Tandem T:Slim X2 Insulin Pump Use in Clinical Practice Among Pregnant Individuals With Type 1 Diabetes: A Retrospective Observational Cohort Study

BACKGROUND

Insulin pump use is increasing in frequency among pregnant individuals with type 1 diabetes (T1D). Automated insulin delivery (AID) technologies have not been studied extensively in pregnancy.

METHOD

We present a retrospective case series of eight individuals with T1D who used the Tandem t:slim X2 insulin pump (Tandem Diabetes Care, Inc., CA, USA) during pregnancy. Weekly continuous glucose monitor and insulin pump data were analyzed from electronic medical records and data-sharing portals. Safety, glycemic control, and pregnancy outcomes were examined with both the control IQ (CIQ) and basal IQ (BIQ) algorithms.

RESULTS

Six CIQ and two BIQ users were studied. The mean glycated hemoglobin (A1C) during pregnancy was 6.1%, and the average time in pregnancy-recommended glycemic range (TIR; 63-140mg/dL) was 67.9%. There were no instances of diabetic ketoacidosis or severe hypoglycemia. CIQ users had a higher mean sensor glucose (127.6 mg/dL) compared to BIQ participants (118.4 mg/dL). However, the average time below range (<63 mg/dL) was 6.1% in BIQ participants compared to 1.5% in CIQ participants. CIQ participants used several strategies to achieve glycemic targets, including daytime use of sleep activity. An increased basal-to-bolus insulin ratio was negatively correlated with TIR (r=-0.415).

CONCLUSIONS

Tandem t:slim X2 insulin pumps were safely used during pregnancy in eight individuals with T1D, with variable success in achieving recommended glycemic targets. Further research is needed to understand differences in CIQ and BIQ use in pregnancy. AID device manufacturers must additionally develop further methods to target lower glucose for pregnant users.

Association between glycemic control and group B streptococcus colonization among pregnant individuals with pregestational diabetes

PROBLEM

Pregestational diabetes increases the risk of group B streptococcus (GBS) colonization in pregnancy. Whether glycemic control is associated with differences in this risk is unknown. We examined the association between glycemic control and GBS colonization among pregnant individuals with pregestational diabetes.

METHOD OF STUDY

A retrospective cohort of pregnant individuals with pregestational diabetes at a tertiary care center. The exposure was glycemic control, measured as hemoglobin A1c (A1c) at >20 weeks and assessed categorically at thresholds of <6.5% and <6.0%, and secondarily, as a continuous percentage. The outcome was maternal GBS colonization. Multivariable logistic regression was used and adjusted for age, parity, race, and ethnicity as a social determinant, body mass index, type of diabetes, and gestational age at A1c assessment.

RESULTS

Among 305 individuals (33% Type 1, 67% type 2), 45.0% (n = 140) were colonized with GBS. Individuals with an A1c < 6.5% were half as likely to be colonized with GBS compared with those with a A1c ≥ 6.5% (38.8% vs. 53.9%; adjusted odds ratio, AOR: 0.55; 95% CI: 0.33-0.91). Results were unchanged at an A1c threshold of <6.0% (35.7% vs. 48.5%; AOR: 0.60; 95% CI: 0.36-0.98). Individuals with a higher A1c as a continuous measure (%) were more likely to be colonized (AOR: 1.57 per 1%; 95% CI: 1.25-1.97).

CONCLUSIONS

Pregnant individuals with pregestational diabetes with worse glycemic control were at an increased risk of GBS colonization. Further study is needed to understand if improved glycemic control leads to lower risk of GBS colonization.

Disparities in Continuous Glucose Monitoring Use Among Women of Reproductive Age with Type 1 Diabetes in the T1D Exchange

We identified characteristics associated with continuous glucose monitoring (CGM) use in women of reproductive age with type 1 diabetes (T1D) in the T1D Exchange clinic registry from 2015 to 2018. Among 6643 assessed women, the frequency of CGM increased from 2015 to 2018 (20.6% vs. 30.0%; adjusted odds ratios [aOR]: 1.72; confidence interval [95% CI]: 1.51-1.95) and was more likely with recent pregnancy (45.3% vs. 25.8%; aOR: 1.63; 95% CI: 1.23-2.16). Non-Hispanic Black and Hispanic race and ethnicity, younger age, lower educational attainment, lower income, and Medicaid insurance were associated with lower odds of CGM. The use of CGM was associated with lower odds of diabetic ketoacidosis and lower hemoglobin A1c without any difference in the odds of symptomatic severe hypoglycemia. In conclusion, although CGM use was associated with better glycemic control, the majority of reproductive-age women still did not use it. Those who did not use CGM were more likely to be those at greatest risk of adverse pregnancy outcomes.

Association Between Social Vulnerability and Achieving Glycemic Control Among Pregnant Individuals With Pregestational Diabetes

OBJECTIVE

To evaluate the association between community-level social vulnerability and achieving glycemic control (defined as hemoglobin A1c [Hb A1c] less than 6.0% or less than 6.5%) among individuals with pregestational diabetes.

METHODS

We conducted a retrospective cohort of individuals with pregestational diabetes with singleton gestations from 2012 to 2016 at a tertiary care center. Addresses were geocoded using ArcGIS and then linked at the census tract to the Centers for Disease Control and Prevention's 2018 SVI (Social Vulnerability Index), which incorporates 15 Census variables to produce a composite score and four scores across thematic domains (socioeconomic status, household composition and disability, minority status and language, and housing type and transportation). Scores range from 0 to 1, with higher values indicating greater community-level social vulnerability. The primary outcome was Hb A1c less than 6.0%, and, secondarily, Hb A1c less than 6.5%, in the second or third trimesters. Multivariable Poisson regression with robust error variance was used to evaluate the association between SVI score as a continuous measure and target Hb A1c.

RESULTS

Among 418 assessed pregnant individuals (33.0% type 1; 67.0% type 2 diabetes), 41.4% (173/418) achieved Hb A1c less than 6.0%, and 56.7% (237/418) Hb A1c less than 6.5% at a mean gestational age of 29.5 weeks (SD 5.78). Pregnant individuals with a higher SVI score were less likely to achieve Hb A1c less than 6.0% compared with those with a lower SVI score. For each 0.1-unit increase in SVI score, the risk of achieving Hb A1c less than 6.0% decreased by nearly 50% (adjusted risk ratio [aRR] 0.53; 95% CI 0.36-0.77), and by more than 30% for Hb A1c less than 6.5% (adjusted odds ratio 0.67; 95% CI 0.51-0.88). With regard to specific SVI domains, those who scored higher on socioeconomic status (aRR 0.50; 95% CI 0.35-0.71) as well as on household composition and disability (aRR 0.55; 95% CI 0.38-0.79) were less likely to achieve Hb A1c less than 6.0%.

CONCLUSION

Pregnant individuals with pregestational diabetes living in an area with higher social vulnerability were less likely to achieve glycemic control, as measured by HgbA1c levels. Interventions are needed to assess whether addressing social determinants of health can improve glycemic control in pregnancy.

Gestational Weight Gain and Adverse Maternal and Neonatal Outcomes for Pregnancies Complicated by Pregestational and Gestational Diabetes

OBJECTIVE

This study aimed to investigate the association between excess and less than recommended gestational weight gain (GWG) and adverse maternal and neonatal outcomes in women with pregestational and gestational diabetes.

STUDY DESIGN

We conducted a secondary analysis of the National Institute of Child Health and Human Development (NICHD) Consortium on Safe Labor (CSL) study. We included deliveries >23 weeks of nonanomalous singletons with either pregestational or gestational diabetes. The exposure was GWG greater than or less than compared with the U.S. Institute of Medicine recommendations for total pregnancy weight gain per prepregnancy body mass index. Consistent with the 2020 Delphi outcome for diabetes in pregnancy, maternal outcomes included cesarean delivery and preeclampsia and neonatal outcomes included small for gestational age (SGA), large for gestational age (LGA), macrosomia >4,000 g, preterm birth <37 weeks, stillbirth, and neonatal death. We modeled both absolute GWG and GWG z-scores, standardized for gestational duration. Multivariable logistic regression with generalized estimating equations was used, adjusting for age, race/ethnicity, parity, prior cesarean delivery, chronic hypertension, tobacco use, U.S. region, and delivery year.

RESULTS

Of 8,322 deliveries (n = 8,087 women) complicated by pregestational or gestational diabetes, 47% were in excess, 27% were within, and 26% were less than GWG recommendations. Deliveries with excess absolute GWG were at higher adjusted odds of cesarean delivery, preeclampsia, LGA, and macrosomia, compared with those within recommendations. Similar results were observed when using standardized GWG z-scores, in addition to higher likelihood of preterm birth and neonatal death. Less than recommended GWG was associated with a lower likelihood of these adverse outcomes but higher SGA. Additionally, less GWG by z-score was associated with a lower likelihood of stillbirth.

CONCLUSION

Excess GWG increases the risk of adverse maternal and neonatal outcomes for women with pregestational and gestational diabetes. Less GWG than recommended may decrease this risk.

KEY POINTS

· Understanding the impact of GWG modeled using both absolute and standardized measures is needed.. · Among pregnant women with diabetes, excess GWG was common and increased the risk of adverse outcomes and less than recommended GWG may decrease the risk of adverse outcomes, including stillbirth.. · Current recommendations may require revision for women with diabetes in pregnancy..

Does Progesterone Treatment Influence Risk Factors for Recurrent Preterm Delivery?

OBJECTIVE

To examine how demographic and pregnancy characteristics can affect the risk of recurrent preterm delivery and the how the effectiveness of progesterone treatment for prevention alters these relationships.

METHODS

This was a secondary analysis of a randomized trial of 17alpha-hydroxyprogesterone caproate to prevent recurrent preterm delivery in women at risk. Associations of risk factors for preterm delivery (less than 37 completed weeks of gestation) were examined separately for the women in the 17alpha-hydroxyprogesterone caproate (n = 310) and placebo (n = 153) groups.

RESULTS

Univariate analysis found that the number of previous preterm deliveries and whether the penultimate delivery was preterm were significant risk factors for preterm delivery in both the placebo and progesterone groups. High body mass index was protective of preterm birth in the placebo group. Multivariate analysis found progesterone treatment to cancel the risk of more than 1 previous preterm delivery, but not the risk associated with the penultimate pregnancy delivered preterm. Obesity was associated with lower risk for preterm delivery in the placebo group but not in the women treated with progesterone.

CONCLUSION

The use of 17alpha-hydroxyprogesterone caproate in women with a previous preterm delivery reduces the overall risk of preterm delivery and changes the epidemiology of risk factors for recurrent preterm delivery. In particular, these data suggest that 17alpha-hydroxyprogesterone caproate reduces the risk of a history of more than 1 preterm delivery.

LEVEL OF EVIDENCE

I.

Progesterone for prevention of recurrent preterm birth: impact of gestational age at previous delivery

OBJECTIVE

Preterm birth occurs in 1 of 8 pregnancies and may result in significant morbidity and mortality. 17-alpha hydroxyprogesterone caproate (17-OHP caproate) has been found to be efficacious in reducing the risk of subsequent preterm delivery in women who have had a previous spontaneous preterm birth (sPTB). This analysis was undertaken to evaluate if 17-OHP caproate therapy works preferentially depending on the gestational age at previous spontaneous delivery. We hypothesized that treatment with 17-OHP caproate is more effective in prolonging pregnancy depending on the gestational age of the earliest previous preterm birth (20-27.9, 28-33.9 vs 34-36.9 weeks).

STUDY DESIGN

This was a secondary analysis of 459 women with a previous sPTB enrolled in a randomized controlled trial evaluating 17-OHP caproate versus placebo. Effectiveness of 17-OHP caproate for pregnancy prolongation was evaluated based on gestational age at earliest previous delivery according to clinically relevant groupings (20-27.9, 28-33.9, and 34-36.9 weeks). Statistical analysis included the chi-square, Fisher exact, and Kruskal-Wallis tests, logistic regression, and survival analysis using proportional hazards.

RESULTS

Gestational age at earliest previous delivery was similar between women treated with 17-OHP caproate or placebo (P = .1). Women with earliest delivery at 20 to 27.9 weeks and at 28 to 33.9 weeks delivered at significantly more advanced gestational age if treated with 17-OHP caproate than with placebo (median 37.3 vs 35.4 weeks, P = .046 and 38.0 vs 36.7 weeks, P = .004, respectively) and were less likely to deliver <37 weeks (42% vs 63%, P = .026 and 34% vs 56%, P = .005, respectively). Those with earliest delivery at 34 to 36.9 weeks were not significantly different between 17-OHP caproate or control.

CONCLUSION

17-OHP caproate therapy given to prevent recurrent PTB is associated with a prolongation of pregnancy overall, and especially for women with a previous spontaneous PTB at <34 weeks.

Plasma CRH measurement at 16 to 20 weeks' gestation does not predict preterm delivery in women at high-risk for preterm delivery

OBJECTIVE

The purpose of this study was to examine the utility of a single second-trimester plasma corticotropin-releasing hormone measurement as a marker for preterm delivery in women at high risk for preterm delivery.

STUDY DESIGN

This is an analysis of data from a multicenter placebo-controlled trial designed to evaluate the role of 17 alpha hydroxyprogesterone caproate (17P) in the prevention of recurrent preterm birth. Women with a documented history of a previous spontaneous preterm birth at <37 weeks were enrolled (16-20 wks) and randomly assigned in a 2 to 1 ratio to weekly injections of 17P or matching placebo. Blood was collected before treatment in 170 patients (113 assigned 17P and 57 placebo) who were enrolled at 11 of the 19 centers. Plasma levels of corticotropin-releasing hormone were compared between those who delivered preterm and those delivering at term. Data were analyzed using the Wilcoxon rank-sum test.

RESULTS

The overall rates of preterm birth in this cohort of 170 patients were 35.9% at <37 weeks (31.9% progesterone, 43.9% placebo), and 19.4% at <35 weeks (18.6% vs 21.1%). The median levels of corticotropin-releasing hormone were similar between those delivering at <37 weeks and those delivering > or = 37 weeks (0.39 ng/mL vs 0.37 ng/mL, P = .08). In addition, there were no differences in corticotropin-releasing hormone levels among those who delivered at <35 weeks or > or = 35 weeks (0.36 vs 0.38, P = .90). Moreover, there were no differences in corticotropin-releasing hormone levels among those in the placebo group who delivered at <37 or > or = 37 weeks (0.40 vs 0.41, P = .72) and at <35 or > or = 35 weeks (P = .64).

CONCLUSION

A single measurement of corticotropin-releasing hormone at 16 to 20 weeks' gestation is not a good biomarker for recurrent preterm delivery in patients at high risk for this complication.

Prevention of recurrent preterm delivery by 17 alpha-hydroxyprogesterone caproate

BACKGROUND

Women who have had a spontaneous preterm delivery are at greatly increased risk for preterm delivery in subsequent pregnancies. The results of several small trials have suggested that 17 alpha-hydroxyprogesterone caproate (17P) may reduce the risk of preterm delivery.

METHODS

We conducted a double-blind, placebo-controlled trial involving pregnant women with a documented history of spontaneous preterm delivery. Women were enrolled at 19 clinical centers at 16 to 20 weeks of gestation and randomly assigned by a central data center, in a 2:1 ratio, to receive either weekly injections of 250 mg of 17P or weekly injections of an inert oil placebo; injections were continued until delivery or to 36 weeks of gestation. The primary outcome was preterm delivery before 37 weeks of gestation. Analysis was performed according to the intention-to-treat principle.

RESULTS

Base-line characteristics of the 310 women in the progesterone group and the 153 women in the placebo group were similar. Treatment with 17P significantly reduced the risk of delivery at less than 37 weeks of gestation (incidence, 36.3 percent in the progesterone group vs. 54.9 percent in the placebo group; relative risk, 0.66 [95 percent confidence interval, 0.54 to 0.81]), delivery at less than 35 weeks of gestation (incidence, 20.6 percent vs. 30.7 percent; relative risk, 0.67 [95 percent confidence interval, 0.48 to 0.93]), and delivery at less than 32 weeks of gestation (11.4 percent vs. 19.6 percent; relative risk, 0.58 [95 percent confidence interval, 0.37 to 0.91]). Infants of women treated with 17P had significantly lower rates of necrotizing enterocolitis, intraventricular hemorrhage, and need for supplemental oxygen.

CONCLUSIONS

Weekly injections of 17P resulted in a substantial reduction in the rate of recurrent preterm delivery among women who were at particularly high risk for preterm delivery and reduced the likelihood of several complications in their infants.

Management of diabetes by obstetrician-gynecologists

OBJECTIVE

To examine the rates of diagnosis and treatment of diabetes mellitus by ACOG Fellows in pregnant and nonpregnant patients.

METHODS

We sent a questionnaire to 1250 ACOG Fellows. Thirty-nine percent responded. Responses were examined for potential differences between recently and less recently trained obstetrician-gynecologists.

RESULTS

Ninety-six percent of obstetricians routinely screen for gestational diabetes mellitus (GDM). Fifty-five percent of obstetrician-gynecologists screen for diabetes in nonpregnant patients if there is a history of diabetes in the patient's family. Moreover, 33% care for women with type-1 diabetes mellitus, and 39% for women with type-2 diabetes mellitus who are not pregnant. Sixty-two percent believed that their patients with GDM are at increased risk for developing nongestational diabetes later in life, and 71% will recommend an evaluation of glucose tolerance in the future for these women. Finally, 99% are willing to prescribe oral contraceptives to women diagnosed previously with GDM.

CONCLUSION

Obstetrician-gynecologists are aware of the need to screen for GDM and the importance of postpartum follow-up in GDM patients to detect type-2 diabetes mellitus. This practice is important because half of the 14 million people with type-2 diabetes mellitus are unaware they have this disorder, and many learn about it only after a serious complication has occurred.

Prenatal detection of fetal anomalies in pregnancies complicated by insulin-dependent diabetes mellitus

OBJECTIVES

We evaluated the clinical utility of a comprehensive program of prenatal diagnostic testing for congenital anomalies in pregnancies complicated by insulin-dependent diabetes mellitus.

STUDY DESIGN

Data were retrospectively analyzed from 289 diabetic women and their newborns from August 1987 to July 1993. Our protocol included initial hemoglobin A1 and maternal serum alpha-fetoprotein determinations and comprehensive fetal ultrasonography inclusive of a standard four-chamber view of the heart and detailed multiimage fetal echocardiography.

RESULTS

Anomalies were identified in 29 of 289 (10%) fetuses and neonates: 12 cardiac only, 14 noncardiac, and 3 combined. In 21 of the 29 (72%) neonates the anomalies were detected prenatally. Twelve of 15 (80%) cardiac and 10 of 17 (59%) noncardiac lesions were identified prenatally. Cardiac lesions, especially of the cardiac septum and great vessels, accounted for 50% of all fetal defects. Malformations of the neuroaxis, skeleton, and genitourinary system were also detected. There were six neonatal deaths and four therapeutic pregnancy terminations associated with congenital anomalies. Although the hemoglobin A1 level was statistically significantly increased in 22 mothers of anomalous fetuses (p = 0.017), the actual difference between affected and nonaffected pregnancies was not clinically meaningful and much overlap occurred. Although 96% of women with a normal hemoglobin A1 level were delivered of normal infants, only 14% of those with an elevated value had a malformed fetus. Similarly, although 89% of gravid women with a normal maternal serum alpha-fetoprotein level were delivered of nonaffected fetuses, only 7.3% of patients with an elevated value had a malformed fetus. For the detection of cardiac defects, the sensitivity of the four-chamber view compared with detailed multiimage fetal echocardiography was 33% and 92%, respectively.

CONCLUSIONS

This study demonstrates the utility of a comprehensive program to detect fetal anomalies in pregnancies complicated by diabetes mellitus.

Screening recommendations for gestational diabetes mellitus

As a result of extensive experiences in multiple centers and a review of the current literature, we conclude that a plasma glucose level obtained 1 hour after a 50 gm oral glucose challenge is the "best" gestational diabetes mellitus screening test. This universal screening is performed at least once during pregnancy. The screening threshold should be no higher than 140 mg/dl, or an unacceptable loss in sensitivity occurs. Universal screening for gestational diabetes mellitus is justified by morbidity reduction, cost, and protocol simplicity and ease.

Measurement of cervical length in pregnancy: comparison between vaginal ultrasonography and digital examination

Evaluation of the gravid cervix uteri is an important part of prenatal care, especially in the patient at risk for preterm birth. Seeking a method of cervical length measurement that could be used easily regardless of patient habitus, location of the cervix, and gestational age, we used a vaginal probe with a 240 degrees scanning angle in gravidas at various gestational ages to test the theoretical advantages of the wide scanning angle. Among the first 201 examinations, cervical length was measured successfully in 99.5% of cases. This success rate compares favorably with those of abdominal sonography and vaginal sonography using the standard 90 degrees scanning angle sector probes. We also compared this method with digital examination in a double-blind fashion. Only a fair degree of association between sonographic cervical measurements and measurements obtained by digital examination was found, reflected in a correlation coefficient of 0.49.

Quantitative assessment of growth and function of the cardiac chambers in the normal human fetus: a prospective longitudinal echocardiographic study

We assessed the changes in cardiac chamber size, architecture and function in the normal fetus in a prospective, longitudinal, two-dimensional, and two-dimensionally directed M mode echocardiographic study. Serial echocardiograms were recorded in 16 normal fetuses at 4 week intervals from 20 weeks gestation to parturition. Fetal gestational age was assessed by biparietal diameter. Left ventricular, right ventricular, and left atrial chamber sizes and aortic diameter all increased linearly with age. The ratios of right and left ventricular diameter, left atrial to aortic diameters, and relative left ventricular wall thickness that we used as an index of short-axis left ventricular architecture remained constant. Fractional right ventricular and left ventricular wall thicknesses were similar both on echocardiograms and in postmortem hearts over the same range of gestational ages. In addition, postmortem right ventricular and left ventricular free wall weights were indistinguishable and contributed the same proportion to total heart weight throughout gestation. Left ventricular echocardiographic mass increased linearly from a mean of 0.86 +/- 0.09 to 7.47 +/- 2.43 g at term and corresponded closely with postmortem left ventricular weight. We conclude that (1) fetal cardiac chamber dimensions, wall thicknesses, and left ventricular mass increased with gestational age, (2) cardiac architecture in terms of the ratios of right ventricular/left ventricular diameters, left atrial/aortic diameters, and relative wall thickness remained constant, (3) right and left ventricular fractional shortening did not change with age, (4) left ventricular mass assessed echocardiographically corresponded closely with postmortem left ventricular weights in fetal hearts of similar gestational ages, and (5) the similarities between right and left ventricular sizes, wall thicknesses, and free wall weights in this study do not support the theory of right ventricular dominance in the human fetus.

Macular edema and pregnancy in insulin-dependent diabetes

Seven women with insulin-dependent diabetes (mean age, 26 years; mean duration of diabetes, 15.4 years) had minimal or no retinopathy before becoming pregnant but developed severe macular edema associated with preproliferative or proliferative retinopathy during the course of their pregnancies. The edema was associated with significant macular capillary nonperfusion, and often with significant proteinuria and mild hypertension. Although proliferation was controlled with panretinal photocoagulation, the macular edema continued to worsen until delivery in all cases and was often aggravated by the photocoagulation. Macular edema and retinopathy both regressed after delivery in some patients but persisted in others, causing significant visual loss. Pregnant women with retinopathy, nephropathy, or hypertension should undergo ophthalmoscopy at least once a month. If proliferative retinopathy develops, panretinal photocoagulation should be applied even if the macular edema is aggravated.