Perinatal mortality in diabetic patients undergoing antepartum fetal evaluation: a case-control study

Diabetes in pregnancy in associations with perinatal and postneonatal mortality in First Nations and non-Indigenous populations in Quebec, Canada: population-based linked birth cohort study

OBJECTIVE

Both pregestational and gestational diabetes mellitus (PGDM, GDM) occur more frequently in First Nations (North American Indians) pregnant women than their non-Indigenous counterparts in Canada. We assessed whether the impacts of PGDM and GDM on perinatal and postneonatal mortality may differ in First Nations versus non-Indigenous populations.

DESIGN

A population-based linked birth cohort study.

SETTING AND PARTICIPANTS

17 090 First Nations and 217 760 non-Indigenous singleton births in 1996-2010, Quebec, Canada.

MAIN OUTCOME MEASURES

Relative risks (RR) of perinatal and postneonatal death. Perinatal deaths included stillbirths and neonatal (0-27 days of postnatal life) deaths; postneonatal deaths included infant deaths during 28-364 days of life.

RESULTS

PGDM and GDM occurred much more frequently in First Nations (3.9% and 10.7%, respectively) versus non-Indigenous (1.1% and 4.8%, respectively) pregnant women. PGDM was associated with an increased risk of perinatal death to a much greater extent in First Nations (RR=5.08[95% CI 2.99 to 8.62], p<0.001; absolute risk (AR)=21.6 [8.6-34.6] per 1000) than in non-Indigenous populations (RR=1.76[1.17, 2.66], p=0.003; AR=4.2[0.2, 8.1] per 1000). PGDM was associated with an increased risk of postneonatal death in non-Indigenous (RR=3.46[1.71, 6.99], p<0.001; AR=2.4[0.1, 4.8] per 1000) but not First Nations (RR=1.16[0.28, 4.77], p=0.35) infants. Adjusting for maternal and pregnancy characteristics, the associations were similar. GDM was not associated with perinatal or postneonatal death in both groups.

CONCLUSIONS

The study is the first to reveal that PGDM may increase the risk of perinatal death to a much greater extent in First Nations versus non-Indigenous populations, but may substantially increase the risk of postneonatal death in non-Indigenous infants only. The underlying causes are unclear and deserve further studies. We speculate that population differences in the quality of glycaemic control in diabetic pregnancies and/or genetic vulnerability to hyperglycaemia's fetal toxicity may be contributing factors.

An audit on a routine antenatal nonstress testing program in pregnant women with preexisting diabetes

INTRODUCTION

The objective was to evaluate the effectiveness of routine (planned) antenatal nonstress tests (NSTs) in pregnant women with preexisting diabetes.

MATERIAL AND METHODS

A retrospective single-center study of 642 consecutive pregnancies in women with preexisting diabetes who gave birth to a singleton ≥22 weeks. Weekly planned NSTs were commenced at 33-35 weeks. In pregnancies with maternal-fetal complications, the initiation and frequency of the planned NST were individualized. Daily maternal assessment of fetal activity was recommended from 28 weeks, and decreased fetal activity indicated an unplanned NST. Data were collected from medical records, and local and regional databases.

RESULTS

In total, 3016 planned NSTs were performed, with a median of five (range 0-12) tests per pregnancy. Ninety-five planned NSTs (3.1%) were abnormal, a finding confirmed by retesting the same day in eight cases (8.4%), thus leading to delivery. Complications were present in seven of these eight pregnancies, whereas no fetal movements for the last 3 days were reported when the planned NST was performed in the eighth pregnancy. When specifically asked, five of the eight women stated that they had observed decreased fetal activity preceding the planned NST. In 86 pregnancies (13.4%), maternal perception of decreased fetal activity indicated in total 127 unplanned NSTs. The combination of decreased fetal activity and further obstetrical assessment led to delivery in 10 of these pregnancies (11.6%). One stillbirth occurred at 37 weeks in a pregnancy complicated by fetal achondroplasia and polyhydramnios, where the weekly planned NSTs had been normal. The overall stillbirth rate was thus 1.6/1000.

CONCLUSIONS

Routine use of planned antenatal NSTs does not appear to be indicated in pregnancies in women with preexisting diabetes in the absence of maternal-fetal complications.

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.