Download bariatric surgery (continued)

Nutritional Deficiencies in
Pregnant Patients who have
undergone Bariatric Surgery
Vaishali Doshi, MD
Assistant Professor of Medicine
Hematology/Oncology
University of Arkansas for Medical Sciences
Gastric bypass and Pregnancy
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Gastric bypass surgery for morbid obesity is considered an
appropriate intervention when other weight-loss measures
have proven unsuccessful.
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Weight loss often brings about improvement in overall
health by lessening the effects of obesity-related
comorbidities.
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In fact, the ability to become pregnant is enhanced, as
weight loss often allows for a normalization of sex
hormones.
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However, the nutrition challenges brought about by the
surgery may have a profound impact on maternal health
and pregnancy outcome.
Outline
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Different procedures
Effects of surgery and nutritional alterations
Implications for pregnancy
Major Categories
Surgical procedures for morbid obesity may be
classified according to the digestive aftereffects
brought about by the particular procedure.
These categories include the
"restrictive" procedures
 "restrictive-malabsorptive" procedures
 less common "malabsorptive" procedures.
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Bariatric Surgery
Nutritional needs
1) vary depending on the degree of restriction
and the degree of malabsorption caused by the
surgery
2)specific area of the intestine is bypassed.
Individual nutrients generally have a specific
site of absorption along the small intestine.
Restrictive procedures
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vertical banded gastroplasty (VBG),
silicon ring vertical banded gastroplasty (SRG)
adjustable silicone gastric banding (ASGB)
weight loss simply by total volume of food
intake.
Patients learn quickly that these surgeries
require them to chew their food very well to
slow down the pace of eating dramatically
Vertical banded gastroplasty
Restrictive procedures
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Food leaves the newly constructed pouch and
empties directly into the original stomach for
normal digestion
It then moves through the entire duodenum and
jejunum for normal absorption.
Malnutrition may occur as a result of the
necessity to limit food ingested ,thus reducing
caloric and nutrient intake.
Restrictive Surgeries
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Generally, an adult multiple vitamin and mineral
supplement is sufficient after restrictive surgeries
since there is no malabsorption of specific
nutrients.
There is a significant decrease in the overall
quantity of food intake and therefore a decrease
in the quantity of all micronutrients; a
supplement should bring intake up to the RDA
levels.
Restrictive
RestrictiveMalabsorbtion
Vertical banded
gastroplasty
Roux-en Y gastric Jejunoileal bypass
bypass
Adjustable gastric Biliopancreatic
banding
diversion
Intragastric
balloon
Horizontal
unreinforced
gastroplasty
Malabsorbtive
Duodenal switch
Roux-en-Y gastric bypass
RYGB
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A small pouch is formed by stapling the upper
portion of the stomach across the fundus
The contents of the newly formed stomach
empty directly into the distal jejunum via a
constructed gastrojejunostomy.
The remainder of the stomach,duodenam,
proximal jejunum are completely bypassed
RYGB
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deficiencies of iron
B12, folate,
calcium.
copper
Iron Deficiency after RYGB
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Iron deficiency is common after RYGB due to
decreased intake of adequate quantities of meat
and other iron rich foods

Anatomic changes resulting from the surgery
prevent iron containing food from being
exposed to the acid environment of the
stomach, which is required for the release of
iron from its protein source
Iron Deficiency after RYGB
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Gastric acidity is essential for the reduction of
iron from the ferric state to the ferrous state
which is necessary for absorption
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Iron is absorbed in the duodenum which is
bypassed, some iron will be absorbed in the
lower jejunum
Folate Deficiency after RYGB
1)decreased intake of folate-rich foods.
2) dietary folate bypasses the duodenum which is the
primary site of folate absorption.
3) Folate absorption, however, can take place along
the entire length of the small bowel with adaptation
after surgery.
B12 absorption and deficiency
1)Intake of foods that are good sources of B12 are consumed in very limited
quantities; secondary,
2) with a less acidic environment in the pouch as compared to a normal
stomach, it is difficult to release protein-bound B12 from foods ingested.
3) the unbound b12 is then joined to R binders
The R binders are normally degraded in the duodenum by pancreatic
enzymes
4 )The absence of an acidic environment prevents the binding and
subsequent release of b12 from food,
B12 Absorption
1
2
It then must pair up with intrinsic factor (IF)
to form IF/B12 complexes for absorption in
the ileum.
A reduction in the availability of IF ,
(produced by parietal cells of stomach)
combined with the decreased prescence of
unbound Vit B12 prevents formation of
IF/B12 complex resulting in malabsorbtion.
B12 Supplementation
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Hyperhomocysteinemia is associated with
cardiac and neurological abnormalities
Long term supplementation of b12 following
bariatric surgery
Daily oral supplementation 350 ucg of b12
sublingual
Occasionally oral supplementation is not
adequate making monthly parenteral therapy a
necessity
Calcium deficiency
Calcium deficiency is common and metabolic bone disease
represents a long-term potential risk associated with RYGB
surgery.
Calcium with VIT D is absorbed in the duodenum
Following RYGB ,the duodenum is bypassed, preventing
access to the primary absorption site for calcium.
Patients who have undergone gastric bypass surgery must rely
on passive diffusion of dietary calcium along the length of the
remaining intestine
Typically, blood levels of calcium will be normal
limits unless other causes create abnormal levels.
calcium deficiency is insidious in nature an
individual is potentially releasing calcium from
the bones constantly to maintain normal serum
calcium.
METABOLIC BONE DISEASE
Over time metabolic bone disease results.
Oftentimes the individual is unaware of the
problem until a bone or a tooth breaks. At this
point the problem is significant.
Copper Deficiency
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Copper is an essential micronutrient that plays a
vital role as a catalytic cofactor for a variety of
metalloenzymes
Copper absorption occurs in the stomach and
duodenum
Case reports of copper deficiency years after a
gastric bypass
Copper Deficiency
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Copper deficiency is associated with iron
deficiency
Copper is a part of hephaestin,which converts
iron to its ferric form which is necessary for its
transport by transferrin
Copper deficiency also causes a microcytic
hypochromic anemia that is not responsive to
iron supplementation
Micronutrient supplementation
It is recommended that all patients following a gastric bypass be
given iron supplementation with 40 to 65 mg of iron per day
However women with an existing iron deficiency or those who
are menstruating may require higher doses .
Women having a restrictive only procedure ,where digestive
continuity is not disrupted, generally do not experience iron
deficiency
.
Some prescription prenatal vitamin supplements do
contain this level of iron.
It is difficult to find an over-the-counter prenatal or a
standard adult vitamin with this level of iron.
If an over-the-counter prenatal vitamin is selected, it is
recommended that an iron supplement is added to total
40 to 60 mg of iron per day. This generally prevents
deficiency in most individuals
Vitamin Supplementation post RYGB
Generally, individuals who take the sublingual B12 very rarely
develop sub optimal B12 levels
A very small percentage of individuals will still become B-12deficient, despite oral therapy
May require monthly injections on an ongoing basis.
Supplementation with prenatal vitamins containing 1 mg of
folicacid prior to and during pregnancy is sufficient to maintain
adequate serunm levels and reduce the risk for neural tube defect
Calcium deficiency is common and can generally
be prevented by consuming the correct form
and amount of calcium.
Calcium citrate is the required form as it does
not require acid to break it down to be
absorbed.
Most supplements contain calcium carbonate,
which is not effective after RYGB surgery.
Micronutrient supplementation
It is recommended to take 1200-1500 mg of
calcium citrate per day.
Tums ® and other calcium carbonate supplements
are not effective with reduced stomach acid.
Periconceptual women
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Folic acid – 1 mg
Calcuim citrate -1200mg-1500mg
Vit D
B12 --- 350 ucg crystalline
Ferrous Iron 45-60 mg
IMPLICATIONS FOR
PREGNANCY
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PRECONCEPTION
ANTENATAL
POST PARTUM
Preconception
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Preconception care is considered preventive care
Most pregnancies are not planned and first prenatal
visit occurs after the period of organogenesis is
completed
Women of childbearing age who have undergone a
bypass ,must continue taking vitamins so that a
deficiency at pregnancy onset can be avoided
Because anemia is not as common following restrictive
bariatric procedures iron supplementation is given only
when necessary
Labs at outset
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Serum iron, total iron binding capacity,
transferrin saturation, ferritin
Vit b12, red cell folate
Homocysteine and methyl malonic acid
S calcuim
Copper level
Antepartum
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If pregnancy was planned and preconception
planning was obtained, the woman is advised to
continue taking the prescribed supplements and
a prenatal vitamin with iron is added
If pregnancy was not planned early evaluation
and correction of nutritional status should be
carried out
Anemia in Pregnancy
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Hyporegenerative ,reticulocytopenic anemia
To compensate for iron for fetal hemoglobin synthesis,
to anticipate the losses due to bleeding
Approximately 4 mg of iron needs to be absorbed daily
Total of 1000 mg of additional iron is needed during the
course of pregnancy
This amount is greater than the normal -500 mg storage
iron pool present in most women
Iron deficient state with low ferritin levels frequently
occurs in the mother
Deficiencies of iron, folate
Physiological anemia of pregnancy
Iron deficiency anemia
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Oral iron (elemental of 200mg/day)
Ferrous sulphate tid ( 300 mg of ferrous
sulphate =65 mg of elemental iron
Iron is best absorbed if given without food
Side effects –constipation, diarrhoea,nauseau
and abdominal pain
If these limit compliance the medication can be
administered with food or the dose reduced by
one half
Oral Iron therapy
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Oral iron therapy usually corrects the anemia
within four to six weeks ,oral iron to be
continued for 3-6 mths for body stores
Addition of VIT C ,to aid absorbtion have been
tried with patients of gastric bypass
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Ferrous products are effective, but they are
associated with more gastrointestinal side effects
than ferric products.
Ferric products tend to have lower absorption
Parenteral Iron Therapy
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As patients with a gastric bypass have a true
inability to absorb iron.
Two forms are availableIron –dextran
Infusion at a single visit
Iron dextran can cause severe allergic reactions
including anaphylaxis
pregnancy criteria - C
Ferrlecet
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soduim ferric gluconate-ferrlecet
Pregnancy criteria –B
125 MG/10 ML – Elemental iron
Slowly as 2.1 mg/min
Weekly dosing
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Response to oral iron can be assesed within 2-3
weeks, if no adequate retic response
May consider Parenteral iron especially patients
with RYGB
Moniter with iron indices and ferritin every 2-3
mths
Vit B12 DEF
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Deficiency of VIT B12, B6 ,FOLIC ACID results in
elevated levels of homocysteine
The presence of hyperhomocysteinaemia may be used
as a marker in pregnancy to indicate the increased risk
for thrombotic events and early pregnancy loss
Vascular disease of placenta increases.
Important to maintain normal b vitamins and folate
levels
Protect against recurrent early pregnancy loss
Complications
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maternal complications --- severe anemia
fetal complications
neural tube defect
intrauterine growth restriction
failure to thrive
Nutrient supplementation following Bariatric surgery
and close supervision before, during, and after
pregnancy can help prevent nutrition-related
complications and improve maternal and fetal health.