Birthweight and other pregnancy outcomes in a cohort of women with pre-gestational insulin-treated diabetes mellitus, Scotland, 1979-95

Trend of pregnancy outcomes in type 1 diabetes compared to control women: a register-based analysis in 1996-2018

Introduction

In 1989, the St Vincent declaration aimed to approximate pregnancy outcomes of diabetes to that of healthy pregnancies. We aimed to compare frequency and trends of outcomes of pregnancies affected by type 1 diabetes and controls in 1996-2018.

Methods

We used anonymized records of a mandatory nation-wide registry of all deliveries between gestational weeks 24 and 42 in Hungary. We included all singleton births (4,091 type 1 diabetes, 1,879,183 controls) between 1996 and 2018. We compared frequency and trends of pregnancy outcomes between type 1 diabetes and control pregnancies using hierarchical Poisson regression.

Results

The frequency of stillbirth, perinatal mortality, large for gestational age, caesarean section, admission to neonatal intensive care unit (NICU), and low Appearance, Pulse, Grimace, Activity, and Respiration (APGAR) score was 2-4 times higher in type 1 diabetes compared to controls, while the risk of congenital malformations was increased by 51% and SGA was decreased by 42% (all p<0.05). These observations remained significant after adjustment for confounders except for low APGAR scores. We found decreasing rate ratios comparing cases and controls over time for caesarean sections, low APGAR scores (p<0.05), and for NICU admissions (p=0.052) in adjusted models. The difference between cases and controls became non-significant after 2009. No linear trends were observed for the other outcomes.

Conclusions

Although we found that the rates of SGA, NICU care, and low APGAR score improved in pregnancies complicated by type 1 diabetes, the target of the St Vincent Declaration was only achieved for the occurrence of low APGAR scores.

Characteristics of Stillbirths Associated With Diabetes in a Diverse U.S. Cohort

OBJECTIVE

To characterize stillbirths associated with pregestational diabetes and gestational diabetes mellitus (GDM) in a large, prospective, U.S. case-control study.

METHODS

A secondary analysis of stillbirths among patients enrolled in a prospective; multisite; geographically, racially, and ethnically diverse case-control study in the United States was performed. Singleton gestations with complete information regarding diabetes status and with a complete postmortem evaluation were included. A standard evaluation protocol for stillbirth cases included postmortem evaluation, placental pathology, clinical testing as performed at the discretion of the health care professional, and a recommended panel of tests. A potential cause of death was assigned to stillbirth cases using a standardized classification tool. Demographic and delivery characteristics among women with pregestational diabetes and GDM were compared with characteristics of women with no diabetes in pairwise comparisons using χ or two-sample t tests as appropriate. Sensitivity analysis was performed excluding pregnancies with genetic conditions or major fetal malformations.

RESULTS

Of 455 stillbirth cases included in the primary analysis, women with stillbirth and diabetes were more likely to be older than 35 years and have a higher body mass index. They were also more likely to have a gestational hypertensive disorder than women without diabetes (28% vs 9.1%; P<.001). Women with pregestational diabetes had more large-for-gestational-age (LGA) neonates (26% vs 3.4%; P<.001). Stillbirths occurred more often at term in women with pregestational diabetes (36%) and those with GDM (52%). Maternal medical complications, including pregestational diabetes and others, were more often identified as a probable or possible cause of death among stillbirths with maternal diabetes (43% vs 4%, P<.001) as compared with stillbirths without diabetes.

CONCLUSION

Compared with stillbirths in women with no diabetes, stillbirths among women with pregestational diabetes and GDM occur later in pregnancy and are associated with hypertensive disorders of pregnancy, maternal medical complications, and LGA.

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.

Intrauterine Adiposity and BMI in 4- to 5-Year-Old Offspring from Diabetic Pregnancies

BACKGROUND

Pregnancies complicated by maternal diabetes are associated with disproportionate intrauterine growth that subsequently may lead to pediatric adiposity.

OBJECTIVES

We investigated whether disproportionate intrauterine growth leads to differences in BMI in 4- to 5-year-old offspring from pregnancies complicated by type 1 (ODM1), type 2 (ODM2), or gestational diabetes (OGDM).

METHODS

Ultrasound data of fetal head-to-abdominal circumference (HC/AC) ratio obtained between 32 and 36 weeks of gestational age were related to offspring anthropometrics that were retrieved from infant welfare centers.

RESULTS

Data from 27 ODM1, 22 ODM2, and 24 OGDM were obtained. Ultrasound measurements for the HC/AC ratio were performed at a mean of 33-34 weeks, with a mean Z-score of the HC/AC ratio of -0.801, -0.879, and 0.017 in ODM1, ODM2, and OGDM. Mean BMI SDS was highest in ODM2 as compared to ODM1 and OGDM. In ODM1 there was a negative correlation between HC/AC ratio and BMI SDS at the ages of 4 and 5 years, but not in ODM2 or OGDM. The birth weight Z-score was positively correlated to BMI SDS in ODM2 and OGDM.

CONCLUSION

Disproportionate intrauterine growth, expressed as the HC/AC ratio, was inversely related with BMI SDS in ODM1 at the ages of 4-5 years, but not in ODM2 or OGDM. Weight and maybe obesity in ODM1 offspring are likely to be related to intrauterine adiposity, whereas overweight in ODM2 and OGDM offspring seems more related to other factors such as birth weight centile, maternal obesity, and altered lifestyle factors during childhood.

Diabetes in Pregnancy and Childhood Cognitive Development: A Systematic Review

CONTEXT

The effect of diabetes during pregnancy on the cognitive development of offspring is unclear because of inconsistent findings from limited studies.

OBJECTIVE

This review was aimed to provide the best available scientific evidence on the associations between maternal pregnancy diabetes and the cognitive development of offspring.

DATA SOURCES

A search was conducted in the Embase, CINAHL, PubMed, PsycINFO, and Scopus databases.

STUDY SELECTION

Studies addressing the cognitive development of offspring (aged ≤12 years) as outcome and any diabetes in pregnancy as an exposure were included.

DATA EXTRACTION

Data were extracted and evaluated for quality by 2 independent reviewers.

RESULTS

Fourteen articles were eligible for the review. Ten studies investigated the associations between maternal pregestational diabetes or both pregestational and gestational diabetes and offspring's cognitive development; 6 studies found at least 1 negative association. Four studies exclusively examined the relationships between gestational diabetes and offspring's cognitive development; 2 studies found a negative association, 1 a positive association, and 1 a null association. The use of diverse cognitive and diabetes assessment tools/criteria, as well as statistical power, contributed to the inconsistent findings.

LIMITATIONS

The English-language restriction and publication bias in the included studies are potential limitations.

CONCLUSIONS

Although there are few data available regarding the associations between maternal pregnancy diabetes and offspring's cognitive development, this review found that maternal diabetes during pregnancy seems to be negatively associated with offspring's cognitive development. Large prospective studies that address potential confounders are needed to confirm the independent effect of maternal diabetes during pregnancy.

Stillbirth in the pregnancy complicated by diabetes

Pregestational diabetes currently complicates 4% of pregnancies, while gestational diabetes complicates approximately 8% of pregnancies. Increased risk of stillbirth in diabetic pregnancies has been a well-known and recognized complication for decades. While stillbirth rates for diabetic pregnancies have decreased due to screening, treatment, and antenatal surveillance of these patients, about 4% of all stillbirths remain attributable to diabetes, and diabetic pregnancies continue to be at increased risk for perinatal mortality. The purpose of this article is to review the literature on the epidemiology, pathophysiology, and prevention, as well as future research, of diabetes-associated perinatal mortality.

Women with pre-gestational diabetes have a higher risk of stillbirth at all gestations after 32 weeks

AIM

To explore the additional risk of stillbirths and to quantify that risk according to gestational age among women with diabetes.

METHODS

Data on pregnancies ending in 2007 and 2008 in women with pre-gestational diabetes in three English regional audits were identified. A prospective audit collected data on all pregnancies delivering between June 2010 and May 2011 in one region and in 13 other units across England. The data on all singleton pregnancies from these two cohorts were combined. Comparisons were made to all births in England and Wales for the same time period using data from the Office for National Statistics.

RESULTS

In the cohort of women with pre-gestational diabetes there were a total of 2085 singleton pregnancies, of which 29 resulted in a stillbirth (overall stillbirth rate 13.9 per 1000, 95% CI 9.7-19.9, relative risk compared with all pregnancies in England and Wales 2.73, 95% CI 2.61-2.84). The relative risk of stillbirth between 32 and 34 weeks' gestation was 4.95 (95% CI 4.24-5.78), 3.77 (95% CI 3.42-4.16) at 35 to 36 weeks, 5.75 (95% CI 5.43-6.09) for deliveries at 37 or 38 weeks and 7.34 (95% CI 6.52-8.25) for those born at 39 weeks or more.

CONCLUSION

Women with diabetes have a significantly higher risk of stillbirth at all gestations after 32 weeks and this additional risk is not just confined to pregnancies at 37 weeks or more.

Pre-existing diabetes, maternal glycated haemoglobin, and the risks of fetal and infant death: a population-based study

AIMS/HYPOTHESIS

Pre-existing diabetes is associated with an increased risk of stillbirth, but few studies have excluded the effect of congenital anomalies. This study used data from a long-standing population-based survey of women with pre-existing diabetes to investigate the risks of fetal and infant death and quantify the contribution of glycaemic control.

METHODS

All normally formed singleton offspring of women with pre-existing diabetes (1,206 with type 1 diabetes and 342 with type 2 diabetes) in the North of England during 1996-2008 were identified from the Northern Diabetes in Pregnancy Survey. RRs of fetal death (≥20 weeks of gestation) and infant death were estimated by comparison with population data from the Northern Perinatal Morbidity and Mortality Survey. Predictors of fetal and infant death in women with pre-existing diabetes were examined by logistic regression.

RESULTS

The prevalence of fetal death in women with diabetes was over four times greater than in those without (RR 4.56 [95% CI 3.42, 6.07], p < 0.0001), and for infant death it was nearly doubled (RR 1.86 [95% CI 1.00, 3.46], p = 0.046). There was no difference in the prevalence of fetal death (p = 0.51) or infant death (p = 0.70) between women with type 1 diabetes and women with type 2 diabetes. There was no evidence that the RR of fetal and infant death had changed over time (p = 0.95). Increasing periconception HbA1c concentration above 49 mmol/mol (6.6%) (adjusted odds ratio [aOR] 1.02 [95% CI 1.00, 1.04], p = 0.01), prepregnancy retinopathy (aOR 2.05 [95% CI 1.04, 4.05], p = 0.04) and lack of prepregnancy folic acid consumption (aOR 2.52 [95% CI 1.12, 5.65], p = 0.03) were all independently associated with increased odds of fetal and infant death.

CONCLUSIONS/INTERPRETATION

Pre-existing diabetes is associated with a substantially increased risk of fetal and infant death in normally formed offspring, the effect of which is largely moderated by glycaemic control.

Factors that affect maternal insulin resistance and modify fetal growth and body composition

Fetal growth is multifactorial and can be altered by a variety of extrinsic and intrinsic factors. The maternal, placental, and fetal contribution to growth must all be considered. Of particular interest are maternal metabolic regulation and the availability of nutrients to the developing fetus. Weight gain, hyperlipidemia, and insulin resistance occur as a normal adaptation to pregnancy. Obesity and underlying insulin resistance among women of reproductive age are rapidly increasing, and the contribution of pregnancy on this abnormal metabolic background poses additional maternal and fetal challenges. Many components of the metabolic syndrome have been associated with changes in fetal growth, including obesity, dyslipidemia, hypertension, and insulin resistance or glucose intolerance. Additional factors affect fetal growth and include diet, exercise, and smoking. In this review, we briefly discuss the importance and descriptions of fetal growth, followed by a discussion of several of the extrinsic and intrinsic established factors affecting fetal growth. We highlight factors that may modify fetal growth and body composition directly or indirectly through alterations in maternal metabolism.

Birth weight in type 1 diabetic pregnancy

Our aim was to investigate whether birth weight in mothers with diabetes mellitus type 1 is higher as compared to nondiabetic controls. Methods. A retrospective study was performed using an existing database covering the region of Flanders, Belgium. Data included the presence of diabetes type 1, hypertension, parity, maternal age, the use artificial reproductive technology, fetal- neonatal death, congenital anomalies, admission to a neonatal intensive care unit, and delivery by Caesarean section or vaginally. Results. In the period studied, 354 women with diabetes type 1 gave birth and were compared with 177.471 controls. Women with type 1 diabetes more often had a maternal age of over 35 years (16.7% versus 12.0%, P = .008, OR 1.46; 95% CI 1.09–1.95). They more frequently suffered hypertension in pregnancy (19.5% versus 4.7%, P < .0001, OR 4.91; 95% CI 3.73–6.44). Perinatal death was significantly higher in the diabetes mellitus group (3.05% versus 0.73%, P < .0001, OR 4.28; 95% CI 2.22–8.01). Caesarean section was performed almost 5 times as frequently in the diabetes versus the control group (OR 4.57; 95% CI 3.70–5.65). Birth weight was significantly higher in diabetic pregnant women from 33 until 38 weeks included, but those reaching 39 weeks and later were not different with control groups. Conclusion. In Belgium, diabetic pregnancy still carries a high risk for fetal and maternal complications; in general birth weight is significantly higher but for those reaching term there is no significant difference in birth weight.

Maternal type 1 diabetes reduces the risk of islet autoantibodies: relationships with birthweight and maternal HbA(1c)

AIMS/HYPOTHESIS

The risk of type 1 diabetes is reduced in the children of mothers with type 1 diabetes compared with children of fathers with type 1 diabetes. We asked whether children of mothers with type 1 diabetes also have a decreased risk of developing islet autoantibodies, and which factors associated with maternal diabetes contribute to a reduced islet autoantibody risk in offspring.

METHODS

Singleton offspring of a mother (n = 1,008) or father with type 1 diabetes (n = 578) from the BABYDIAB study were included. Children were followed from birth for the development of islet autoantibodies defined as two or more autoantibodies to insulin, glutamic acid decarboxylase or insulinoma antigen 2 in two or more blood samples.

RESULTS

Islet autoantibody risk was lower in children of mothers with type 1 diabetes (5 year risk, 3.2% vs 5.7% in children of fathers with type 1 diabetes; p = 0.04). Among factors that differed between pregnancies from mothers with and without type 1 diabetes, birthweight was associated with islet autoantibody risk. Risk was reduced in children with birthweights in the lower (adjusted HR 0.33; 95% CI 0.14-0.75; p = 0.009) and upper (HR 0.45; 95% CI 0.21-0.97; p = 0.04) tertiles compared with the middle tertile. A sub-analysis of maternal HbA(1c) suggested that moderately elevated third trimester maternal HbA(1c) was also associated with a reduced islet autoantibody risk in children of mothers with type 1 diabetes (5.7-7%; HR 0.38; 95% CI 0.15-0.96; p = 0.04 vs children of mothers with HbA(1c) < 5.7%).

CONCLUSIONS/INTERPRETATION

The risk of islet autoimmunity is modified by maternally influenced events such as birthweight.

A multicenter Italian study on pregnancy outcome in women with diabetes

BACKGROUND AND AIM

To determine pregnancy outcome in women with type 1 and type 2 diabetes.

METHODS AND RESULTS

A prospective study was conducted in 33 centers in Italy between 1999 and 2003, mainly recording preterm delivery, stillbirths, neonatal mortality, congenital malformations and birthweight. Of the 668 women examined, 504 had type 1 diabetes and 164 had type 2. Pre-pregnancy counseling had been provided to 43.9% of the women who had type 1 diabetes and 29.1% of the women who had type 2 diabetes and correlated with a better HbA1c value throughout pregnancy. The preterm delivery rate was significantly higher in type 1 and 2 diabetics than in normal pregnant women and was related to HbA1c values higher than 8%, gestational hypertension, pre-eclampsia and the presence of retinopathy before pregnancy. The stillbirth and neonatal mortality rates were also higher in diabetic pregnant women (1.26% and 0.63%, respectively) than in Italian pregnancies in general (0.30% and 0.32%), and the same was true for major congenital malformations (4.9% for diabetic pregnancies, 0.86% for normal Italian pregnancies).

CONCLUSIONS

In our population, pregnancy in diabetic women was still associated with a high rate of stillbirths, neonatal mortality and congenital malformations. Unplanned pregnancies and non-optimal glycemia control may help explain the high rates of maternal and neonatal complications.

Diabetic-associated stillbirth: incidence, pathophysiology, and prevention

All forms of diabetes during pregnancy are associated with an increased risk for stillbirth, defined as fetal death at greater than 20 weeks. The incidence of stillbirth in women who have diabetes has decreased dramatically with improved diabetes care. Diabetic-associated stillbirth is associated with hyperglycemia, resulting in fetal anaerobic metabolism with hypoxia and acidosis. Prevention of stillbirth in women who have diabetes hinges on intensive multidisciplinary prenatal care with control of blood sugars and appropriate fetal surveillance.

Diabetic-associated stillbirth: incidence, pathophysiology, and prevention

All forms of diabetes during pregnancy are associated with an increased risk for stillbirth, defined as fetal death at greater than 20 weeks. The incidence of stillbirth in women who have diabetes has decreased dramatically with improved diabetes care. Diabetic-associated stillbirth is associated with hyperglycemia, resulting in fetal anaerobic metabolism with hypoxia and acidosis. Prevention of stillbirth in women who have diabetes hinges on intensive multidisciplinary prenatal care with control of blood sugars and appropriate fetal surveillance.

Fetal and neonatal outcomes of diabetic pregnancies

OBJECTIVE

To estimate whether the incidences of adverse fetal and neonatal outcomes in infants of mothers with preexisting types 1 and 2 diabetes 1) differ from infants of nondiabetic mothers in Nova Scotia (NS); and 2) have changed between 1988 and 2002.

METHODS

Population-based cohort study using the NS Atlee Perinatal Database, a well-validated source of standardized clinical information.

RESULTS

A total of 516 infants of diabetic mothers and 150,589 infants of nondiabetic mothers from singleton pregnancies were studied. Infants of diabetic mothers had significantly higher rates of perinatal mortality (17.4/1,000 compared with 5.9/1,000, relative risk [RR] 3.01, 95% confidence interval [CI] 1.55-5.84), major congenital anomaly (9.1% compared with 3.1%, RR 2.97, 95% CI 2.25-3.90), and large for gestational age birth (LGA, more than 90th percentile weight for gestational age) (45.2% compared with 12.6%, RR 3.59, 95% CI 3.26-3.95) than infants of nondiabetic mothers. In infants of diabetic mothers, there was no improvement in perinatal mortality (23.4/1,000 in 1988-1995 compared with 11.5/1000 in 1996-2002, P = .340), incidence of LGA (48.0% in 1988-1995 compared with 42.3% in 1996-2002, P = .237), or rate of major congenital anomaly (8.2% in 1988-1995 compared with 10.0% in 1996-2002, P = .560). Diabetes remained an independent risk factor for LGA infants and major congenital anomaly after adjusting for possible confounders.

CONCLUSION

Rates of adverse neonatal outcomes are 3-9 times greater in infants of diabetic mothers compared with those of nondiabetic mothers. There were no significant improvements in rates of perinatal mortality, congenital anomaly, or LGA birth in infants of diabetic mothers in 1996-2002 compared with 1988-95.

Type 1 diabetes and pregnancy: trends in birth weight over 40 years at a single clinic

OBJECTIVE

To examine changes in perinatal mortality and birth weight of babies born to mothers with pregestational type 1 diabetes over 40 years in a single teaching hospital clinic.

METHODS

This was a retrospective survey of cases from the combined diabetes and obstetrics antenatal clinic at the Royal Infirmary of Edinburgh and Simpson Memorial Maternity Pavilion, Edinburgh, Scotland. Birth weight, standardized birth weight, and perinatal mortality were obtained from 643 singleton babies born after 28 weeks of gestation to mothers with pregestational type 1 diabetes between 1960 and 1999.

RESULTS

There was a dramatic improvement in perinatal mortality rate, falling from 225 (per 1,000 total births after 28 weeks of gestation) in the 1960s to 102 in the 1970s, 21 in the 1980s, and 10 in the 1990s (P < .001 for effect of birth year). In contrast, standardized birth weight (adjusted for sex, gestational age, and parity), which was significantly higher than the background population (+1.41 standard deviations above the population norm, P < .001) showed no significant change over time.

CONCLUSION

Changes in diabetic management and obstetric practice over the 40 years of our survey have resulted in enormous improvements in the outlook for offspring of mothers with diabetes. Somewhat surprisingly this has not been associated with a reduction in overgrowth of the fetus.

LEVEL OF EVIDENCE

II-2.