Hypoglycemia during oral glucose tolerance test among post-bariatric surgery pregnant patients: incidence and perinatal significance

Pregnancy After Metabolic Bariatric Surgery: Risks and Rewards for Mother and Child

As the prevalence of obesity increases worldwide, and lifestyle modification or pharmaceutical treatment yields insufficient results for patients with severe obesity, an increasing number of patients opt for metabolic bariatric surgery as an effective and durable treatment of this disease. Seeing as 80% of these patients are women, many of whom are of reproductive age, pregnancies after metabolic bariatric surgery become increasingly common. Metabolic bariatric surgery has many benefits for overall health and pregnancy outcomes, but certain risks are also reported. This leads to the rise of a new population of patients with their own specific needs regarding follow-up. This review discusses the various benefits and risks of these types of surgery for pregnancy. We provide an overview of the current state of the evidence and look into future research goals.

A systematic review on clinical practice guidelines for managing pregnancy following metabolic-bariatric surgery

OBJECTIVE

The ongoing pandemic of obesity is associated with an increase of weight loss surgeries in women of reproductive age. This study was conducted to review clinical practice guidelines (CPGs) for managing pregnancy following metabolic-bariatric surgery.

METHODS

We conducted a comprehensive literature search of all CPGs that covered the management of pregnancy following metabolic-bariatric surgery, 2010 through 2022, and that were published in English. Two authors independently scored the quality and usefulness of CPGs using the Appraisal of Guidelines for Research and Evaluation II tool (AGREE II).

RESULTS

From a total of 20 CPGs, consistent recommendations included the following: 1) contraception with long-acting reversible contraceptives before surgery until the optimal time of pregnancy; 2) nutritional care by a dietitian; 3) considering gastrointestinal discomforts during pregnancy as a potential surgical complication; and 4) modified screening for gestational diabetes instead of glucose tolerance tests preventing post-bariatric hypoglycemia. There was a lack of uniformity concerning surgery-to-conception interval and dose of supplements, as well as research gaps regarding the surgical type, mental health, delivery type, breastfeeding, neonatal care, and weight retention.

CONCLUSIONS

All recommendations for managing pregnancy after metabolic-bariatric surgery were deemed clinically useful. Although consistent recommendations should be implemented, inconsistencies should be the focus of research.

The Challenges of Diagnosing Gestational Diabetes after Bariatric Surgery: Where Do We Stand?

BACKGROUND

Obesity, gestational diabetes mellitus (GDM), and bariatric metabolic surgery (BMS) are increasingly common conditions during pregnancy.

SUMMARY

However, clinical knowledge regarding GDM that occurs after BMS remains full of uncertainties. Given its prevalence and potential consequences for the dyad pregnant and offspring, it is imperative to increase knowledge about GDM after BMS, define diagnostic criteria and consequently strategies capable of improving pregnancy outcomes.

KEY MESSAGES

This paper aimed to review GDM screening methods after BMS and gives insights regarding new paths of research on this paramount obstetric condition.

Investigation of maternal serum hepassocin concentrations in pregnant women with gestational diabetes mellitus: a prospective case-control study

OBJECTIVE

We aimed to investigate the relationship between gestational diabetes mellitus (GDM) and maternal serum hepassocin concentrations.

MATERIALS AND METHODS

This cross-sectional study was conducted with 88 pregnant women who applied to the Ümraniye Training and Research Hospital Gynecology and Obstetrics Clinic between April 2022 and November 2022. The GDM group consisted of 44 pregnant women who had a 75-g OGTT between the 24th and 28th week of pregnancy and were diagnosed with GDM. The control group consisted of 44 healthy pregnant women who were matched with the GDM group in terms of age and body mass index (BMI) and had a normal 75-g OGTT result. Demographic characteristics, laboratory findings, and perinatal outcomes were noted. Two groups were compared in terms of maternal serum hepassocin concentrations.

RESULTS

Both groups were similar in terms of age, BMI, weight gain, gravida, parity, polycystic ovary syndrome history, history of diabetes mellitus in the family, and the gestational week at blood sampling for hepassocin (p>0.05 for each). The median maternal serum hepassocin concentration was found to be 18.21 ng/ml in the GDM group, while it was determined as 13.05 ng/ml in the non-GDM group (p=0.012). The GDM group was divided into two groups: the group that only dieted until birth and the group that used insulin until birth for blood glucose regulation. The median hepassocin concentration was found to be 17.99 ng/ml in the diet-only GDM group and 32.15 ng/ml in the insulin-using GDM group. ROC analysis was performed to determine the value of maternal serum hepassocin concentration in predicting GDM. AUC analysis of maternal serum hepassocin for estimation of GDM was 0.656 (p=0.012, 95% CI=0.53-0.77). The optimal threshold value for maternal serum hepassocin concentration was determined as 14.13 ng/ml with 61.4% sensitivity and 61.4% specificity.

CONCLUSION

Serum hepassocin concentration evaluated between 24 and 28 weeks of gestation was found to be higher in pregnant women with GDM than in the non-GDM group. The highest serum hepassocin concentration was found in the GDM group using insulin for blood glucose regulation. Hepassocin seems to be a promising molecule that can be used in GDM screening in pregnant women who do not want to have an OGTT in the future.

Nutritional Implications of Bariatric Surgery on Pregnancy Management-A Narrative Review of the Literature

One in three women of reproductive age is obese. The mainstay treatment for obesity is bariatric surgery, and the following weight reduction results in a decrease in pregnancy adverse effects, including gestational diabetes mellitus, pregnancy-induced hypertension, and macrosomia. However, nutritional and vitamin deficiencies due to changes in the gastrointestinal tract after bariatric surgery are associated with an increase in the risk of fetal growth retardation and small for gestational-age neonates. The purpose of this review was to analyze the available recent literature on the subject of the management of pregnancy after bariatric surgery. We searched for available articles from 2007 to 2023 and chose articles of the greatest scientific and clinical value. Micronutrient, vitamin, and protein supplementation is recommended in the prenatal period and throughout the pregnancy. It is advised that pregnant women with a history of bariatric surgery should be provided with regular specialist dietary care. There is still a lack of recommendations about the optimum gestational weight gain after different types of bariatric surgery and for patients of different metabolic statuses. Women of reproductive age undergoing bariatric procedures should be provided with appropriate counseling about adequate contraception, the recommended time-to-conception interval, and the positive and negative influence of bariatric surgery on perinatal outcomes.

Hypoglycaemia in non-diabetic pregnancy

Hypoglycaemia in non-diabetic pregnancy is rare, the majority of reported cases being due to insulinoma, acute fatty liver of pregnancy, malaria and inborn errors of metabolism. A case of hypoglycaemia in a woman with previous laparoscopic sleeve gastrectomy, and hypothalamic-pituitary-adrenal axis insufficiency in the setting of opioid dependence is presented. The timing of low interstitial glucose levels was atypical for late dumping syndrome following bariatric surgery, and a change in the woman's glucocorticoid replacement resulted in resolution of hypoglycaemic symptoms. The incidence of opioid dependence in pregnancy is increasing rapidly. Health professionals should be aware of the possibility of opioids causing hypothalamic-pituitary-adrenal axis insufficiency, and the additional mechanisms by which opioids may cause hypoglycaemia.

Benefits and Risks of Bariatric Surgery on Women's Reproductive Health: a Narrative Review

Bariatric surgery (BS) is escalating as the most efficient and endurable therapy for severe obesity. Women's reproductive health is essential to women's quality of life and is receiving increasing attention. However, despite the high prevalence of BS among women, the effect of BS on reproductive health remains underemphasis. The purpose of this narrative review is to provide an overview of BS on women's reproductive health, including their reproductive health before, during, and after pregnancy. Although limited attention has been given, current evidence highlights the substantial implications of bariatric surgery on reproductive health and reminds us of the importance of adopting decision-making conversations about reproductive health before bariatric surgery.

Pregnancy after Bariatric Surgery: Nutrition Recommendations and Glucose Homeostasis: A Point of View on Unresolved Questions

Obesity is increasing in all age groups and, consequently, its incidence has also risen in women of childbearing age. In Europe, the prevalence of maternal obesity varies from 7 to 25%. Maternal obesity is associated with short- and long-term adverse outcomes for both mother and child, and it is necessary to reduce weight before gestation to improve maternal and fetal outcomes. Bariatric surgery is an important treatment option for people with severe obesity. The number of surgeries performed is increasing worldwide, even in women of reproductive age, because improving fertility is a motivating factor. Nutritional intake after bariatric surgery is dependent on type of surgery, presence of symptoms, such as pain and nausea, and complications. There is also a risk of malnutrition after bariatric surgery. In particular, during pregnancy following bariatric surgery, there is a risk of protein and calorie malnutrition and micronutrient deficiencies due to increased maternal and fetal demand and possibly due to reduction of food intake (nausea, vomiting). As such, it is necessary to monitor and manage nutrition in pregnancy following bariatric surgery with a multidisciplinary team to avoid any deficiencies in each trimester and to ensure the well-being of the mother and fetus.

Roux-en-Y Gastric Bypass Increases Glycemic Excursions During Pregnancy and Postpartum: A Prospective Cohort Study

OBJECTIVE

Roux-en-Y gastric bypass (RYGB) and pregnancy markedly alter glucose metabolism, but evidence on glucose metabolism in pregnancy after RYGB is limited. Thus, the aims of the Bariatric Surgery and Consequences for Mother and Baby in Pregnancy study were to investigate interstitial glucose (IG) profiles during pregnancy, risk factors associated with hypoglycemia, and the association between fetal growth and hypoglycemia in pregnant women previously treated with RYGB, compared with control participants.

RESEARCH DESIGN AND METHODS

Twenty-three pregnant women with RYGB and 23 BMI- and parity-matched pregnant women (control group) were prospectively studied with continuous glucose monitoring in their first, second, and third trimesters, and 4 weeks postpartum. Time in range (TIR) was defined as time with an IG level of 3.5-7.8 mmol/L.

RESULTS

Women with RYGB were 4 years (interquartile range [IQR] 0-7) older than control participants. Pregnancies occurred 30 months (IQR 15-98) after RYGB, which induced a reduction in BMI from 45 kg/m2 (IQR 42-54) presurgery to 32 kg/m2 (IQR 27-39) prepregnancy. Women with RYGB spent decreased TIR (87.3-89.5% vs. 93.3-96.1%; P < 0.01) owing to an approximately twofold increased time above range and increased time below range (TBR) throughout pregnancy and postpartum compared with control participants. Women with increased TBR had a longer surgery-to-conception interval, lower nadir weight, and greater weight loss after RYGB. Finally, women giving birth to small-for-gestational age neonates experienced slightly increased TBR.

CONCLUSIONS

Women with RYGB were more exposed to hypoglycemia and hyperglycemia during pregnancy compared with control participants. Further research should investigate whether hypoglycemia during pregnancy in women with RYGB is associated with decreased fetal growth.

Risk factors of lower birth weight, small-for-gestational-age infants, and preterm birth in pregnancies following bariatric surgery: a scoping review

PURPOSE

Bariatric surgery increases the risk of lower birth weight, small-for-gestational-age (SGA) infants, and preterm birth in a subsequent pregnancy. However, the factors that contribute to these adverse birth outcomes are unclear. This review aimed to collate available information about risk factors of lower birth weight, SGA, and preterm birth following bariatric surgery.

METHODS

A literature search was conducted using five databases (PubMed, PsycINFO, EMBASE, Web of Science, and Cochrane Library) to obtain relevant studies.

RESULTS

A total number of 85 studies were included. Studies generally excluded surgery-to-conception interval, pregnancy complications, cigarette use, and maternal age as influencing factors of birth weight, SGA, or preterm birth. In contrast, most studies found that malabsorptive procedures, lower gestational weight gain, lower glucose levels, abdominal pain, and insufficient prenatal care were associated with an elevated risk of adverse birth outcomes. Findings were mixed regarding the effects of surgery-to-conception weight loss, pre-pregnancy body mass index, micronutrient deficiency, and lipid levels on birth outcomes. The examination of maternal microbiome profiles, placental function, alcohol use, and exercise was limited to one study; therefore, no conclusions could be made.

CONCLUSION

This review identified factors that appear to be associated (e.g., surgery type) or not associated (e.g., surgery-to-conception interval) with birth outcomes following bariatric surgery. The mixed findings and the limited number of studies on several variables (e.g., micronutrients, exercise) highlight the need for further investigation. Additionally, future studies may benefit from exploring interactions among risk factors and expanding to assess additional exposures such as maternal mental health.

Women's experiences of pregnancy and lactation after bariatric surgery: A scoping review

BACKGROUND

Obesity is a global public health problem, and in high income countries such as Australia, approximately 60 percent of women are overweight, and half of these women are classed in the obese range. A large proportion of women who are obese are of childbearing age and many are undergoing surgical weight loss procedures (bariatric surgery) before becoming pregnant.

OBJECTIVE

To collate and synthesize available literature regarding women's experiences of pregnancy and/or lactation following bariatric surgery.

DESIGN

A scoping review was undertaken of published research between 1990 and 2021, written in English, involving human participants, which described experiences of pregnancy and/or lactation after bariatric surgery.

RESULTS

From a total of 4673 abstracts identified using search terms and strings, only 5 items (4 published conference abstracts and one full paper) were identified. Women had little knowledge of how the bariatric surgery might impact pregnancy and only a minority received additional medical/nutrition care during pregnancy. Women wanted more information and support managing their pregnancies, and often received inconsistent advice. For some women experiences of conflict between eating well for the developing fetus and eating little to minimize weight gain or undo the weight loss they had achieved was reported.

CONCLUSIONS

Ensuring that both health care providers and women are informed about promoting a healthy pregnancy and lactation after bariatric surgery is paramount. More research is required to understand women's experiences and information needs to ensure advice and care is tailored to their specific needs.

Maternal antagonism of Glp1 reverses the adverse outcomes of sleeve gastrectomy on mouse offspring

Mothers that underwent bariatric surgery are at higher risk for delivering a small-for-gestational age (SGA) infant. This phenomenon is attributed to malabsorption and rapid weight loss following surgery. We compared pregnancy outcomes in lean mice that underwent sham surgery or sleeve gastrectomy (SG). SG led to a reduction in glucose levels and an increase in postprandial levels of glucagon-like peptide 1 (Glp1) without affecting mice weight during pregnancy. Pups of SG-operated mice (SG pups) were born SGA. The placenta and pancreas of the pups were not affected by SG, although a high-fat diet caused hepatic steatosis and glucose intolerance in male SG pups. Treatment with a Glp1 receptor antagonist during pregnancy normalized the birth weight of SG pups and diminished the adverse response to a high-fat diet without affecting glucose levels of pregnant mice. The antagonist did not affect the birth weight of pups of sham-operated mice. Our findings link elevated Glp1 signaling, rather than weight loss, to the increased prevalence of SGA births following bariatric surgery with metabolic consequences for the offspring. The long-term effects of bariatric surgery on the metabolic health of offspring of patients require further investigation.

Hypoglycemia in Pregnancies Following Gastric Bypass-a Systematic Review and Meta-analysis

The aims of this systematic review were to identify the prevalence of hypoglycemia among pregnant women treated with gastric bypass, and risk factors of hypoglycemic events in pregnancy. We searched MEDLINE, EMBASE, Cochrane, and Scopus databases from inception to April 6, 2021. Six studies investigating glucose metabolism in pregnancy following gastric bypass were included (n = 330). As assessed by the oral glucose tolerance test and continuous glucose monitoring, 57.6% (95% CI [40.1, 75.1]) of women with gastric bypass were exposed to hypoglycemia during pregnancy. No studies performed the mixed meal test, and no studies reported on risk factors associated with hypoglycemia. Further studies are required to determine the magnitude of hypoglycemia in these women's everyday-life using continuous glucose monitoring and mixed meal test.

Recurrent gestational diabetes : Breaking the transgenerational cycle with lifestyle modification

PURPOSE

This literature review is aimed at examining the benefits of lifestyle modifications in preventing recurrent gestational diabetes (GDM). Worldwide GDM affects approximately 16.2% of all pregnancies with significant maternal, fetal and neonatal complications. Almost two thirds of pregnant women with GDM will develop type 2 diabetes mellitus (T2DM) in the years following pregnancy. The proportion of women affected by GDM is on the rise and reflects increasing trends in T2DM as well as adult and childhood obesity.

METHODS

Using predefined subject headings, we searched for relevant articles from the PubMed, Scopus, and Cochrane databases.

RESULTS

For high-risk women lifestyle modifications, such as dietary and exercise changes, are the mainstay of treatment to reduce negative outcomes for both women and their pregnancies. This includes reducing the incidence of recurrent GDM and future T2DM by intervening during pregnancy and in the postnatal period.

CONCLUSION

This review provides an overview of the literature to date, discusses different targeted approaches and how these interventions can optimise their benefits, and where further research is required.

An Update on Screening Strategies for Gestational Diabetes Mellitus: A Narrative Review

Gestational diabetes mellitus (GDM) is a frequent medical complication during pregnancy. Screening and diagnostic practices for GDM are inconsistent across the world. This narrative review includes data from 87 observational studies and randomized controlled trials (RCTs), and aims to give an overview of the current evidence on screening strategies and diagnostic criteria for GDM. Screening in early pregnancy remains controversial and studies show conflicting results on the benefit of screening and treatment of GDM in early pregnancy. Implementing the one-step "International Association of Diabetes and Pregnancy Study Groups" (IADPSG) screening strategy at 24-28 weeks often leads to a substantial increase in the prevalence of GDM, without conclusive evidence regarding the benefits on pregnancy outcomes compared to a two-step screening strategy with a glucose challenge test (GCT). In addition, RCTs are needed to investigate the impact of treatment of GDM diagnosed with IADPSG criteria on long-term maternal and childhood outcomes. Selective screening using a risk-factor-based approach could be helpful in simplifying the screening algorithm but carries the risk of missing significant proportions of GDM cases. A two-step screening method with a 50g GCT and subsequently a 75g oral glucose tolerance test (OGTT) with IADPSG could be an alternative to reduce the need for an OGTT. However, to have an acceptable sensitivity to screen for GDM with the IADPSG criteria, the threshold of the GCT should be lowered from 7.8 to 7.2 mmol/L. A pragmatic approach to screen for GDM can be implemented during the COVID-19 pandemic, using fasting plasma glucose (FPG), HbA1c or even random plasma glucose (RPG) to reduce the number of OGTTs needed. However, usual guidelines and care should be resumed as soon as the COVID pandemic is controlled.

Pregnancy after Bariatric Surgery: A Nested Case-Control Study of Risk Factors for Small for Gestational Age Babies in AURORA

Bariatric surgery prior to pregnancy is a significant risk factor for small for gestational age (SGA) babies. This case-control study investigated differences between mothers delivering an SGA baby following bariatric surgery, compared to those delivering an appropriate for gestational age (AGA) baby. Out of 129 babies born to mothers in the AURORA cohort study, 25 were SGA (<10th percentile) and 97 were AGA (10th-90th percentile). Higher gestational weight gain (GWG) was significantly associated with decreased odds of SGA (aOR per kg 0.92, 95% CI 0.85-0.99). According to the Institute of Medicine GWG guidelines, 44% of SGA mothers had 'inadequate' GWG compared to 17% of AGA mothers. Nearly half of the mothers had 'excessive' GWG yet still gave birth to an SGA or AGA baby. Mothers of SGA babies lost more weight following bariatric surgery (45.6 ± 14.4 kg vs. 39.0 ± 17.9 kg). Women who reported receiving nutritional advice following bariatric surgery were significantly less likely to have an SGA baby (aOR 0.15, 95% CI 0.0.4-0.55). Women with a history of bariatric surgery should be provided with specialized support before and during pregnancy to encourage adequate nutritional intake and weight gain to support healthy fetal growth.

Pregnancy after bariatric surgery - a narrative literature review

The purpose of this review was to analyze the literature about pregnancy after bariatric surgery. We searched for available articles on the subject from the last decade (2010 to 2020). The positive impact of bariatric surgery on the level of comorbidities and pregnancy and neonatal outcomes cannot be overrated. Weight loss after bariatric surgery reduces the incidence of obesity-related conditions in pregnancy. A pregnancy in a woman after bariatric surgery should be considered a high-risk pregnancy and taken care of by a multidisciplinary team with appropriate micronutrient and vitamin supplementation provided. Optimum time to conception should be chosen following the international recommendations. Every woman after bariatric surgery should be aware of symptoms of surgical complications and immediately contact their surgeon in case of abdominal pain.

Glucose Homeostasis, Fetal Growth and Gestational Diabetes Mellitus in Pregnancy after Bariatric Surgery: A Scoping Review

BACKGROUND

Pregnancies in women with a history of bariatric surgery are becoming increasingly prevalent. Surgically induced metabolic changes benefit mother and child, but can also lead to some adverse pregnancy outcomes. Knowledge about glucose homeostasis in these pregnancies could elucidate some of the mechanisms behind these outcomes. This review focusses on glucose homeostasis and birth weight.

METHODS

We considered papers dealing with glucose homeostasis, gestational diabetes mellitus (GDM) and/or small-for-gestational age infants (SGA) in pregnancies with a history of sleeve gastrectomy (SG) or Roux-en-y gastric bypass (RYGB).

RESULTS

Since an OGTT is unreliable to diagnose GDM in a pregnancy after bariatric surgery, the true incidence of GDM is unknown. Alternative screening strategies are needed. Furthermore, these pregnancies are marked by frequent hypoglycemic events as well as wide and rapid glycemic excursions, an issue that is very likely underreported. There is a lack of uniformity in reporting key outcomes and a large variation in study design and control population.

CONCLUSION

Alteration of glucose homeostasis in a pregnancy after bariatric surgery should be further studied using unequivocal definition of key concepts. Glycemic control may prove to be a modifiable risk factor for adverse pregnancy outcomes such as the delivery of an SGA baby.

The Influence of Bariatric Surgery on Pregnancy and Perinatal Outcomes-A Case-Control Study

INTRODUCTION

Obesity in pregnant women increases the incidence of pregnancy-induced comorbidities and the rate of operative deliveries.

PURPOSE OF THE STUDY

As bariatric surgery is the reference method of treatment of obesity, we wanted to evaluate its influence on the course of pregnancy and perinatal outcomes.

MATERIAL AND METHODS

Data was collected from 627 female patients after bariatric surgery, of whom 107 had a history of pregnancy after the surgery, and 345 non-bariatric patients who had a delivery at a tertiary perinatal center. Sixty-one cases were matched (1:1) with controls for age, pre-pregnancy BMI and presence of pre-pregnancy comorbidities. The main endpoints were gestational diabetes mellitus (GDM), pregnancy-induced hypertension (PIH), small (SGA) and large for gestational age infants (LGA) and cesarean sections (CS).

RESULTS

Patients after bariatric procedures were significantly less likely to have GDM (19.67%/37.7%; p = 0.0433), PIH (11.47%/16.39%; p = 0.6072) and preterm delivery (13.11%/37.7%; p = 0.0026). The CS rate was higher (57.38%/40.98%; p = 0.0987). There was an increased risk of SGA (18.03%/13.11%; p = 0.6072) and a decreased risk of LGA (6.56%/16.39%; p = 0.146).

CONCLUSIONS

Patients after bariatric surgery have a decreased risk of pregnancy-induced comorbidities, preterm deliveries and LGA infants, with an increase in rate of CS and SGA infants compared to general population matched for pre-pregnancy BMI, age and presence of pre-pregnancy comorbidities.

Association between time interval from bariatric surgery to pregnancy and maternal weight outcomes

BACKGROUND

The majority of patients having bariatric surgery are reproductive-age women who are advised to delay pregnancy for at least 12 months after surgery. Many women become pregnant sooner and the association between gestational weight gain (GWG) and maternal long-term weight is unknown.

OBJECTIVES

The primary objective of this study was to compare weight outcomes in pregnancies occurring < 12 months versus ≥ 12 months after bariatric surgery. The secondary objectives were to determine the association between time interval from bariatric surgery to pregnancy and maternal nutritional status and maternal and neonatal outcomes.

STUDY DESIGN

This is a retrospective cohort study of women with singleton livebirths after bariatric surgery who received care at a single tertiary care center between 2009 and 2017. GWG was the difference in weight between the first prenatal visit and delivery. GWG adequacy was determined by the IOM 2009 guidelines according to prepregnancy BMI (inadequate, adequate, excessive). Postpartum weight retention was calculated as the difference between weight at first prenatal visit and measured postpartum weight. Weight outcomes along with maternal nutritional status and maternal and neonatal outcomes were compared between < 12 months versus ≥ 12 months after bariatric surgery with t-tests, Mann-Whitney U and chi-square tests, as appropriate.

RESULTS

Of the 76 pregnancies that met inclusion criteria, 36.8% occurred < 12 months (median 7.2 months) and 63.2% occurred ≥ 12 months after surgery (median 26.9 months). Of those with pregnancies < 12 months from surgery, 34% had a restrictive procedure (adjustable gastric band or sleeve gastrectomy) while 66% had a combined restrictive-malabsorptive procedure (Roux-en-Y gastric bypass). In the ≥ 12 months group, 42.3% had a restrictive procedure while 57.7% had a combined restrictive-malabsorptive procedure. There were no significant differences in maternal age, ethnicity or nulliparity between groups, but there were more women with obesity in the < 12 months group (75 vs. 52%, p = .03). The mean prepregnancy BMI in the < 12 months group was 34.3 vs. 31.2 kg/m² in the ≥ 12 months group. The < 12 months group had lower mean GWG (4.9 vs. 10.9 kg, p = .01) and higher frequency of weight loss during pregnancy (28.6 vs. 4.2%, p < .01) compared to the ≥ 12 months group. The < 12 months group had significantly less postpartum weight retention at 6 months compared to the ≥ 12 months group (-1.3 vs. 8.3 kg, p = .02). The < 12 months group had a higher prevalence of vitamin B12 deficiency (23.1 versus 4.9%, p = .05). There were no differences in hyperemesis, hypertensive disorders, gestational diabetes or delivery mode between groups (p > .05). There were no differences in gestational age at delivery, birth weight and small for gestational age infants between groups (p > .05).

CONCLUSION

Pregnancy < 12 months after bariatric surgery is associated with significantly lower mean GWG and a higher frequency of weight loss during pregnancy as well as less postpartum weight retention at 6 months. Although there were no differences birthweight, weight loss during pregnancy and its accompanying metabolic changes are concerning for a developing fetus. Further study is needed to determine the optimal timing of pregnancy after bariatric surgery with respect to both maternal and infant short and long-term outcomes.

High maternal osteocalcin levels during pregnancy is associated with low birth weight infants: A nested case-control study in China

BACKGROUND

Low birth weight infants (LBW) are at risk of chronic diseases in later life due to the disorder of energy metabolism during pregnancy. Osteocalcin (OC) has been identified as a hormone that regulate energy metabolism. However, few studies have researched on the associations between maternal serum OC levels and low birth weight infants.

OBJECTIONS

To examine the associations between maternal serum OC concentrations and LBW.

METHODS

This was a nested case-control study involving a total of 230 pregnant women delivering LBW and 382 control pregnant women (matched for infant gender, gestational age at blood draw, region of Maternity and Child Healthcare Hospital and maternal age in 1: (1-2) ratio). One serum sample was collected from each pregnant woman at 5-35 weeks' gestation. Pregnant women were divided into 3 groups (1st, 2nd and 3rd trimester group). There were 60 and 142 and 28 pregnant women delivering LBW in the first, second and third trimester, respectively. Similarly, there were 101 and 233 and 48 controls in the first, second and third trimester, respectively. Maternal serum OC and 25(OH)D concentrations were categorized into low and high levels, the low level used as reference in analyses. Binary logistic regression model was used to compute odd radio (ORs) for LBW according to levels of maternal serum OC and 25(OH)D.

RESULTS

Compared with the subjects in low level in first trimester, LBW was two times as likely to occur among pregnancy women with high serum OC concentrations (OR = 2.04, 95%CI:1.05-3.96). After adjusted for confounding factors, a significant positive relationship still existed (adjusted ORs = 2.29, 95%CI: 1.11-4.72). In second trimester, women in high level of serum OC had nearly 1.6 times the risk of delivering LBW infants as those in the low level (OR = 1.55, 95%CI: 1.01-2.37). After adjusted for confounding factors, the ORs increased (ORs = 1.59, 95%CI:1.03-2.45). No significant associations were found between maternal serum OC levels and LBW in third trimester. In addition, there were no associations between maternal 25(OH)D concentrations and LBW during pregnancy.

CONCLUSION

High maternal serum OC levels in the first or the second trimester during pregnancy may be associated with the risk of LBW.

Screening and Management of Gestational Diabetes Mellitus after Bariatric Surgery

Gestational diabetes mellitus (GDM) is a frequent medical complication during pregnancy. This is partly due to the increasing prevalence of obesity in women of childbearing age. Since bariatric surgery is currently the most successful way to achieve maintained weight loss, increasing numbers of obese women of childbearing age receive bariatric surgery. Bariatric surgery performed before pregnancy significantly reduces the risk to develop GDM but the risk is generally still higher compared to normal weight pregnant women. Women after bariatric surgery therefore still require screening for GDM. However, screening for GDM is challenging in pregnant women after bariatric surgery. The standard screening tests such as an oral glucose tolerance test are often not well tolerated and wide variations in glucose excursions make the diagnosis difficult. Capillary blood glucose measurements may currently be the most acceptable alternative for screening in pregnancy after bariatric surgery. In addition, pregnant women after bariatric surgery have an increased risk for small neonates and need careful nutritional and foetal monitoring. In this review, we address the risk to develop GDM after bariatric surgery, the challenges to screen for GDM and the management of women with GDM after bariatric surgery.