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

Urgent Follow-up after Outpatient Nonstress Tests and the Potential for Fetal Monitoring at Home

OBJECTIVE

This study aimed to measure the proportion of patients needing urgent clinical follow-up after an abnormal outpatient nonstress test (NST). We further sought to capture the patient perspective on the acceptability of performing NSTs at home.

STUDY DESIGN

A retrospective cohort study was performed over a 2-year period to determine the frequency of abnormal NSTs in a hospital-based, antepartum testing unit in patients greater than or equal to 32 weeks' gestation. The proportion of patients who delivered within 24 hours of an abnormal NST was also determined. A cross-sectional, web-based patient survey was conducted to obtain insight into the patient's comfort level with potentially performing NSTs at home.

RESULTS

The chart review yielded 665 patients who underwent 2,122 NSTs at greater than or equal to 32 weeks. Of the 2,122 NSTs, 111 were categorized as abnormal and required urgent clinical follow-up, or 5.2% (95% confidence interval [CI] 4.3, 6.3%). Of the 665 patients, 13 delivered within 24 hours of an abnormal NST, or 2.0% (95% CI 1.0, 3.3%). In the web-based survey, the proportion of respondents who would feel comfortable or very comfortable conducting NSTs at home was 87/125, or 69.6% (95% CI 60.9, 77.1%).

CONCLUSION

This study revealed that 5.2% of NSTs performed in a hospital-based antepartum testing unit were abnormal and required urgent clinical follow-up. Of the patients being followed in the antepartum testing unit, 2.0% delivered within 24 hours of an abnormal NST. The majority of the survey respondents indicated they would feel comfortable performing NSTs at home. The present study adds important information regarding the risks and benefits of NSTs at home.

KEY POINTS

· Telehealth for NSTs offers advantages over in-person NSTs.. · The proportion of NSTs that need urgent follow-up was 5.2%.. · A majority of patients are interested in telehealth for NSTs.. · Guidelines are needed before adoption of telehealth for NSTs..

Falling Insulin Requirement in Pregnant Women With Diabetes Delivering Preterm: Prevalence, Predictors, and Consequences

CONTEXT

Falling insulin requirements often lead to considerations of whether a pregnancy can continue safely or if delivery is indicated.

OBJECTIVE

To evaluate prevalence and predictors of falling insulin requirements in pregnant women with preexisting diabetes delivering preterm and to explore the relationship to fetal asphyxia and neonatal morbidity.

METHODS

A prospective cohort study of 101 consecutive singleton pregnant women with preexisting diabetes delivering preterm < 37 weeks (68 type 1 and 33 type 2 diabetes) where the prevalence of falling insulin requirements (≥20%) before delivery was recorded.

RESULTS

In total, 27% (27/101) experienced falling insulin requirements of median 30% (interquartile range 24-40) before delivery. In all women with type 1 diabetes, the prevalence was 37% (25/68), whereas it was 43% (24/56) in those with indicated preterm delivery and 6% (2/33) among women with type 2 diabetes. In women with type 1 diabetes and indicated preterm delivery, falling insulin requirements were first identified at 34 + 5 (33 + 6-35 + 4) weeks + days and delivery occurred 3 (1-9) days later. Gestational age at delivery, prevalence of suspected fetal asphyxia, and neonatal morbidity were similar in women with and without falling insulin requirements. Neither glycemic control, nausea, or preeclampsia was associated with falling insulin requirement.

CONCLUSION

Falling insulin requirements often preceded preterm delivery in women with type 1 diabetes, foremost when preterm delivery was indicated, but was not related to fetal asphyxia or neonatal morbidity. Whether falling insulin requirements in late pregnancy are a warning sign of placental insufficiency or mainly reflects variations in normal physiology needs further investigation.

Potentially modifiable risk factors of preterm delivery in women with type 1 and type 2 diabetes

AIMS/HYPOTHESIS

We aimed to identify potentially modifiable risk factors and causes for preterm delivery in women with type 1 or type 2 (pre-existing) diabetes.

METHODS

A secondary analysis of a prospective cohort study of 203 women with pre-existing diabetes (117 type 1 and 86 type 2 diabetes) was performed. Consecutive singleton pregnancies were included at the first antenatal visit between September 2015 and February 2018.

RESULTS

In total, 27% (n = 55) of the 203 women delivered preterm at median 36 + 0 weeks. When stratified by diabetes type, 33% of women with type 1 diabetes delivered preterm compared with 20% in women with type 2 diabetes (p = 0.04). Women delivering preterm were characterised by a higher prevalence of pre-existing kidney involvement (microalbuminuria or diabetic nephropathy) (16% vs 3%, p = 0.002), preeclampsia (26% vs 5%, p < 0.001), higher positive ultrasound estimated fetal weight deviation at 27 gestational weeks (2.7% vs -1.6% from the mean, p = 0.008), higher gestational weight gain (399 g/week vs 329 g/week, p = 0.01) and similar HbA_1c levels in early pregnancy (51 mmol/mol [6.8%] vs 49 [6.6%], p = 0.22) when compared with women delivering at term. Independent risk factors for preterm delivery were pre-existing kidney involvement (OR 12.71 [95% CI 3.0, 53.79]), higher gestational weight gain (per 100 g/week, OR 1.25 [1.02, 1.54]), higher positive ultrasound estimated fetal weight deviation at 27 gestational weeks (% from the mean, OR 1.07 [1.03, 1.12]) and preeclampsia (OR 7.04 [2.34, 21.19]). Two-thirds of preterm deliveries were indicated and one-third were spontaneous. Several contributing factors to indicated preterm delivery were often present in each woman. The main indications were suspected fetal asphyxia (45%), hypertensive disorders (34%), fetal overgrowth (13%) and maternal indications (8%). Suspected fetal asphyxia mainly included falling insulin requirement and abnormal fetal haemodynamics.

CONCLUSIONS/INTERPRETATIONS

Presence of preeclampsia, higher positive ultrasound estimated fetal weight deviation at 27 gestational weeks and higher gestational weight gain were independent potentially modifiable risk factors for preterm delivery in this cohort of women with pre-existing diabetes. Indicated preterm delivery was common with suspected fetal asphyxia or preeclampsia as the most prevalent causes. Prospective studies evaluating whether modifying these predictors will reduce the prevalence of preterm delivery are warranted.

Routine use of antenatal nonstress tests in pregnant women with diabetes-What is the practice?

OBJECTIVE

Pregnancies complicated by maternal preexisting diabetes have a 4-5-fold increased risk of stillbirth, and consequently routine antenatal nonstress testing (NST) was implemented into clinical practice decades ago. Though, international guidelines lack consensus and recommend anything from twice weekly testing from 32 weeks to once weekly testing from 38 weeks. The objective of this study was to examine how routine antenatal NST was used in centers with specific interest and dedication in the care of pregnant women with preexisting diabetes.

STUDY DESIGN

An electronic survey concerning the routine use of antenatal NST was sent to members of the European Diabetic Pregnancy Study Group (DPSG) between October 2016 and January 2017, representing in total 55 centers in 26 countries taking care of pregnant women with diabetes.

RESULTS

Answers from 38 centers (69.1 % (38/55)) in 22 countries were received. Based on real world information from these primarily European centers, anything from avoiding routine antenatal NST to testing twice weekly from early in third trimester in women with preexisting diabetes was reported. NST was commonly used (71.1 % of centers) if insulin treatment was needed. NST was also used among diet treated women with type 2 diabetes in several places. The use varied markedly within and between countries. The most common practice was routine NST once weekly from 32 weeks.

CONCLUSION

Among pregnant women with preexisting diabetes, routine antenatal testing practice with NST differs considerably both within and between countries. Studies examining the cost benefit of routine antenatal NST in pregnancies in women with the different types of diabetes are needed.