Relation between low 50-g glucose challenge test results and small-for-gestational-age infants

The association between a low 50-gram, 1-hour glucose challenge test value and neonatal morbidity

OBJECTIVE

To evaluate the association between a low 50-gram, 1-hour glucose challenge test (GCT) value and adverse maternal and neonatal outcomes among patients receiving care at a single center tertiary care academic hospital.

METHODS

We performed a retrospective cohort study of pregnant patients with a documented result of a 50-gram, 1-hour GCT performed ≥24 weeks 0 days gestation at a single tertiary care academic hospital from 2013-2021. Patients with a low GCT value, defined as cohort specific ≤10th percentile (<82 mg/dL), were compared to patients with a GCT value ≥82 mg/dL who were not diagnosed with gestational diabetes (GDM) to examine adverse maternal and neonatal outcomes. Additionally, these comparisons were repeated across patients with low GCT (<82 mg/dL), those with a GCT ≥82 mg/dL without diagnosis of GDM (heretofore referred to as normal glycemic screening) and patients diagnosed with GDM. Our primary outcome was a composite neonatal morbidity variable, inclusive of stillbirth, neonatal death, neonatal hypoglycemia with neonatal intensive care unit (NICU) admission, neonatal hyperbilirubinemia with NICU admission, respiratory distress with NICU admission, and/or small for gestational age (SGA). Multivariable logistic regression modeling was used to examine the association of low GCT value and the composite neonatal morbidity outcome, compared to those with the normal glycemic screening.

RESULTS

Of 36,342 eligible patients, 3,789 (10.4%) had a low GCT value of <82 mg/dL, 30,729 (84.6%) had a GCT value ≥82 mg/dL and were not diagnosed with GDM, and 1,824 (5.0%) had a diagnosis of GDM. Patients with a low GCT value were significantly less likely to be diagnosed with hypertensive disorder of pregnancy (HDP) (12.4% vs 16.3%, p < .01), undergo cesarean delivery (22.8% vs 29.9%, p < .01), or experience postpartum hemorrhage (7.8% vs 9.4%, p < .01) as compared to patients with normal glycemic screening. Compared to newborns whose mothers had normal glycemic screening, newborns of mothers with a low GCT value were significantly more likely to experience the composite morbidity outcome (OR 1.17; 95% CI 1.08-1.27); this persisted after adjusting for potential confounders (aOR 1.18; 95% CI 1.09-1.29).

CONCLUSION

A low maternal GCT value after 24 weeks gestation is significantly associated with an increased risk of morbidity in the newborn, driven by higher rates of SGA. Patients with a low GCT value may have underlying maternal hypoglycemia or other glycemic dysregulation affecting fetal development and may benefit from enhanced antenatal surveillance.

Perinatal outcomes after bariatric surgery

BACKGROUND

Bariatric surgery is a widely used treatment option for obesity that often provides long-term weight control and health benefits. Although a growing number of women are becoming pregnant after bariatric surgery, only a few population-based studies have assessed the impact thereof on perinatal outcomes.

OBJECTIVE

This study aimed to examine the association between bariatric surgery and adverse perinatal outcomes in pregnant women and to examine whether the risk for adverse perinatal outcomes is modified by the postsurgery weight, gestational weight gain, type of bariatric surgery, timing of pregnancy after bariatric surgery, and maternal comorbidities.

STUDY DESIGN

A retrospective cohort study was performed with the use of the Bariatric Surgery Registry and hospital inpatient and outpatient physician encounter records. The International Classification of Diseases, Ninth and Tenth Revision codes from hospitalizations during pregnancy and infant birth records were used to ascertain the outcomes of interest. Women eligible for BS who delivered at ≥20 weeks of gestation (n=20,213) at Kaiser Permanente Southern California hospitals (January 1, 2007 to December 31, 2018) were included in the study. Adjusted odds ratios were derived from logistic regression models with inverse probability of treatment weighting to adjust for confounding using propensity scores.

RESULTS

Bariatric surgery was associated with a reduction in the risks for gestational diabetes (adjusted odds ratio, 0.60; 95% confidence interval, 0.53-0.69; P<.001), preeclampsia (adjusted odds ratio, 0.53; 95% confidence interval, 0.46-0.61; P<.001), chorioamnionitis (adjusted odds ratio, 0.45; 95% confidence interval, 0.32-0.63; P<.001), cesarean delivery (adjusted odds ratio, 0.65; 95% confidence interval, 0.59-0.72; P<.001), large for gestational age neonate (adjusted odds ratio, 0.23; 95% confidence interval, 0.19-0.29; P<.001), macrosomia (adjusted odds ratio, 0.24; 95% confidence interval, 0.19-0.30; P<.001), and neonatal intensive care unit admission (adjusted odds ratio, 0.70; 95% confidence interval, 0.61-0.81; P<.001). However, bariatric surgery was also associated with a significantly increased risk for small for gestational age neonates (adjusted odds ratio, 2.46; 95% confidence interval, 2.16-2.79; P<.001). The risk for the adverse outcomes is independent of the time interval between the surgery and subsequent pregnancy.

CONCLUSION

These data suggest that there are many pregnancy outcome benefits for women with severe obesity who undergo bariatric surgery; however, women who have undergone bariatric surgery before pregnancy should be monitored closely to reduce the risk for small for gestational age neonates and postpartum hemorrhage.

Hypoglycemia during the oral glucose tolerance test in pregnancy-maternal characteristics and neonatal outcomes

OBJECTIVE

To evaluate maternal and neonatal outcomes in pregnancies complicated by hypoglycemia on 100-g oral glucose tolerance test (OGTT).

METHODS

A retrospective cohort analysis of all live-born deliveries in a single medical center during 2018 and 2019 with available OGTT results and birth outcomes. Preterm deliveries (<34 weeks), multiple pregnancies and major anomalies were excluded. Hypoglycemia during OGTT was defined as at least one glucose value below 60 mg/dl. Maternal characteristics and perinatal outcomes were compared between three groups: Hypoglycemia on OGTT, Normal OGTT and Abnormal OGTT. Univariate followed by multivariate analyses were used to control for confounders.

RESULTS

Overall, 2079 women were entered into the analysis. Of these, 216 (10.4%) had at least one hypoglycemic value, 1072 (51.6%) had normal OGTTs and 791 (38%) abnormal OGTTs. Hypoglycemia in OGTT was more prevalent in multiparous women and was associated with fetal male gender. Absolute birth weight, low birth weight and small for gestational age differed between groups; however, there was no difference between groups in overall birth weight centiles (60.1 ± 26.8 versus 63 ± 26 versus 60.9 ± 27; P > 0.05). Following adjustment of confounders, hypoglycemia was not associated with rates of low birth weight or small for gestational age (P < 0.05). There were no other differences in perinatal outcomes between groups.

CONCLUSION

Hypoglycemia in OGTT is not associated with maternal or neonatal adverse outcomes.

A Low 50-gram, 1-hour Glucose Challenge Test Value Predicts Neonatal Birth Weight Less than the 10th Percentile: A Systematic Review and Meta-Analysis

OBJECTIVE

This study aimed to perform a systematic review with meta-analysis to investigate if women with a low 50-g, 1-hour glucose challenge test (GCT) value are at risk for having neonates with a birth weight less than the 10th percentile.

STUDY DESIGN

A computerized literature search was conducted to identify studies that compared outcomes of pregnant women with a low GCT value versus women with a normal GCT value during routine screening for gestational diabetes.

RESULTS

Sixteen cohort studies were included for analysis. Women with a low GCT value were noted to have a 43% increased odds of having neonates with birth weight less than the 10th percentile (odds ratio [OR]: 1.43; 95% confidence interval [CI]: 1.28-1.60) and 30% increased odds of having neonates with a birth weight less than 2,500 g (OR: 1.3; 95% CI: 1.0-1.7) when compared with women with a normal GCT value. The rates of preterm delivery, neonatal intensive care unit (NICU) admission, pregnancy-induced hypertension (PIH)/preeclampsia, respiratory distress, NICU, and Apgar scores less than 7 were similar in the two groups.

CONCLUSION

A low GCT value defined as less than 90 mg/dL identifies pregnancies at elevated risk for having neonates with a birth weight less than the 10th percentile.

Use of the 50-g glucose challenge test to predict small-for-gestational-age neonates

BACKGROUND

To determine a cutoff value for the 50-g glucose challenge test (50-g GCT) for the prediction of small-for-gestational-age (SGA) neonates.

METHODS

This retrospective cohort study was conducted among pregnant women who were screened with the 50-g GCT at Hacettepe University Hospital between 1 January 2016 and 31 March 2019. Patients with 50-g GCT values <74 mg/dL (<10th percentile) served as the study group (n = 244), while patients with 50-g GCT values between 74 to 139 mg/dL served as the control group (n = 3104). Groups were compared in terms of demographic features, clinical characteristics, and obstetric outcomes. Logistic regression analysis was used to determine independent predictors of SGA. Receiver operating characteristic curves were used to assess the performance of 50-g GCT values in predicting SGA.

RESULTS

Lower birthweight, birthweight percentile, and 5th-minute Apgar values, together with higher rates of SGA, were observed in the study group (P < .001 for all). A 50-g GCT value below the 10th percentile (odds ratio: 3.29, 95% CI: 2.31-4.69, P < .001) was a significant independent factor for SGA. A cutoff value of 89.5 mg/dL (84.9% sensitivity, 85.6% specificity) was determined for SGA.

CONCLUSIONS

Low 50-g GCT values (<89.5 mg/dL) may be an early indicator for SGA.

Pregnancy outcomes of women with hypoglycemia in the oral glucose tolerance test

OBJECTIVE

The aim of this study was to investigate the effects of hypoglycemia measured using 2-h 75-g oral glucose tolerance test (OGTT) on neonatal biometrics (birth weight, head circumference and body length of newborns) and perinatal outcomes.

MATERIALS AND METHODS

According to the definition of hypoglycemia by the American Diabetes Association, women with blood glucose levels of ≤70 mg/dL after fasting or at 1 or 2 h after eating measured using on 2-h 75-g OGTT were grouped into a hypoglycemia group. In accordance with the criteria of World Health Organization and the International Association of Diabetes and Pregnancy Study Groups, as per the 2-h 75-g OGTT performed in the second trimester, women with gestational diabetes and were excluded from the study. Also, women meeting the following criteria were excluded from the study: missing records, aged <19 or ≥35 years, multiple pregnancies, delivery before the 24^th gestational week, and ≤500-g newborn. Other exclusion criteria included pregnant women with known type 1 and type 2 diabetes mellitus, gestational or essential hypertension, cigarette and/or alcohol abuse, thyroid disease, BMI of <19 and >30, placental abnormalities with variation and/or dysfunction, intrauterine growth restriction, and abnormalities of the umbilical cord.

RESULTS

A total of 625 pregnant women who met the inclusion criteria were included in the study. Hypoglycemia was found in 71 pregnant women according to 2-h 75-g OGTT. The remaining 554 women were grouped into the normoglycemia group. The birth weight, head circumference, and body length of newborns were significantly lower in the hypoglycemia group (p < 0.001, p = 0.004, and p = 0.006, respectively). There was no significant difference between both groups in terms of body mass index, parity, fetal sex, delivery type, and Apgar scores.

CONCLUSIONS

Glycemia with blood glucose levels of ≤70 mg/dL measured using 75-g OGTT during pregnancy is associated with lower birth weight, small head circumference, and short body length in newborns compared to the normoglycemic group. Hence, pregnant women who are diagnosed with blood glucose levels of ≤70 mg/dL using 2-h 75-g OGTT should be carefully managed.

The Association Between Low 50 g Glucose Challenge Test Values and Adverse Pregnancy Outcomes

BACKGROUND

The implications of low values on the 50 g glucose challenge test (GCT) in pregnancy are not clearly defined. Few studies have evaluated the influence of maternal low GCT values on obstetrical outcomes. This study aimed to compare pregnancy outcomes between women with low 50 g GCT values and those with normal values.

MATERIALS AND METHODS

Women undergoing gestational diabetes mellitus screening at 24-28 weeks of gestational age between January 2010 and December 2016 were retrospectively evaluated. Women with multifetal pregnancies, prepregnancy type I or II diabetes, GCT performed before 24 or after 28 weeks of gestational age, and women undergoing multiple GCTs in the same pregnancy were excluded. Low GCT values and normal GCT values were defined as ≤85 mg/dL and 86-130 mg/dL, respectively.

RESULTS

Of 3875 screened subjects, 519 (13.4%) women were included in the low GCT group and 3356 (86.6%) in the normal GCT group. Low GCT women had a significantly higher rate of small for gestational age (SGA) infants than normal GCT women (10.8% vs. 7.9%, p = 0.02). Cesarean section and postpartum hemorrhage (PPH) were less frequent in low GCT women than in normal women (32.6% vs. 42.8%, p < 0.01 and 0.2% vs. 1.2%, p = 0.03, respectively). Low GCT women had a 1.38-fold increased risk of bearing SGA infants (95% confidence intervals: 1.01-1.88, p = 0.04).

CONCLUSIONS

Rate of SGA infants was significantly higher and cesarean delivery and PPH rates were significantly lower in women with low GCT values. Low GCT values were independently associated with an increased risk of SGA.

Relationship between maternal hypoglycaemia and small-for-gestational-age infants according to maternal weight status: a retrospective cohort study in two hospitals

OBJECTIVE

The relationship between pre-pregnancy body mass index (BMI) and low glucose challenge test (GCT) results by maternal weight status has not been examined. This study aimed to clarify the relationship between a low GCT result and small for gestational age (SGA) by maternal weight status.

DESIGN

A retrospective cohort study in 2 hospitals.

SETTING

This study evaluated the obstetric records of women who delivered in a general community hospital and a tertiary perinatal care centre.

PARTICIPANTS

The number of women who delivered in both hospitals between January 2012 and December 2013 and underwent GCT between 24 and 28 weeks of gestation was 2140. Participants with gestational diabetes mellitus or diabetes during pregnancy, and GCT results of ≥140 mg/dL were excluded. Finally, 1860 women were included in the study.

PRIMARY AND SECONDARY OUTCOME MEASURES

The participants were divided into low-GCT (≤90 mg/dL) and non-low-GCT groups (91-139 mg/dL). The χ² tests and multivariate logistic regression analyses were conducted to investigate the association between low GCT results and SGA by maternal weight status.

RESULTS

The incidence of SGA was 11.4% (212/1860), and 17.7% (330/1860) of the women showed low GCT results. The patients were divided into 3 groups according to their BMI (underweight, normal weight and obese). When the patients were analysed separately by their weight status after controlling for maternal age, pre-pregnancy maternal weight, maternal weight gain during pregnancy, pregnancy-induced hypertension, thyroid disease and difference in hospital, low GCT results were significantly associated with SGA (OR 2.10; 95% CI 1.14 to 3.89; p=0.02) in the underweight group.

CONCLUSIONS

Low GCT result was associated with SGA at birth among underweight women. Examination of maternal glucose tolerance and fetal growth is necessary in future investigations.

Small-for-gestational age and its association with maternal blood glucose, body mass index and stature: a perinatal cohort study among Chinese women

OBJECTIVE

To examine whether maternal low blood glucose (BG), low body mass index (BMI) and small stature have a joint effect on the risk of delivery of a small-for-gestational age (SGA) infant.

DESIGN

Women from a perinatal cohort were followed up from receiving perinatal healthcare to giving birth.

SETTING

Beichen District, Tianjin, China between June 2011 and October 2012.

PARTICIPANTS

1572 women aged 19-39 years with valid values of stature, BMI and BG level at gestational diabetes mellitus screening (gestational weeks 24-28), glucose challenge test <7.8 mmol/L and singleton birth (≥37 weeks' gestation).

MAIN OUTCOME MEASURES

SGA was defined as birth weight <10th centile for gender separated gestational age of Tianjin singletons.

RESULTS

164 neonates (10.4%) were identified as SGA. From multiple logistic regression models, the ORs (95% CI) of delivery of SGA were 0.84 (0.72 to 0.98), 0.61 (0.49 to 0.74) and 0.64 (0.54 to 0.76) for every 1 SD increase in maternal BG, BMI and stature, respectively. When dichotomises, maternal BG (<6.0 vs ≥6.0 mmol/L), BMI (<24 vs ≥24 kg/m(2)) and stature (<160.0 vs ≥160.0 cm), those with BG, BMI and stature all in the lower categories had ∼8 times higher odds of delivering an SGA neonate (OR (95% CI) 8.01 (3.78 to 16.96)) relative to the reference that had BG, BMI and stature all in the high categories. The odds for an SGA delivery among women who had any 2 variables in the lower categories were ∼2-4 times higher.

CONCLUSIONS

Low maternal BG is associated with an increased risk of having an SGA infant. The risk of SGA is significantly increased when the mother is also short and has a low BMI. This may be a useful clinical tool to identify women at higher risk for having an SGA infant at delivery.