Obesity and Contraception: Emerging Issues

Amitasrigowri S. Murthy, M.D., M.P.H., F.A.W.G.


Semin Reprod Med. 2010;28(2):156-163. 

In This Article

Obesity Treatment

Current treatment of obesity includes lifestyle modifications, caloric restriction, and exercise. Many studies have shown that a weight loss of ≥20 pounds can result in decreases in cardiovascular and cancer mortality. A decrease of only 5 to 10% in body weight can reestablish ovulatory function in most obese women with polycystic ovary syndrome.[43] This same decrease will improve insulin levels, which in turn will improve androgen levels and SHBG levels. Regular exercise is essential for weight loss; a minimum of 30 minutes of moderately intense exercise is recommended. Unfortunately, lifestyle changes and diet are often not maintained and ultimately fail. Sixty percent of lost weight is often regained within 3 years.[43]

In the morbidly obese, however, the success of these methods is even lower. Surgical treatment is often recommended to achieve the levels of weight loss necessary for improvement of quality of life.[45] The number of bariatric surgeries performed in the United States has increased significantly, with >72,000 procedures performed in 2002.[45,46] More than 85% of the patients were women. There has also been an increase in the number of procedures being performed in adolescents.[46]

There are three types of surgical procedures for obesity treatment. The first type is procedures that decrease gastric capacity, including laparoscopic gastric banding and vertical banded gastroplasty. The second type is procedures that combine gastric restriction along with a certain degree of malabsorption; most commonly, the Roux en Y procedure. The third type is the malabsorptive procedures that have been mostly abandoned due to long-term complications. All procedures are associated with nutritional deficiencies, although there is less risk with gastric banding as compared with gastric bypass.[47] Other complications include vomiting, gastric prolapse, stomal obstruction, pouch dilation, erosion, and access port problems. When compared with gastric bypass, gastric banding is associated with fewer short-term complications, shorter operative times, and less hospitalization time. Long-term complications, however, are more commonly seen in gastric banding than with gastric bypass. Port problems or band slippage were the most common reasons for reoperation. Gastric bypass can be complicated by dumping syndrome, stomal stenosis, staple line disruption, hernias, and nutrient deficiencies.[47]

Weight loss outcomes are consistently better with gastric bypass procedures.[47] Differences in amount of weight lost compared between gastric banding and gastric bypass can range by as much as 25%. Improvements in comorbidities like diabetes and hypertension were also greater in patients with gastric bypass than gastric banding.[47]

Strong evidence supports waiting for 1 year after surgery before attempting pregnancy.[45,46] The first year postsurgery is associated with the most rapid weight loss; pregnancies that occur during this time, especially after a gastric bypass, are associated with higher rates of miscarriage as well as preterm labor.[46] In addition, mild nutritional deficiencies are common, and if pregnancy occurs early, the risk of clinically relevant deficiencies increases.[45,46] To overcome specific nutrient decreases that could affect the postnatal growth of the infant, supplementation may be recommended. Most studies indicate there was no difference in intrauterine growth restriction, small for gestational age, or birthweight for pregnancies conceived early in the postoperative time period or later, no matter whether a restrictive procedure was performed or a malabsorptive one. More cesarean deliveries and neonatal deaths, however, have been seen following a gastric bypass procedure than after a gastric banding procedure.[45,46]

Some data suggest that OC use following these procedures may not be sufficient to protect against pregnancy.[48] In a population of 40 patients followed after a malabsorptive procedure, two of nine women using OCs became pregnant in the first year. Contraceptive failure was attributed to malabsorptive complications (diarrhea, steatorrhea, vomiting) rather than noncompliance with the OC.[48,49] One woman became pregnant while using DMPA, and three women became pregnant while using the IUD. Another study followed a small number of women (N = 7) after jejunoileal bypass and measured serum levels of ethinyl estradiol and progestin.[49] Hormone serum levels were lower in the bypass group when compared with a control group normal weight fertile women taking the same OC. The author concluded that lack of absorption due to a malabsorptive procedure led to the lower hormone levels.

In the setting of bariatric surgery, it may be prudent to consider use of contraceptive methods that avoid the oral route. Methods like the patch or ring that avoid both hepatic first-pass metabolism as well as absorption through the shortened intestines may have higher effectiveness against pregnancy. Patients are counseled to avoid pregnancy early in their postoperative period, but only a few studies have examined what contraception women were using in the year after their surgery. A self-administered survey of 45 women after bariatric surgery showed that 97% knew they were to avoid pregnancy for 1 year, and 90% used contraception during this time. Although 30% of women used highly effective method of contraception (sterilization, IUD, DMPA), 15% of women used OC, and 37% used only condoms. Women who obtained their contraception from an obstetrician/gynecologist (24%) all used highly effective methods of contraception.[50]


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