Monday, August 13, 2007
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)
(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