How soon after bariatric surgery is it safe for me to get pregnant? This is a common question from young women who are thinking of a gastric band, gastric bypass or sleeve gastrectomy for weight loss. We know that weight loss surgery can have huge health benefits. The worry is whether weight loss surgery may be harmful to the baby. In an earlier post, we explored the benefits and risks to both mother and baby. In this post, we will look at the safe interval between weight loss surgery and pregnancy.

Benefits of Pregnancy After Weight Loss Surgery

Weight loss increases the safety of pregnancy and delivery in many ways. The mother’s risks for high blood pressure and diabetes during pregnancy are substantially lower after weight loss surgery. Also, the risk that baby may be large for gestational age is significantly lower after weight loss surgery. Also, the rate caesarean section is much lower after weight loss surgery

Risks of Pregnancy After Weight Loss Surgery

But, there is worry that weight loss surgery can harm the development of the baby because the mother has nutritional deficiencies. Studies have shown that the risk for small for gestational age babies is increased after gastric bypass surgery. Also, there seems to be increased risk for premature delivery. For detailed information about these risks, see our earlier post.

Does the Timing of Pregnancy after Bariatric Surgery Matter?

Weight loss surgery increases the safety of pregnancy and delivery in many ways. But, it does increase the risk of preterm delivery and small for gestational age babies. The important question is whether these increased risks come down with time. Can pregnancy after weight loss surgery be timed to reduce these risks?

Generally, weight loss takes place during the first 1-2 years after the operation. After a gastric bypass or gastric sleeve, most of the weight loss happens during the first year. Although, some more weight can be lost in the second year. After a gastric band, weight loss is usually spread out over 2 years. Most women will have reached their new steady weight by the end of two years.

The body is a said to be in a ‘catabolic’ state during weight loss. Catabolic means breakdown. When weight is being lost, the body’s stores of fat are being broken down. Complex changes take place in the human body. Deficiencies of energy, vitamins and minerals can develop during this period. Pregnancy puts extra nutritional demands on the mother. During the catabolic phase, the mother’s body may not be able to cope with these extra demands.

What is the Safe Interval for Pregnancy after Bariatric Surgery?

The American College of Gynaecologists has recommended that pregnancy should be avoided for 12-24 months after weight loss surgery. Suitable contraception should be used so that pregnancy is spaced after the operation. A 2-year safety interval is logical and sensible advice. But, until recently, the actual safety of a 2-year interval had not been tested.

What is the Recent Scientific Evidence on Pregnancy after Bariatric Surgery?

Researchers from the University of Washington analysed data on births in Washington State, USA, between 1980 and 2013. There was a total of 2.6 million births. Of these, 1859 births were to mothers who had previous weight loss surgery. The researchers compared the risks between weight loss surgery-mothers and mothers from the general population. They divided the weight loss surgery mothers into three groups. The first group was mothers who became pregnant and delivered within 2 years after their weight loss operation. The second group had mothers who delivered between 2 and 4 years after their operation. The third group had mothers who delivered at more than 4 years after their operation.

Let’s look at three important findings from this study:

First, let’s look at the mothers who became pregnant and delivered within 2 years after their weight loss operation. As expected, the rates of preterm delivery and small for gestational age babies were significantly higher in comparison to the general population.

Second, let’s look at the mothers who delivered between 2 and 4 years after weight loss surgery. They had higher risk for small for gestational age babies. In fact, their risk was similar to the risk for mothers who delivered at less than 2 years. But, the risk for preterm births was not different from the general population.

Finally, let’s look at the weight loss surgery mothers who delivered after 4 years. The risk of preterm delivery and small for gestational age babies was not different from the general population. So, after 4 years the risks seem to come down to the baseline risks that apply to any pregnancy.

How long should I wait after weight loss surgery to get pregnant?

The bottom line seems that it is safest to wait for about 4 years after weight loss surgery to get pregnant. But, these findings come from only one study. Like most medical studies, there are several shortcomings in this study. Regardless, there is a clear message: it is important to not plan pregnancy soon after weight loss surgery.

Call 0113 388 2127 to make an appointment to see Mr Sarela, consultant surgeon in Leeds, for weight loss surgery.

Is it OK to get pregnant after having a weight loss operation? This is a worrying question for many young women who want to lose weight. The benefits of weight loss surgery are now well known. But, how do weight loss operations affect the mother and baby during pregnancy? This blog post explains up to date medical evidence on this topic.

Let’s consider Jane, a 29 year-old women who weighs 21 stones (133 kg). Her height is 5 feet and 6 inches (167 cm). Her BMI works out to be 48. She has been told that she could lose 7-8 stones with a gastric bypass operation. Jane and her husband are keen to start a family. They have been told that Jane’s obesity increases risks for both her and her baby.(1) Obese mothers have higher risk for getting diabetes and high blood pressure during pregnancy. The risk for diabetes and high blood pressure is about 3 times higher in obese mothers. Also, obese mothers are more likely to need caesarean section instead of normal delivery. Babies of obese mothers have higher risk for premature birth, miscarriage, large size, birth injuries, stillbirth and death after delivery.

Jane is worried about the effect of a gastric bypass on her own safety and the safety of her baby during pregnancy? Basically, her question is whether the pregnancy-risks after gastric bypass are any different from her risks now with a BMI of 48? Will pregnancy be safer or will it be more risky if she has a weight loss operation?

Medical studies have compared the risks of pregnancy in women after gastric bypass surgery with obese women who have not had weight loss surgery. These studies matched gastric bypass mothers with obese mothers who have the same pre-bypass BMI. Let’s say Jane gets down to a BMI of 31 after gastric bypass and then become pregnant. Her risks during pregnancy are compared with the risks for a woman who has BMI of 48 (the same as Jane before the bypass).

The risk for diabetes and high blood pressure during pregnancy was significantly lower in mothers who had gastric bypass. Diabetes was seen in about 2% of gastric bypass mothers versus 7% of obese mothers.(2) High blood pressure was seen in about 3% of gastric bypass mothers versus 15% of obese mothers.(3) Also, significantly fewer gastric bypass mothers need caesarean sections than obese mothers.(4) On all counts, gastric bypass makes pregnancy safer for mothers.

But, the studies bring up some worries for the safety of the baby. On the positive side, babies of gastric bypass mothers are less likely to be large for gestational age. About 8% of gastric bypass mothers had large babies versus 22% of obese mothers. But, babies of gastric bypass mother are more likely to be small for gestational age. About 15% of gastric bypass mothers had small babies versus 7% of obese mothers.(2) Also, there seems to be increased risk for premature births and stillbirths for gastric bypass mothers, although these differences were not statistically significant. In a nutshell, there is a trade-off. Before bypass, the baby is at higher risk of being too large. After bypass, the baby is at higher risk of being too small.

What should Jane do? Overall, it is very clear that weight loss surgery will improve Jane’s health and quality of life. Also, pregnancy will be safer for Jane after weight loss surgery. The risk that her baby is too large is less after weight loss surgery. But, there is greater risk that her baby could be too small or prematurely born.

For detailed and accurate advice on the pros and cons of weight loss surgery, make an appointment to see Mr Sarela, consultant surgeon in Leeds. Call 0113 388 2127

References:

1. Gonzalez I, Lecube A, Rubio MA, Garcia-Luna PP. Pregnancy after bariatric surgery: improving outcomes for mother and child. International Journal of Womens Health. 2016;8:721-9.
2. Johansson K, Cnattingius S, Naslund I, Roos N, Trolle Lagerros Y, Granath F, et al. Outcomes of Pregnancy After Bariatric Surgery. New England Journal of Medicine. 2015;372(9):814-24.
3. Bennett WL, Gilson MM, Jamshidi R, Burke AE, Segal JB, Steele KE, et al. Impact of Bariatric Surgery on Hypertensive Disorders in Pregnancy: Retrospective Analysis of Insurance Claims Data. British Medical Journal. 2010;340:c1662.
4. Drew S, Ibikunle C, Sanni A. Women Who Undergo Weight-Loss Operations Have a Lower Risk for Cesarean Section Later On 2016 [Available from: https://www.facs.org/media/press-releases/2016/young101716.

Vitamin B1, also known as Thiamine, is a member of the class of water-soluble B vitamins. Thiamine is converted in the human body to its active form, called Thiamine Pyrophosphate (TPP), which plays an important role in carbohydrate metabolism. Deficiency of vitamin B1 develops if there is insufficient dietary intake for 2-3 months, or even shorter in susceptible populations. The disease that is caused by deficiency of vitamin B1 has been called beriberi: from ‘I can’t, I can’t’ in the Sinhalese language (Sri Lanka), referring to its crippling effects. The World Health Organization’s report on Thiamine deficiency provides a global overview of this disorder.

In the UK and in other developed countries, chronic alcoholism and weight loss (bariatric) surgery have been highlighted as conditions at risk for thiamine deficiency. Nutrition is restricted intentionally by bariatric surgery, and renders patients vulnerable to various vitamin deficiencies. After a bariatric operation (gastric band, gastric bypass or sleeve gastrectomy), sufficient thiamine can be provided usually through a nutritionally balanced diet and daily multi-vitamin supplement tablets or capsules. But, deficiency can develop rapidly if there is persistent regurgitation of food or vomiting. There is special vulnerability in the early phase after weight loss surgery, when dietary intake is intentionally restricted to liquid and pureed consistency. Prolonged regurgitation and vomiting can occur simply because of difficulty to adjust to the altered anatomy. Mechanical complications of bariatric surgery, such as stenosis, band slippage or bowel obstruction, can lead to regurgitation and vomiting that persist until the problem is rectified. Whatever the cause, bariatric surgery patients with persistent vomiting or extraordinarily rapid weight loss are at risk of thiamine deficiency. The disease caused by thiamine deficiency in weight loss surgery patients has dubbed ‘bariatric beriberi’.

Thiamine deficiency can disrupt carbohydrate metabolism, leading to disorders in the: 1) central nervous system (called Wernicke’s encephalopathy and Korsakov’s psychosis); 2) peripheral nervous system (called polyneuropathy); and 3) cardiovascular system. Thiamine deficiency does not necessarily cause symptoms related to all three systems; often, symptoms related to one system predominate.

The classic presentation of Wernicke’s encephalopathy is a triad of mental status changes, eye movement abnormalities, and cerebellar dysfunction. Altered mental status may result in confusion, memory deficits or impaired consciousness. Korsakov’s psychosis is acute manifestation of severe loss of memory for recent events and confabulation (fabrication of memories). Abnormalities in eye movement may present as nystagmus (involuntary eye movements), opthalmoplegia (paralysis of the muscles of the eyeball) or diplopia (double vision). A devastating symptom is acute, bilateral blindness. Dysfunction of the cerebellum (the hind-brain) can lead to gait abnormalities and ataxia (imbalance).

Polyneuropathy – disease of peripheral nerves – may produce paraesthesiae (sensations of tingling and numbness), weakness and muscle wasting in the arms and particularly in the legs.

Cardiovascular dysfunction – disorder of the heart and circulatory system – arises because of cardiopathy (dysfunction of the muscles of the heart). Common symptoms are palpitations (because of sinus tachycardia) and oedema, mainly of the legs (because of high output ventricular failure). If thiamine deficiency presents with prominent cardiac symptoms, it can be called ‘wet beriberi’ (referring to fluid overload), as opposed to ‘dry beriberi’ with polyneuropathy.

Finally, there can be vague symptoms related to the gastrointestinal tract, including loss of appetite and constipation (possible because of altered gut motility).

An oft-quoted review of Wernicke’s encephalopathy following bariatric surgery highlights that 94% of patients were admitted to hospital within 6 months after surgery. Recurrent vomiting was reported in 90% of cases, and had lasted for a median duration of 21 days. When vomiting was not reported, patients had rapid weight loss, loss of appetite or eating avoidance, or did not take vitamin supplements. The classic triad of eye movement abnormalities, mental status changes and ataxia was present in 38%; 2 signs were present in 43%; and one sign was present in 19%. Blurred vision or impaired visual acuity was noted in 20%. Peripheral polyneuropathy (both motor and sensory) was noted in 76%, and it was more common in the lower limbs than in the upper limbs. Complete recovery was observed in 51%; the remainder was considered to have incomplete recovery. Frequent sequelae were cognitive impairments, gait difficulties and nystagmus.

Persistent vomiting, regurgitation, excess alcohol intake or rapid weight loss after bariatric surgery create susceptibility to thiamine deficiency. Patients at risk for thiamine deficiency should be prescribed thiamine tablets (200-300 mg day). Thiamine should be given intravenously to patients who are unable to take medicines orally or if there are symptoms of thiamine deficiency. If thiamine deficiency is suspected because of the presence of symptoms, intravenous treatment should be started immediately and should not be delayed pending test results. The recommended dose of intravenous thiamine is 500 mg/day for 3-5 days, followed by 250 mg/day for 3 to 5 days until resolution of symptoms, and then 100 mg/day, orally, usually indefinitely or until risk factors have resolved. If thiamine deficiency does not resolve with thiamine supplementation then small bowel bacterial overgrowth should be considered.

Oral or intravenous glucose must not be given to patients at risk of or with suspected thiamine deficiency as it can precipitate Wernicke-Korsakoff syndrome. Thiamine is a co-factor in glucose metabolism, and glucose administration can cause thiamine deficiency to manifest acutely, perhaps by using up remaining thiamine stores. If thiamine deficiency is suspected, thiamine administration should precede glucose.

In summary, investigations should never delay thiamine administration in patients with possible Wernicke’s encephalopathy. Investigations may help to confirm Wernicke’s encephalopathy and exclude other diseases, but cannot replace clinical diagnosis.

It is well recognised that bariatric (weight loss) surgery can harm bones. Bone mineral density can suffer because of changes in calcium and vitamin D metabolism. The section on What is the risk to the health of bones after bariatric surgery? in my website  gives a simple outline of calcium and vitamin D physiology. Nutritional guidelines from the British Obesity and Metabolic Surgeons Society explain the necessary care for bone health.

A recently published study in the British Medical Journal highlights the increase risk for fractures after bariatric surgery. Also, the pattern of fractures is different before and after bariatric surgery. Before surgery, obese people have increased risk for distal lower limb fractures (fractures below the knee) than non-obese people. After surgery, the risk of below knee factures is halved. But, the proportion of fractures of the hip, pelvis and femur (thigh bone) is tripled! Also, the risk for arm fractures is increased. This change in the distribution of fractures can be explained by osteoporosis. Fractures after bariatric surgery occur in the sites that are most prone to loss of bone mineral density (osteoporosis).

There are some limitations in this study, and further research is needed. But, one message is clear: we should emphasize attention to bone health after bariatric surgery.