Pregnancy complicated by diabetes: what is the best level of HbA1c for conception?

Joint Effect of Maternal Tobacco Smoking and Pregestational Diabetes on Preterm Births and Congenital Anomalies: A Population-Based Study in Northern Italy

Smoking and pregestational diabetes (PGD) are recognized risk factors for adverse pregnancy outcomes, but to date, no population-based study has investigated their joint effects. Using hospital discharges, we identified all women with PGD delivering in Emilia-Romagna region during 2007-2010 matched 1 : 5 with parturients without diabetes. Our study endpoints were preterm births and congenital anomalies. We measured interaction between PGD and maternal smoking, by calculating excess prevalence and prevalence ratio due to interaction, relative excess risk due to interaction (RERI), attributable proportion (AP), and the synergy index (S). Analyses were performed in the overall study population and in the subgroup whose PGD was validated through diabetes registers. The study included 992 women with PGD (10.5% smokers) and 4788 comparison women (11.9% smokers). The effects of PGD and maternal tobacco smoking were greater than additive for both preterm birth (excess prevalence due to interaction = 11.7%, excess ratio due to interaction = 1.5, RERI = 2.39, AP = 0.51, S = 2.82) and congenital anomalies (excess prevalence due to interaction = 2.2%, excess ratio due to interaction = 1.3, RERI = 1.33, AP = 0.49, S = 5.03). Joint effect on both endpoints was confirmed in the subgroup whose PGD status was validated. In conclusion, we found that maternal tobacco smoking and PGD intensify each other's effect on preterm birth and congenital anomalies.

Use of Insulin Lispro Protamine Suspension in Pregnancy

Maternal metabolism changes substantially during pregnancy, which poses numerous challenges to physicians managing pregnancy in women with diabetes. Insulin is the agent of choice for glycemic control in pregnant women with diabetes, and the insulin analogs are particularly interesting for use in pregnancy. These agents may reduce the risk of hypoglycemia and promote a more physiological glycemic profile than regular human insulin in pregnant women with type 1 (T1D), type 2 (T2D), or gestational (GDM) diabetes. However, there have been concerns regarding potential risk for crossing the placental barrier, mitogenic stimulation, teratogenicity, and embryotoxicity. Insulin lispro protamine suspension (ILPS), an intermediate- to long-acting insulin, has a stable and predictable pharmacological profile, and appears to have a favorable time–action profile and produce desirable basal and postprandial glycemic control. As the binding of insulin lispro is unaffected by the protamine molecule, ILPS is likely to have the same mitogenic and immunogenic potential as insulin lispro. Insulin lispro produces similar outcomes to regular insulin in pregnant women with T1D, T2D, or GDM, does not cross the placental barrier, and is considered a useful treatment option for pregnant women with diabetes. Clinical data support the usefulness of ILPS for basal insulin coverage in non-pregnant patients with T1D or T2D, and suggest that the optimal regimen, in terms of balance between efficacy and hypoglycemic risk, is a once-daily injection, especially in patients with T2D. Available data concerning use of ILPS in pregnant women are currently derived from retrospective analyses that involved, in total, >1200 pregnant women. These analyses suggest that ILPS is at least as safe and effective as neutral protamine Hagedorn insulin. Thus, available experimental and clinical data suggest that ILPS once daily is a safe and effective option for the management of diabetes in pregnant women.

Funding: Eli Lilly and Company.

An early pregnancy HbA1c ≥5.9% (41 mmol/mol) is optimal for detecting diabetes and identifies women at increased risk of adverse pregnancy outcomes

OBJECTIVE

Pregnant women with undiagnosed diabetes are a high-risk group that may benefit from early intervention. Extrapolating from nonpregnancy data, HbA1c ≥6.5% (48 mmol/mol) is recommended to define diabetes in pregnancy. Our aims were to determine the optimal HbA1c threshold for detecting diabetes in early pregnancy as defined by an early oral glucose tolerance test (OGTT) at <20 weeks' gestation and to examine pregnancy outcomes relating to this threshold.

RESEARCH DESIGN AND METHODS

During 2008-2010 in Christchurch, New Zealand, women were offered an HbA1c measurement with their first antenatal bloods. Pregnancy outcome data were collected. A subset completed an early OGTT, and HbA1c performance was assessed using World Health Organization criteria.

RESULTS

HbA1c was measured at a median 47 days' gestation in 16,122 women. Of those invited, 974/4,201 (23%) undertook an early OGTT. In this subset, HbA1c ≥5.9% (41 mmol/mol) captured all 15 cases of diabetes, 7 with HbA1c <6.5% (<48 mmol/mol). This HbA1c threshold was also 98.4% (95% CI 97-99.9%) specific for gestational diabetes mellitus (GDM) before 20 weeks (positive predictive value = 52.9%). In the total cohort, excluding women referred for GDM management, women with HbA1c of 5.9-6.4% (41-46 mmol/mol; n = 200) had poorer pregnancy outcomes than those with HbA1c <5.9% (<41 mmol/mol; n = 8,174): relative risk (95% CI) of major congenital anomaly was 2.67 (1.28-5.53), preeclampsia was 2.42 (1.34-4.38), shoulder dystocia was 2.47 (1.05-5.85), and perinatal death was 3.96 (1.54-10.16).

CONCLUSIONS

HbA1c measurements were readily performed in contrast to the low uptake of early OGTTs. HbA1c ≥5.9% (≥41 mmol/mol) identified all women with diabetes and a group at significantly increased risk of adverse pregnancy outcomes.

Screening with HbA1c identifies only one in two individuals with diagnosis of prediabetes at oral glucose tolerance test: findings in a real-world Caucasian population

OBJECTIVE

Discordance between HbA1c and OGTT in screening pre-diabetes may occur because of lack of laboratory standardization, distinct underlying pathophysiological processes or different ethnicity. We evaluated HbA1c efficacy for screening OGTT-defined IFG and IGT conditions in a large Caucasian population using the newly revised IFCC protocol.

RESEARCH DESIGN AND METHODS

A total of 501 consecutive subjects were screened for pre-diabetic conditions with OGTT with 75 g of glucose. Testing for HbA1c, lipid profile and fasting insulin levels was also performed. For detecting differences between continuous variables, ANOVA followed by Tukey's honestly significant difference (HSD) post hoc test was used. Logistic regression and ROC curve analysis were also performed for assessing HbA1c screening efficacy.

RESULTS

ROC curve analysis showed that optimal HbA1c cut-off for detecting IFG was 5.6 % (sensitivity of 78 % and specificity of 63 %), while for IGT, the optimal cut-off was 5.9 % (sensitivity of 46 % and specificity of 84 %), with AUCs < 0.8. Screening with HbA1c identified 53.4 % of the 193 patients with IFG and/or IGT diagnosed at OGTT. As regards surrogate markers of insulin resistance, we observed a trend towards higher values of HOMA-IR and lower QUICKI values in subjects with IFG than in those with IGT. Patients with pre-diabetes at both tests had similar values of HOMA and QUICKI, compared with those with altered OGTT only.

CONCLUSIONS

IFCC-aligned HbA1c assay proved scarcely effective in detecting IFG and/or IGT in a large Caucasian population, identifying only half of the patients with abnormal OGTT. Moreover, adding HbA1c screening to OGTT may be of little benefit in identifying subjects with a worse metabolic profile.

Can hemoglobin A1c in early pregnancy predict adverse pregnancy outcomes in diabetic patients?

OBJECTIVE

To examine the association of elevated early pregnancy hemoglobin A1c (HbA1c) levels with adverse pregnancy outcomes in women with preexisting diabetes mellitus.

STUDY DESIGN

Retrospective cohort study of 330 women with preexisting diabetes enrolled in a Diabetes in Pregnancy Program at an academic institution between 2003 and 2011 who had an early HbA1c determination. The frequencies of composite maternal adverse pregnancy outcomes (birth at<37 weeks, preeclampsia, and medically indicated birth <39 weeks), and composite fetal adverse pregnancy outcomes [shoulder dystocia, Apgar scores<7 at 5 minutes, small for gestational age (SGA), large for gestational age (LGA), and stillbirth] were compared between HbA1c categories (<6.5, 6.5-7.4, 7.5-8.4 and ≥ 8.5%).

RESULTS

There was no statistically significant difference between composite adverse maternal pregnancy outcomes and composite adverse fetal pregnancy outcomes as well as other individual outcomes between different HbA1c categories. Of the vaginally delivered women in our cohort, the 37 patients with HbA1c levels of ≥ 8.5% had a significantly higher frequency of fetal shoulder dystocia than the 62 with HbA1c levels of < 8.5% (24.2 vs. 1.6%, P = 0.002). Neonates of patients with HbA1c ≥ 8.5% were more likely to have low five minute Apgar scores than neonates of patients with HbA1c < 8.5%, but this was of borderline statistical significance (7.4% vs. 0.5%, P = 0.05).

CONCLUSION

In patients with preexisting diabetes mellitus, HbA1c levels of ≥ 8.5% during early pregnancy are not useful in predicting most adverse outcomes, although there may be an increased risk for shoulder dystocia.

Video-EEG recordings in full-term neonates of diabetic mothers: observational study

OBJECTIVE

To determine whether full-term newborn infants of diabetic mothers (IDM) present immature/disorganised EEG patterns in the immediate neonatal period, and whether there was any relationship with maternal glycaemic control.

DESIGN AND SETTING

Cohort study with an incidental sample performed in a tertiary hospital neonatal unit.

PATIENTS

23 IDM and 22 healthy newborns born between 2010 and 2013.

INTERVENTIONS

All underwent video-EEG recording lasting >90 min at 48-72 h of life.

MAIN OUTCOME MEASURES

We analysed the percentage of indeterminate sleep, transient sharp waves per hour and mature-for-gestational age EEG patterns (discontinuity, maximum duration of interburst interval (IBI), asynchrony, asymmetry, δ brushes, encoches frontales and α/θ rolandic activity). The group of IDM was divided into two subgroups according to maternal HbA1c: (1) HbA1c≥6% and (2) HbA1c<6%.

RESULTS

Compared with healthy newborns, IDM presented significantly higher percentage of indeterminate sleep (57% vs 25%; p<0.001), discontinuity (2.5% vs 0%; p=0.044) and δ brushes in the bursts (6% vs 3%; p=0.024); higher duration of IBI (0.3 s vs 0 s; p=0.017); fewer encoches frontales (7/h vs 35/h; p<0.001), reduced θ/α rolandic activity (3/h vs 9/h; p<0.001); and more transient sharp waves (25/h vs 5/h; p<0.001). IDM with maternal HbA1c≥6% showed greater percentage of δ brushes in the burst (14% vs 4%; p=0.007).

CONCLUSIONS

Full-term IDM newborns showed video-EEG features of abnormal development of brain function. Maternal HbA1c levels<6% during pregnancy could minimise the risk of cerebral dysmaturity.

Pregnancy in women with type 1 diabetes: have the goals of St. Vincent declaration been met concerning foetal and neonatal complications?

OBJECTIVE

In 1989 the St. Vincent declaration set a five-year target for approximating outcomes of pregnancies in women with diabetes to those of the background population. We investigated and quantified the risk of adverse pregnancy outcomes in pregnant women with type 1 diabetes (T1DM) to evaluate if the goals of the 1989 St. Vincent Declaration have been obtained concerning foetal and neonatal complications.

METHODS

Twelve population-based studies published within the last 10 years with in total 14,099 women with T1DM and 4,035,373 women from the background population were identified. The prevalence of four foetal and neonatal complications was compared.

RESULTS

In women with T1DM versus the background population, congenital malformations occurred in 5.0% (2.2-9.0) (weighted mean and range) versus 2.1% (1.5-2.9), relative risk (RR) = 2.4, perinatal mortality in 2.7% (2.0-6.6) versus 0.72% (0.48-0.9), RR = 3.7, preterm delivery in 25.2% (13.0-41.7) versus 6.0% (4.7-7.1), RR = 4.2 and delivery of large for gestational infants in 54.2% (45.1-62.5) versus 10.0%, RR = 4.5. Early pregnancy HbA1c was positively associated with adverse pregnancy outcomes.

CONCLUSION

The risk of adverse pregnancy outcomes was two to five times increased in women with T1DM compared with the general population. The goals of the St. Vincent declaration have not been achieved.

Assessment of HbA1c as a diagnostic tool in diabetes and prediabetes

To evaluate HbA1c as a diagnostic tool in prediabetes-impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), and newly detected diabetes (NDD), defined by plasma glucose and OGTT. 2,231 subjects, of mean age 50.3 ± 13.9 years and mean BMI 29.5 ± 6.2 kg/m(2), underwent an OGTT. HbA1c performance was assessed using the area under the receiver operating characteristics curve (AUC-ROC). HbA1c was significantly higher in all groups with altered glucose tolerance-5.72 ± 0.61% in IFG, 5.84 ± 0.63% in IGT, and 7.5 ± 1.69% in NDD when compared to normal glucose tolerance-5.23 ± 0.65% (P < 0.0001). HbA1c of both prediabetic groups was significantly lower in comparison with NDD (P < 0.0001); in IGT being significantly higher than in IFG (P = 0.02). ROC analysis demonstrated good performance of HbA1c for diagnosing diabetes-AUC-ROC 0.958 (95% CI: 0.946-0.970), as well as prediabetes-AUC-ROC 0.729 (95% CI: 0.702-0.755). The optimal cut-off level of HbA1c for diagnosing diabetes was 6.1% (sensitivity 86%, specificity 92%) and for undiagnosed prediabetes-5.5% (sensitivity 71%, specificity 64%). HbA(1c) appears to be a useful, convenient, and reliable tool for identifying subjects with prediabetes and diabetes and should be considered in the development of diagnostic strategies.

The oldest gravidas: a review of pregnancy risks in women over 45

As a result of delayed childbearing and increasingly sophisticated assisted reproductive technologies, pregnancy in women aged ≥45 years is becoming more common. Women in this age-group should receive thorough preconception evaluation and counseling about their specific risks in pregnancy. Although many pregnancies in women >45 years old are achieved via assisted reproductive technologies with associated preconception counseling, as many as 45% may be spontaneously conceived. It is therefore important for obstetrician-gynecologists to incorporate education for older women about the risks of pregnancy into routine office visits, and to ask women in this age-group about pregnancy planning. Additionally, many pregnancies in women aged >45 years may be safely managed in a nontertiary care center, avoiding the need for referral and transfer of care to an unfamiliar setting. This review addresses preconception evaluation and counseling, real and perceived risks in older mothers, common pregnancy complications and management of pregnancy in women >45 years old.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be better able to counsel women about the risks of pregnancy for women aged ≥45, evaluate older women for common risk factors that may further increase risk in pregnancy, assess pregnancy complications that are more common in women aged >45, and manage otherwise uncomplicated pregnancies in women in this age-group.