Oral contraceptives
Obesity is associated with infertility in women by various mechanisms89, which seems to be (totally or partially)
reversible after bariatric surgery 90. As
reproductive-aged women are advised to avoid pregnancy twelve to
twenty-four months after bariatric surgery, contraceptives are
recommended 91–93. An anticipated reduction in
absorption area, residence time and enterohepatic circulation after
bariatric surgery may potentially decrease the reliability of oral
contraceptives. There is however limited information on the use of oral
contraceptives after bariatric surgery. Victor et al. showed that
norethisterone and levonorgestrel levels were lower after jejunoileal
bypass at 1-8 hours after ingestion even though at 24 hours, there was
no difference 94. Furthermore a reduced effect of oral
contraceptives after biliopancreatic bypass was described95. Two of the nine patients who used oral
contraceptives postoperatively were unexpectedly pregnant. These two
patients suffered from chronic diarrhea. No unexpected pregnancies were
reported among users of non-oral contraceptives 95.
Ciangura et al. showed reduced norgestrel levels six months after RYGB,
however, these values were considered sufficiently high for a
contraceptive effect 96.
In conclusion, the absorption of oral contraceptives may be reduced,
particularly in the event of chronic diarrhea following restrictive and
malabsorptive bariatric surgery. Oral contraceptives should be
discouraged or alternative contraception should be used. Of note, Damhof
et al. showed that 16% of the women undergoing bariatric surgery are
using potentially unsafe contraception postoperatively warranting the
attention of the health care professional for this problem97.