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  • Nathan Riley, MD

Obgyno Wino Podcast Episode 65 - Bariatric Surgery and Pregnancy

"Your visions will become clear only when you can look into your own heart. Who looks outside, dreams; who looks inside, awakes." - Carl Jung


2017 Pinot Noir from Ferrandière


PB#105 - Published July 2009 (Reaffirmed 2017)


Five Pearls

1. Combined oral contraceptives may be poorly absorbed in patients who have undergone malabsorptive bariatric surgery (e.g. Roux-en-Y)

2. Micronutrient and macronutrient deficiences are common in pregnancy after Roux-en-Y. These include iron, calcium, vitamin B12, protein, folate, and vitamin D. It's reasonable to screen widely for nutrient and micronutrient deficiencies pre-pregnancy or early in pregnancy and supplemental as appropriate.

3. For patients who underwent a banding procedure, early consultation with a bariatric surgeon is recommended in order to actively manage the band

4. Dumping syndrome is caused by ingestion of refined sugars that are rapidly dumped from the stomach into the small intestine; this causes hyperinsulinemia -> hypoglycemia -> tachycardia; otherwise characterized by bloating, nausea, abdominal pain, n/v, and diarrhea.

5. Patient with dumping syndrome can be screened for GDM by regular glucose fingerstick checks at 24-28 wga


Obesity is a big problem in our country

- 2/3 of Americans are overweight or live with obesity, and it's trending upward

- obesity is defined as BMI >30

- black women and Hispanics are impacted more than white women


Recall: BMI is calculated by dividing weight in kilograms by height in meters squares (BMI = kg/m^2)


Effects of obesity on pregnancy for mom

- women with obesity are less fertile due to oligo-ovulation and anovulation (also less likely to respond to ovulation induction)

- higher risk for gestational diabetes, preeclampsia, c-section, and infection

- c-sections take longer with higher blood loss

- regional and general anesthesia induction can have specific challenges related to obesity

- independent risk factor for venous thromboembolic events

- more likely to be recommended induction of labor, preterm delivery, oxytocin augmentation

- associated with longer labor

- less likely to have successful VBAC


Effects of obesity on pregnancy for fetus/baby

- higher risk of congenital anomalies (independent of diabetes), growth abnormalities, miscarriage, and stillbirth (2-4x risk)

- most common anomalies are: cardiac, neural tube defects, and facial clefts

- higher likelihood of childhood obesity


Options for losing weight for pretty limited

- lifestyle change is still your best bet for lasting change (I can help you with this...consider it my gift to you)

- bariatric surgery is available for women with BMI 40 or greater (or BMI 35 or greater if other comorbidities present)


Two types of bariatric surgery

- adjustable gastric banding: restrictive

- Roux-en-Y: malabsorptive + restrictive (aka "gastric bypass")

- gastric sleeve: restrictive; most common bariatric surgery performed in the U.S. but not even mentioned in the practice bulletin



- other bariatric procedure include vertical banded gastroplasty and biliopancreatic diversion, which are rare nowadays; jejunoileal bypass is no longer performed


Effects of bariatric surgery on fertility and health

- rapid weight loss can improve anovulation, irregular menses, and infertility (but bariatric surgery is not considered a treatment for infertility!)

- some evidence suggests that combined oral contraceptives are poorly absorbed so therefore may be less effective after Roux-en-Y bariatric surgery

- you can expect improvements in HTN and diabetes

- even after bariatrics surgery, these women are more likely to begin pregnancy in a state of obesity, and they still carry an increased risk of c-section (though the study that reported these increased risks also noted that the population of women enrolled in the study also have a higher prevalence of past c-section)

- rate of hypertensive disease (including chronic, gestational, and preeclampsia) improves with surgery (45% in pregnancies before Roux-en-Y, 8% after)

- GDM risk is improved but still elevated over the risk if a patient weren't living with obesity

- intestinal obstruction is a possible long-term sequelae in patients who undergo bariatric surgery before pregnancy, but it's quite rare (requires ex-lap)


Effects of bariatric surgery on fetus and newborn

- no increased risk of congenital anomalies

- data suggests a trend towards lower mean birth weight

- bariatric surgery is not associated with increased perinatal death


Counsel bariatric surgery patients about contraception

- first off, your fertility will likely improve after surgery, so if you weren't thoughtful about it before, get cracking!

- COCs ("the pill") is not recommended if patient undergoes malabsorptive procedure given poor absorption of COCs

- the in-utero environment may be resource deplete during the rapid weight loss phase that follows bariatric surgery; therefore, many experts recommend waiting 12-24 months to conceive (serial fetal growth ultrasound reasonable if patient conceives within that window)


After Roux-en-Y, nutritional deficiencies are common in pregnancy

- iron, calcium, vitamin B12, protein, folate, and vitamin D

- reasonable to screen widely for nutrient and micronutrient deficiencies pre-pregnancy or early in pregnancy

- if deficiencies are found, you can try oral supplementation but you may need to try parenteral (as the underlying issue is gut absorption, duh)

- furthermore, caloric restriction to continue losing weight during pregnancy is a bad idea

- no evidence that additional folic acid supplementation is required in pregnancy

- additional vitamin supplementation may be reasonable, but be careful with fat soluble vitamins like vitamin A, which, if taken in excess of 5000 Iu/day, may cause birth defects

- nutritional counseling from a professional from pre-conception through pregnancy and into the postpartum period will help optimize nutritional status


After banding procedures, insufficient calories is more commonly the issue

- these patients have decreased appetite and intolerance to certain foods (e.g. bloating, etc.)

- early consultation with a bariatric surgeon is recommended in order to actively manage the band


Pregnant patients with history of bariatric surgery should be monitored for signs of more serious complications

- nausea and vomiting is common in pregnancy, but it may be a sign of intestinal obstruction

- other serious complications include anastomotic leaks, hernias, band erosions, and band migration

- dumping syndrome is caused by ingestion of refined sugars that are rapidly dumped from the stomach into the small intestine; this causes hyperinsulinemia -> hypoglycemia -> tachycardia; otherwise characterized by bloating, abdominal pain, n/v, diarrhea, palpitations, anxiety


How do I screen for glucose intolerance in patients with dumping syndrome?

- obviously a 50-g glucose challenge is going to be disastrous

- alternative: check fasting and 2-hour postprandial glucose for one week using home testing kits at some point in the 24-28 wga period


Other medication considerations

- extended release formulations of meds aren't recommended

- NSAIDs aren't recommended

- any medication that requires serum level monitoring will likely require even closer monitoring in a patient who has questionable absorptive capacity

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