Clinical Considerations and Recommendations for Pregnancy after Bariatric Surgery

| October 14, 2011 | 0 Comments

by Kim Delamont, NP, MSN, PNNP, WHCNP, CNM

Author affiliation: Ms. Delamont is the Bariatric Director, Rose Medical Center in Denver, Colorado. Ms. Delamont created the the Pregnancy after Bariatric Surgery Program and the Weight Management Programs for Teens and Young Adults at Rose Medical Center.

Funding: No funding was provided for the preparation of this article.

Financial disclosure: Ms. Delamont reports no conflicts of interest relevant to the content of this article.

Bariatric Times. 2011;8(10):12–14

Over the last decade, obstetricians have seen an increased number of pregnant patients with obesity. With bariatric surgery on the rise, many obstetricians are being presented with a new patient population—pregnant women who have undergone bariatric surgery. This article provides guidelines for the practicing clinician caring for the pregnant patient after bariatric surgery. It discusses important recommendations and considerations in treating this unique patient popluation before, during, and after pregnancy, such as timing of pregnancy, nutrition, labwork, delivery considerations, contraception, and breastfeeding.

With the obesity epidemic spreading throughout the United States, it is not surprising that about 36 percent of woman have obesity (BMI≥35kg/m2), a percentage that includes women of childbearing age (18–45 years).[1] From 1993 to 2003, the prevalence of pre-pregnancy obesity increased 70 percent in nine states, reflecting a nationwide trend.[2]

About half of the bariatric procedures performed each year are on women of childbearing age (18–45 years old).[3] Obstetricians are presented with new considerations when caring for a patient who has undergone bariatric surgery and wish to achieve pregnancy. While much research has been reported on maternal and neonatal outcomes, pregnancy following bariatric surgery is a relatively new area that requires more research.

Pregnancies managed with care in patients without obesity who have undergone bariatric surgery have shown similar neonatal outcomes to pregnancies in patients without obesity who have not undergone bariatric surgery.[3,4] Therefore, proper gestational management is important in optimizing a healthy pregnancy in the patient who has undergone bariatric surgery. This article will discuss important considerations and provide recommendations for this unique patient population.

Important Considerations in Achieving Pregnancy after Bariatric Surgery

Timing. The timing of conception after bariatric surgery is important in establishing a healthy early pregnancy and identifying any maternal health concerns that need to be addressed prior to conception. Pregnancy should be avoided during the first 1 to 2 years following bariatric surgery, as it is a time where the patient is still experiencing change.[5,6]

One area of change is in the comorbidites of obesity. Bariatric surgery has been shown to alleviate or resolve many comorbidities of obesity, such as type 2 diabetes mellitus (T2DM) and obstructive sleep apnea (OSA).[7,8,9] Prior to conception, these comorbidities should be appropriately managed or resolved completely in the patient. This 1- to 2-year waiting period postoperatively can also help decrease risk factors, such as hormonal instability in the mother, that may strain a developing fetus.10 Hormonal instability during the first trimester of pregnancy can affect growth in mothers with thyroid conditions, diabetes, and hypertension, which may impact the necessary nutritional environment of a growing fetus.[11,12 ]The improvement or resolution of maternal comorbidities prior to the first trimester can decrease the impact of these conditions on fetal development.

Miscarriage. One out of four pregnancies end in spontaneous miscarriage, an incidence that is increased in women age of 40 or more.[13] A woman of childbearing age with obesity is at an even greater risk of experiencing miscarriage during pregnancy.[14]
Nutrition. The first year following bariatric surgery is a time of rapid weight loss that may present nutritional challenges to the patient. When counseling women who wish to achieve pregnancy after bariatric surgery, the clinician should consider the patient’s nutrition, including complete vitamin panel. If pregnancy is achieved, the clinician should conduct routine prenatal labs.[15] If the patient is at risk for maternal obesity (obesity during pregnancy) or has a history of diabetes, early glucose screening should also be conducted. The clinician should monitor levels of vitamin B-12, folate, vitamin B-1 (thiamin), vitamin D (25 hydroxy), albumin and pre-albumin, and iron, including ferritin.[15]

Protein deficiency during pregnancy. Protein is necessary in repair and growth of cell tissue and is also a source of energy for an expecting mother. Protein deficiencies in the mother can lead to hampered growth in the fetus causing intrauterine growth restriction (IUGR) in extreme cases.[16,17] Babies with IUGR fall below the length and weight for their particular phase of fetal development. This condition can lead to stillbirth or problems after birth, including respiratory, neurological, circulatory, and intestinal disorders.[18]

Glucose. Unrecognized high glucose levels can be harmful to fetal development[19] and should be tested early in pregnancy and again in the third trimester when human placental lactogen (HPL) is secreted, which can adversely alter glucose levels.[19]

Vitamin deficiencies. Deficiencies in vitamin B-1or thiamine in a pregnant woman can adversely affect cerebral neuron and cognitive development in the fetus.[20] Pregnancies deficient in folate have been shown to increase spinal cord defects, such as spina bifida.[15] Fetal effects caused by vitamin D deficiency include increased risk for respiratory infections, low birth weight, type 1 diabetes, cavities, asthma, and other neurologic impairments.[21] Women deficient in vitamin D during pregnancy have been shown to experience an increase in pre-eclampsia (pregnancy-induced hypertension), gestational diabetes, and bacterial vaginosis, which is associated with immune deficiency.[22]

Albumin/pre-albumin. A decreased albumin level can compromise the necessary nutrition to every vital cell in the body.[23]

Iron/ferritin. Chronic or new onset anemia can directly affect oxyhemoglobin levels in the developing fetus, which can affect growth and cognitive development.[24]

Fertility. It has been shown that fertility rates increase when a woman experiences weight loss.[3] Weight loss can also have an improved effect on polycystic ovary syndrome (PCOS), a condition that affects women’s hormone levels, periods, ovulation, and fertility.[15]

Considerations and recommendations during pregnancy
Ultrasounds. Once the clinician has confirmed pregnancy in the patient by measuring early human chorionic gonadotropin (hCG) levels, which double every 48 to 72 hours in a pregnant patient, an early ultrasound should be initiated to establish viability.[25] A heart rate of the fetus can be confirmed as early as five weeks after conception.[26] Many obstetricians establish prenatal care at approximately eight weeks, but when working with a pregnant patient who has undergone baritric surgery, it is best for the clinician to establish prenatal care as early as possible to treat any nutritional deficiencies that may arise.[15]

To identify the important markers of the first trimester, it is prudent practice to confirm the pregnancy as early as 5 to 6 weeks after conception and to conduct an ultrasound at 11 to 13 weeks after conception. Performing another ultrasound between 18 and 20 weeks is also suggested. The patient should continue to have regular ultrasounds (every 4–6 weeks) into the third trimester.[27]

Women who have undergone bariatric surgery who have not achieved a BMI considered normal for their weight may continue to lose weight during pregnancy. This stabilization or decrease in maternal weight can decrease the risk of the fetus growing abnormally as weight stabilization improves comorbities such as diabetes and hypertension, which increase this risk.[15]

Diabetic screening. When treating a pregnant patient who has undergone bariatric surgery, the clinician should conduct screening for diabetes during the first or early second trimester and again in the third trimester when HPL levels can influence glucose metabolism. Diabetes screeening is necessary in pregnant patients who have undergone Roux-en-Y gastric bypass (RYGB) or duodenal switch (DS) operations as malabsorption of increased glucose loads can precipitate dumping to offer a fasting blood sugar. Patients who have undergone sleeve gastrectomy (SG) or adjustable gastric banding can tolerate the 50gm glucose load so diabetes screening can be offered to them without concern for glucose intolerance.[15]

If it is confirmed that a patient has gestational diabetes, the patient or clinician should schedule an appointment with a dietitian who is familiar with baritric surgery.

Nutritional guidelines. In 2008, The American Society of Metabolic and Bariatric Surgery (ASMBS) published allied health nutritional guidelines for the surgical weight loss patient.[28] The following nutritional needs of the pregnant bariatric patient are based on smaller quantities and an emphasis on higher protein intake than the recommended dietary allowance (RDA)[28,29] of complex carbohydrates from fruits/vegetables/whole grains, and low intake of fats.

Protein. Seventy-five percent of each meal should contain lean protein, and 65 to 90g per day is recommended. Protein supplements, including protein shakes, especially during the first and second trimesters, are sufficient in fulfilling this requirement. For a pregnant patient who has not undergone bariatric surgery and weighs 300lbs or less at conception, the protein recommendations are 1g/kg per day. For a pregnant patient who has not undergone bariatric surgery and weighs 300lbs or more, the recommendations are 0.8g/kg per day and an additional 15 to 20g per day for each baby she is carrying during the pregnancy.[28,29,30]

Carbohyates. A minimum of 25 percent, approximately 100 to 150g/day, should come from complex carbohydrates, such as fruits, vegetables, and 100-percent whole grains.

Fats. Mono- and polyunsaturated fats help develop nerve sheaths in the growing fetus and are a source of energy for the pregnant patient. It is recommended that the patient consumes 25 to 35g of mono- and polyunsaturated fats/day.

Meal size and frequency. Each meal should equal between 6 to 8oz of food. and the patient should eat approximately 5 to 6 meals per day. It is recommended that 75 percent of the day’s total meals consist of protein and 25 percent of carbohydrates to allow a continuous fueling of nutrition to both mother and fetus, and to stabilize blood sugar levels.

Water. The suggested daily intake of water for the pregnant patient after bariatric surgery is 64oz.

Supplements. Not all patients adhere to a vitamin regimen after bariatric surgery; therefore, it is important for the clinician to counsel the patient and to be aware of nutritional deficiencies upon conception.

Recommendations for supplementation in the bariatric patient who wishes to achieve pregnancy include a regimen of multivitamins containing vitamins A, D, and E (i.e., fat-soluble vitamins). Dosage of these vitamins should not be greater than two times the daily recommended intake. (Table 1),[28] as consumption of levels more than the recommended dosage can be toxic. Vitamin A beta-carotene is a nontoxic form of vitamin A and is found in most prenatal vitamins. Prenantal vitamins both over the counter (OTC) and by prescription contain betacarotene. Labels should be checked on OTC prenatal vitamins.

The patient should not exceed 5,000IU of Vitamin K intake daily. Meeting the recommended dosage of 1 to 2mg/day of folic acid will help to protective against neural tube defects in the fetus.[15]

The recommendation of intake for vitamin B12 is 1,000mcg/day. Patients who have undergone gastric bypass, gastric sleeve, or duodenal switch should take 1,000mcg sublingually daily, intranasally one time per week, or subcutaneously (SQ) or intramuscularly (IM) one time per  month.

Vitamin B-1 (thiamine) recommendations are 1 to 2mg/day and calcium (my bariatric program prefers patients take calcium citrate 1,500 to 1,800mg/day. Vitamin D intake recommendation is 2,000IU/day and 25 to 35gms per day of fiber.
Omega 3 fatty acids, which assist in fetus brain and eye development, are recommended at 1,000 to 2,000mg/day and iron (ferrous fumarate) 30 to 60mg/day.15,23

Bariatric-Specific Considerations and Complications
When caring for the pregnant postoperative bariatric patient it is important that the obstetrician knows and understands the type of bariatric procedure performed. This can help guide him or her in the decision process for care and for ruling out other etiologies if a concern arises.

Gastric band. Rising HCG levels in the first trimester (doubling every 48–72 hours) can cause nausea and vomiting. Maternal stores of nutrition achieved prior to conception can help the patient through these symptoms. Hypermesis gravidarum (HG), commonly referred to as “morning sickness,” can prevent adequate intake of fluids; therfore hydration is important. Symptoms include nausea and vomiting, gastroesophageal reflux disease (GERD), intolerance to solid foods, abdominal pain, and pain at port site.[31] As hCG levels stabilize, the nausea often also subsides, but it may be necessary to prescribe antiemetic class B medications, such as metoclopramide, ondansetron, hydrochloride, or promethazine.[32] HG can be overlooked when indeed a gastric prolapse or gastric slip has occurred. HG can put the gastric band patient at risk for band slippage or gastric prolapse. Unfilling fluid from the gastric band may be necessary for some due to discomfort, food intolerance, nausea and vomiting, or from the higher levels of progesterone found in pregnancy. The patient should not receive fills during the first trimester. Band fluid may need to be reduced if HG or concerns for maternal health and dietary needs are reduced.[31] If needed, a fill may be performed by the patient’s treating bariatric physician after 14 weeks gestation.

A pregnant gastric band patient may experience discomfort at port site due to her growing abdomen. With both rapid weight loss and pregnancy, the incidence of gallstones and kidney stones is increased.[33, 34]

Gastric bypass, sleeve, gastrectomy, and duodenal switch. HG can put the gastric bypass patient at risk for ulcerations of the gastric pouch. Symptoms may include N/V, intolerance to foods, and GERD. Gastric or duodenal ulcers may be perceived as heartburn typically experienced during the second and third trimester.[35] An obstetrician not familiar with bariatric surgery may attribute symptoms, such as HG, GERD, and food intolerance, to normal pregnancy symptoms instead of the previous bariatric surgery, thus delaying treatment. For instance, an internal hernia may be overlooked as initial abdominal discomfort until it becomes an evident emergent situation. Abdominal pain can be a sign of intestinal hernia or other surgical etiology and consult with a bariatric surgeon is advised. In all bariatric patients, increased gallstones, kidney stones, and gout are slightly increased due to rapid weight loss and pregnancy.[33,34]

Medication. In the pregnant patient who has undergone any type of bariatric surgery, tablet or suspension is advised for medications.[36] Due to possible poor absorption and limited gastric secretions, the patient should not take extended-release or gelatin capsules. Antiemetics may be advisable due to their improved effects on gastric emptying and during postpartum if breast milk supply is suspected to be inadequate.

Weight gain. The measurement of BMI at conception guides maternal weight gain (Table 2).[28,29,30] The obstetrician should monitor the health of the fetus, while not placing too much emphasis on maternal weight gain as many factors come in to play. The bariatric pregnant patient may express concern about gaining weight during pregnancy. The clinician can help by reminding the patient that good nutrition is of utmost importance for the developing fetus and its prenatal stage. Fetal health and nutrition can be monitored through ultrasound growth and maternal nutritional blood values.

Delivery Considerations
Many studies have shown an increase in caesarean (C) section delivery in patients who have undergone bariatric surgery.[37] Similar rates of C-section births would be expected in the patient with obesity who has not undergone bariatric surgery. Patients who have experienced massive weight loss prior to pregnancy are at risk of soft tissue shoulder dystocia loss occuring during vaginal births.[38] Soft tissue shoulder dystocia can occur from the added weight of maternal soft tissue in the lower abdomen that can compress against the uterus and add an increased risk of shoulder dystocia.

Exercise During and after Pregnancy
A healthy activity/exercise regimen is recommended during pregnancy. The latest recommendations are based on perceived exertion scales rather than heart rate. An activity/exercise regimen of a minimum of 30 minutes/day five times/week is encouraged.[39] Heart rate should not exceed 75 percent of the patient’s maximum heart rate or eight on a perceived exertion scale (1–10).

After delivery, the patient may express concern over her body image and desire to be on a diet after delivery. Breastfeeding presents other concerns, such as loose skin, which may make positioning the baby for feeding difficult.

Immune properties of breast milk include, IgA, IgM, IgG, lactoferin, lysosome, and linoleic acid, making breastfeeding optimal to those delivering after bariatric surgery. The immune properties of breastmilk have been linked to improved immunity and improved brain development from fatty acids.

Breast implants in the patient present other concerns during breastfeeding. If the incision is around the areola, some of the milk ducts and nerves may have been cut, which may result in a decreased amount of available milk. If the incision is under the fold of the breast or by the axilla, the implants have probably been inserted behind the milk ducts and not affect milk production.

Some medical contraindications to breastfeeding include anti-metabolites, therapeutic doses of radiopharmaceuticals, illegal street drugs, and human immunodeficiency virus (HIV) drugs.[40]

Contraception Following Bariatric Surgery
Estrogen-based contraception may not provide the best protection alone as weight and estrogen levels can be affected by rapid weight loss. In addition to oral contraceptive use, use of a backup method of contraception, such as condoms, is recommended.[41,42] Contraceptive methods that are not influenced by hormones, such as the interuterine device (IUD) is another option for the bariatric patient.

It is recommended not to start oral contraceptives or estrogen containg birth control for at least six weeks after bariatric surgery due to the increased risks for blood clots.[41,42] Barier methods, such as condoms, diapghragms, or the cervical cap do not pose a problem and may be used upon return to sexual activities following surgery. Barrier methods are a good additional method and a good idea to use with oestrogen based birth control to increase effectiveness that may be inhibited by obesity or rapid weight loss. Progesterone-based birth control such, as transdermal methods (e.g., Depo-Provera [Pfizer Inc., New York, New York] and Implanon [N.V. Organon, a subsidary of Merck and Co., Inc., Kenilworth, New Jersey]) do not pose any concerns or risks and may be placed at any time.[41,42] There is a decreased effectiveness in the patient who is 195lbs or more and another method should be used.[41,42]
Oral contraceptives can be used on a variety of schedules from daily to continous with or without a breakthrough bleeding week. Patients should be cautious when taking pills that contain less than 30 to 35mcg of estrogen as they may effectiveness may be compromised in patients who have obesity and/or have epxperienced rapid weight loss following bariatric surgery. IUDs are a good option and can be used as early as four weeks after delivery or bariatric surgery.[42]

Pregnancy after bariatric surgery should be managed appropriately with help of the obstetrician, bariatric surgeon, and patient. Adverse effects are usually related to maternal health upon conception rather than the presence of obesity. Management considerations in this patient population include proper nutrition before, during, and after pregnancy. Identifying and correcting maternal nutritional deficiencies early in the pregnancy is vital to both the health and development of the fetus and the mother. Baritric surgery itself does not impact the pregnancy and delivery. Outcomes of all pregnancies are typically based on the mother’s health (nutrition and weight) upon conception.

A relationship between the obstetrician and bariatric surgeon can be mutually beneficial to both maternal and fetal health. Good communication between the obstetrician and bariatric surgeon may prevent or rapidly diagnose conditions that could affect maternal or fetal health during the pregnancy.

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