Potentially modifiable risk factors of preterm delivery in women with type 1 and type 2 diabetes

Preterm delivery and maternal obesity remain common complications in pregnancies with type 1 diabetes-A nationwide study in Sweden

AIM

A primary goal of obstetric care of women with type 1 diabetes (T1D) is to reduce the risks of preterm birth (PTB). Besides hyperglycaemia, maternal obesity is an important risk factor for PTB in T1D. However, it's unclear if public health efforts decreased risks of maternal obesity and PTB in pregnancies with T1D. We examined time-trends over the last 20 years in the distribution of gestational ages at birth (GA) in offspring of women with T1D in Sweden, and in maternal BMI in the same mothers.

METHODS

Population-based cohort study, using data from national registries in Sweden. To capture differences not only in the median values, we used quantile regression models to compare the whole distributions of GA's and early pregnancy BMI between deliveries in 1998-2007 (P1) and 2008-2016 (P2). Multivariable models were adjusted for differences in maternal age, smoking and education between periods 1 and 2.

RESULTS

The study included 7639 offspring of women with T1D between 1998 and 2016. The 10% percentile GA, increased with 0.09 days (95% CI: -0.11 to 0.35) between P1 and P2. The 90% percentile for BMI was 1.20 kg/m2 higher (95% CI: 0.57 to 1.83) in P2. Risks of PTB remained stable over time also when adjusting for maternal BMI.

CONCLUSION

Despite modern diabetes management, the distribution of GA, and consequently the risk of PTB in T1D, remained unchanged from 1998 to 2016. During the same time, maternal BMI increased, particularly in the already obese.

Prematurity and congenital malformations differ according to the type of pregestational diabetes

BACKGROUND

Diabetes mellitus (DM) is the most common metabolic disorder in pregnancy. Women with Type 2 DM seems to have no better perinatal outcomes than those with Type 1 DM.

METHODS

Single-center prospective cohort observational study. Pregnant women with diabetes (141 with Type 1 DM and 124 with Type 2 DM) that were followed in the university hospital between 2009 and 2021 were included in this study. Clinical data and obstetric and perinatal outcomes were collected.

RESULTS

As expected, women with Type 1 DM were younger and had a longer duration of diabetes than women with Type 2 DM. Obesity and chronic hypertension were higher in the group of women with Type 2 DM and their value of HbA1c in the second and third trimesters were lower than in Type 1 DM. No differences in prematurity were found, but more extreme prematurity was observed in Type 2 DM, as well as a higher rate of congenital malformations. The frequency of hypoglycemia and the weight of the newborn was higher in Type 1 DM. The maternal independent factors related to the weight of the newborn were: the glycemic control at the third trimester, the weight gain during pregnancy, and pregestational BMI.

CONCLUSIONS

Newborns born to mothers with Type 1 DM were larger and had a higher frequency of hypoglycemia, while congenital malformations and precocious preterm was more associated to Type 2 DM. Metabolic control, weight gain and pregestational weight were important determinants of both obstetric and neonatal complications.

Mean Glucose and Gestational Weight Gain as Predictors of Large-for-Gestational-Age Infants in Pregnant Women with Type 1 Diabetes Using Continuous Glucose Monitoring

Aims/hypothesis: To compare glycemic metrics during pregnancy between women with type 1 diabetes (T1D) delivering large-for-gestational-age (LGA) and appropriate-for-gestational-age (AGA) infants, and to identify predictors of LGA infants. Materials and Methods: A cohort study including 111 women with T1D using intermittently scanned continuous glucose monitoring from conception until delivery. Average sensor-derived metrics: mean glucose, time in range in pregnancy (TIRp), time above range in pregnancy, time below range in pregnancy, and coefficient of variation throughout pregnancy and in pregnancy intervals of 0-10, 11-21, 22-33, and 34-37 weeks were compared between women delivering LGA and AGA infants. Predictors of LGA infants were sought for. Infant growth was followed until 3 months postdelivery. Results: In total, 53% (n = 59) delivered LGA infants. Mean glucose decreased during pregnancy in both groups, with women delivering LGA infants having a 0.4 mmol/L higher mean glucose from 11-33 weeks (P = 0.01) compared with women delivering AGA infants. Mean TIRp >70% was obtained from 34 weeks in women delivering LGA infants and from 22-33 weeks in women delivering AGA infants. Independent predictors for delivering LGA infants were mean glucose throughout pregnancy and gestational weight gain. At 3 months postdelivery, infant weight was higher in infants born LGA compared with infants born AGA (6360 g ± 784 and 5988 ± 894, P = 0.04). Conclusions/interpretations: Women with T1D delivering LGA infants achieved glycemic targets later than women delivering AGA infants. Mean glucose and gestational weight gain were independent predictors for delivering LGA infants. Infants born LGA remained larger postdelivery compared with infants born AGA.

Fetal Overgrowth and Preterm Delivery in Women With Type 1 Diabetes Using Insulin Pumps or Multiple Daily Injections: A Post Hoc Analysis of the EVOLVE Study Cohort

OBJECTIVE

To compare the risk of fetal overgrowth and preterm delivery in pregnant women with type 1 diabetes (T1D) treated with insulin pumps versus multiple daily injections (MDI) and examine whether possible differences were mediated through improved glycemic control or gestational weight gain during pregnancy.

RESEARCH DESIGN AND METHODS

The risk of pregnancy and perinatal outcomes were evaluated in a cohort of 2,003 pregnant women with T1D enrolled from 17 countries in a real-world setting during 2013-2018.

RESULTS

In total, 723 women were treated with pumps and 1,280 with MDI. At inclusion (median gestational weeks 8.6 [interquartile range 7-10]), pump users had lower mean HbA1c (mean ± SD 50.6 ± 9.8 mmol/mol [6.8 ± 0.9%] vs. 53.6 ± 13.8 mmol/mol [7.1 ± 1.3%], P < 0.001), longer diabetes duration (18.4 ± 7.8 vs. 14.4 ± 8.2 years, P < 0.001), and higher prevalence of retinopathy (35.3% vs. 24.4%, P < 0.001). Proportions of large for gestational age (LGA) offspring and preterm delivery were 59.0% vs. 52.2% (adjusted odds ratio [OR] 1.36 [95% CI 1.09; 1.70], P = 0.007) and 39.6% vs. 32.1% (adjusted OR 1.46 (95% CI 1.17; 1.82), P < 0.001), respectively. The results did not change after adjustment for HbA1c or gestational weight gain.

CONCLUSIONS

Insulin pump treatment in pregnant women with T1D, prior to the widespread use of continuous glucose monitoring or automated insulin delivery, was associated with a higher risk of LGA offspring and preterm delivery compared with MDI in crude and adjusted analyses. This association did not appear to be mediated by differences in glycemic control as represented by HbA1c or by gestational weight gain.

Evaluating the effect of maternal non-communicable disease on adverse pregnancy outcomes and birthweight in Pakistan, a facility based retrospective cohort study

Non-communicable diseases (NCDs) claim 74% of global lives, disproportionately affecting lower and middle-income countries like Pakistan. NCDs may increase the risk of preterm birth (PTB), caesarean section (CS), and low birthweight. This study aims to determine whether the high prevalence of NCDs in Pakistan play a role in the high rates of preterm births, and CS. This retrospective cohort study from Aga Khan University Hospital, Pakistan, investigated effects of pre-existing NCDs on pregnancy outcomes of 817 pregnant women. Medical records were used to generate odds ratios for the risk of PTB, labour outcome and birthweight in women with type 1 and type 2 diabetes, hypertension, asthma and thyroid disorders. Multinomial logistic regression and general linear models were used to adjust for confounding variables using IBM SPSS Statistics (v27). Type 2 diabetes significantly increased the risk of PTB and elective CS (both P < 0.05). Elective CS was significantly increased by hypertension and asthma (both, P < 0.05). Surprisingly, asthma halved the risk of PTB (P < 0.05), while type 1 diabetes significantly increased birthweight from 2832 to 3253g (P < 0.001). In conclusion, pre-existing NCDs increase the risk of negative pregnancy outcomes, including PTB, elective CS and birthweight. Asthma, however reduced PTB and justifies further investigation.

Prediction and prevention of preeclampsia in women with preexisting diabetes: the role of home blood pressure, physical activity, and aspirin

Women with type 1 or type 2 (preexisting) diabetes are four times more likely to develop preeclampsia compared with women without diabetes. Preeclampsia affects 9%-20% of pregnant women with type 1 diabetes and 7%-14% of pregnant women with type 2 diabetes. The aim of this narrative review is to investigate the role of blood pressure (BP) monitoring, physical activity, and prophylactic aspirin to reduce the prevalence of preeclampsia and to improve pregnancy outcome in women with preexisting diabetes. Home BP and office BP in early pregnancy are positively associated with development of preeclampsia, and home BP and office BP are comparable for the prediction of preeclampsia in women with preexisting diabetes. However, home BP is lower than office BP, and the difference is greater with increasing office BP. Daily physical activity is recommended during pregnancy, and limiting sedentary behavior may be beneficial to prevent preeclampsia. White coat hypertension in early pregnancy is not a clinically benign condition but is associated with an elevated risk of developing preeclampsia. This renders the current strategy of leaving white coat hypertension untreated debatable. A beneficial preventive effect of initiating low-dose aspirin (150 mg/day) for all in early pregnancy has not been demonstrated in women with preexisting diabetes.

Management of type 1 diabetes in pregnancy: update on lifestyle, pharmacological treatment, and novel technologies for achieving glycaemic targets

Glucose concentrations within target, appropriate gestational weight gain, adequate lifestyle, and, if necessary, antihypertensive treatment and low-dose aspirin reduces the risk of pre-eclampsia, preterm delivery, and other adverse pregnancy and neonatal outcomes in pregnancies complicated by type 1 diabetes. Despite the increasing use of diabetes technology (ie, continuous glucose monitoring and insulin pumps), the target of more than 70% time in range in pregnancy (TIRp 3·5-7·8 mmol/L) is often reached only in the final weeks of pregnancy, which is too late for beneficial effects on pregnancy outcomes. Hybrid closed-loop (HCL) insulin delivery systems are emerging as promising treatment options in pregnancy. In this Review, we discuss the latest evidence on pre-pregnancy care, management of diabetes-related complications, lifestyle recommendations, gestational weight gain, antihypertensive treatment, aspirin prophylaxis, and the use of novel technologies for achieving and maintaining glycaemic targets during pregnancy in women with type 1 diabetes. In addition, the importance of effective clinical and psychosocial support for pregnant women with type 1 diabetes is also highlighted. We also discuss the contemporary studies examining HCL systems in type 1 diabetes during pregnancies.

Alterations in the Gut Microbiota in Pregnant Women with Pregestational Type 2 Diabetes Mellitus

Human gut dysbiosis is associated with type 2 diabetes mellitus (T2DM); however, the gut microbiome in pregnant women with pregestational type 2 diabetes mellitus (PGDM) remains unexplored. We investigated the alterations in the gut microbiota composition in pregnant women with or without PGDM. The gut microbiota was examined using 16S rRNA sequencing data of 234 maternal fecal samples that were collected during the first (T1), second (T2), and third (T3) trimesters. The PGDM group presented a reduction in the number of gut bacteria taxonomies as the pregnancies progressed. Linear discriminant analyses revealed that Megamonas, Bacteroides, and Roseburia intestinalis were enriched in the PGDM group, whereas Bacteroides vulgatus, Faecalibacterium prausnitzii, Eubacterium rectale, Bacteroides uniformis, Eubacterium eligens, Subdoligranulum, Bacteroides fragilis, Dialister, Lachnospiraceae, Christensenellaceae R-7, Roseburia inulinivorans, Streptococcus oralis, Prevotella melaninogenica, Neisseria perflava, Bacteroides ovatus, Bacteroides caccae, Veillonella dispar, and Haemophilus parainfluenzae were overrepresented in the control group. Correlation analyses showed that the PGDM-enriched taxa were correlated with higher blood glucose levels during pregnancy, whereas the taxonomic biomarkers of normoglycemic pregnancies exhibited negative correlations with glycemic traits. The microbial networks in the PGDM group comprised weaker microbial interactions than those in the control group. Our study reveals the distinct characteristics of the gut microbiota composition based on gestational ages between normoglycemic and PGDM pregnancies. Further longitudinal research involving women with T2DM at preconception stages and investigations using shotgun metagenomic sequencing should be performed to elucidate the relationships between specific bacterial functions and PGDM metabolic statuses during pregnancy and to identify potential therapeutic targets. IMPORTANCE The incidence of pregestational type 2 diabetes mellitus (PGDM) is increasing, with high rates of serious adverse maternal and neonatal outcomes that are strongly correlated with hyperglycemia. Recent studies have shown that type 2 diabetes mellitus is associated with gut microbial dysbiosis; however, the gut microbiome composition and its associations with the metabolic features of patients with PGDM remain largely unknown. In this study, we investigated the changes in the gut microbiota composition in pregnant women with and without PGDM. We identified differential taxa that may be correlated with maternal metabolic statuses during pregnancy. Additionally, we observed that the number of taxonomic and microbial networks of gut bacteria were distinctly reduced in women with hyperglycemia as their pregnancies progressed. These results extend our understanding of the associations between the gut microbial composition, PGDM-related metabolic changes, and pregnancy outcomes.

Falling Insulin Requirement in Pregnant Women With Diabetes Delivering Preterm: Prevalence, Predictors, and Consequences

CONTEXT

Falling insulin requirements often lead to considerations of whether a pregnancy can continue safely or if delivery is indicated.

OBJECTIVE

To evaluate prevalence and predictors of falling insulin requirements in pregnant women with preexisting diabetes delivering preterm and to explore the relationship to fetal asphyxia and neonatal morbidity.

METHODS

A prospective cohort study of 101 consecutive singleton pregnant women with preexisting diabetes delivering preterm < 37 weeks (68 type 1 and 33 type 2 diabetes) where the prevalence of falling insulin requirements (≥20%) before delivery was recorded.

RESULTS

In total, 27% (27/101) experienced falling insulin requirements of median 30% (interquartile range 24-40) before delivery. In all women with type 1 diabetes, the prevalence was 37% (25/68), whereas it was 43% (24/56) in those with indicated preterm delivery and 6% (2/33) among women with type 2 diabetes. In women with type 1 diabetes and indicated preterm delivery, falling insulin requirements were first identified at 34 + 5 (33 + 6-35 + 4) weeks + days and delivery occurred 3 (1-9) days later. Gestational age at delivery, prevalence of suspected fetal asphyxia, and neonatal morbidity were similar in women with and without falling insulin requirements. Neither glycemic control, nausea, or preeclampsia was associated with falling insulin requirement.

CONCLUSION

Falling insulin requirements often preceded preterm delivery in women with type 1 diabetes, foremost when preterm delivery was indicated, but was not related to fetal asphyxia or neonatal morbidity. Whether falling insulin requirements in late pregnancy are a warning sign of placental insufficiency or mainly reflects variations in normal physiology needs further investigation.

Unchanged Prevalence of Preeclampsia After Implementation of Prophylactic Aspirin for All Pregnant Women With Preexisting Diabetes: A Prospective Cohort Study

OBJECTIVE

To evaluate the prevalence of preeclampsia after implementation of prophylactic aspirin for all pregnant women with preexisting diabetes compared with the prevalence in a previous risk-based prophylaxis.

RESEARCH DESIGN AND METHODS

A prospective observational cohort study of 410 consecutive pregnant women with preexisting diabetes categorized according to aspirin prophylaxis strategy, with the prevalence of preeclampsia as primary outcome. In total, 207 women were included after implementation of prophylactic aspirin for all pregnant women with preexisting diabetes in February 2018 (all-cohort). The 203 women included before this date, where aspirin prophylaxis was risk based and only prescribed to selected women (selected-cohort), were studied for comparison.

RESULTS

Aspirin was prescribed at ∼10 gestational weeks for 88% (all-cohort) compared with 25% (selected-cohort). HbA1c, parity, chronic hypertension, home blood pressure, microalbuminuria/diabetic nephropathy, and smoking were similar in the two cohorts in early pregnancy. In the all-cohort, fewer women had type 2 diabetes (32% vs. 42%, respectively; P = 0.04) and BMI tended to be lower (P = 0.05). The prevalence of preeclampsia was similar (12% vs. 11%, P = 0.69) in the two cohorts, and this was also the case with stratification for diabetes type. Prevalence of preterm delivery <37 weeks (23% vs. 27%, P = 0.30), preterm preeclampsia (7% vs. 7%, P = 0.96), and infants large (40% vs. 32%, P = 0.07) and small (7% vs. 6%, P = 0.88) for gestational age was similar in the two cohorts.

CONCLUSIONS

Implementation of prophylactic aspirin for all pregnant women with diabetes did not reduce the prevalence of preeclampsia compared with the previous risk-based prophylaxis in this cohort study.