Bariatric surgery is considered an effective intervention for lasting weight loss but reports have been inconsistent with its impact on pregnancy outcomes. There is a need for explicit perioperative instructions regarding fertility, pregnancy, and contraception with the increasing number of women of reproductive age utilizing bariatric surgery. Based on several systematic reviews and meta-analysis, there is a consensus that bariatric surgery resulted in a reduced risk of gestational diabetes mellitus, hypertensive disorders, large for gestational age, and macrosomia in subsequent pregnancies. However, the odds of preterm delivery, small for gestational age infants, and intrauterine growth restriction were increased [4,5,6].
There have been reports of adverse maternal and fetal outcomes for pregnancies occurring within 1 year of surgery such as maternal internal herniation and consequent bowel obstruction [7,8,9,10], intussusception [11], volvulus [12], maternal micronutrient deficiencies [13], fetal neural tube defects [14], and chondrodysplasia punctata [15].
The literature also contains two other case reports of early-stage pregnancy at the time of bariatric surgery. Mavor et al. reported a 26-year-old woman with an intensive weight loss prior to sleeve gastrectomy who was discovered to be pregnant at the time of surgery. Her pregnancy ended with a healthy newborn, but she herself failed to achieve a healthy BMI throughout 24 months of follow up [16]. A second case, reported by Rye et al., involved a 33-year-old woman who underwent 6 weeks of liquid meal replacement preoperatively, and then laparoscopic Roux-en Y gastric bypass. She experienced upper GI symptoms following surgery, and it was found accidentally on abdominal ultrasound that she was pregnant. She decided to undergo elective termination of pregnancy [17]. Both cases indicated pregnancy as a result of increased fertility from preoperative weight loss. However, our case report illustrates pre-operative contraception failure.
Current guidelines recommend delaying pregnancy for up to 18 months after surgery but there is no compelling evidence that pregnancy during the first postoperative year might adversely affect the outcomes. However, preventing unintended pregnancy is significant in the perioperative period because it is a weight dilemma: gaining weight to support adequate growth and development of the fetus which contradicts the goals of the surgery and ultimately may alter the weight loss achieved.
The current guideline emphasizes counseling for contraceptive use following surgery, but preoperative contraception recommendation in order to avoid pregnancy at the time of surgery is neglected. It seems reasonable to recommend starting a contraceptive method prior to surgery and continuing with it after surgery. Although there are no quality data exists to help guide appropriate contraceptive choice, any contraception method is more efficacious and safer than no method at all. The choice of contraception for these patients requires careful consideration to balance the risk of decreased efficacy associated with obesity and the type of bariatric surgery against the individual needs and preferences [18].
In theory, bariatric surgery may affect the efficacy of oral contraceptives by altering the absorptive capacity of the gut. Dietary restrictions, as well as vomiting and diarrhea for the first few weeks postoperatively may even further reduce the effectiveness of oral contraceptives. Thus, non-oral methods of contraception, including long-acting reversible contraception methods (intrauterine devices and implants) should be considered and offered when women receiving counselling regarding bariatric surgery [19].
In addition to initiating an appropriate method of contraception well before surgery, a routine pregnancy test for all patients of reproductive age should be performed on the day of surgery, but a very early gestation cannot be identified by commonly used pregnancy tests. To eliminate cases like ours, we suggest delaying surgery until pregnancy can be definitively excluded, for instance, by taking a thorough sexual history. In the case of pregnancy at the time of or following surgery, women should receive detailed information about maternal and fetal risks such as preterm delivery, small for gestational age infants, and intrauterine growth restriction as previously discussed. If a woman desires to maintain her pregnancy, she should be followed closely throughout her pregnancy to assess weight changes, nutritional deficiencies, and fetal health to ensure optimal pregnancy outcomes.
In conclusion, to prevent unintended pregnancy pre-operatively, patients of reproductive age should be provided appropriate referrals and counseled by a family planning physician on each contraceptive method’s risks, benefits and alternatives and have a plan in place prior to surgery. Pregnancy should be excluded confidently on the day of surgery using a reliable and sensitive test. In the case of pregnancy and a woman’s desire to continue it, close monitoring of maternal-fetal wellbeing is necessary.
