diabetes diagnosed if ≥2 of the following

levels are exceeded:– Overnight fast 95 mg/dL– 1-hour after glucose load 180 mg/dL– 2-hours after glucose load 155 mg/dL– 3-hours after glucose load 140 mg/dL

Low Risk Women Not Needing Glucose Screens

• Age <25 years• Not Hispanic, African American, South or East

Asian, Pacific Islander, Native American, or Indigenous Australian

• No diabetes in first-degree relatives• Normal prepregnancy weight & normal weight gain

during pregnancy• No history of glucose intolerance• No prior obstetrical outcomes

Treatment of Gestational Diabetes

• First approach is to normalize blood glucose levels with diet & exercise

• If postprandial glucose remains high 2 weeks after adhering to diet & exercise, insulin injections are added

• Medical nutrition therapy decreases risk of adverse perinatal outcomes

Exercise Benefits & Recommendations

• Regular aerobic exercise decreases insulin resistance & blood glucose in gestational diabetes

• Exercise should approximate 50-60% of VO2 max, 3 times per week

Nutritional Management of Women with Gestational

Diabetes• Assess dietary & exercise habits

• Develop individualized diet & exercise plan

• Monitor weight gain

• Interpret blood glucose & urinary ketone results

• Ensure follow-up during & after pregnancy

THE DIET PLAN

• Whole-grain breads & cereals, vegetables, fruits, & high-fiber foods

• Limited intake of simple sugars

• Low-GI foods, or carbohydrate foods that do not greatly raise glucose levels

• Monounsaturated fats

• Three regular meals & snacks

Estimating Levels of Caloric Need in Women with Gestational

Diabetes

• Distribute calories among 3 meals & several snacks

• Caloric levels & meal/snack plans are starting points and my need modifications.

Consumption of Foods with Low Glycemic Index

• Benefits of low-GI foods has been debated and is controversial

• Blood glucose response with type 2 diabetes from meals of white bread or spaghetti is shown in graph

• Note Lower-GI spaghetti improves blood glucose levels

Menus for Women with Gestational Diabetes

Other Topics on Diabetes in Pregnancy

• Urinary Ketone Testing– Monitored with dipsticks

• Postpartum Follow-Up– 15% will remain glucose intolerant postpartum

– 10-15% will develop Type 2 diabetes in 2-5 yrs

• Prevention of Gestational Diabetes– Reduce excessive weight and obesity

– Increase physical activity

– Decrease insulin resistance prior to pregnancy

Type 1 Diabetes during Pregnancy

• Potentially, a more hazardous condition than most cases of gestational diabetes

• Mother with type 1 is at risk of:– Kidney disease

– Hypertension

– Other complications

• Newborn born to her is at risk of:– Mortality

– Being SGA or LGA

– Hypoglycemia within 12 hours after birth

Nutritional Management of Type 1 Diabetes during Pregnancy

• Control of blood glucose levels

• Nutritional adequacy of diet

• Achieve recommended weight gain

• Careful home monitoring of glucose levels & dietary intake, exercise, insulin dose, & urinary ketone levels

Multifetal Pregnancies

• U.S. rates of multifetal pregnancies have increased– Linked to assisted reproductive technologies

• Spontaneous multifetal pregnancy after 35 years of age

• Incidence highest in women 45 to 54 y/o (1 in 5 are multifetal)

Background InformationAbout Multifetal Pregnancies

• Dizygotic– 2 eggs are fertilized

– AKA Fraternal

– ~70% of twins

– Different genetic “fingerprints”

– Incidence increased by perinatal nutrient supplements

• Monozygotic– 1 egg is fertilized

– AKA Identical• (or almost identical)

– Always same sex

– ~30% of twins

– Rates appear not to be influenced by heredity

Note the Differences in Placentas and Amniotic Sacs

The Vanishing Twin Phenomeon

• It is estimated that 6 to 12% of pregnancies begin as twins with only 3% born as twins

• Most fetal losses silently occur by absorption into the uterus within the 1st 8 months

Risks Associated with Multifetal Pregnancy

Complications Increase as Number of Fetuses Increases

Nutrition and the Outcome of Multifetal Pregnancy

• Weight gain in multifetal pregnancy– IOM recommends 25-54 pounds

• Rate of weight gain in twin pregnancy– 0.5 pounds per week in 1st trimester– 1.5 pounds per week in 2nd & 3rd trimesters

• Weight gain in triplet pregnancy– Gain of ~50 pounds or 1.5 pounds per week

Nutrition and the Outcome of Multifetal Pregnancy

• Dietary intake in twin pregnancy– Benefits from increases in essential fatty acids,

iron & calcium

• Vitamin and mineral supplements– Needs unknown

• Nutritional recommendations– Based on logical assumptions & theories– Table 5.16 indicates “Best Practice”

HIV/AIDS during Pregnancy

• Treatment of HIV/AIDS– Needed before, during & after pregnancy

• Consequences of HIV/AIDS during pregnancy– Infection does not appear to be related to adverse

pregnancy outcome• Nutritional factors and HIV/AIDS during pregnancy

– Nutritional needs increase the most in advanced stages of HIV/AIDS

Nutritional Management for Women With HIV/AIDS during

Pregnancy

• Goals for nutritional management include:– Maintenance of positive nitrogen balance & preservation of

lean muscle & bone mass

– Adequate intake of energy & nutrients to support maternal physiological changes & fetal growth & development

– Correction of elements of poor nutritional status identified by nutritional assessment

– Adoption of safe food-handling practices

– Delivery of a healthy newborn

Eating Disorders in Pregnancy

• Eating disorders are rare in pregnancy since most females with disorders are subfertile or infertile

• Bulimics more likely to become pregnant than those with anorexia nervosa

• Eating disorder symptoms subside in 2nd & 3rd trimester but return postpartum


• Consequences of eating disorders in pregnancy risk – Spontaneous abortion– Hypertension– Difficult deliveries– Smaller newborns– Higher rates neonatal complications


• Treatment of women with eating disorders during pregnancy– Refer to eating disorders clinic

• Nutritional interventions for women with eating disorders– Behavioral changes– Improve nutritional status– Appropriate weight gain

Fetal Alcohol Spectrum

• “Fetal alcohol spectrum” describes range of effects that fetal alcohol exposure has on mental development & physical growth

• Effects include:– Behavioral problems

– Mental retardation

– Aggressiveness

– Nervousness & short attention span

– Stunting growth & birth defects

Fetal Alcohol Spectrum

• Fetal exposure to alcohol is a leading preventable cause of birth defects– ~1 in 12 American pregnant women drink

alcohol – 1 in 30 consume ≥5 drinks on 1 occasion at

least monthly– 1 in 1000 newborns are affected by fetal

alcohol syndrome

Effects of Alcohol on Pregnancy Outcome

• Alcohol easily crosses placenta to fetus

• Alcohol remains in fetal circulation because fetus lacks enzymes to break down alcohol

• Alcohol exposure during critical periods of growth & development can permanently impair organ & tissue formation, growth, health and mental development

Effects of Alcohol on Pregnancy Outcome

• Heavy drinking (4-5 drinks/day) increases risk of miscarriage, stillbirth, & infant death

• ~40% of fetuses born to women who drink heavily will have fetal alcohol syndrome

• Because a “safe” dose of alcohol consumption during pregnancy has not been identified, it is recommended that women do not drink alcohol while pregnant

Fetal Alcohol Syndrome

• First identified in 1973• Characteristics

include:– Anomalies of eyes,

nose, heart & CNS

– Growth retardation

– Small head

– Mental retardation

Nutrition and Adolescent Pregnancy

• Growth during adolescent pregnancy

– Teen growth in height & weight at expense of fetus

– Infants born to teens average 155g less than those born to older adults

Nutrition and Adolescent Pregnancy

Obesity, Excess Weight Gain and Adolescent Pregnancy

• Overweight & obese adolescents are at increased risk for:– Cesarean delivery– Hypertensive disorders of pregnancy– Gestational diabetes– Delivery of excessively large infants

Dietary Recommendations for Pregnant Adolescents

• Young adolescents may need more calories to support their own growth as well as that of fetus

• Caloric need should be from nutrient-dense diet

• Calcium DRI for pregnant teens is 1300 mg

Nutritional Management of Adolescent Pregnancy

• Multidisciplinary counseling services should include:– Individualized nutrition assessment– Intervention education– Guidance on weight gain– Follow-up birthweight outcomes

Nutritional Management of Adolescent Pregnancy

• Services should focus on: – Psychosocial needs

– Support/discussion groups

– Home visits

Evidence-Based Practice

“Enormous amounts of new knowledge are barreling down the information highway, but they are not arriving at the doorsteps of our patients.”

− Claude Lenfant, National Institutes of Health

chapter 5 nutrition during pregnancy: conditions and interventions nutrition through the life cycle...

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