Pregnancy Risk Factors as Predictors of Offspring Cerebrovascular Disease: The Northern Finland Birth Cohort Study 1966

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Independent and concomitant associations of gestational diabetes and maternal obesity to perinatal outcome: A register-based study

AIMS

Gestational diabetes (GDM) is often accompanied by maternal overweight. Our aim was to evaluate the separate and concomitant effects of GDM and maternal overweight/obesity on perinatal outcomes.

METHODS

We used the Finnish Medical Birth Register to identify all 24,577 women with a singleton pregnancy who delivered in 2009 in Finland and underwent an oral glucose tolerance test (OGTT). Women were divided into groups according to the result of OGTT (GDM/no GDM) and pre-pregnancy body mass index (BMI): normal weight (≤24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30.0 kg/m2). Primary outcomes included macrosomia, caesarean delivery, and treatment at neonatal ward. Normal weight women without GDM constituted the reference group.

RESULTS

Compared to reference group, overweight or obese women without GDM had an increased risk of macrosomia [odds ratio adjusted for age, parity, smoking and socio-economic status (aOR)1.18 (95% CI 1.09-1.28) and 1.50 (95% CI 1.19-1.88)], and caesarean delivery [aORs 1.17 (95% CI 1.07-1.28) and 1.52 (95% CI 1.37-1.69)], respectively. In normal weight GDM women the risk of macrosomia [aOR 1.17 (95% CI 0.85-1.62)] and caesarean delivery [aOR 1.10 (95% CI 0.96-1.27)] was not significantly increased as compared to normal weight women without GDM. GDM increased the risk of treatment at neonatal ward in all BMI categories and maternal obesity without GDM was also a risk factor for treatment at neonatal ward. Interaction p values between BMI and GDM on these outcomes were <0.001.

CONCLUSIONS

Maternal overweight and obesity without GDM increased the risk of macrosomia and caesarean delivery when compared to the reference group. These risks were amplified when overweight/obesity was accompanied by GDM. Obesity without GDM was a risk factor for treatment at neonatal ward; GDM increased this risk in all BMI categories. Our results suggest that especially maternal obesity should be considered as a risk factor for adverse pregnancy outcomes and GDM further amplifies this risk.

Long-Term Effects of Oral Antidiabetic Drugs During Pregnancy on Offspring: A Systematic Review and Meta-analysis of Follow-up Studies of RCTs

INTRODUCTION

Antidiabetic drugs (OADs) are increasingly prescribed to treat hyperglycaemia during pregnancy in women with gestational diabetes mellitus (GDM) or polycystic ovary syndrome (PCOS), even though long-term effects on offspring are unknown. This systematic review summarises the evidence of follow-up studies of randomised controlled trials (RCTs) reporting on long-term effects of prenatal exposure to OADs on offspring.

METHODS

The MEDLINE, EMBASE and CENTRAL databases were searched from inception to April 2018 for the concepts antidiabetic agents and prenatal exposure (or pregnancy and offspring/child) in combination with an RCT search filter. RCTs evaluating post-neonatal health effects in offspring and comparing maternal treatment with an OAD with no treatment, placebo, an alternative OAD or insulin during pregnancy were eligible for inclusion. Two independent researchers selected, extracted and assessed the data. Meta-analyses were performed using a random effects model and the Cochrane Collaboration's risk of bias tool was used for quality assessment.

RESULTS

Ten studies were included, with a maximal follow-up duration of 9 years, comprising 778 children of mothers with GDM or PCOS who were randomised to either metformin or insulin/placebo during pregnancy. Meta-analysis showed that children prenatally exposed to metformin were heavier compared to controls (standardised mean difference (SMD) 0.26 [95% CI 0.11-0.41]), but not taller (SMD 0.10 [95% CI -0.14-0.33]). Additionally, offspring body mass index (BMI) z scores did not differ according to metformin exposure (mean difference 0.30 [95% CI -0.01-0.61]). Individual small studies reported that prenatal exposure to metformin was associated with greater mid-upper arm, head and waist circumferences, biceps skinfolds, waist-to-height ratio, more arm fat, higher fasting glucose, ferritin and lower LDL cholesterol in offspring.

CONCLUSION

Prenatal exposure to metformin is associated with increased offspring weight, but not with height or BMI. Larger follow-up studies are needed to confirm and look into the implications of these findings. Plain language summary available for this article.

Polycystic ovary syndrome and risk factors for gestational diabetes

OBJECTIVE

To study the roles of self-reported symptoms and/or prior diagnosis of polycystic ovary syndrome (PCOS) and other potential risk factors for gestational diabetes mellitus (GDM) and to clarify whether the screening of GDM in early pregnancy is beneficial for all women with PCOS.

DESIGN

The FinnGeDi multicentre case-control study including 1146 women with singleton pregnancies diagnosed with GDM and 1066 non-diabetic pregnant women. There were 174 women with PCOS (symptoms and/or diagnosis self-reported by a questionnaire) and 1767 women without PCOS (data missing for 271).

METHODS

The study population (N = 1941) was divided into four subgroups: GDM + PCOS (N = 105), GDM + non-PCOS (N = 909), non-GDM + PCOS (N = 69), and controls (N = 858). The participants' characteristics and their parents' medical histories were compared.

RESULTS

The prevalence of PCOS was 10.4% among GDM women and 7.4% among non-diabetics (odds ratios (OR) 1.44, 95% CI: 1.05-1.97), but PCOS was not an independent risk for GDM after adjustments for participants' age and pre-pregnancy BMI (OR 1.07, 95% CI: 0.74-1.54). In a multivariate logistic regression analysis, the most significant parameters associated with GDM were overweight, obesity, age ≥35 years, participant's mother's history of GDM, either parent's history of type 2 diabetes (T2D) and participant's own preterm birth.

CONCLUSIONS

The increased risk of GDM in women with PCOS was related to obesity and increased maternal age rather than to PCOS itself, suggesting that routine early screening of GDM in PCOS women without other risk factors should be reconsidered. Instead, family history of GDM/T2D and own preterm birth were independent risk factors for GDM.

Pre-pregnancy overweight overtakes gestational diabetes as a risk factor for subsequent metabolic syndrome

OBJECTIVE

Gestational diabetes mellitus (GDM) is associated with an increased risk of subsequent diabetes and metabolic syndrome (MS). The independent significance of overweight, often associated with GDM, is controversial. This study was aimed to investigate the prevalence of MS and carotid intima-media thickness (CIMT) values in normal and overweight women with previous insulin-treated GDM and control without GDM 19 years after the index pregnancy.

METHODS

The study group consisted of 61 women with prior GDM and 55 controls who gave birth in Oulu University Hospital between 1988 and 1993. These women were further divided into subgroups according to pre-pregnancy BMI (<25 or ≥25 kg/m(2)). In 2008-2010, anthropometrics and blood pressure were measured, blood samples were taken, and an oral glucose tolerance test was performed to investigate the components of MS. CIMT was measured by Doppler ultrasound.

RESULTS

Total prevalence of MS was 62% in the GDM group and 31% in the control group (P=0.001); it was highest (86%) in GDM women with pre-pregnancy overweight. CIMT was significantly thicker (0.67 vs 0.56 mm, P=0.007) and more often abnormal (71.7 vs 45.3%, P=0.004) in the GDM group compared with the controls. In logistic regression analysis, the strongest factor predicting MS in the whole study population was pre-pregnancy overweight.

CONCLUSIONS

Pre-pregnancy overweight was the strongest predictive factor for later MS, whereas GDM indicated increased risk of subsequent diabetes and subclinical atherosclerosis. The risk of MS was highest when both of these factors were present.

Metformin should be considered in the treatment of gestational diabetes: a prospective randomised study

OBJECTIVE

To examine if oral metformin is as effective as insulin in the prevention of fetal macrosomy in pregnancies complicated with gestational diabetes mellitus (GDM).

DESIGN

Open-label prospective randomised controlled study.

SETTING

Maternity outpatient clinics in a secondary and tertiary level hospital in Finland.

SAMPLE

One hundred women with GDM who did not attain euglycaemia with diet.

METHODS

Women were randomised to therapy with insulin (n = 50) or oral metformin (n = 50).

MAIN OUTCOME MEASURES

Incidence of large-for-gestational-age (LGA) infants and neonatal morbidity.

RESULTS

There were no statistically significant differences in the incidence of LGA (8.5 versus 10.0%, P = 0.97), mean birthweight, mean cord artery pH or neonatal morbidity between the insulin and metformin groups. Fifteen (31.9%) of the 47 women randomised to metformin needed supplemental insulin. They were more obese (with a body mass index of 36 versus 30 kg/m(2), P = 0.002), had higher fasting blood glucose levels in an oral glucose tolerance test (6.1 versus 5.0 mmol/l, P = 0.001) and needed medical treatment for GDM earlier (26 versus 31 gestational weeks, P = 0.002) than women who were normoglycemic with metformin. There was a tendency to a higher rate of caesarean sections in the metformin group than in the insulin group (RR 1.9; 95% CI 0.99-3.71).

CONCLUSIONS

Metformin seems to be suitable for the prevention of fetal macrosomy, especially in lean or moderately overweight women developing GDM in late gestation. Women with considerable obesity, high fasting blood glucose and an early need for pharmacological treatment may be more suitable for insulin therapy.