Glucose tolerance in singleton, twin and triplet pregnancies

Chorionicity and gestational diabetes mellitus in twin pregnancies in relation to placental weight

BACKGROUND

Gestational diabetes mellitus (GDM) is glucose intolerance first detected during pregnancy. Twin pregnancies have a higher risk of GDM, likely due to increased placental mass and elevated placental lactogen levels.

OBJECTIVE

The aims of this study were 1) to assess the impact of chorionicity on the development of GDM in twin pregnancies and 2) to assess a possible association between placenta weight and the development of GDM.

METHODS

We conducted a prospective cohort study of all women with twin pregnancies (N = 819) at the department of Obstetrics and Gynecology, Lillebaelt University Hospital, Kolding, Denmark, between January 1, 2007 and April 30, 2019. Information on chronicity was determined at the first visit with ultrasonic imaging, during weeks' gestation 11-13. Oral glucose-tolerance test was performed to diagnose gestational diabetes mellitus.

RESULTS

Among 819 twins, 17.8 % were monochorionic twins and 82.2 % were dichorionic twins. There were no statistically significant difference of GDM prevalence between monochorionic twins group 7.4 % and dichorionic twins group 9.8 % (P = 0.42). Placenta's weight in dichorionic twins was larger compared with monochorionic twins. No association was found between the weight of placenta and the prevalence of GDM (P = 0.21), even after adjustment for body mass index, gestational age, and fertility treatment (P = 0.87).

CONCLUSIONS

Our study could not find an association between chorionicity, placental weight, and GDM. It is, therefore, possible that twin pregnancies, regardless of chorionicity and placental weight, have the same risk for GDM.

Gestational diabetes in twin pregnancies-a pathology requiring treatment or a benign physiological adaptation?

There is level-1 evidence that screening for and treating gestational diabetes in singleton pregnancies reduce maternal and neonatal morbidity. However, similar data for gestational diabetes in twin pregnancies are currently lacking. Consequently, the current approach for the diagnosis and management of gestational diabetes in twin pregnancies is based on the same diagnostic criteria and glycemic targets used in singleton pregnancies. However, twin pregnancies have unique physiological characteristics, and many of the typical gestational diabetes-related complications are less relevant for twin pregnancies. These differences raise the question of whether the greater increase in insulin resistance observed in twin pregnancies (which is often diagnosed as diet-treated gestational diabetes) should be considered physiological and potentially beneficial in which case alternative criteria should be used for the diagnosis of gestational diabetes in twin pregnancies. In this review, we summarize the most up-to-date evidence on the epidemiology, pathophysiology, and clinical consequences of gestational diabetes in twin pregnancies and review the available data on twin-specific screening and diagnostic criteria for gestational diabetes. Although twin pregnancies are associated with a higher incidence of diet-treated gestational diabetes, diet-treated gestational diabetes in twin pregnancies is less likely to be associated with adverse outcomes and accelerated fetal growth than in singleton pregnancies and may reduce the risk for intrauterine growth restriction. In addition, there is currently no evidence that treatment of diet-treated gestational diabetes in twin pregnancies improves outcomes, whereas preliminary data suggest that strict glycemic control in such cases might increase the risk for intrauterine growth restriction. Overall, these findings provide support to the hypothesis that the greater transient increase in insulin resistance observed in twin pregnancies is merely a physiological exaggeration of the normal increase in insulin resistance observed in singleton pregnancies (that is meant to support 2 fetuses) rather than a pathology that requires treatment. These data illustrate the need to develop twin-specific screening and diagnostic criteria for gestational diabetes to avoid overdiagnosis of gestational diabetes and to reduce the risks associated with overtreatment of diet-treated gestational diabetes in twin pregnancies. Although data on twin-specific screening and diagnostic criteria are presently scarce, preliminary data suggest that the optimal screening and diagnostic criteria in twin pregnancies are higher than those currently used in singleton pregnancies.

Twin Pregnancy Complicated by Gestational Diabetes Mellitus: Maternal and Neonatal Outcomes

Context

The risk of gestational diabetes mellitus (GDM) in twin pregnancies is more than double that of singleton pregnancies. Although twin pregnancies present unique challenges for fetal growth and prenatal management, the approach to GDM diagnosis and treatment is the same regardless of plurality. Data on pregnancy outcomes for individuals with GDM and a twin pregnancy are limited and conflicting.

Objective

To describe the maternal characteristics associated with GDM in twin pregnancies and to assess the associated pregnancy outcomes compared to twin pregnancies unaffected by GDM.

Methods

A retrospective cohort study was conducted at Mayo Clinic, Rochester, Minnesota, USA, and included predominantly Causasian women aged 18 to 45 years who received prenatal care for a twin pregnancy from 2017-2022. Maternal characteristics and a broad spectrum of pregnancy outcomes were evaluated. Universal GDM screening involved a 50 g oral glucose challenge test +/- a 100 g oral glucose tolerance test.

Results

GDM was diagnosed in 23% pregnancies (n = 104/452). Compared to those without, women with GDM had known risk factors including a higher prepregnancy body mass index (31.1vs 26.3 kg/m2; P < .01) and a prior history of GDM (21.7 vs 5.9%; P < .01). There were no differences in maternal pregnancy complications or neonatal outcomes between groups. Attendance at postpartum glucose testing among women with GDM was poor at 27.9% (29/104).

Conclusion

These data suggest that women with twin pregnancies share a similar GDM risk profile to those with singleton pregnancies and provide reassuring evidence that current management for GDM twin pregnancies produces similar outcomes to twin pregnancies without GDM.

Maternal diabetes following gestational diabetes: Does multiple gestation multiply the risk?

OBJECTIVE

To assess whether the risk for future diabetes is higher among women diagnosed with gestational diabetes (GD) during twin versus singleton gestations.

METHOD

A retrospective cohort study was performed including all women who delivered at a tertiary medical center between the years 1991 and 2021 and had at least one GD diagnosis. The first GD diagnosis per women was defined as the index pregnancy. Women diagnosed with GD during multiple gestations were compared with women diagnosed with GD during singleton gestations. The outcomes included first hemoglobin A1C (Hba1C) level > 6.4 mg/dL post partum, and the highest level measured during the follow-up period of up to 30 years. Multivariable logistic and Cox proportional analysis were used to compare the risk between the two groups while adjusting for confounding variables.

RESULTS

The current study included 13 770 mothers, with 458 patients (3.3%) diagnosed with GD during twin gestations and 13 312 (96.7%) during singleton gestations. The mean follow-up was 12.25 ± 9.3 years. Mothers of both groups did not differ in age at index pregnancy; however, mothers of twins were more likely to conceive following fertility treatments. Incidence of diabetes and prediabetes (defined as Hba1C > 6.4 and >5.7, respectively) were lower among the twin-gestation group, both during the 6-month postpartum period (for diabetes: 15.5% vs 22.1%; odds ratio [OR], 0.65 [95% confidence interval (CI), 0.46-0.91]) and during the long-term follow-up (for diabetes: 31.8% vs 40.7%; OR, 0.68 [95% CI, 0.52-0.88]). These results remained significant in the multivariable analysis, while accounting for age, ethnicity, and fertility treatments.

CONCLUSION

GD diagnosis during multiple versus singleton gestations is associated with a lower risk for future diabetes.

Clinical Factors for Predicting Pharmacotherapy in Twin Pregnancies Complicated by Gestational Diabetes Mellitus

Controlling blood glucose levels is the main target in pregnant women with gestational diabetes mellitus (GDM). Twin pregnancies are offered the same screening selection and have the same diagnostic criteria as well as treatment of gestational diabetes as singleton pregnancies, even though the risks for pregnancy complications are increased. The aim of this study was to assess the association between predicting factors, OGTT glucose levels and pharmacotherapy requirements in twin pregnancies with GDM. This retrospective cohort study included 446 GDM patients with twin pregnancies (246 managed with lifestyle modifications and 200 requiring pharmacotherapy) over a time period of 18 years. An evaluation of maternal characteristics and a standardized 75 g oral glucose test (OGGT) for glucose concentrations at fasting, 1 h and 2 h were conduced. OGTT glucose levels at fasting (=0 min, p < 0.01) and 1 h (p < 0.01) were significantly associated with the later requirement of pharmacotherapy. Also, clinical risk factors (pre-pregnancy BMI p < 0.01, multiparity p < 0.05, GDM in previous pregnancy p < 0.01, assisted reproduction p < 0.05) showed a predictive accuracy for insulin therapy in twin pregnancies complicated by GDM, whereas age and chorionicity had no effect. OGTT glucose measures in addition to clinical risk factors are promising variables for risk stratification in mothers with GDM and twin pregnancy.

Characteristics of the oral glucose tolerance test in women with different pre-pregnancy body mass index and the effect of gestational diabetes mellitus on twin pregnancy outcomes

OBJECTIVE

This study aimed to investigate the mid-pregnancy blood glucose levels of women with singleton or twin pregnancies.

METHOD

The relationship between blood glucose levels and Gestational Diabetes Mellitus (GDM) was studied in women with different pre-pregnancy Body Mass Index (BMI), and the effect of GDM on twin pregnancy outcomes was analyzed. Women with twin (n = 1,985) and singleton (n = 1,985) pregnancies were categorized into underweight (BMI < 18.5 kg/m2, n = 597), normal weight (BMI: 18.5-23.9 kg/m2, n = 2,575), and overweight/obese (BMI ≥ 24 kg/m2, n = 798) groups.

RESULTS

The incidence of GDM was 21.01% in women with twin pregnancies. Among the women with GDM in twin pregnancies, 38.37% had at least two abnormal blood glucose levels. The incidence of these parameters increased with preconception BMI, and the incidence of twin pregnancies was higher than that of singleton pregnancies (p < 0.001). In the normal weight and overweight/obese group, the oral glucose tolerance test glucose level and incidence of GDM were higher in women with twin than singleton pregnancies (p < 0.05). For twin pregnancies, the prevalence of selective fetal growth restriction was higher and anemia was lower in the GDM group than in the non-GDM group (all p < 0.05).

CONCLUSION

Therefore, a greater emphasis should be placed on BMI before conception, and well-controlled GDM does not increase adverse pregnancy outcomes for twin pregnancies.

Association between One Abnormal Value on 3-Hour Oral Glucose Tolerance Test and Adverse Perinatal Outcomes in Twin Gestation

AIM

To investigate whether women with twin gestation and one abnormal value on the diagnostic 3-hour oral glucose tolerance test (OGTT) are at an increased risk of adverse perinatal outcomes.

METHODS

This was a retrospective multicenter study of women with twin gestation, comparing four groups: (1) normal 50-g screening, (2) normal 100-g 3-hour OGTT, (3) one abnormal value on the 3-hour OGTT, and (4) GDM. Multivariable logistic regressions adjusted for maternal age, gravidity, parity, previous CDs, fertility treatments, smoking, obesity and chorionicity were used.

RESULTS

The study included 2,597 women with twin gestations, of which 79.7% had a normal screen, and 6.2% had one abnormal value on the OGTT. In adjusted analyses, women with one abnormal value were found to have higher rates of preterm delivery <32 weeks, large for gestational age neonates, and composite neonatal morbidity of at least one fetus, however, similar maternal outcomes as those with a normal screen.

CONCLUSION

Our study provides evidence that women with twin gestation and one abnormal value on the 3-hour OGTT are at an increased risk of unfavorable neonatal outcomes. This was confirmed by multivariable logistic regressions. Further research is needed to determine whether interventions such as nutritional counseling, blood glucose monitoring, and treatment with diet and medication would improve perinatal outcomes in this population.

Gestational Diabetes Mellitus Does Not Worsen Obstetrical and Neonatal Outcomes of Twin Pregnancy

The specific effects of gestational diabetes mellitus (GDM) on twin pregnancy outcomes, which are at high risk per se, are unclear. The present study analyzes outcomes of twin pregnancies complicated by GDM (n = 227) by comparing them with GDM singleton pregnancies (n = 1060) and with twin pregnancies without GDM (n = 1008), all followed up at Sant'Anna Hospital, Turin (Italy), between January 2010 and March 2020. The prevalence of GDM among twin pregnancies (n = 1235) was 18.4%. Compared to GDM singletons, GDM twins had higher rates of preeclampsia (aOR 2.0; 95% CI 1.2-3.8), cesarean section (aOR 7.5; 95% CI 5.2-10.8), and neonatal hypoglycemia (aOR 2.5; 95% CI 1.1-5.3). They had a higher incidence of abnormal 2 h OGTT values (aOR 7.1; 95% CI: 3.2-15.7) and were less likely to require insulin therapy (aOR 0.5; 95% CI: 0.3-0.7). In comparison with twin pregnancies without GDM, women with GDM twins were significantly older (35.0 vs. 33.0 years; p < 0.001) and had higher BMI (23.0 versus 22.0 kg/m²; p < 0.001); they had a higher incidence of LGA newborns (aOR 5.3; 95% CI 1.7-14.8), and lower incidence of low APGAR scores (0.5; 95% CI 0.3-0.9). Overall, GDM does not worsen outcomes of twin pregnancy, which is per se at high risk for adverse outcomes.

The prevalence and associated factors of prenatal depression and anxiety in twin pregnancy: a cross-sectional study in Chongqing, China

Background

Pregnant women expecting twins are more likely to experience stress, which can lead to anxiety and depression. Our aim was to investigate the prevalence of prenatal anxiety and depressive symptoms in women with twin pregnancies and the associated factors.

Methods

In a cross-sectional survey, 210 women with twin pregnancies who satisfied the inclusion and exclusion criteria in two tertiary centers in Southwestern China were asked to complete a basic information form, the Self-Rating Anxiety Scale (SAS) and the Self-Rating Depression Scale (SDS). To compare statistics with normal distribution in distinct characteristic groups, a paired t-test, and one-way ANOVA were utilized. Binary logistic step regression was used to analyze the associated factors of antenatal anxiety and depressive symptoms.

Results

The 210 women with twin pregnancies (age = 30.8 ± 4.2 years) were between 7 and 37 gestational weeks (29.2 ± 1.2 weeks), were typically well-educated (72.4% had a post-high-school degree), and reasonably affluent (88.1% were above the low-income cutoff). Among them, 34.8% had symptoms associated with clinical levels of anxiety, and 37.1% had symptoms indicating possible depression. The prevalence of co-morbid anxiety and depressive symptoms was 24.3%. Binary stepwise logistic regression analysis showed that previous health status and sleep disturbance during pregnancy were the associated factors of anxiety symptoms in women with twin pregnancies (P < 0.05), whereas age, previous health status, negative life events, and physical activity during pregnancy were the associated factors of depressive symptoms in women with twin pregnancies (P < 0.05).

Conclusion

About one-third of women with twin pregnancies had symptoms of anxiety or depression; these were most strongly predicted by some modifiable factors, suggesting that early preventive mind-body interventions may be a promising strategy to protect against mental health issues for women with twin pregnancies.

Screening Accuracy of the 50 g-Glucose Challenge Test in Twin Compared With Singleton Pregnancies

CONTEXT

The optimal 50 g-glucose challenge test (GCT) cutoff for the diagnosis of gestational diabetes mellitus (GDM) in twin pregnancies is unknown.

OBJECTIVE

This work aimed to explore the screening accuracy of the 50 g-GCT and its correlation with the risk of large for gestational age (LGA) newborn in twin compared to singleton pregnancies. A population-based retrospective cohort study (2007-2017) was conducted in Ontario, Canada. Participants included patients with a singleton (n = 546 892 [98.4%]) or twin (n = 8832 [1.6%]) birth who underwent screening for GDM using the 50 g-GCT.

METHODS

We compared the screening accuracy, risk of GDM, and risk of LGA between twin and singleton pregnancies using various 50 g-GCT cutoffs.

RESULTS

For any given 50 g-GCT result, the probability of GDM was higher (P = .0.007), whereas the probability of LGA was considerably lower in the twin compared with the singleton group, even when a twin-specific growth chart was used to diagnose LGA in the twin group (P < .001). The estimated false-positive rate (FPR) for GDM was higher in twin compared with singleton pregnancies irrespective of the 50 g-GCT cutoff used. The cutoff of 8.2 mmol/L (148 mg/dL) in twin pregnancies was associated with an estimated FPR (10.7%-11.1%) that was similar to the FPR associated with the cutoff of 7.8 mmol/L (140 mg/dL) in singleton pregnancies (10.8%).

CONCLUSION

The screening performance of the 50 g-GCT for GDM and its correlation with LGA differ between twin and singleton pregnancies.

Perinatal Outcomes and Related Risk Factors of Single vs Twin Pregnancy Complicated by Gestational Diabetes Mellitus: Meta-Analysis

Objective

Perinatal outcomes and related risk factors of single vs twin pregnancy complicated with gestational diabetes mellitus (GDM) were clarified, providing evidence for developing preventive measures.

Methods

The Chinese National Knowledge Infrastructure (CNKI), China Biology Medicine (CBM), CQVIP, Wanfang, and PubMed databases were searched for published research on the perinatal outcomes and risk factors of single and twin pregnancy complicated by GDM from 2000 to 2021. The quality of the included literature was evaluated according to the Newcastle-Ottawa Scale (NOS). Meta-analysis of the included literature was conducted using RevMan5.3 software.

Results

Relative to a single pregnancy group, infertility, gestational weight gain, and family history of diabetes presented statistical significance in the twin pregnancy group (P < 0.05); gestational age at delivery, cesarean section, preterm birth < 37 weeks, and preeclampsia presented statistical significance in the twin pregnancy group (P < 0.05); and neonatal birth weight, small for gestational age (SGA), neonatal asphyxia, neonatal hypoglycemia, neonatal respiratory distress syndrome (NRDS), neonatal hyperbilirubinemia, and neonatal death presented statistical significance in the twin pregnancy group (P < 0.05).

Conclusion

Infertility, prenatal weight gain, and diabetes in the family are all risk factors for postpartum impaired glucose metabolism in pregnant women with GDM who are carrying twins. The gestational age at delivery, cesarean section, preterm birth < 37 weeks, and preeclampsia of twin pregnant women with diabetes will affect the perinatal status of twin pregnant women. Neonatal birth weight, SGA, neonatal asphyxia, neonatal hypoglycemia, NRDS, neonatal hyperbilirubinemia, neonatal death, etc. should be paid special attention in the perinatal process.

WHO criteria for diabetes in pregnancy: a retrospective cohort

BACKGROUND

Recognizing that hyperglycemia in pregnancy can impact both individually a patient's health and collectively the healthcare system and that different levels of hyperglycemia incur different consequences, we aimed to evaluate the differences and similarities between patients who met the diagnostic criteria for gestational diabetes mellitus (GDM) or diabetes in pregnancy (DIP) according to the World Health Organization diagnostic criteria based on the 75 g oral glucose tolerance test (OGTT).

METHODS

This retrospective study included a cohort of 1064 women followed-up at the Gestational Diabetes Unit of Hospital das Clinicas da Faculdade de Medicina da Universidade de Sao Paulo (Sao Paulo, Brazil). Patients were classified into GDM and DIP groups, according to their OGTT results. Their electronic charts were reviewed to obtain clinical and laboratory data for all participants.

RESULTS

Women in the DIP group had a higher pre-pregnancy body mass index (30.5 vs 28.1 kg/m², odds ratio [OR] 1.07, 95% confidence interval [CI] 1.02-1.11), more frequently experienced GDM in a previous pregnancy (25% vs. 11%, OR 2.71, 95% CI 1.17-6.27), and were more likely to have chronic hypertension (43.1% vs. 23.5%, OR 2.46, 95% CI 1.47-4.11), a current twin pregnancy (10.8% vs. 2.9%, OR 4.04, 95% CI 1.70-9.61), or require insulin (46.1% vs. 14.3%, OR 5.14, 95% CI 3.06-8.65) than those in the GDM group. Patients in the DIP group also had a higher frequency of large-for-gestational-age infants (12.3% vs. 5.1%, OR 2.78, 95% CI 1.23-6.27) and abnormal postpartum OGTT (45.9% vs. 12.6%, OR 5.91, 95% CI 2.93-11.90) than those in the GDM group. Nevertheless, in more than half of the DIP patients, glucose levels returned to normal after birth.

CONCLUSIONS

Diabetes in pregnancy is associated with an increased risk of adverse perinatal outcomes but does not equate to a diagnosis of diabetes post-pregnancy. It is necessary to identify and monitor these women more closely during and after pregnancy. Keeping patients with hyperglycemia in pregnancy engaged in healthcare is essential for accurate diagnosis and prevention of complications related to abnormal glucose metabolism.

Gestational Diabetes in Twin Versus Singleton Pregnancies With Normal Weight or Overweight Pre-Pregnancy Body Mass Index: The Mediating Role of Mid-Pregnancy Weight Gain

BACKGROUND

Gestational diabetes might be more common in twin versus singleton pregnancies, yet the reasons for this are unclear. We evaluated the extent to which this relationship is explained by higher mid-pregnancy weight gain within normal weight and overweight pre-pregnancy body mass index (BMI) strata.

METHODS

We analyzed serial weights and glucose screening and diagnostic data abstracted from medical charts for twin (n = 1397) and singleton (n = 3117) pregnancies with normal or overweight pre-pregnancy BMI delivered from 1998 to 2013 at Magee-Womens Hospital in Pennsylvania. We used causal mediation analyses to estimate the total effect of twin versus singleton pregnancy on gestational diabetes, as well as those mediated (natural indirect effect) and not mediated (natural and controlled direct effects) by pathways involving mid-pregnancy weight gain.

RESULTS

Odds of gestational diabetes were higher among twin pregnancies [odds ratios (ORs) for total effect = 2.83 (95% CI = 1.54, 5.19) for normal weight and 2.09 (95% CI = 1.16, 3.75) for overweight pre pregnancy BMI], yet there was limited evidence that this relationship was mediated by mid-pregnancy weight gain [ORs for natural indirect effect = 1.21 (95% CI = 0.90, 1.24) for normal weight and 1.06 (95% CI = 0.92, 1.21) for overweight pre-pregnancy BMI] and more evidence of mediation via other pathways [ORs for natural direct effect = 2.34 (95% CI = 1.24, 4.40) for normal weight and 1.97 (95% CI = 1.08, 3.60) for overweight pre-pregnancy BMI].

CONCLUSIONS

While twin pregnancies with normal weight or overweight pre-pregnancy BMI experienced higher odds of gestational diabetes versus singletons, most of this effect was explained by pathways not involving mid-pregnancy weight gain.

Early Initiation and Long-Term Use of Vaginal Progesterone may Cause Gestational Diabetes Mellitus

BACKGROUND

Preterm birth (PTB) is an important cause of neonatal mortality and morbidity. Spontaneous PTB (sPTB) is the most common cause of PTB. In patients with a singleton pregnancy, progesterone treatment appears to reduce the rate of spontaneous preterm birth in those with a previous history of spontaneous preterm labor and/or cervical shortening in the current pregnancy. Progesterone therapies used for the prevention of sPTB may increase the risk of gestational diabetes mellitus (GDM) towards the end of pregnancy owing to their effects on carbohydrate metabolism.

AIM

We aimed to show the effects of vaginal progesterone use, starting time, and duration of treatment on GDM.

METHODS

A retrospective cohort study was carried out in pregnant women 18 to 39 years old who came to our hospital between January 1, 2021, and August 31, 2021, and who had a 2-hour 75-g oral glucose tolerance test (OGTT) at 24 to 28 weeks of gestation. In a total of 540 patients, 68 were diagnosed with GDM based on at least one abnormal plasma glucose value at screening. The remaining 472 patients with normal plasma glucose levels were considered as the control group. The groups were compared in terms of age, parity, pre-pregnancy body mass index (BMI), smoking, gestational age, and vaginal progesterone use. Patients using vaginal progesterone with and without GDM were then compared again in terms of indications for vaginal progesterone use, initiation time of progesterone therapy, duration of progesterone use, and cervical length.

RESULTS

The incidence of GDM in our study group was 12.5%. Despite the use of vaginal progesterone at a higher rate in the GDM group than in the control group (23.5 vs. 13.9%; p=0.07), it was not statistically significant. When we examined patients using progesterone as a subgroup analysis, the mean time to start vaginal progesterone treatment was 19.8±2.6 (14-24), and it was significantly earlier in the GDM group (18.1±2.0 vs. 20.2±2.6; p=0.007). Initiation of vaginal progesterone before 20 weeks of gestation was statistically significantly more frequent in the GDM group than the control group (68.8 vs. 39.4%; p=0.050 OR :3.3, 95%CI: 1.0-10.8). The mean duration of vaginal progesterone use was 50.0±15.6 days (28-90) and it was longer in the GDM group (57.8±13.4 vs. 48.1±15.6; p=0.027).

CONCLUSION

Since the duration of vaginal progesterone use will be prolonged, there may be a risk of GDM, especially in patients who started vaginal progesterone before the 20th week of pregnancy. Even if the OGTT test performed between 24-28 weeks is normal, it should be kept in mind that these patients may have GDM in the later weeks of pregnancy, and repeating the OGTT test should be considered if necessary.

Gestational diabetes and fetal growth in twin compared with singleton pregnancies

BACKGROUND

Gestational diabetes mellitus is associated with accelerated fetal growth in singleton pregnancies but may affect twin pregnancies differently because of the slower growth of twin fetuses during the third trimester of pregnancy and their greater predisposition to fetal growth restriction.

OBJECTIVE

This study aimed to evaluate the association of gestational diabetes mellitus with longitudinal fetal growth in twin pregnancies and to compare this association with that observed in singleton pregnancies.

STUDY DESIGN

This was a retrospective cohort study of all women with a singleton or twin pregnancy who were followed up at a single tertiary referral center between January 2011 and April 2020. Data on estimated fetal weight and individual fetal biometric indices were extracted from ultrasound examinations of eligible women. Generalized linear models were used to model and compare the change in fetal weight and individual biometric indices as a function of gestational age between women with and without gestational diabetes mellitus in twin pregnancies and between women with and without gestational diabetes mellitus in singleton pregnancies. The primary outcome was estimated fetal weight as a function of gestational age. The secondary outcomes were longitudinal growth of individual fetal biometric indices and the rate of small for gestational age and large for gestational age at birth.

RESULTS

A total of 26,651 women (94,437 ultrasound examinations) were included in the analysis: 1881 with a twin pregnancy and 24,770 with a singleton pregnancy. The rate of gestational diabetes mellitus in the twin and singleton groups was 9.6% (n=180) and 7.6% (n=1893), respectively. The estimated fetal weight in singleton pregnancies with gestational diabetes mellitus was significantly higher than that in pregnancies without gestational diabetes mellitus (P<.001) starting at approximately 30 weeks of gestation. The differences remained similar after adjusting for maternal age, chronic hypertension, nulliparity, and neonatal sex (P<.001). In twin pregnancies, fetal growth was similar between pregnancies with and without gestational diabetes mellitus (P=.105 and P=.483 for unadjusted and adjusted models, respectively). The findings were similar to the association of gestational diabetes mellitus with the risk of large for gestational fetuses and the growth of each biometric index. When stratified by type of gestational diabetes mellitus treatment, twin pregnancies with gestational diabetes mellitus was associated with accelerated fetal growth only in the subgroup of women with medically treated gestational diabetes mellitus (P<.001), which represented 12% (n=21) of the twin pregnancy group with gestational diabetes mellitus.

CONCLUSION

In contrast to singleton pregnancies, twin pregnancies with gestational diabetes mellitus is less likely to be associated with accelerated fetal growth. This finding has raised the question of whether the diagnostic criteria for gestational diabetes mellitus and the blood glucose targets in women diagnosed with gestational diabetes mellitus should be individualized for twin pregnancies.

First-Trimester Screening for Gestational Diabetes Mellitus in Twin Pregnancies

We previously reported a logistic regression model for prediction of GDM from maternal characteristics and medical history in 75,161 singleton pregnancies. In this study of 1376 twin and 13,760 singleton pregnancies recruited at 11-13 weeks' gestation, we extend the model to include terms for twin pregnancies. We found the respective odds of GDM in dichorionic and monochorionic twin pregnancies to be 1.36 (95% CI: 1.02-1.81) and 2.78 (95% CI: 1.72-4.48) times higher than in singleton pregnancies. In both singleton and twin pregnancies, the risk for GDM increased with maternal age and weight and birth weight z-score of a baby in a previous pregnancy and is higher in women with a previous pregnancy complicated by GDM; in those with a first- or second-degree relative with diabetes mellitus; in women of Black, East Asian, and South Asian racial origin; and in pregnancies conceived through the use of ovulation-induction drugs. In singleton pregnancies, at 10% and 20% false-positive rate, the detection rate was 43% and 58%, respectively. In twin pregnancies, using risk cut-offs corresponding to 10% and 20% false-positive rates in singletons, the respective false-positive rates were 27% and 47%, and the detection rates were 63% and 81%.

Oral Glucose Tolerance Test Results in Pregnancy Can Be Used to Individualize the Risk of Future Maternal Type 2 Diabetes Mellitus in Women With Gestational Diabetes Mellitus

OBJECTIVE

We aimed to quantify the risk of future maternal type 2 diabetes mellitus (T2DM) in women with gestational diabetes mellitus (GDM) based on the type and number of abnormal 75-g oral glucose tolerance test (OGTT) values and the diagnostic criteria used for the diagnosis of GDM.

RESEARCH DESIGN AND METHODS

We conducted a population-based retrospective cohort study of all nulliparous women with a live singleton birth who underwent testing for GDM using a 75-g OGTT in Ontario, Canada (2007-2017). We estimated the incidence rate (per 1,000 person-years), overall risk (expressed as adjusted hazard ratio [aHR]), and risk at 5 years after the index pregnancy of future maternal T2DM. Estimates were stratified by the type and number of abnormal OGTT values, as well as by the diagnostic criteria for GDM (Diabetes Canada [DC] vs. International Association of the Diabetes and Pregnancy Study Groups [IADPSG] criteria).

RESULTS

A total of 55,361 women met the study criteria. The median duration of follow-up was 4.4 (interquartile range 2.8-6.3; maximum 10.3) years. Using women without GDM as reference (incidence rate 2.18 per 1,000 person-years), women with GDM were at an increased risk of future T2DM; this risk was greater when using the DC compared with the IADPSG criteria (incidence rate 18.74 [95% CI 17.58-19.90] vs. 14.07 [95% CI 13.24-14.91] per 1,000 person-years, respectively). The risk of future maternal T2DM increased with the number of abnormal OGTT values and was highest for women with three abnormal values (incidence rate 49.93 per 1,000 person-years; aHR 24.57 [95% CI 21.26-28.39]). The risk of future T2DM was also affected by the type of OGTT abnormality: women with an abnormal fasting value had the greatest risk, whereas women with an abnormal 2-h value had the lowest risk (aHR 14.09 [95% CI 12.46-15.93] vs. 9.22 [95% CI 8.19-10.37], respectively). Similar findings to those described above were observed when the risk of T2DM at a fixed time point of 5 years after the index pregnancy was considered as the outcome of interest.

CONCLUSIONS

In women with GDM, individualized information regarding the future risk of T2DM can be provided based on the type and number of abnormal OGTT values, as well as the diagnostic criteria used for the diagnosis of GDM.

DEVELOPING twin-specific 75-g oral glucose tolerance test diagnostic thresholds for gestational diabetes based on the risk of future maternal diabetes: a population-based cohort study

OBJECTIVE

To develop twin-specific outcome-based oral glucose tolerance test (OGTT) diagnostic thresholds for GDM based on the risk of future maternal type-2 diabetes.

DESIGN

A population-based retrospective cohort study (2007-2017).

SETTING

Ontario, Canada.

METHODS

Nulliparous women with a live singleton (n = 55 361) or twin (n = 1308) birth who underwent testing for gestational diabetes mellitus (GDM) using a 75-g OGTT in Ontario, Canada (2007-2017). We identified the 75-g OGTT thresholds in twin pregnancies that were associated with similar incidence rates of future type-2 diabetes to those associated with the standard OGTT thresholds in singleton pregnancies.

RESULTS

For any given 75-g OGTT value, the incidence rate of future maternal type-2 diabetes was lower for women with a twin than women with a singleton pregnancy. Using women with a negative OGTT as reference, the risk of future maternal type-2 diabetes in twin pregnancies with a positive OGTT based on the standard OGTT thresholds (9.86 per 1000 person years, adjusted hazard ratio (aHR) 4.79, 95% CI 2.69-8.51) was lower than for singleton pregnancies with a positive OGTT (18.74 per 1000 person years, aHR 8.22, 95% CI 7.38-9.16). The twin-specific OGTT fasting, 1-hour and 2-hour thresholds identified in the current study based on correlation with future maternal type-2 diabetes were 5.8 mmol/l (104 mg/dl), 11.8 mmol/l (213 mg/dl) and 10.4 mmol/l (187 mg/dl), respectively.

CONCLUSIONS

We identified potential twin-specific OGTT thresholds for GDM that are associated with a similar risk of future type-2 diabetes to that observed in women diagnosed with GDM in singleton pregnancies based on standard OGTT thresholds.

TWEETABLE ABSTRACT

Potential twin-specific OGTT thresholds for GDM were identified.

Management of multiple gestations

Multiple gestations are commonly encountered in both high-risk and low-risk pregnancies and, since the advent of assisted reproductive technologies in the 1980s, the numbers of multiple gestations have grown rapidly. Thus, an understanding of both the maternal and fetal risks associated with multiple gestations should be central to all obstetric practice. The ability to foresee issues and the know how to respond to the complications that develop are central to the correct management of these pregnant women. For some, appropriate management may include referral to a specialist maternal and fetal medicine physician or, in some cases, to a specialist fetal center. The present review provides a comprehensive and simplified overview of multiple gestations, including incidence, diagnosis, genetic considerations, complications (both general and specific to multiple gestation subtypes), and delivery management. It is essential that providers recognize the high-risk and specific complications that may affect a multiple gestation in order to provide the highest possible level of care for these pregnant women.

Vaginal Progesterone Has No Diabetogenic Potential in Twin Pregnancies: A Retrospective Case-Control Study on 1686 Pregnancies

Background: In this study, we aimed to investigate the incidence of gestational diabetes mellitus (GDM) in women who carried twin pregnancies and received vaginal progesterone. Methods: In this retrospective cohort study, 203 out of 1686 women with twin pregnancies received natural progesterone (200 mg/day between gestational weeks 16 + 0 and 36 + 0) vaginally for ≥ 4 weeks. The control group consisted of 1483 women with twin pregnancies without progesterone administration. Pearson’s Chi squared test, Fisher’s exact test, and Student’s t-test was used to compare differences between the control and the progesterone-treated groups. A multivariate binary logistic regression was performed to assess relative independent associations on the dependent outcome of GDM incidence. Results: Vaginal progesterone treatment in twin pregnancies had no significant influence on developing GDM (p = 0.662). Higher pre-pregnancy BMI (OR 1.1; p < 0.001), GDM in previous pregnancy (OR 6.0; p < 0.001), and smoking during pregnancy (OR 1.6; p = 0.014) posed an increased risk for developing GDM. Conclusion: In twin pregnancies, the use of vaginal progesterone for the prevention of recurrent preterm delivery was not associated with an increased risk of GDM.

The Association between Glucose Levels and Adverse Pregnancy Outcomes in Nondiabetic Twin Pregnancies

Objective  The aim of this study is to determine if hyperglycemia in twin pregnancies without gestational diabetes mellitus (GDM) is associated with an increased risk of adverse pregnancy outcomes. Study Design  Retrospective cohort study of twin pregnancies in a single Maternal-Fetal Medicine practice between 2005 and 2019 who underwent two-step GDM screening at 24 to 28 weeks. We excluded women with pregestational or gestational diabetes. We examined the association between maternal glycemia and adverse pregnancy outcomes. Glycemia was defined as the 1-hour GCT in all women, and each of the four values of the 3-hour OGTT in women who failed the GCT (≥130 mg/dL). Primary outcomes were preeclampsia, cesarean delivery, and neonatal hypoglycemia in either twin. Statistical tests used included Pearson's correlation, Student's t -test, Mann-Whitney U test, Chi-square test for trend, and logistic regression. Results  A total of 847 women underwent a GCT and 246 women underwent an OGTT. Increasing maternal glucose levels had no positive association with adverse outcomes. Women with preeclampsia, cesarean delivery, and neonatal hypoglycemia did not have higher mean GCT or OGTT values than women without these outcomes. There was no increased risk of adverse outcomes with increasing quartiles of the GCT or OGTT values. Conclusion  In women with twin pregnancies without GDM, elevated maternal glucose levels are not associated with preeclampsia, cesarean delivery, or neonatal hypoglycemia. The altered physiology of twin gestations may modify the effect of maternal hyperglycemia on perinatal outcomes as compared with singleton pregnancies. Current approaches to screening for and treating GDM during pregnancy might not adequately account for these unique considerations among twins.

Prevalence of Gestational Diabetes in Triplet Pregnancies: A Retrospective Cohort Study and Meta-Analysis

Background: Over the last decades, there has been a substantial increase in the incidence of higher-order multiple gestations. Twin pregnancies are associated with an increased risk of gestational diabetes mellitus (GDM). The literature on GDM rates in triplet pregnancies is scarce. Methods: A retrospective cohort study was performed to assess the prevalence of GDM in women with a triplet pregnancy. GDM was defined through an abnormal oral glucose tolerance test (OGTT). A meta-analysis of GDM prevalence was also carried out. Results: A cohort of 60 women was included in the analysis. Of these, 19 (31.7%) were diagnosed with GDM. There were no differences in pregnancy outcomes between women with and without GDM. In the meta-analysis of 12 studies, which used a sound GDM definition, an estimated pooled prevalence of 12.4% (95% confidence interval: 6.9–19.1%) was found. In a leave-one-out sensitivity analysis, the estimated GDM prevalence ranged from 10.7% to 14.1%. Conclusion: The rate of GDM seems increased in women with triplets compared to singleton pregnancies. However, GDM did not impact short-term pregnancy outcomes.

The relationship between maternal body mass index and pregnancy outcomes in twin compared with singleton pregnancies

OBJECIVE

Women with twins have an a priori increased risk for many of the complications associated with maternal obesity. Thus, the impact of maternal obesity in twins may differ from that reported in singletons. In addition, given the increased metabolic demands in twin pregnancies, the impact of maternal underweight may be greater in twin compared with singleton gestations. Our objective was to test the hypothesis that the relationship between maternal pre-pregnancy body mass index (BMI) and adverse pregnancy outcomes differ between twin and singleton gestations.

METHODS

This was a retrospective population-based study of all women who had a singleton or twin hospital birth in Ontario, Canada, between April 2012 and March 2016. Data were obtained from the Better Outcomes Registry & Network (BORN) Ontario. The relationship between maternal BMI category and pregnancy complications was assessed separately in twin and singleton gestations. The primary outcome was a composite variable that included any of the following complications: preeclampsia, gestational diabetes, or preterm birth before 32^0/7 weeks. Relative risk (aRR) and 95% confidence intervals (CI) for adverse outcomes for each BMI category as defined by WHO (using normal weight category as reference) were generated using modified Poisson regression, adjusting for maternal age, nulliparity, smoking, previous preterm birth, and fetal sex.

RESULTS

A total of 487,870 women with singleton (n = 480,010) and twin (n = 7860) pregnancies met the inclusion criteria. The risk of the composite primary outcome, preeclampsia, gestational diabetes, and cesarean delivery increased with high maternal BMI in both singleton and twin gestations, but these associations were weaker in twin compared with singleton gestations (association of BMI ≥ 40.0 kg/m² with primary outcome: aRR = 3.10, 95%-CI 2.96-3.24 in singletons compared with aRR = 1.74, 95%-CI 1.37-2.20 in twins). In singleton pregnancies the risk of preterm birth at < 32^0/7 weeks increased with maternal BMI, mainly due to an increased risk of provider-initiated preterm birth. In twin gestations, however, underweight (but not overweight or obesity) was associated with the greatest risk of preterm birth at < 32 weeks (aRR 1.67, 95%-CI 1.17-2.37), mainly due to an increased risk of spontaneous preterm birth (aRR 2.10, 95%-CI 1.44-3.08).

CONCLUSION

In healthy women with twin pregnancies, underweight is associated with the greatest risk for preterm birth, while the association of maternal obesity with adverse pregnancy outcomes is weaker than that observed in singletons.

Gestational diabetes mellitus is associated with adverse outcomes in twin pregnancies

BACKGROUND

Among singleton pregnancies, gestational diabetes mellitus is associated with adverse outcomes. In twin pregnancies, this association may be attenuated, given the higher rate of prematurity and the a priori increased risk of some of these complications.

OBJECTIVE

Our aim was to test the hypothesis that gestational diabetes mellitus is less likely to be associated with adverse pregnancy outcomes in twin compared with singleton gestations.

METHODS

This retrospective cohort study comprised all twin and singleton live births in Ontario, Canada, 2012-2016. Pregnancy outcomes were compared between women with vs without gestational diabetes mellitus, analyzed separately for twin and singleton births. Adjusted risk ratios and 95% confidence intervals were generated using modified Poisson regression, adjusting for maternal age, nulliparity, smoking, race, body mass index, preexisting hypertension, and assisted reproductive technology.

RESULTS

A total of 270,843 women with singleton (n = 266,942) and twin (n = 3901) pregnancies met the inclusion criteria. In both the twin and singleton groups, gestational diabetes mellitus was associated with (adjusted risk ratio, [95% confidence interval]) cesarean delivery (1.11 [1.02-1.21] and 1.20 [1.17-1.23], respectively) and preterm birth at <37^0/7 weeks (1.21 [1.08-1.37] and 1.48 [1.39-1.57]) and at <34^0/7 weeks (1.45 [1.03-2.04] and 1.25 [1.06-1.47]). In singletons, but not twins, gestational diabetes mellitus was associated with gestational hypertension (1.66 [1.55-1.77]) and preeclampsia. With respect to neonatal outcomes, gestational diabetes mellitus was associated with birthweight greater than the 90th percentile in both twins and singletons, with the risk being 2-fold higher in twins (2.53 [1.52-4.23] vs 1.18 [1.13-1.23], respectively, P = .004). Gestational diabetes mellitus was associated with jaundice in both twins (1.56 [1.10-2.21]) and singletons (1.49 [1.37-1.62) but was associated with the following complications only in singletons: neonatal intensive care unit admission (1.44 [1.38-1.50]), respiratory morbidity (1.09 [1.02-1.16]), and neonatal hypoglycemia (3.20 [3.01-3.40]).

CONCLUSION

In contrast to singleton pregnancies, gestational diabetes mellitus in twins was not associated with hypertensive complications and certain neonatal morbidities. Still, the current study highlights that gestational diabetes mellitus is associated with some adverse pregnancy outcomes including accelerated fetal growth also in twin pregnancies.

Excessive Neutrophil Activity in Gestational Diabetes Mellitus: Could It Contribute to the Development of Preeclampsia?

Gestational diabetes mellitus is a transient form of glucose intolerance occurring during pregnancy. Pregnancies affected by gestational diabetes mellitus are at risk for the development of preeclampsia, a severe life threatening condition, associated with significant feto-maternal morbidity and mortality. It is a risk factor for long-term health in women and their offspring. Pregnancy has been shown to be associated with a subliminal degree of neutrophil activation and tightly regulated generation of neutrophil extracellular traps (NETs). This response is excessive in cases with preeclampsia, leading to the presence of large numbers of NETs in affected placentae. We have recently observed that circulatory neutrophils in cases with gestational diabetes mellitus similarly exhibit an excessive pro-NETotic phenotype, and pronounced placental presence, as detected by expression of neutrophil elastase. Furthermore, exogenous neutrophil elastase liberated by degranulating neutrophils was demonstrated to alter trophoblast physiology and glucose metabolism by interfering with key signal transduction components. In this review we examine whether additional evidence exists suggesting that altered neutrophil activity in gestational diabetes mellitus may contribute to the development of preeclampsia.