Pregnancy after bariatric surgery — structured SAQ (15 marks)

(a) Booking nutritional assessment and supplementation (5 marks)

One mark per element, maximum five. [3]

• Booking nutritional bloods: full blood count, iron studies, vitamin B12, folate, 25-hydroxyvitamin D, calcium, magnesium, vitamin A, parathyroid hormone, INR (vitamin K); repeat every trimester.
• Standard prenatal vitamins are insufficient — post-bariatric women need two to three times the routine doses.[3]
• Iron 45 to 60 mg elemental daily (duodenum bypassed, acid reduced).
• Vitamin B12 1 mg orally daily, or 1000 micrograms intramuscularly every 12 weeks (intrinsic factor lost). Folic acid up to 1 mg daily (some societies 4 to 5 mg in malabsorptive procedures).[3]
• Vitamin D 1000 IU standard, 3000 to 6000 IU if deficient, target 50 nmol/L; calcium 1000 to 2000 mg daily; beta-carotene vitamin A not exceeding 5000 IU; thiamine 12 mg daily (higher if vomiting).[3]

(b) Gestational diabetes screening strategy (3 marks)

One mark per point. [2][3]

• The 75 g OGTT is contraindicated after Roux-en-Y bypass — it provokes dumping syndrome and reactive hypoglycaemia. The OEGGG consensus is explicit on this.[2]
• Measure HbA1c at the start of pregnancy, and perform home glucose monitoring (fasting and one- to two-hour postprandial) between 24 and 28 weeks.[3]
• Diagnose GDM by the IADPSG home-glucose thresholds — fasting 5.1 mmol/L or above, or one-hour postprandial 7.0 mmol/L or above, on two occasions.

(c) Differential, the must-not-miss diagnosis, and immediate management (4 marks)

One mark for the must-not-miss diagnosis, one for the differential, two for management. [4]

• The diagnosis you must not miss is internal hernia with small bowel obstruction. Postprandial colicky abdominal pain in the third trimester after bypass is hernia until proven otherwise — not hyperemesis, not round-ligament pain, not reflux.[4]
• Differential: hyperemesis gravidarum (first trimester, no postprandial pattern), dumping syndrome (provoked by glucose, vasomotor within an hour), obstetric causes (abruption, appendicitis, cholecystitis), and band problems (not applicable — she has a bypass).
• Immediate management: resuscitate the mother — NPO, intravenous fluids, nasogastric tube if vomiting, correct electrolytes, fetal monitoring as the maternal state allows; early surgical review; imaging (ultrasound first, CT with contrast if stable); do not let imaging delay surgical assessment.[4]
• Operate if obstruction is confirmed or suspected — laparoscopy is the preferred approach in pregnancy after bypass (Deleus series, 32 cases, no maternal or fetal deaths).[4]

(d) Postnatal plan and contraception (3 marks)

One mark per point. [3][5]

• Continue supplements through lactation (breastmilk composition is comparable when the mother is replete, but supply may be reduced — monitor infant weight); repeat the nutritional panel at six weeks postpartum; arrange bariatric surgical follow-up for weight trajectory.[3]
• Contraception: prefer a long-acting reversible method that does not depend on gastrointestinal absorption — a subdermal implant or a levonorgestrel intrauterine device. Oestrogen-containing options are usually avoided after bypass (raised VTE risk, unreliable absorption).[3][5]
• Counsel on the surgery-to-conception interval for any future pregnancy — wait for weight stabilisation, ideally 12 to 24 months from the last surgery (Mahawar 2016).[6]