Perinatal outcomes in type 2 diabetic patients compared with non-diabetic patients matched by body mass index

Novel insights into the complex interplay of immune dysregulation and inflammatory biomarkers in preeclampsia and fetal growth restriction: A two-step Mendelian randomization analysis

Background

The relationship between genetic immune dysregulation and the occurrence of preeclampsia (PE) or PE with fetal growth restriction (PE with FGR) has yielded inconsistent findings, and the underlying mediators of this association remain elusive. We aimed to explore the causal impact of genetic immune dysregulation on the risk of PE or PE with FGR and to elucidate the role of specific transcriptomes in mediating this relationship.

Methods

A two-step Mendelian randomization (MR) analysis was performed to explore the link between immune dysregulation and PE or PE with FGR, as well as to identify potential inflammatory biomarkers that act as mediators. GWAS summary data for outcomes were obtained from the FinnGen dataset. The analyses encompassed five systemic immune-associated diseases, four chronic genital inflammatory diseases, and thirty-one inflammatory biomarkers. Summary-data-based MR (SMR) and HEIDI analysis were conducted to test whether the effect size of single nucleotide polymorphisms (SNPs) on outcomes was mediated by the expression of immune-associated genes.

Results

The primary univariable analysis revealed a significant positive correlation between systemic lupus erythematosus (SLE), type 1 diabetes (T1D), type 2 diabetes (T2D), and rheumatoid arthritis (RA) with the risk of PE or PE with FGR. Surprisingly, a counterintuitive finding showed a significant negative association between endometriosis of pelvic peritoneum (EMoP) and the risk of PE with FGR. None of the inflammatory factors had a causal relationship with PE or PE with FGR. However, there was a significant association between lymphocyte count and the risk of PE with FGR. Within the lymphocyte subset, both the proportion of Natural Killer (NK) cells and absolute counts of naïve CD4+ T cells demonstrated significant effects on the risk of PE with FGR. Two-step MR analysis underscored the genetically predicted lymphocyte count as a significant mediator between T1D and PE with FGR. Additionally, SMR analysis indicated the potential involvement of SH2B3 in the occurrence of PE with FGR.

Conclusions

Our findings provided substantial evidence of the underlying causal relationship between immune dysregulation and PE or PE with FGR and some of these diseases proved to accelerate immune cells disorders and then contribute to the risk of incident PE or PE with FGR.

Genetically predicted body mass index and maternal outcomes of pregnancy: A two-sample Mendelian randomisation study

OBJECTIVE

Observational studies have described associations between obesity and adverse outcomes of pregnancy but observational results are liable to influence by residual confounding. Mendelian randomisation (MR) leverages the 'natural' genetic randomisation to risk of an exposure occurring at allele assortment and conception. Similar to randomisation in a clinical trial, this limits the potential for the influence of confounding.

DESIGN

A two-sample MR study.

SETTING

Summary statistics from published genome wide association studies (GWAS) in European ancestry populations.

POPULATION OR SAMPLE

Instrumental variants for body mass index (BMI) were obtained from a study on 434 794 females.

METHODS

Inverse-variance weighted MR was used to assess the association between BMI and all outcomes. Sensitivity analyses with weighted median and MR-Egger were also performed.

MAIN OUTCOME MEASURES

Female-specific genetic association estimates for outcomes were extracted from the sixth round of analysis of the FINNGEN cohort data.

RESULTS

Higher genetically predicted BMI was associated with higher risk of pre-eclampsia (odds ratio [OR] per standard deviation 1.68, 95% confidence interval [CI] 1.46-1.94, P = 8.74 × 10-13 ), gestational diabetes (OR 1.67, 95% CI 1.46-1.92, P = 5.35 × 10-14 ), polyhydramnios (OR 1.40, 95% CI 1.00-1.96, P = 0.049). There was evidence suggestive of a potential association with higher risk of premature rupture of membranes (OR 1.16, 95% CI 1.00-1.36, P = 0.050) and postpartum depression (OR 1.12, 95% CI 0.99-1.27, P = 0.062).

CONCLUSIONS

Higher genetically predicted BMI is associated with marked increase in risk of pre-eclampsia, gestational diabetes and polyhydramnios. The relation between genetically predicted BMI and premature rupture of membranes and postpartum depression should be assessed in further studies. Our study supports efforts to target BMI as a cardinal risk factor for maternal morbidity in pregnancy.

Metformin Plus Insulin for Preexisting Diabetes or Gestational Diabetes in Early Pregnancy: The MOMPOD Randomized Clinical Trial

Importance

Insulin is recommended for pregnant persons with preexisting type 2 diabetes or diabetes diagnosed early in pregnancy. The addition of metformin to insulin may improve neonatal outcomes.

Objective

To estimate the effect of metformin added to insulin for preexisting type 2 or diabetes diagnosed early in pregnancy on a composite adverse neonatal outcome.

Design, Setting, and Participants

This randomized clinical trial in 17 US centers enrolled pregnant adults aged 18 to 45 years with preexisting type 2 diabetes or diabetes diagnosed prior to 23 weeks' gestation between April 2019 and November 2021. Each participant was treated with insulin and was assigned to add either metformin or placebo. Follow-up was completed in May 2022.

Intervention

Metformin 1000 mg or placebo orally twice per day from enrollment (11 weeks -<23 weeks) through delivery.

Main Outcome and Measures

The primary outcome was a composite of neonatal complications including perinatal death, preterm birth, large or small for gestational age, and hyperbilirubinemia requiring phototherapy. Prespecified secondary outcomes included maternal hypoglycemia and neonatal fat mass at birth, and prespecified subgroup analyses by maternal body mass index less than 30 vs 30 or greater and those with preexisting vs diabetes early in pregnancy.

Results

Of the 831 participants randomized, 794 took at least 1 dose of the study agent and were included in the primary analysis (397 in the placebo group and 397 in the metformin group). Participants' mean (SD) age was 32.9 (5.6) years; 234 (29%) were Black, and 412 (52%) were Hispanic. The composite adverse neonatal outcome occurred in 280 (71%) of the metformin group and in 292 (74%) of the placebo group (adjusted odds ratio, 0.86 [95% CI 0.63-1.19]). The most commonly occurring events in the primary outcome in both groups were preterm birth, neonatal hypoglycemia, and delivery of a large-for-gestational-age infant. The study was halted at 75% accrual for futility in detecting a significant difference in the primary outcome. Prespecified secondary outcomes and subgroup analyses were similar between groups. Of individual components of the composite adverse neonatal outcome, metformin-exposed neonates had lower odds to be large for gestational age (adjusted odds ratio, 0.63 [95% CI, 0.46-0.86]) when compared with the placebo group.

Conclusions and Relevance

Using metformin plus insulin to treat preexisting type 2 or gestational diabetes diagnosed early in pregnancy did not reduce a composite neonatal adverse outcome. The effect of reduction in odds of a large-for-gestational-age infant observed after adding metformin to insulin warrants further investigation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02932475.

Hypertensive disorders of pregnancy pre- and postaspirin guideline publication in individuals with pregestational diabetes mellitus

BACKGROUND

The US Preventive Services Taskforce published guidelines in 2014 recommending that low-dose aspirin be initiated between 12 and 28 weeks of gestation among high-risk patients for preeclampsia prophylaxis. Moreover, low-dose aspirin is recommended by some clinicians for the prevention of preterm birth.

OBJECTIVE

This study aimed to evaluate whether there is an association between the US Preventive Services Taskforce aspirin guideline hypertensive disorders of pregnancy and the rates of hypertensive disorders of pregnancy and preterm birth in individuals with pregestational diabetes mellitus.

STUDY DESIGN

This was a repeated cross-sectional analysis of individuals with pregestational diabetes mellitus and at least 1 singleton delivery at >20 weeks of gestation with records available in the National Vital Statistics System between 2010 and 2018. The primary outcome was hypertensive disorders of pregnancy, and the secondary outcome was preterm birth. Demographics and clinical characteristics among individuals in the pre-US Preventive Services Taskforce guideline cohort (2010-2013) were compared with that of individuals in the post-US Preventive Services Taskforce guideline cohort (2015-2018). Multivariable regression estimated the odds ratios and 95% confidence intervals for the association between guideline publication and the selected endpoints. Effect modification was assessed for access to prenatal care using the Kotelchuck Index (<80% vs ≥80%). Furthermore, a sensitivity analysis limited to nulliparas was performed.

RESULTS

Overall, 224,065 individuals were included. Individuals in the post-US Preventive Services Taskforce guideline cohort were more likely to be older, be obese, and have a history of preterm birth. In unadjusted and adjusted modeling, delivery in the post-US Preventive Services Taskforce guideline cohort was associated with hypertensive disorders of pregnancy (adjusted odds ratio, 1.25; 95% confidence interval, 1.22-1.28) and preterm birth (adjusted odds ratio, 1.10; 95% confidence interval, 1.08-1.12). The adjusted odds ratios for hypertensive disorders of pregnancy and preterm birth were more pronounced among those with less than adequate access to care. The findings were similar in the sensitivity analysis of only nulliparas.

CONCLUSION

Delivery after US Preventive Services Taskforce aspirin guideline publication was associated with higher rates of hypertensive disorders of pregnancy and preterm birth in a population of individuals with diabetes mellitus. It is unknown whether patient or practitioner factors, or other changes in obstetrical care, contributed to these findings.

Group B streptococcal infection of the genitourinary tract in pregnant and non-pregnant patients with diabetes mellitus: An immunocompromised host or something more?

Group B Streptococcus (GBS), also known as Streptococcus agalactiae is a Gram-positive bacterium commonly encountered as part of the microbiota within the human gastrointestinal tract. A common cause of infections during pregnancy, GBS is responsible for invasive diseases ranging from urinary tract infections to chorioamnionitis and neonatal sepsis. Diabetes mellitus (DM) is a chronic disease resulting from impaired regulation of blood glucose levels. The incidence of DM has steadily increased worldwide to affecting over 450 million people. Poorly controlled DM is associated with multiple health comorbidities including an increased risk for infection. Epidemiologic studies have clearly demonstrated that DM correlates with an increased risk for invasive GBS infections, including skin and soft tissue infections and sepsis in non-pregnant adults. However, the impact of DM on risk for invasive GBS urogenital infections, particularly during the already vulnerable time of pregnancy, is less clear. We review the evolving epidemiology, immunology, and pathophysiology of GBS urogenital infections including rectovaginal colonization during pregnancy, neonatal infections of infants exposed to DM in utero, and urinary tract infections in pregnant and non-pregnant adults in the context of DM and highlight in vitro studies examining why DM might increase risk for GBS urogenital infection.

Metformin Exposure and Risk of Hypertensive Disorders of Pregnancy in Patients with Type 2 Diabetes

OBJECTIVE

Metformin has been found to have a role in promoting vascular remodeling and angiogenesis which may reduce the risk of developing preeclampsia. Prior studies have shown a decrease in the incidence of hypertensive disorders of pregnancy in patients with type 2 and gestational diabetes taking metformin. We hypothesize metformin exposure decreases the risk of developing hypertension in patients with type 2 diabetes.

STUDY DESIGN

Retrospective cohort study from 2009 to 2019 of singleton pregnancies was complicated by type 2 diabetes. We compared patients who received metformin throughout pregnancy to those with no metformin exposure. The primary outcome was a hypertension composite defined as gestational hypertension, preeclampsia with or without severe features, HELLP syndrome, or eclampsia. Individual hypertensive outcomes and neonatal outcomes were secondarily evaluated. Logistic regression was used to adjust for confounding variables.

RESULTS

A total of 254 pregnancies were included. Women exposed to metformin were significantly less likely to develop hypertension composite compared with nonexposed women (22.7 vs. 33.1%, aOR 0.53, 95% CI 0.29-0.96). The incidence of preeclampsia with severe features was also significantly lower in those who received metformin compared with those who did not (12.1 vs. 20.7%, aOR 0.38, 95% CI 0.18-0.81). There were no differences in preterm birth prior to 34 or 37 weeks, fetal growth restriction, or birth weight between the study groups. A subgroup analysis of women without chronic hypertension also had a significantly lower risk of developing preeclampsia with severe features (7.6 vs. 17.8%, aOR 0.35, 95% CI 0.13-0.94).

CONCLUSION

Metformin exposure was associated with a decreased risk of composite hypertensive disorders of pregnancy in patients with pregestational type 2 diabetes. These data suggest that there may be benefit to metformin administration beyond glycemic control in this patient population.

KEY POINTS

· Metformin use showed a decreased risk of a hypertension composite.. · Results were consistent in patients without chronic hypertension.. · Metformin may show benefit beyond glycemic control in women with type 2 diabetes..

Gestational diabetes is associated with postpartum hemorrhage in Indigenous Australian women in the PANDORA study: A prospective cohort

OBJECTIVE

To assess associations of hyperglycemia in pregnancy with the risk of postpartum hemorrhage (PPH) in a prospective cohort of Indigenous and non-Indigenous women, compared with normoglycemia.

METHODS

Data were from 1102 (48% Indigenous) women of the Pregnancy And Neonatal Diabetes Outcomes in Remote Australia (PANDORA) Study. Age-adjusted associations of gestational diabetes mellitus (GDM) or pre-existing type 2 diabetes mellitus (T2DM), obstetric and demographic covariables with PPH (blood loss ≥500 ml) were assessed using logistic regression. Multivariable-adjusted models included Indigenous ethnicity, diabetes type and their interaction.

RESULTS

A higher proportion of Indigenous women developed PPH than non-Indigenous women (32% versus 22%; P < 0.001). Compared with non-Indigenous women with normoglycemia, risks of PPH for Indigenous women with GDM or T2DM were higher (odds ratio [OR] 1.83, 95% confidence intervals [CI] 1.11-3.02, and OR 1.72, 95% CI 0.99-3.00 after age adjustment, OR 1.84, 95% CI 1.06-3.19, and OR 1.33, 95% CI 0.70-2.54 after adjustment for school education and delivery mode, and OR 1.62, 95% CI 0.95-2.77, and OR 0.99, 95% CI 0.53-1.86 after adjustment for birth weight). Importantly, Indigenous women without hyperglycemia in pregnancy were not at increased risk of PPH.

CONCLUSION

The significantly higher rates of PPH experienced by Indigenous women compared with non-Indigenous women may be explained by a greater effect of GDM among Indigenous women that was only partly accounted for by birth weight.

Insulin-mediated immune dysfunction in the development of preeclampsia

Epidemiological observations implicate insulin resistance as a predisposing factor in the development of preeclampsia (PE). It is also well established that PE manifests in the context of a dysregulated immune response at the maternal-foetal interface, though all the underlying drivers of such immune dysregulation remains to be accounted for. Although it has long been known that various immune cells express insulin receptors following immune activation, it is only recently that insulin signalling has been shown to play a key role in immune cell differentiation, survival and effector function through its canonical activation of the PI3K/Akt/mTOR pathway. Here we argue that hyperinsulinemia, manifesting either from insulin resistance or from intensive insulin therapy, likely plays a direct role in driving immune cell dysfunction which plays a central role in the development of PE. This line of reasoning also explains the superior results of insulin-sparing interventions compared to intensive insulin therapy as monotherapy.

Twenty years of pediatric diabetes surveillance: what do we know and why it matters

SEARCH for Diabetes in Youth (SEARCH) was initiated in 2000 as a multicenter study to address major gaps in the understanding of childhood diabetes in the United States. An active registry of youth diagnosed with diabetes at age <20 years since 2002 assessed prevalence, annual incidence, and trends by age, race/ethnicity, sex, and diabetes type. An observational cohort nested within the population-based registry was established to assess the natural history and risk factors for acute and chronic diabetes-related complications, as well as the quality of care and quality of life of children and adolescents with diabetes from diagnosis into young adulthood. SEARCH findings have contributed to a better understanding of the complex and heterogeneous nature of youth-onset diabetes. Continued surveillance of the burden and risk of type 1 and type 2 diabetes is important to track and monitor incidence and prevalence within the population. SEARCH reported evidence of early diabetes complications highlighting that continuing the long-term follow-up of youth with diabetes is necessary to further our understanding of its natural history and to develop the most appropriate approaches to primary, secondary, and tertiary prevention of diabetes and its complications. This review summarizes two decades of research and suggests avenues for further work.

Insulin Dosing, Glycemic Control, and Perinatal Outcomes in Pregnancies Complicated by Type-2 Diabetes

OBJECTIVE

This study aimed to evaluate the prevalence of severe insulin resistance (insulin requirements ≥2 units/kg) at delivery and the relationship between severe insulin resistance, glycemic control, and adverse perinatal outcomes in pregnant women with type-2 diabetes mellitus.

STUDY DESIGN

This is a retrospective cohort study of women with type-2 diabetes mellitus who delivered between January 2015 and December 2017 at a tertiary academic medical center. Maternal demographic information, self-monitored blood sugars, and insulin doses were abstracted from the medical record. Multivariable logistic regression was used to identify maternal baseline characteristics associated with severe insulin resistance at delivery.

RESULTS

Overall 72/160 (45%) of women had severe insulin resistance. Women in the severe insulin resistance group demonstrated evidence of suboptimal glycemic control as evidenced by higher mean hemoglobin A1c (HbA1c) values (7.2 [ ±  1.1] vs. 6.6 [ ±  1.3%], p = 0.003), higher mean fasting (104.0 [ ±  17.4] vs. 95.2 [ ±  11.7 mg/dL], p < 0.001) and postprandial glucose values (132.4 [ ±  17.2] vs. 121.9 [ ± 16.9 mg/dL]), p < 0.001), and a higher percentage of total glucose values that were elevated above targets (37.7 [95% confidence interval (CI): 26.8-50] vs. 25.6 [95% CI: 13.3-41.3%], p < 0.001). Maternal HbA1c ≥6.5% and insulin use prior to pregnancy were associated with a higher prevalence of severe insulin resistance, while Hispanic ethnicity and non-White race were associated with a lower prevalence of severe insulin resistance. The rates of adverse perinatal outcomes including large for gestational age (LGA) birth weight, cesarean delivery, and hypertensive disorders of pregnancy did not differ between groups.

CONCLUSION

Severe insulin resistance is common among pregnant women with type-2 diabetes, and it is associated with suboptimal glycemic control. Future studies are necessary to develop strategies to identify women with severe insulin resistance early in pregnancy and facilitate adequate insulin dosing.

KEY POINTS

· Severe insulin resistance is common.. · BMI does not predict severe insulin resistance.. · Suboptimal glycemic control is common..

Association of Maternal Prepregnancy Diabetes and Gestational Diabetes Mellitus With Congenital Anomalies of the Newborn

OBJECTIVE

To examine the association of maternal prepregnancy diabetes, gestational diabetes mellitus (GDM), and 12 subtypes of congenital anomalies of the newborn.

RESEARCH DESIGN AND METHODS

We included 29,211,974 live births with maternal age ranging from 18 to 49 years old documented in the National Vital Statistics System in the U.S. from 2011 to 2018. Information on prepregnancy diabetes, GDM, and congenital anomalies was retrieved from birth certificates. Log-binomial regression was used to estimate risk ratios (RRs) and 95% CIs for congenital anomalies overall and by subtypes.

RESULTS

Of the 29,211,974 live births, there were 90,061 infants who had congenital anomalies identified at birth. The adjusted RRs of congenital anomalies at birth were 2.44 (95% CI 2.33-2.55) for prepregnancy diabetes and 1.28 (95% CI 1.24-1.31) for GDM. The associations were generally consistent across subgroups by maternal age, race/ethnicity, prepregnancy obesity status, and infant sex. For specific subtypes of congenital anomalies, maternal prepregnancy diabetes or GDM was associated with an increased risk of most subtypes. For example, the adjusted RRs of cyanotic congenital heart disease were 4.61 (95% CI 4.28-4.96) for prepregnancy diabetes and 1.50 (95% CI 1.43-1.58) for GDM; the adjusted RRs of hypospadias were 1.88 (95% CI 1.67-2.12) for prepregnancy diabetes and 1.29 (95% CI 1.21-1.36) for GDM.

CONCLUSIONS

Prepregnancy diabetes and, to a lesser extent, GDM were associated with several subtypes of congenital anomalies of the newborn. These findings suggest potential benefits of preconception counseling in women with preexisting diabetes or at risk for GDM for the prevention of congenital anomalies.

Effect of Metformin on a Preeclampsia-Like Mouse Model Induced by High-Fat Diet

BACKGROUND

Metformin has been reported to decrease insulin resistance and is associated with a lower risk of pregnancy-induced hypertension and preeclampsia. It is widely accepted that the placenta plays a crucial role in the development of preeclampsia. Our aim is to explore the effect of metformin on preeclampsia.

STUDY DESIGN

We examined control diet-fed (isocaloric diet) pregnant mice (CTRL group), pregnant mice fed a high-fat diet (HF group), and high-fat-diet-fed pregnant mice treated with metformin (HF-M group). The HF mice were fed a high-fat diet six weeks before pregnancy to establish a preeclampsia-like model; then, the group was randomly divided into a HF group and a HF-M group after pregnancy. Blood pressure, urine protein, pregnancy outcomes, protein expression, and histopathological changes in the placentas of all groups were examined and statistically analysed.

RESULTS

We observed that metformin significantly improved high blood pressure, proteinuria, and foetal and placental weights in the HF-M group compared with the HF group. Metformin significantly improved placental labyrinth and foetal vascular development in preeclampsia. In addition, metformin effectively increased matrix metalloproteinase-2 (MMP-2) and vascular endothelial growth factor (VEGF) levels in the placenta.

CONCLUSIONS

Our results suggest that metformin can improve preeclamptic symptoms and pregnancy outcomes.

Maternal and neonatal outcomes in Korean women with type 2 diabetes

BACKGROUND/AIMS

The purpose of this study was to compare maternal and neonatal outcomes in Korean women with type 2 diabetes and nondiabetic controls.

METHODS

We performed a retrospective survey of 200 pregnancies in women with type 2 diabetes (n = 100) and nondiabetic controls (n = 100) who delivered from 2003 to 2010 at Cheil General Hospital & Women's Healthcare Center, Korea. We compared maternal characteristics as well as maternal and neonatal outcomes between groups matched by age, pre-pregnancy weight, body mass index, parity, and gestational age at delivery.

RESULTS

The number of infants that were small for gestational age and the rate of major congenital malformations were not significantly different. However, women with type 2 diabetes showed a slightly higher risk for primary caesarean section (35.0% vs. 18.0%, p = 0.006) as well as pre-eclampsia (10.0% vs. 2.0%, p = 0.017), infections during pregnancy (26.0% vs. 2.0%, p < 0.001), neonatal weight (3,370 ± 552.0 vs. 3,196 ± 543.3, p = 0.025), large for gestational age (22.0% vs. 9.0%, p = 0.011), and macrosomia (15.0% vs. 5.0%, p = 0.018) compared to nondiabetic controls.

CONCLUSION

Maternal and neonatal outcomes for women with type 2 diabetes were worse than those for nondiabetic controls. Diabetic women have a higher risk for primary caesarean section, pre-eclampsia, infections during pregnancy, large neonatal birth weight, large for gestational age, and macrosomia.

Original Findings and Updated Meta-Analysis for the Association Between Maternal Diabetes and Risk for Congenital Heart Disease Phenotypes

Maternal diabetes is associated with congenital heart defects (CHDs) as a group, but few studies have assessed risk for specific CHD phenotypes. We analyzed these relationships using data from the Texas Birth Defects Registry and statewide vital records for deliveries taking place in 1999-2009 (n = 48,249 cases). We used Poisson regression to calculate prevalence ratios for the associations between maternal diabetes (pregestational or gestational) and each CHD phenotype, adjusting for potential confounders. Analyses were repeated by type of diabetes. To address the potential for misclassification bias, we performed logistic regression, using malformed controls. We also conducted meta-analyses, combining our estimates of the association between pregestational diabetes and each CHD phenotype with previous estimates. The prevalence of every CHD phenotype was greater among women with pregestational diabetes than among nondiabetic women. Most of these differences were statistically significant (adjusted prevalence ratios = 2.47-13.20). Associations were slightly attenuated for many CHD phenotypes among women with gestational diabetes. The observed associations did not appear to be the result of misclassification bias. In our meta-analysis, pregestational diabetes was significantly associated with each CHD phenotype. These findings contribute to a better understanding of the teratogenic effects of maternal diabetes and improved counseling for risk of specific CHD phenotypes.

Impact of type 2 diabetes, obesity and glycaemic control on pregnancy outcomes

BACKGROUND

There are no contemporary cohorts examining pregnancy outcomes in women with type 2 diabetes (T2D) in Australia.

AIM

To compare pregnancy outcomes in women with and without T2D, and assess effects of body mass index (BMI) and glycaemic control on outcomes.

MATERIALS AND METHODS

An historical cohort study was conducted of all singleton births > 20 weeks gestation at a specialist maternity network in Australia from 2010 to 2013. Data were extracted from the Birthing Outcomes System database. Multivariable logistic regression analysis was used to examine associations between presence of T2D and pregnancy outcomes.

RESULTS

Outcomes for 138 pregnancies with T2D and 27 075 pregnancies in women without diabetes were compared (type 1 diabetes and gestational diabetes excluded). Women with T2D were older and more overweight compared to women without diabetes (P < 0.01). Their babies were born earlier (P < 0.01) with increased risk of large for gestational age (adjusted odds ratio 2.13 (95% CI 1.37-3.32)), hypoglycaemia (4.90 (2.79-8.61)), jaundice (2.58 (1.61-4.13)) and shoulder dystocia (2.72 (1.09-6.78)), but not congenital malformations or perinatal death. Women with T2D had a higher risk of induction (4.03 (2.71-5.99)), caesarean section (2.10 (1.44-3.04)), preterm birth (2.74 (1.78-4.24)) and pre-eclampsia (2.75 (1.49-5.10)). An HbA1c ≥ 6.0% (42 mmol/mol) was associated with increased preterm birth, special care nursery admission, hypoglycaemia and jaundice.

CONCLUSIONS

Despite availability of preconception care, good glycaemic control and specialist management, T2D remains associated with increased adverse obstetric and neonatal outcomes. Further research to examine predictors of adverse outcomes may assist in targeted antenatal surveillance and management.

Metformin in women with type 2 diabetes in pregnancy (MiTy): a multi-center randomized controlled trial

Background

The incidence of type 2 diabetes in pregnancy is rising and rates of serious adverse maternal and fetal outcomes remain high. Metformin is a biguanide that is used as first-line treatment for non-pregnant patients with type 2 diabetes. We hypothesize that metformin use in pregnancy, as an adjunct to insulin, will decrease adverse outcomes by reducing maternal hyperglycemia, maternal insulin doses, maternal weight gain and gestational hypertension/pre-eclampsia. In addition, since metformin crosses the placenta, metformin treatment of the fetus may have a direct beneficial effect on neonatal outcomes. Our aim is to compare the effectiveness of the addition of metformin to insulin, to standard care (insulin plus placebo) in women with type 2 diabetes in pregnancy.

Methods

The MiTy trial is a multi-centre randomized trial currently enrolling pregnant women with type 2 diabetes, who are on insulin, between the ages of 18–45, with a gestational age of 6 weeks 0 days to 22 weeks 6 days. In this randomized, double-masked, parallel placebo-controlled trial, after giving informed consent, women are randomized to receive either metformin 1,000 mg twice daily or placebo twice daily. A web-based block randomization system is used to assign women to metformin or placebo in a 1:1 ratio, stratified for site and body mass index. The primary outcome is a composite neonatal outcome of pregnancy loss, preterm birth, birth injury, moderate/severe respiratory distress, neonatal hypoglycemia, or neonatal intensive care unit admission longer than 24 h. Secondary outcomes are large for gestational age, cord blood gas pH < 7.0, congenital anomalies, hyperbilirubinemia, sepsis, hyperinsulinemia, shoulder dystocia, fetal fat mass, as well as maternal outcomes: maternal weight gain, maternal insulin doses, maternal glycemic control, maternal hypoglycemia, gestational hypertension, preeclampsia, cesarean section, number of hospitalizations during pregnancy, and duration of hospital stays. The trial aims to enroll 500 participants.

Discussion

The results of this trial will inform endocrinologists, obstetricians, family doctors, and other healthcare professionals caring for women with type 2 diabetes in pregnancy, as to the benefits of adding metformin to insulin in this high risk population.

Trial registration

ClinicalTrials.gov Identifier: no. NCT01353391. Registered February 6, 2009.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-0954-4) contains supplementary material, which is available to authorized users.

The status of diabetic embryopathy

Diabetic embryopathy is a theoretical enigma and a clinical challenge. Both type 1 and type 2 diabetic pregnancy carry a significant risk for fetal maldevelopment, and the precise reasons for the diabetes-induced teratogenicity are not clearly identified. The experimental work in this field has revealed a partial, however complex, answer to the teratological question, and we will review some of the latest suggestions.

Associations between body mass index and maternal weight gain on the delivery of LGA infants in Chinese women with gestational diabetes mellitus

BACKGROUND

Women with gestational diabetes mellitus (GDM) are at increased risk for maternal and fetal complications including delivery of large for gestational age (LGA) infants. Maternal body mass index (BMI) and excessive weight gain during pregnancy are associated with delivery of LGA infants. However, whether maternal BMI and weight gain are associated with LGA infants in women with GDM is unclear.

BASIC PROCEDURES

Data on 1049 pregnant women who developed GDM were collected from a university teaching hospital in China and retrospectively analyzed. Data included maternal BMI, weight gain, incidence of LGA and gestational week at diagnosis.

MAIN FINDINGS

The incidence of LGA infants was significantly associated with maternal BMI (p=0.0002) in women with GDM. The odds of delivery of LGA for obese or overweight pregnant women are 3.8 or 2 times more than normal weight pregnant women. The incidence of LGA infants was also significantly associated with maternal weight gain in women with GDM. The odds ratio of delivery of LGA for pregnant women with excessive weight gain was 3.3 times more than pregnant women with normal weight gain. The effect of weight gain was not significantly different between different maternal BMI.

PRINCIPAL CONCLUSION

The incidence of delivery of LGA infants in Chinese women with GDM who were overweight or obese is higher than Caucasians, Hispanic, and Asian-Americans. The effects of maternal BMI and weight gain on the delivery of LGA infants by women with GDM are additive.

Expression and functional characterisation of System L amino acid transporters in the human term placenta

BACKGROUND

System L transporters LAT1 (SLC7A5) and LAT2 (SLC7A8) mediate the uptake of large, neutral amino acids in the human placenta. Many System L substrates are essential amino acids, thus representing crucial nutrients for the growing fetus. Both LAT isoforms are expressed in the human placenta, but the relative contribution of LAT1 and LAT2 to placental System L transport and their subcellular localisation are not well established. Moreover, the influence of maternal body mass index (BMI) on placental System L amino acid transport is poorly understood. Therefore the aims of this study were to determine: i) the relative contribution of the LAT isoforms to System L transport activity in primary human trophoblast (PHT) cells isolated from term placenta; ii) the subcellular localisation of LAT transporters in human placenta; and iii) placental expression and activity of System L transporters in response to maternal overweight/obesity.

METHODS

System L mediated leucine uptake was measured in PHT cells after treatment with si-RNA targeting LAT1 and/or LAT2. The localisation of LAT isoforms was studied in isolated microvillous plasma membranes (MVM) and basal membranes (BM) by Western blot analysis. Results were confirmed by immunohistochemistry in sections of human term placenta. Expression and activity System L transporters was measured in isolated MVM from women with varying pre-pregnancy BMI.

RESULTS

Both LAT1 and LAT2 isoforms contribute to System L transport activity in primary trophoblast cells from human term placenta. LAT1 and LAT2 transporters are highly expressed in the MVM of the syncytiotrophoblast layer at term. LAT2 is also localised in the basal membrane and in endothelial cells lining the fetal capillaries. Measurements in isolated MVM vesicles indicate that System L transporter expression and activity is not influenced by maternal BMI.

CONCLUSIONS

LAT1 and LAT2 are present and functional in the syncytiotrophoblast MVM, whereas LAT2 is also expressed in the BM and in the fetal capillary endothelium. In contrast to placental System A and beta amino acid transporters, MVM System L activity is unaffected by maternal overweight/obesity.

Comparing type 1 and type 2 diabetes in pregnancy- similar conditions or is a separate approach required?

BACKGROUND

Pregnancy in women with type 1 (T1DM) or type 2 diabetes (T2DM) is associated with increased risk. These conditions are managed similarly during pregnancy, and compared directly in analyses, however they affect women of different age, body mass index and ethnicity.

METHODS

We assess if differences exist in pregnancy outcomes between T1DM and T2DM by comparing them directly and with matched controls. We also analyze the effect of glycemic control on pregnancy outcomes and analyze predictive variables for poor outcome.

RESULTS

We include 323 women with diabetes and 660 glucose-tolerant controls. T2DM women had higher BMI, age and parity with a shorter duration of diabetes and better glycemic control. Preeclampsia occurred more in women with T1DM only. Rates of elective cesarean section were similar between groups but greater than in controls, emergency cesarean section was increased in women with type 1 diabetes. Maternal morbidity in T1DM was double that of matched controls but T2DM was similar to controls. Babies of mothers with diabetes were more likely to be delivered prematurely. Neonatal hypoglycemia occurred more in T1DM than T2DM and contributed to a higher rate of admission to neonatal intensive care for both groups. Adverse neonatal outcomes including stillbirths and congenital abnormalities were seen in both groups but were more common in T1DM pregnancies. HbA1C values at which these poor outcomes occurred differed between T1 and T2DM.

CONCLUSIONS

Pregnancy outcomes in T1DM and T2DM are different and occur at different levels of glycemia. This should be considered when planning and managing pregnancy and when counseling women.

Preeclampsia and diabetes

Preeclampsia is diagnosed in women presenting with new onset hypertension accompanied by proteinuria or other signs of severe organ dysfunction in the second half of pregnancy. Preeclampsia risk is increased 2- to 4-fold among women with type 1 or type 2 diabetes. The limited number of pregnant women with preexisting diabetes and the difficulties associated with diagnosing preeclampsia in women with proteinuria prior to pregnancy are significant barriers to research in this high-risk population. Gestational diabetes mellitus (GDM) also increases preeclampsia risk, although it is unclear whether these two conditions share a common pathophysiological pathway. Nondiabetic women who have had preeclampsia are more likely to develop type 2 diabetes later in life. Among women with type 1 diabetes, a history of preeclampsia is associated with an increased risk of retinopathy and nephropathy. More research examining the pathophysiology, treatment, and the long-term health implications of preeclampsia among women with preexisting and gestational diabetes is needed.

Diabetes and congenital heart defects: a systematic review, meta-analysis, and modeling project

CONTEXT

Maternal pregestational diabetes (PGDM) is a risk factor for development of congenital heart defects (CHDs). Glycemic control before pregnancy reduces the risk of CHDs. A meta-analysis was used to estimate summary ORs and mathematical modeling was used to estimate population attributable fractions (PAFs) and the annual number of CHDs in the U.S. potentially preventable by establishing glycemic control before pregnancy.

EVIDENCE ACQUISITION

A systematic search of the literature through December 2012 was conducted in 2012 and 2013. Case-control or cohort studies were included. Data were abstracted from 12 studies for a meta-analysis of all CHDs.

EVIDENCE SYNTHESIS

Summary estimates of the association between PGDM and CHDs and 95% credible intervals (95% CrIs) were developed using Bayesian random-effects meta-analyses for all CHDs and specific CHD subtypes. Posterior estimates of this association were combined with estimates of CHD prevalence to produce estimates of PAFs and annual prevented cases. Ninety-five percent uncertainty intervals (95% UIs) for estimates of the annual number of preventable cases were developed using Monte Carlo simulation. Analyses were conducted in 2013. The summary OR estimate for the association between PGDM and CHDs was 3.8 (95% CrI=3.0, 4.9). Approximately 2670 (95% UI=1795, 3795) cases of CHDs could potentially be prevented annually if all women in the U.S. with PGDM achieved glycemic control before pregnancy.

CONCLUSIONS

Estimates from this analysis suggest that preconception care of women with PGDM could have a measureable impact by reducing the number of infants born with CHDs.

Diabetes in pregnancy: timing and mode of delivery

Diabetes in pregnancy represents a risk condition for adverse maternal and feto-neonatal outcomes and many of these complications might occur during labor and delivery. In this context, the obstetrician managing women with pre-existing and gestational diabetes should consider (1) how these conditions might affect labor and delivery outcomes; (2) what are the current recommendations on management; and (3) which other factors should be considered to decide about the timing and mode of delivery. The analysis of the studies considered in this review leads to the conclusion that the decision to deliver should be primarily intended to reduce the risk of stillbirth, macrosomia, and shoulder dystocia. In this context, this review provides useful information for managing specific subgroups of diabetic women that may present overlapping risk factors, such as women with insulin-requiring diabetes and/or obesity and/or prenatal suspicion of macrosomic fetus. To date, the lack of definitive evidences and the complexity of the problem suggest that the "appropriate" clinical management should be customized according with the clinical condition, the type and mode of intervention, its consequences on outcomes, and considering the woman's consent and informed decisions.

The effect of maternal body mass index on perinatal outcomes in women with diabetes

OBJECTIVE

To determine the effect of increasing maternal obesity, including superobesity (body mass index [BMI] ≥ 50 kg/m2), on perinatal outcomes in women with diabetes.

STUDY DESIGN

Retrospective cohort study of birth records for all live-born nonanomalous singleton infants ≥ 37 weeks' gestation born to Missouri residents with diabetes from 2000 to 2006. Women with either pregestational or gestational diabetes were included.

RESULTS

There were 14,595 births to women with diabetes meeting study criteria, including 7,082 women with a BMI > 30 kg/m2 (48.5%). Compared with normal-weight women with diabetes, increasing BMI category, especially superobesity, was associated with a significantly increased risk for preeclampsia (adjusted relative risk [aRR] 3.6, 95% confidence interval [CI] 2.5, 5.2) and macrosomia (aRR 3.0, 95% CI 1.8, 5.40). The majority of nulliparous obese women with diabetes delivered via cesarean including 50.5% of obese, 61.4% of morbidly obese, and 69.8% of superobese women. The incidence of primary elective cesarean among nulliparous women with diabetes increased significantly with increasing maternal BMI with over 33% of morbidly obese and 39% of superobese women with diabetes delivering electively by cesarean.

CONCLUSION

Increasing maternal obesity in women with diabetes is significantly associated with higher risks of perinatal complications, especially cesarean delivery.

Perinatal outcomes in type 2 diabetes

Over the past decade the prevalence of type 2 diabetes in pregnancy has continued to increase. It is vital that health care professionals recognize that preconception care is just as important for mothers with type 2 diabetes as it is in type 1 diabetes. All women with type 2 diabetes should be advised regarding safe effective contraception and the benefits of optimal glycemic control, folic acid supplementation, and avoidance of potentially harmful mediations before attempting pregnancy. Glycemic control is the most important modifiable risk factor for congenital anomaly in women with type 2 diabetes, whereas maternal obesity and social disadvantage are associated with large for gestational age neonates. This review aims to bring the reader up to date with the burden of perinatal outcomes and clinical interventions to improve maternal and infant health. It warns that the consequences of type 2 diabetes pregnancy do not end at birth.

Association between neonatal hypoglycaemia and prediabetes in postpartum women with a history of gestational diabetes

AIMS AND OBJECTIVES

To determine the association between hypoglycaemia among neonates born to mothers with gestational diabetes mellitus and their postpartum prediabetes.

BACKGROUND

Infants born to mothers with diabetes who experienced hyperglycaemia are more likely to develop hypoglycaemia.

DESIGN

A prospective-descriptive research was conducted in three tertiary hospitals in southern Thailand.

METHODS

One hundred and fifty matched pairs of mothers and their newborns were included in the study. Data were analysed using descriptive statistic, odds ratio, Spearman's rho correlation and binary logistic regression.

RESULTS

The incidence of neonatal hypoglycaemia was 42·37% and odds ratio was 0·30. The findings showed the significant association between neonatal hypoglycaemia and postpartum blood sugar levels of women with a history of gestational diabetes mellitus.

CONCLUSIONS

Neonatal hypoglycaemia was associated with maternal hyperglycaemia and prediabetes.

RELEVANCE TO CLINICAL PRACTICE

Neonatal hypoglycaemia might be used to predict prediabetes of postpartum women with a history of gestational diabetes mellitus.