Kidney Stones, Obesity and Bariatric Surgery

The most common type of kidney stones in the general population, and bariatric surgery is no exception, is "calcium oxalate" stones. Historically, calcium oxalate kidney stones formation was a complication of the obsolete jejuno-ileal bypass (JI Bypass) of the 1970s. The risk for kidney stones, kidney failure, and liver disease led to the abandonment of that surgery more than 20 years ago.

A Mayo Clinic retrospective study showed that by 12 months after gastric bypass, the mean urinary oxalate and calcium oxalate supersaturation were both increased in a group of patients who did not have a history of forming stones.

Notice that, even without surgery, recent data have suggested an increased prevalence of stones with diabetes and obesity. Insulin resistance may lower urinary citrate and increase urinary calcium. Obesity may increase oxalates in urine.

It is safe to say that bariatric surgery can increase the risk of forming kidney stones, and certain recommendations need to be followed. Water and fluid intake, calcium citrate supplements and a low fat diet, go a long way. Remember: Oxalate is not good. Citrate is good. Calcium is good in the intestine but not good in the urine. Sodium is not good. Too much fat in the stool is not good. Here are more details.

Water and fluid intake: Drinking plenty of water is one of the most important measures to help preventing kidney stones. At least 10 glasses (cups) of water (80 ounces = two and a half liters) is recommended. In the presence of a history of kidney stones, even more is required. Lemonade (made from real lemons or a frozen concentrate), is good because it increases the citrates in the urine, which helps preventing kidney stones. Citrate is good; it inhibits the formation and growth of calcium crystals. But grapefruit Juice is not so good in this situation. A number of studies reported an increased risk for kidney stones from drinking grapefruit juice.

Low fat diet: The amount of oxalate in the urine increases with the amount of fat in the stool (fecal fat). After JI bypass the overall fat absorption was reported to be only 15%. So, the amount of fat passing into the stool, because of not being absorbed, is huge, and hence the higher likelihood of developing kidney stones. After purely restrictive surgeries (adjustable gastric band or vertical banded gastroplasty), fat absorption is normal, that is 97%. Biliopancreatic diversion +/- duodenal switch caused only 19% fat absorption. After gastric bypass, it was intermediate (67%) although the study group was very small. Probably the effect is less with proximal than distal bypass.

Restricting foods rich in oxalates: These include chocolate, cocoa, spinach and other dark green leafy items, most nuts, soy products, most berries, beets, beans, and tea. Because oxalates are so common in otherwise healthy food items, it is very difficult to completely eliminate them from a daily healthy diet. You can diminish the effect of oxalate rich foods by accompanying them with dietary sources of calcium to lower oxalate absorption, and by drinking additional fluids along the day.

Dietary calcium and calcium supplements: Calcium in the diet binds with oxalates in the gastrointestinal tract. So, less oxalates will be absorbed in the intestine, and less will be available by the kidney to form stones. Calcium supplements seem to have the same protective effect, but they have to be taken with meals. Calcium citrate is preferred because it helps to increase urinary citrate excretion.

Notice that vitamin C can convert to oxalate. Therefore, vitamin C supplements should be limited to less than 1000 mg/d.

Sodium: Sodium is not your friend. Lowering sodium intake lowers calcium in urine, since calcium excretion is linked to sodium excretion. So, less sodium makes less calcium available in the urine to form stones.

Protein: Animal protein was shown to lower citrate excretion in urine and to increase calcium and uric acid excretion. It is unknown if the malabsorption accompanying gastric bypass (which is why patients are asked to take more proteins), would weaken that bad effect. Also, a study showed that urinary calcium, oxalate, magnesium, citrate, and phosphorus did not differ between a diet of plant protein and beef protein.

Medications: Thiazide diuretics (example, hydrochlorothiazide "HCTZ" ): have been proven to be effective in reducing calcium in urine and stone recurrence. These "water pills" help decreasing the calcium in urine, and lowering the chance of developing kidney stones. Usually patients also receive potassium supplementation, which, in this case, could be potassium citrate to provided more citrate.

Oxalobacter formigenes: This organism relies completely on oxalate as its source of energy . This colonic bacterium could be a promising treatment for oxaluria.


References:

Asplin JR, Coe FL. Hyperoxaluria in kidney stone formers treated with modern bariatric surgery. J Urol. 2007 Feb;177(2):565-9. PMID: 17222634 (Abstract)

Lieske JC, Kumar R, Collazo-Clavell ML. Nephrolithiasis After Bariatric Surgery for Obesity. Semin Nephrol. 2008 Mar;28(2):163-173. PMID: 18359397 (Abstract)

Finkielstein VA, Goldfarb DS.Strategies for preventing calcium oxalate stones.CMAJ. 2006 May 9;174(10):1407-9. PMID: 16682705 (Full Text)

Nelson WK, Houghton SG, Milliner DS, Lieske JC, Sarr MG. Enteric hyperoxaluria, nephrolithiasis, and oxalate nephropathy: potentially serious and unappreciated complications of Roux-en-Y gastric bypass. Surg Obes Relat Dis. 2005 Sep-Oct;1(5):481-5. PMID: 16925274 (Abstract)

Duncan SH, Richardson AJ, Kaul P, Holmes RP, Allison MJ, Stewart CS. Oxalobacter formigenes and its potential role in human health. Appl Environ Microbiol. 2002 Aug;68(8):3841-7. PMID: 12147479 (Full Text)

Lieske JC, Goldfarb DS, De Simone C, Regnier C. Use of a probiotic to decrease enteric hyperoxaluria.Kidney Int. 2005 Sep;68(3):1244-9. PMID: 16105057 (Abstract)

Abdominal Pain after Gastric Bypass

Let's start with a bottom-line statement: Abdominal pain after gastric bypass (other than the early postoperative recovery) is not normal. You are not expected to have on and off severe pains, nausea or vomiting. Chronic abdominal pain is debilitating and may lead to avoiding eating, and, therefore, unnecessary malnutrition.

Here are some causes of pain after gastric bypass:

1. Bowel obstruction from internal herniation. This condition can be very serious, and may lead to loss of bowel or life. A loop of small bowel glides (herniates) into a defect inside the peritoneal cavity, then becomes trapped. The herniated loop may become strangulated, cutting off the blood supply, which could lead to death of that part of the bowel. I placed this as #1 not because it is common, but because it is probably the most serious and dreaded of all causes of later pain after abdominal surgery.

2. An ulcer, either in the pouch, on the anastomosis, or in the bypassed stomach or duodenum. Ulcers can cause not only severe pain, debilitation and malnutrition, but also may lead to bleeding. An ulcer may even perforate, causing peritonitis. Smoking and chronic intake of non-steroidal anti-inflammatory medications (NSAIDs) are risk factors for the development of ulcers.

3. Gallstones and gallbladder disease.

4. Abdominal wall hernia (incisional hernia, also called ventral hernia) my entrap a loop of bowel causing severe pain. When a hernia does not reduce itself, it is called "incarcerated". An incarcerated hernia may become strangulated, cutting off the blood supply to that loop of intestine. Incisional hernias can occur after any abdominal surgery, and bariatric surgery is no exception.

It is important to not accept pain after gastric bypass surgery as a normal sequence. Make sure that you seek expert help.

Hair Loss after Weight Loss Surgery

Here is a common question: Will I lose all my hair after gastric bypass? How do I keep my hair from falling out? The reality is that hair loss after bariatric surgery is common. But patients do not lose all their hair. In the most severe cases, patients may find clumps of hair in their hair brushes, or in the shower drain. However the hair loss normally corrects itself. The most accepted explanation is inadequate protein intake. Hair loss tends to start about three to five months after surgery. The best way to prevent hair loss is to make sure that you take your proteins first, with each meal.

Hair loss after bariatric surgery is considered a type of Telogen Effluvium. To explain, we need to talk a little bit about the normal phases of the cycle of hair development. Each strand of hair goes through three stages of development. These stages are Anagen – the growing phase, Catagen – the intermediate or transitional phase, and Telogen – the resting phase.

Anagen (The Growth Phase): Lasts 2-6 years. About 85% of all the hairs are in the growth phase at any given period of time.

Catagen (The Transitional Phase): The outer root sheath of the hair follicle shrinks and stops producing hair. The catagen phase usually lasts 2-3 weeks.

Telogen (The Resting Phase) The hair does not grow at all. This phase lasts about 3 months (100 days). An average of 5-15% of all hair is in the resting phase at any given period of time. At the end of this phase, the hair follicle starts a new Anagen phase. The resting (telogen) hair remains in the follicle until it is pushed out by growth of a new anagen hair, unless it was shed earlier. There is some recent evidence suggesting that shedding of a telogen hair might be an active process, independent of an emerging anagen hair.

Telogen effluvium occurs when an event prematurely terminates anagen and causes an abnormally high number of normal hairs to enter the resting, or telogen phase. Not all hair enters the telogen phase, but the percentage is much higher than normal. The hairs that are shed due to telogen effluvium are in the telogen phase. Examples of such events include childbirth, gastric bypass surgery, crash diets with inadequate protein intake, acute blood loss, and high fever. Notice that the follicle is not diseased. Simply, the hair follicle’s biologic clock has been reset. On the average, telogen hair loss occurs 3 months after the event.

For the record, this is very different from another type of hair loss called "Anagen Effluvium". The latter is abrupt loss of hair in the anagen phase, which may be caused by cancer chemotherapy and irradiation therapy. This is very different from telogen effluvium.

In conclusion, hair loss after bariatric surgery (a form of acute telogen effluvium) is fully reversible. Patients never completely lose all their scalp hair, although the hair can be very thin. The hair follicles are not irreversibly affected. With restoration of the nutritional balance, helped by increasing the intake of proteins, hair regrowth is expected within 3 - 6 months.

Video clip of animated bariatric procedures

A very good and easy-to-understand animation of the principles of the Roux-en-Y gastric bypass, the biliopancreatic diversion with duodenal switch procedure and the Lap Band, can be viewed in a video clip on the Mayo Clinic website.

http://www.mayoclinic.com/health/gastric-bypass/MM00703

Alcohol after Gastric Bypass

A glass of wine or two. A beer. A little mixed drink. Would that be OK after a gastric bypass? Well, early after the surgery, while the stomach is healing, you really want to avoid the irritant effect of alcohol. You want your pouch to heal well. So, the answer, as far as we know, is "no". But, what about drinking, let's say 6 months, a year, or more after the surgery? A very interesting study confirmed the previous opinion, that is, alcohol levels go higher after gastric bypass than people who had no such surgery. In a study published in the September issue of the journal "Surgery for Obesity and Related Diseases" (SOARD), researchers from Stanford School of Medicine, Stanford, California, concluded that the gastric bypass patients had a greater peak alcohol level and a longer time for the alcohol level to come back down to zero than the individuals who did not have gastric bypass. A particularly interesting finding was that the gastric bypass patients did not feel that alcohol influenced them any more than the no-surgery group. Could that explain why there are reports of post-gastric bypass patients who were cited for driving under the influence (DUI) after a small social alcoholic drink? Maybe. But also remember that there are other complications related to alcohol intake. Liver disease from alcohol is well-known. To develop alcoholic liver disease on top of the known obesity-related liver disease can be particularly dangerous. Alcohol is not good for peptic ulcers, either. Alcohol calories are empty calories, which is not what gastric bypass patients want to ingest. Also alcohol drinking has been linked to vitamin B1 deficiency. Severe vitamin B1 deficiency can lead to serious nerve damage, that is, Wernicke’s encephalopathy. So far, we do not have a perfectly scientific answer to the question: Is it OK to drink, in moderation, if you are not driving, several months or years after gastric bypass? We just do not have the final answer, and prefer to err on the cautious side. Better be safe than sorry.

References:
Klockhoff H, Naslund I, Jones AW. Faster absorption of ethanol and higher peak concentration in women after gastric bypass surgery.Br J Clin Pharmacol. 2002 Dec;54(6):587-91.

Hagedorn JC, Encarnacion B, Brat GA, Morton JM. Does gastric bypass alter alcohol metabolism? SOARD. 2007 Sept;3(5):543-8. (Note: This is the study quoted above)

Gallbladder, stones, sludge, and Gastric Bypass

Formation of gallstones or sludge in the gallbladder is known to increase with obesity and with rapid weight loss. According to one report, at 6 months, gallstones had developed in 36% and gallbladder sludge in additional 13% of patients

But another question is: What percentage of patients will actually develop symptoms or problems from gallstones or sludge after bariatric surgery? Well, reports quote anywhere from 3% to 30%.


There are different ways of dealing with the gallbladder, in relation to gastric bypass, and all of them are acceptable. A new trend in recent reports concluded no need to screen for gallbladder disease, based on the low incidence of patients who will actually have symptoms from gallstones after gastric bypass. Some reports will even not consider it necessary to remove a gallbladder with stones during a gastric bypass, because the majority of those with no symptoms before, will not develop symptoms after gastric bypass.


Many surgeons, however, still routinely order an ultrasound of the gallbladder before a gastric bypass. If abnormal, the gallbladder may be removed the same time of a gastric bypass. Surgical removal of the gallbladder is called "Cholecystectomy". Also, if a patient has symptoms of typical biliary pain, even if the ultrasound appears normal, a cholecystectomy may be considered.


Other surgeons routinely recommend the removal of the gallbladder at the time of a gastric bypass surgery, particularly with the open technique. If it is chosen that the gallbladder not be removed at the time of a gastric bypass, most will wait until symptomatic gallbladder disease develops, at which time the gallbladder would be removed (cholecystectomy). Some surgeons will ask patients to take a medication, Ursodiol (Brand Name: Actigall) to help lowering the chance of developing gallstones. One report documented a decrease in the incidence of development of gallstones from 32%, with no treatment to 2%. As you realize, there is no one unified approach.


The symptoms of gallstones or sludge after gastric bypass are not different from the general. In the most typical form, right upper quadrant pain in the abdomen, radiating to the back. However, there are so many variations of this typical picture.


Doing a cholecystectomy after a patient loses weight may be technically easier than during maximum obesity, and will almost always be covered by insurance companies when performed for symptoms. But, notice that treating gallstones, if they migrate to the common bile duct, is much more challenging after gastric bypass. The reason is that, after gastric bypass, patients can no longer have an endoscopic retrograde cholangiopancreatography (ERCP) performed in the usual manner. ERCP is a procedure performed using an endoscope, and allows the extraction of those migrating stones from the common duct, without a need to do surgical cutting into the abdomen. The procedure becomes much more difficult or impossible because the stomach has been completely divided, so the endoscope can no more be guided in the usual way from the stomach to the duodenum. Alternatives do exist, but none of them is that easy, nor the necessary set-up and expertise may be available. Therefore, after gastric bypass, a bigger operation, that is an open common bile duct exploration may be needed. Although the incidence of this particular challenging situation is low, it is still a significant occurrence for the individual unfortunate patient. This possibility needs also to be factored when deciding, weighing the benefits vs. the risks of removing the gallbladder along with a gastric bypass.

Life Expectancy - again

A very good article reporting and commenting on the 2 studies from the August 23 issue of the New England Journal of Medicine (NEJM), appeared in the Independant Weekly of Lafayette, Louisiana. It is titled "Life Expectancy - New studies show bariatric surgery patients are living longer." By following this Link, you can access the article. This "Bariatrics Lounge" blog reported on the NEJM article on August 22, so our readers were among the first to be informed. You can go back to that blog entry by clicking this Link.

Just to be thinner?

I read a statement like "It's sad what some put themselves (or their kids) through, in order to be thin." Of course, referring to going through bariatric surgeries like Lap Band, gastric bypass, etc. This statement shows a major misconception as to what bariatric surgery is all about. The name "weight loss surgery" is correct in that bariatric surgery is designed to lead to weight loss. That is true. But the above statement implies that the entire reason for the weight loss is for a "thin" image. Here comes the misunderstanding. Although many patients like being thinner, which is a bonus result of the surgery, the real reason to have the surgery is for health purposes. Morbid obesity leads to three categories of major problems: (1) Life expectancy may be shortened (2) Co-morbidities may get worse, and certainly would not be cured (please, see note below) (3) Quality of life may deteriorate. Those are the real reasons why someone should consider bariatric surgery. Patients do not come and say, "I need weight loss surgery because I want to be thinner." They say things like "I want to get my [type 2] diabetes cured", "I want to be able to play with the kids", "I have many in my family who died from heart disease, and I am still young and would like to prevent that", "my orthopedic surgeon wanted me to lose weight before he replaces my bad knees", "I have sleep apnea, and my doctor said if I lose weight, I may be able to come off the CPAP machine." You've got the picture. So, my counterstatement to the first line here would be "It's sad what some put themselves (or their kids) through, by not controlling their weight and allowing an unhealthy life style to continue." And, as an aside, yes, weight loss will also lead to being thinner. Remember, bariatric surgery is not for everyone who has a problem with weight or obesity. In well-selected patients, the risk of bariatric surgery is, statistically, less than the risk of morbid obesity itself. It is an option if non-surgical weight loss fails to achieve a sustained healthy weight.



Note: "Co-morbidities" is the term given to describe medical problems that are either caused by, or made worse by, obesity.

Plastic Surgery after Massive Weight Loss

This posting is in response to a request to comment on cosmetic surgery for excess skin in the abdomen and other places, after weight loss surgery.

Body contouring, body lift, body shaping or body reshaping are alternative terms used to describe a group of plastic surgery procedures performed after massive weight loss, to manage hanging excess skin. Patients have to have reached a stable plateau weight before any such plastic surgery procedures. The person should have lost at least 100 pounds or achieved the target or maximum weight loss, had a stable weight for a good length of time after the weight loss surgery, and be in good health and not planning on becoming pregnant. Good candidates for a body lift should also have no medical problems that prevent them from going under general anesthesia for major surgery, and should not smoke. Smoking decreases blood flow to the tissues and, therefore, may slow healing.

Plastic surgery procedures after weight loss surgery include the following:

1. Panniculectomy: This is excising the "pannus", which is the excess hanging skin that is present below the belly-button.

2. Abdominoplasty (Tummy Tuck): Includes dissection and preservation of the umbilicus itself, and a more extensive skin mobilization and more aggressive skin removal than panniculectomy. A complete abdominoplasty also includes tightening of the abdominal wall muscles. Abdominoplasty and incisional hernia repair can be combined into a single procedure.

3. Arm lift or brachioplasty.

4. Breast lift or mastopexy.

5. Lower body lift is a combination of an abdominoplasty, plus a thigh and buttock lift. It requires a large incision around the belt line to lift the lower body.

6. Liposuction uses small, narrow tubes to remove fat and is often used in combination with other lifting procedures to help achieve better contouring in various parts of the body.

Combining multiple "lifts" entails longer operative time, and more potential blood loss, but is very appealing to many patients, from the stand-point of time off work and out-of-pocket costs. Combined procedures are avoided if there is active smoking history or medical problems that make a longer operation a particularly risky undertaking.

Insurance coverage varies from carrier to carrier, and a carrier may have different plans with different provisions. Almost all insurance carriers specify that coverage of aesthetic (cosmetic) surgery is excluded. Definition of medical necessity, that is essential for coverage, is variable.

Possible complications after body-contouring surgery include seroma (collection of thin serous or serosnaguineous fluid), hematoma (collection of blood), wound separation (usually minor), swelling and scarring. All patients will have scars, and basically the surgery trades excess skin for scars. For a small number of patients, scars can be excessively thick or inflamed. Before going for body contouring surgery, any nutritional deficiencies (as protein malnutrition, anemia, loss of muscle mass, and osteopenia/osteoporsis) need to be addressed and corrected.

Body contouring is considered major surgery. The outcome of body shaping is generally extremely satisfying to patients. It may take several months to see the final results of the procedure.

Bariatric Surgery Lowers Long-Term Mortality

More data to support that bariatric surgery may improve mortality. Two new studies are published in the August 23, 2007 issue of the New England Journal of Medicine, indicating that bariatric surgery resulted in decreased overall mortality, in addition to the known effective long-term weight loss. One study came from Utah (Adams et al.). The other came from Sweden (Sjöström, et al). In an Editorial in the Journal, Dr. George A. Bray of the Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, commented that those articles "may provide the missing link between intentional weight loss and lives saved for obese patients"

The Utah study is a retrospective study that aimed at determining the long-term mortality among more than 9000 patients who had undergone gastric bypass and a comparable number of severely obese persons who applied for driver's licenses. During follow-up averaging 7 years, mortality in the surgery group decreased by 56% for coronary artery disease, by 92% for diabetes, and by 60% for cancer. On the other hand, mortality from accidents and suicide, was 58% higher in the surgery group than in the control group. All in all, there was a survival benefit from bariatric surgery.

The other article titled "Effects of Bariatric Surgery on Mortality in Swedish Obese Subjects" reports a prospective, controlled Swedish Obese Subjects study involving more than 4000 obese subjects. The study reports on the overall mortality during an average of 10.9 years of follow-up with an impressive follow-up rate of 99.9%. The study concluded that bariatric surgery for severe obesity is associated with long-term weight loss and decreased overall mortality.

References:

Adams TD, Gress RE, Smith SC, Halverson RC, Simper SC, Rosamond WD, Lamonte MJ, Stroup AM, Hunt SC.Long-term mortality after gastric bypass surgery.N Engl J Med. 2007 Aug 23;357(8):753-61. PMID: 17715409 (Full Text)

Sjöström L, Narbro K, Sjöström CD, Karason K, Larsson B, Wedel H, Lystig T, Sullivan M, Bouchard C, Carlsson B, Bengtsson C, Dahlgren S, Gummesson A, Jacobson P, Karlsson J, Lindroos AK, Lönroth H, Näslund I, Olbers T, Stenlöf K, Torgerson J, Agren G, Carlsson LM; Swedish Obese Subjects Study.Effects of bariatric surgery on mortality in Swedish obese subjects.N Engl J Med. 2007 Aug 23;357(8):741-52. PMID: 17715408 (Full Text)

Does fibromyalgia improve after weight loss surgery?

Well, there are not too many studies that specifically address this issue. Of course the medical literature is full of evidence that musculoskeletal painful conditions in weight-bearing joints do improve with weight loss surgery in the vast majority of patients. However, when it comes to non-weight-bearing joints, and to fibromyalgia in particular, such information is scarce.

However, a study from the University Hospitals of Cleveland that was published in January 2007 did, indeed address that issue. (1)

Fibromyalgia syndrome (FMS) is one of the most common musculoskeletal diseases. Patients have fatigue, chronic diffuse musculoskeletal pains, poor sleep, and stiffness. There is no blood test to diagnose fibromyalgia. To make a diagnosis of FMS, widespread pain symptoms must exist for at least 3 months. The diagnosis is confirmed by finding at least 11 of 18 specific areas of point tenderness. Almost 9:1 patients are females.

In the study from Cleveland, FMS decreased by an impressive 90% after bariatric surgery. As for upper extremity pain, that is, of course,non-weight-bearing, 79% of patients had pain before surgery, compared to 40% after bariatric surgery.

References:

(1) Hooper MM, Stellato TA, Hallowell PT, Seitz BA, Moskowitz RW. Musculoskeletal findings in obese subjects before and after weight loss following bariatric surgery. Int J Obes (Lond). 2007 Jan;31(1):114-20.

Pregnancy and Bariatric Surgery

A recent article from the University of Texas at Houston, TX (1), that appeared in the August issue of the Archives of Pediatric and Adolescent Medicine, reported that the mothers of offspring with some important birth defects (including spina bifida and heart defects) are more likely to be obese than mothers of offspring who do not have any of those defects. The authors admitted that the mechanisms are unknown, but a relationship to undiagnosed diabetes was proposed.

Is it good to have low birth weight? The answer is, generally, No. Studies of populations in the United States and Europe have indicated a significant increase in the incidence of certain diseases in adulthood (coronary artery disease, stroke, and type 2 diabetes) among the low birth weight. This is interesting because the same adult diseases have higher incidence with adulthood obesity. So, does low birth weight correlate with obesity later on? A study about a famine in the Netherlands in the 1940s (2) did show that at the age of 19, the offspring of mothers exposed to the famine during the first half of pregnancy did have higher incidence of obesity.

Previous reports concluded that fetal exposure to diabetes in the uterus is an independant risk for the development of diabetes later in life. Pregnancy in patients with morbid obesity may lead to higher incidence of gestational diabetes and hypertension, preeclampsia, large-for-age fetus, preterm labor, and antepartum stillbirth. (3,4)

So, is it good to be pregnant after bariatric surgery? A review article that appeared in May 2007 in the journal "Medical Clinics of North America" (5) concluded that pregnancy after weight loss surgery is safe and has good outcomes. Cesarean deliveries occur more frequently in all of the reports of pregnancies after bariatric surgery when compared with the general population. Interestingly, there is also a higher incidence of cesarean section deliveries with obesity (3)

In general, it is recommended that pregnancy be avoided during the period of maximal weight loss, typically the first 18-24 months after a gastric bypass. When pregnancy does occur, there is a risk of malnutrition and anemia if ntritional supplements are not taken as advised. With that precaution in mind, studies of pregnancy after gastric bypass (6) and Lap Band (7) showed normal and healthy outcomes. A study from Australia (6) reported that pregnancy outcomes after Laparoscpic Adjustable Gastric Band Placement (Lap Band) are consistent with general community outcomes rather than outcomes from severely obese women.

A word of warning. There have been reports of rare incidences of internal herniation causing dangerous bowel obstruction late in pregnancy after laparoscopic gastric bypass. Though rare, such a possibility should be kept in mind if a pregnant develops acute abdominal pain or signs of bowel obstruction late during pregnancy.(8-10)

References:

(1) Waller DK, Shaw GM, Rasmussen SA, Hobbs CA, Canfield MA, Siega-Riz AM, Gallaway MS, Correa A; National Birth Defects Prevention Study. Prepregnancy obesity as a risk factor for structural birth defects. Arch Pediatr Adolesc Med. 2007 Aug;161(8):745-50. PMID: 17679655

(2) Ravelli GP, Stein ZA, Susser MW. Obesity in young men after famine exposure in utero and early infancy. N Engl J Med. 1976 Aug 12;295(7):349-53. PMID: 934222

(3) Hall LF, Neubert AG. Obesity and pregnancy. Obstet Gynecol Surv. 2005 Apr;60(4):253-60. PMID: 15795633

(4) Cedergren MI. Maternal morbid obesity and the risk of adverse pregnancy outcome. Obstet Gynecol. 2004 Feb;103(2):219-24. PMID: 14754687

(5) Patel JA, Colella JJ, Esaka E, Patel NA, Thomas RL. Improvement in infertility and pregnancy outcomes after weight loss surgery. Med Clin North Am. 2007 May;91(3):515-28, xiii. PMID: 17509393

(6) Dao T, Kuhn J, Ehmer D, Fisher T, McCarty T. Pregnancy outcomes after gastric-bypass surgery. Am J Surg. 2006 Dec; 192(6):762-6. PMID: 17161090

(7) Dixon JB, Dixon ME, O'Brien PE. Birth outcomes in obese women after laparoscopic adjustable gastric banding. Obstet Gynecol. 2005 Nov;106(5 Pt 1):965-72. PMID: 16260513

(8) Ahmed AR, O'Malley W. Internal hernia with Roux loop obstruction during pregnancy after gastric bypass surgery. Obes Surg. 2006 Sep;16(9):1246-8. PMID: 16989713

(9) Baker MT, Kothari SN. Successful surgical treatment of a pregnancy-induced Petersen's hernia after laparoscopic gastric bypass. Surg Obes Relat Dis. 2005 Sep-Oct;1(5):506-8. PMID: 169252793

(10) Charles A, Domingo S, Goldfadden A, Fader J, Lampmann R, Mazzeo R. Small bowel ischemia after Roux-en-Y gastric bypass complicated by pregnancy: a case report. Am Surg. 2005 Mar;71(3):231-4. PMID: 15869139