Timing of delivery in women with diabetes in pregnancy

Systematic review of the use of metformin compared to insulin for the management of gestational diabetes: Implications for low-resource settings

Introduction

This systematic review examines the effectiveness of metformin treatment compared to insulin treatment for gestational diabetes within the context of a low-resource environment.

Methods

Electronic data searches of Medline, EMBASE, Scopus and Google scholar databases from 1 January, 2005 to 30 June, 2021 were performed using medical subject headings: 'gestational diabetes or pregnancy diabetes mellitus' AND 'Pregnancy or pregnancy outcomes' AND 'Insulin' AND 'Metformin Hydrochloride Drug Combination/or Metformin/or Hypoglycemic Agents' AND 'Glycemic control or blood glucose'. Randomized controlled trials were included if: participants were pregnant women with gestational diabetes mellitus (GDM); the interventions were metformin and/or insulin. Studies among women with pre-gestational diabetes, non-randomised control trials or studies with a limited description of the methodology were excluded. Outcomes included adverse maternal outcomes: weight gain, C-section, pre-eclampsia and glycaemic control and adverse neonatal outcomes: birth weight, macrosomia, pre-term birth and neonatal hypoglycaemia. The revised Cochrane Risk of Bias Assessment for randomised trials was used for the evaluation of bias.

Results

We screened 164 abstracts and 36 full-text articles. Fourteen studies met the inclusion criteria. The studies provide moderate to high-quality evidence demonstrating the effectiveness of metformin as an alternative therapy to insulin. Risk of bias was low; multiple countries and robust sample sizes improved external validity. All studies were from urban centres with no rural data.

Conclusion

These recent high quality studies comparing metformin to insulin for the treatment of GDM generally found either improved or equivalent pregnancy outcome and good glycaemic control for most patients, although many required insulin supplementation. Its ease of use, safety and efficacy suggest metformin may simplify the management of gestational diabetes, particularly in rural and other low-resource environments.

The Effects of Gestational Diabetes on Fetus: A Surveillance Study

INTRODUCTION

Gestational diabetes is an intolerance to glucose diagnosed during pregnancy that goes away postpartum. Gestational diabetes may result in outcomes such as birth trauma, increased rates of cesarean sections, and macrosomia. This study aims to determine the outcomes of gestational diabetes mellitus (GDM) on maternal and fetal health in a tertiary care hospital setting.

MATERIALS AND METHODS

This is a retrospective study of 52 patients who presented with gestational diabetes mellitus (GDM) and were treated at Tentishev Satkynbai Memorial Asian Medical Institute, Kyrgyzstan, between April 2021 and January 2022. The information was taken from the medical records of the patients. The baby's age, the mother's body mass index (BMI), history of pregnancy, deaths, birth weight, and the number of births were all taken into account.

RESULTS

Out of all the cases during the study period at the Tentishev Satkynbai Memorial Asian Medical Institute, Kyrgyzstan, 52 were found to be complicated with gestational diabetes mellitus, which is 2.7% of the total deliveries. There was a significant difference found among both study groups in gestational age and history of GDM. The neonatal intensive care unit (NICU) admission rate of neonates born to GDM mothers was found to be significant with a difference of 10.9% (p < 0.0003), which is higher compared to the control group.

CONCLUSION

Incidences of macrosomia, NICU admissions of preterm babies, and large for gestational age (LGA) and increased rates of hypertensive disorders were found among GDM pregnancies compared to control cases. The study shows higher rates of maternal and fetal/neonatal complications in females with GDM.

Maternal and Fetal Outcomes in Women with Diabetes in Pregnancy Treated before and after the Introduction of a Standardized Multidisciplinary Management Protocol

BACKGROUND

Diabetes in pregnancy is associated with an increased risk to the woman and to the developing fetus. Currently, there is no consensus on the optimal management strategies for the follow-up and the timing of delivery of pregnancies affected by gestational and pregestational diabetes, with different international guidelines suggesting different management options.

MATERIALS AND METHODS

We conducted a retrospective cohort study from January 2017 to January 2021, to compare maternal and neonatal outcomes of pregnancies complicated by gestational and pregestational diabetes, followed-up and delivered in a third level referral center before and after the introduction of a standardized multidisciplinary management protocol including diagnostic, screening, and management criteria.

RESULTS

Of the 131 women included, 55 were managed before the introduction of the multidisciplinary management protocol and included in group 1 (preprotocol), while 76 were managed according to the newly introduced multidisciplinary protocol and included in group 2 (after protocol). We observed an increase in the rates of vaginal delivery, rising from 32.7% to 64.5% (<0.001), and the rate of successful induction of labor improved from 28.6% to 86.2% (P < 0.001). No differences were found in neonatal outcomes, and the only significant difference was demonstrated for the rates of fetal macrosomia (20% versus 5.3%, P: 0.012). Therefore, the improvements observed in the maternal outcomes did not impact negatively on fetal and neonatal outcomes.

CONCLUSION

The introduction of a standardized multidisciplinary management protocol led to an improvement in the rates of vaginal delivery and in the rate of successful induction of labor in our center. A strong cooperation between obstetricians, diabetologists, and neonatologists is crucial to obtain a successful outcome in women with diabetes in pregnancy.

Optimizing Term Delivery and Mode of Delivery

Full-term deliveries are defined as occurring between 39 weeks and 40 weeks and 6 days. Because contemporary research suggests improved outcomes with delivery in the term period compared with the early term period, nonindicated delivery should be pursued no earlier than 39 weeks. There are, however, multiple medical, obstetric, and fetal indications for delivery before 39 weeks, and the obstetric provider must weigh the risks and benefits of delivery versus expectant management on both the mother and fetus. This review serves to provide a basic framework of evidentiary support toward optimizing the term delivery.

Metabolic profiling of pre-gestational and gestational diabetes mellitus identifies novel predictors of pre-term delivery

Background

Pregnant women with gestational diabetes mellitus (GDM) or type 2 diabetes mellitus (T2DM) are at increased risks of pre-term labor, hypertension and preeclampsia. In this study, metabolic profiling of blood samples collected from GDM, T2DM and control pregnant women was undertaken to identify potential diagnostic biomarkers in GDM/T2DM and compared to pregnancy outcome.

Methods

Sixty-seven pregnant women (21 controls, 32 GDM, 14 T2DM) in their second trimester underwent targeted metabolomics of plasma samples using tandem mass spectrometry with the Biocrates MxP^® Quant 500 Kit. Linear regression models were used to identify the metabolic signature of GDM and T2DM, followed by generalized linear model (GLMNET) and Receiver Operating Characteristic (ROC) analysis to determine best predictors of GDM, T2DM and pre-term labor.

Results

The gestational age at delivery was 2 weeks earlier in T2DM compared to GDM and controls and correlated negatively with maternal HbA1C and systolic blood pressure and positively with serum albumin. Linear regression models revealed elevated glutamate and branched chain amino acids in GDM + T2DM group compared to controls. Regression models also revealed association of lower levels of triacylglycerols and diacylglycerols containing oleic and linoleic fatty acids with pre-term delivery. A generalized linear model ROC analyses revealed that that glutamate is the best predictors of GDM compared to controls (area under curve; AUC = 0.81). The model also revealed that phosphatidylcholine diacyl C40:2, arachidonic acid, glycochenodeoxycholic acid, and phosphatidylcholine acyl-alkyl C34:3 are the best predictors of GDM + T2DM compared to controls (AUC = 0.90). The model also revealed that the triacylglycerols C17:2/36:4 and C18:1/34:1 are the best predictors of pre-term delivery (≤ 37 weeks) (AUC = 0.84).

Conclusions

This study highlights the metabolite alterations in women in their second trimester with diabetes mellitus and identifies predictive indicators of pre-term delivery. Future studies to confirm these associations in other cohorts and investigate their functional relevance and potential utilization for targeted therapies are warranted.

Characterization of women with gestational diabetes who failed to achieve glycemic control by lifestyle modifications

PURPOSE

To identify specific characteristics of women diagnosed with gestational diabetes who failed to achieve good glycemic control by lifestyle modifications only.

METHODS

Retrospective analysis of women carrying a singleton pregnancy diagnosed with gestational diabetes. The cohort included 314 women who achieved good glycemic control by lifestyle modifications and 328 women who required anti-diabetic medications. Lifestyle modifications included medical nutrition therapy and physical exercise recommendations. Anti-diabetic medications included either oral treatment with metformin or glyburide and\or insulin.

RESULTS

Women in the lifestyle modifications group were younger (32.87 vs. 33.79 years, p = 0.012) and had lower pre-pregnancy body-mass-index (25.86 vs. 27.93 kg/m², p < 0.001). Glucose challenge test (GCT) was significantly lower in the lifestyle modifications group (158.31 vs. 171.04 mg/dL in the anti-diabetic treatment group, p < 0.001). Moreover, fasting oral-glucose-tolerance-test (fOGTT) results were significantly lower in the lifestyle modifications group (88.22 vs. 96.34 mg/dL in the anti-diabetic treatment group, p < 0.001). In a receiver-operator-curve analysis, GCT + 4*fOGTT, was the best model to predict lifestyle modifications failure with an area under the curve of 0.7419. Higher rates of vaginal delivery and lower rates of maternal hypoglycemia in the lifestyle modifications group were observed.

CONCLUSIONS

Maternal baseline characteristics and diabetes diagnostic parameters may predict which women will fail to achieve good glycemic control solely by lifestyle modifications.

Time trends in pregnancy-related outcomes among women with type 1 diabetes mellitus, 2004-2017

OBJECTIVE

To examine time trends in US pregnant women with type 1 diabetes mellitus for maternal characteristics and pregnancy outcomes.

STUDY DESIGN

We abstracted clinical data from the medical records of 700 pregnant women from 2004 to 2017. For each time period, means and percentages were calculated. P values for trend were calculated using linear and logistic regression.

RESULTS

HbA1c in each trimester was unchanged across the analysis period. The prevalence of nephropathy decreased from 4.8% to 0% (P = 0.002). Excessive gestational weight gain increased (P = 0.01). Gestation length also increased (P = 0.01), as did vaginal deliveries (P = 0.03). There were no change in birthweight over time (P = 0.07) and the percentage of neonates with macrosomia and large for gestational age (LGA) neonates also remained unchanged.

CONCLUSION

Obstetric guideline changes may have improved gestation length and mode of delivery; however, other outcomes need more attention, including excessive gestational weight gain, macrosomia, and LGA.

Adverse Maternal Outcomes of Fijian Women with Gestational Diabetes Mellitus and the Associated Risk Factors

The purpose of this study is to determine the factors associated with adverse maternal outcomes in pregnancies complicated by gestational diabetes mellitus (GDM) in urban Fiji. This cross-sectional study used data from existing records of singleton pregnant women with GDM attending the Colonial War Memorial Hospital (CWMH) Suva Fiji between June 2013 and May 2014. Data retrieved included demographic data, antenatal and intrapartum care data, route of delivery, treatment modality, and maternal risk factors. The prevalence of GDM is 3.0%, n = 255/8698, and the most frequent maternal complications were induction of labor (66%), C-section (32%), and preeclampsia (19%), and 25% had babies with birthweight > 4 kg. Older women (≥ 36 years) and those treated with insulin were 5.2 times and 10.7 times, respectively, more likely to have labor induction during childbirth compared with younger women and those on dietary management. Family history of diabetes was associated with 2.4× and/or 2.5× higher odds of cesarean delivery and/or develop hypertension in pregnancy, respectively. Parity > 5 children and diagnoses of GDM after the first trimester reduced the odds of cesarean delivery. The odds of developing preeclampsia in GDM was 3.4 times higher (95% confidence interval (CI) of adjusted odds ratio (aOR): 1.03, 18.78) among obese women than normal-weight women, and married women were less likely to have babies with birthweight > 4 kg. The prevalence of and adverse outcomes among women with GDM attending antenatal public health care in Suva Fiji were higher than previously reported from the hospital. Older and multiparous women with GDM, those insulin treated, and with a strong family history and high body mass index (BMI) need special attention and better monitoring by health care personnel to reduce adverse outcomes during pregnancy.

Trends in the incidence of fetal macrosomia and its phenotypes in the United States, 1971-2017

PURPOSE

Studies have reported a surge in the prevalence of obesity among various demographic groups including pregnant women in the U.S. Given the association between maternal obesity and risk of fetal macrosomia, we hypothesized that the incidence of fetal macrosomia will be on the rise in the U.S. We examined trends in fetal macrosomia and macrosomia phenotypes in the U.S. among singleton live births within the gestational age of 28-42 weeks inclusive.

METHODS

This was a retrospective cohort study covering the period 1971-2017 using U.S. Natality Data files. We applied Joinpoint regression models to derive the average annual percentage change in the outcome. We measured incidence and trends of fetal macrosomia which was defined as birth weight ≥ 4000 g. We further subdivided macrosomia into its phenotypes as previously recommended: Grade 1 (4000-4499 g), Grade 2 (4500-4999 g) and Grade 3 (≥ 5000 g).

RESULTS

A total of 147,331,305 singleton births over the entire study period of 47 years were analyzed. From a baseline incidence of 8.84%, the rate of fetal macrosomia declined to 8.07% by the end of the study representing a drop of 8.70% in relative terms. The greatest drop was among infants with Grade 3 macrosomia, the most severe and lethal phenotype. The most impactful factors were maternal age and gestational weight gain.

CONCLUSION

This study is the largest population-based study conducted regarding fetal macrosomia. The rate of fetal macrosomia declined over the previous 5 decades with the most substantial drop observed in the phenotype with the worst prognosis.

Pregestational Diabetes in Pregnancy

Diabetes is a common chronic condition in women of reproductive age. Preconception care is crucial to reducing the risk of adverse maternal and fetal outcomes, such as hypertensive disorders, abnormal fetal growth, traumatic delivery and stillbirth, associated with poor glycemic control. Insulin is the preferred medication to optimize glucose control in women with pregestational diabetes. Frequent dose adjustments are needed during pregnancy to achieve glycemic goals, and team-based multidisciplinary care may help. Postpartum care should include lactation support, counseling on contraceptive options, and transition to primary care.

Optimal Obstetric Management for Women with Diabetes: the Benefits and Costs of Fetal Surveillance

PURPOSE OF REVIEW

To elaborate on the risks and benefits associated with antenatal fetal surveillance for stillbirth prevention in women with diabetes.

RECENT FINDINGS

Women with pregestational diabetes have a 3- to 5-fold increased odds of stillbirth compared to women without diabetes. The stillbirth risk in women with gestational diabetes (GDM) is more controversial; while recent data suggest the odds for stillbirth are approximately 50% higher in women with GDM at term (37 weeks and beyond) than in those without GDM, it is unclear if this risk is seen in women with optimal glycemic control. Current professional society guidelines are broad with respect to fetal testing strategies and delivery timing in women with diabetes. The data supporting strategies to reduce the risk of stillbirth in women with diabetes are limited. Antepartum fetal surveillance should be performed to reduce stillbirth rates; however, the optimal test, frequency of testing, and delivery timing are not yet clear. Future studies of obstetric management for women with diabetes should consider not just individual but also system level costs and benefits associated with antenatal surveillance.

GWAS on prolonged gestation (post-term birth): analysis of successive Finnish birth cohorts

Background

Gestation is a crucial timepoint in human development. Deviation from a term gestational age correlates with both acute and long-term adverse health effects for the child. Both being born preterm and post-term, that is, having short and long gestational ages, are heritable and influenced by the prenatal and perinatal environment. Despite the obvious heritable component, specific genetic influences underlying differences in gestational age are poorly understood.

Methods

We investigated the genetic architecture of gestational age in 9141 individuals, including 1167 born post-term, across two Northern Finland cohorts born in 1966 or 1986.

Results

Here we identify one globally significant intronic genetic variant within the ADAMTS13 gene that is associated with prolonged gestation (p=4.85×10−8). Additional variants that reached suggestive levels of significance were identified within introns at the ARGHAP42 and TKT genes, and in the upstream (5’) intergenic regions of the B3GALT5 and SSBP2 genes. The variants near the ADAMTS13, B3GALT5, SSBP2 and TKT loci are linked to alterations in gene expression levels (cis-eQTLs). Luciferase assays confirmed the allele specific enhancer activity for the BGALT5 and TKT loci.

Conclusions

Our findings provide the first evidence of a specific genetic influence associated with prolonged gestation. This study forms a foundation for a better understanding of the genetic and long-term health risks faced by induced and post-term individuals. The long-term risks for induced individuals who have a previously overlooked post-term potential may be a major issue for current health providers.