Markers of Glycemic Control and Neonatal Morbidity in High-Risk Insulin-Resistant Pregnancies

OBJECTIVE

This study aims to determine whether fructosamine, glycated hemoglobin A1C (HbA1c), or mean fasting glucose levels associate with birth outcomes in diabetic women.

STUDY DESIGN

A prospective cohort study of women with singleton, nonanomalous pregnancies and diagnosis of diabetes (gestational or pregestational). Daily average self-measured fasting serum glucose levels were collected, as well as HbA1c and fructosamine levels at delivery. The primary outcome was neonatal composite morbidity, defined as having one or more of the following: respiratory distress syndrome, hyperbilirubinemia, perinatal death, shoulder dystocia, and hypoglycemia requiring treatment. Secondary outcomes included macrosomia (≥ 4,000 g).

RESULTS

Among neonates delivered by 301 study-eligible women (97 with gestational and 204 with pregestational diabetes), incidences of composite morbidity (n = 147, 48.8%) and macrosomia (n = 49, 16.3%) were high. Macrosomia occurred more frequently in infants of pregestational than gestational diabetic mothers (22.7 vs. 13.2%, p = 0.04), composite morbidities were not significantly different (52.2 vs. 42.3%, p = 0.14). HbA1c > 8.0 significantly increased risk of morbidity and macrosomia (relative risk, 4.29; 95% confidence interval, 1.62-11.3).

CONCLUSIONS

Late third-trimester HbA1c, but not fructosamine or mean blood glucose levels, was associated with increased morbidity in infants of diabetic mothers. Third-trimester HbA1c could be clinically useful for counseling regarding neonatal risks in women with diabetes.

Optimal Admission Cervical Dilation in Spontaneously Laboring Women

OBJECTIVE

To estimate the impact of admission cervical dilation on the risk of cesarean in spontaneously laboring women at term.

STUDY DESIGN

Secondary analysis of a prospective cohort study of women admitted in term labor with a singleton gestation. Women with rupture of membranes before admission, induction of labor, or prelabor cesarean were excluded. The association between cesarean and cervical dilation at admission was estimated, and results were stratified by parity. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated, using cervical dilation ≥ 6 cm as the reference group. Cesarean for arrest was secondarily explored.

RESULTS

A total of 2,033 spontaneously laboring women met inclusion criteria. Women admitted at <6 cm dilation had an increased risk of cesarean compared with those admitted at ≥6 cm (13.2 vs. 3.5%; RR 3.73; 95% CI 1.94-7.17). The increased risk was noted in nulliparous (16.8 vs. 7.1%; RR 2.35; 95% CI 0.90-6.13) and multiparous (11.0 vs. 2.5%; RR 4.36; 95% CI 1.80-10.52) women, but was statistically significant only in multiparous women.

CONCLUSIONS

Decreasing cervical dilation at admission, particularly <6 cm, is a modifiable risk factor for cesarean, especially in multiparous women. This should be considered in the decision-making process about timing of admission in term labor.

Electronic fetal monitoring patterns associated with respiratory morbidity in term neonates

OBJECTIVE

The purpose of this study was to identify electronic fetal monitoring patterns that are associated with neonatal respiratory morbidity.

STUDY DESIGN

In an on-going prospective cohort study of >8000 consecutive term, vertex, nonanomalous singleton pregnancies during labor, we performed this analysis within the first 5000 women as a representative sample. Electronic fetal monitoring patterns in the 30 minutes preceding delivery were extracted by trained obstetrics research nurses, who were blinded to clinical data, using the National Institute of Child Health and Human Development system; the data were compared between those with respiratory morbidity and healthy infants (no morbidities). The primary outcome was neonatal respiratory morbidity, which was defined as either oxygen requirement at ≥6 hours of life or any mechanical ventilation in the first 24 hours. Multivariable logistic regression was used to adjust for confounders.

RESULTS

Of 4736 neonates, 175 (3.4%) experienced respiratory morbidity. Most electronic fetal monitoring patterns were category II (96.6%; n = 4575). Baseline tachycardia (adjusted odds ratio [aOR], 2.9; 95% confidence interval [CI], 1.9-4.4), marked variability (aOR, 2.7; 95% CI, 1.5-5.0), and prolonged decelerations (aOR,2.7; 95% CI, 1.5-5.0) were significantly associated with an increased likelihood of term neonatal respiratory morbidity. Accelerations and persistent moderate variability were both significantly associated with a decreased likelihood of respiratory morbidity.

CONCLUSION

Specific features of category II electronic fetal monitoring patterns make respiratory morbidity more likely in nonanomalous term infants. Tachycardia, marked variability, or prolonged decelerations before delivery can assist providers in anticipating the potential need for neonatal respiratory support.

Accuracy of Estimated Blood Loss in Predicting Need for Transfusion after Delivery

OBJECTIVE

The definition of postpartum hemorrhage (PPH) was developed more than 50 years ago. Since then, the obstetric population has changed dramatically. We sought to determine how well we estimated blood loss (EBL) and find thresholds predicting need for transfusion.

STUDY DESIGN

We performed a prospective cohort study from 2010 to 2012, comparing those who needed transfusion postpartum and those who did not. EBL, calculated EBL (cEBL), and change in hematocrit were calculated for patients who did not receive transfusion, and EBL was calculated for those who did receive transfusion, stratified by delivery type. Receiver operator curves were created and optimal thresholds of EBL to predict transfusion were estimated.

RESULTS

Among 4,804 patients, transfusion was required for 0.65% of vaginal and 8.7% of cesarean deliveries. Median EBL was higher in women requiring transfusion. A weak correlation was noted between EBL and cEBL for all deliveries. Thresholds of 500 mL blood loss for vaginal delivery and 1,000 mL for cesarean had the best predictive ability for transfusion.

CONCLUSION

In this modern obstetric, cohort EBL is weakly correlated with cEBL, suggesting that accuracy of clinical estimates of blood loss is modest. However, EBL predicts need for transfusion, with optimal thresholds of 500 mL for a vaginal delivery and 1,000 mL in a cesarean. This validates the traditional definitions of PPH in our modern population.

Prepregnancy body mass index in a first uncomplicated pregnancy and outcomes of a second pregnancy

OBJECTIVE

This study examined the effect of body mass index (BMI) before a first uncomplicated pregnancy on maternal and fetal outcomes in a subsequent pregnancy, including preterm births, preeclampsia, cesarean delivery, small for gestational age, large for gestational age, and neonatal deaths.

STUDY DESIGN

We conducted a population-based cohort study (n = 121,092) using the Missouri maternally linked birth registry (1989 through 2005). Multivariable binary logistic regression models were fit to estimate odds ratios and 95% confidence intervals for the parameters of interest after controlling for sociodemographic and pregnancy-related confounders in the second pregnancy.

RESULTS

Compared to women with a normal BMI in their first pregnancy, those who were underweight prepregnancy had increased odds for preterm birth by 20% and small for gestational age by 40% in their second pregnancy, while those with prepregnancy obesity had increased odds for large for gestational age, preeclampsia, cesarean delivery, and neonatal deaths in their second pregnancy by 54%, 156%, 85%, and 37%, respectively.

CONCLUSION

Women starting a first pregnancy with suboptimal BMI may be at risk of adverse maternal and fetal outcomes in a subsequent pregnancy, even if their first pregnancy was uncomplicated or if they reached a normal weight by their second pregnancy. The long-term consequences of suboptimal BMI carry considerable public health implications.

Progress of induced labor in trial of labor after cesarean delivery

OBJECTIVE

The purpose of this study was to compare the first stage of labor progress in women who undergo an induction of labor after cesarean delivery with women who have spontaneous labor after cesarean delivery.

STUDY DESIGN

We conducted a retrospective cohort study of consecutive women who had been admitted for delivery with a vertex-presenting fetus who achieved vaginal delivery after cesarean delivery. We compared women who underwent an induction of labor after cesarean delivery with women with spontaneous labor after cesarean delivery. Labor curves were constructed with a repeated-measures analysis; interval-censored regression was used to estimate the median time spent to dilate 1 cm, stratified by induction status, and adjusted by obesity, macrosomia, epidural, and previous vaginal delivery.

RESULTS

Of 473 laboring women with a previous cesarean delivery, 234 women (49%) were induced. After adjustment for obesity, macrosomia, epidural, and previous vaginal delivery, women who underwent an induction had significantly longer labors than those women who experienced spontaneous labor. The median time to dilate from 4-10 cm took 5.6 hours (95% confidence interval, 1.8-18.0 hours) in the induction group and 3.2 hours (95% confidence interval, 1.0-10.3 hours) in the spontaneous labor group (P < .01). The time to progress 1 cm in dilation from 3-7 cm was different; however, after 7 cm, the time to progress 1 cm was not statistically different.

CONCLUSION

Women who undergo an induction of labor after cesarean delivery have a longer latent labor phase, but a similar active phase than those women who experience spontaneous labor. When making the diagnosis of labor dystocia for women who undergo an induction of labor after cesarean delivery, clinicians should use the same normative standards for labor treatment of women without a previous cesarean delivery as has been shown in previous work.

Timing of elective delivery in gastroschisis: a decision and cost-effectiveness analysis

OBJECTIVE

To determine the most cost-effective timing of delivery in pregnancies complicated by gastroschisis, using a decision-analytic model.

METHODS

We created a decision-analytic model to compare planned delivery at 35, 36, 37, 38 and 39 weeks' gestation. Outcomes considered were stillbirth, death within 1 year of birth and respiratory distress syndrome (RDS). Probability estimates of events (stillbirth, complex gastroschisis and RDS for each gestational age at delivery and risk of death with simple and complex gastroschisis), utilities and costs assigned to the outcomes were obtained from the published literature. Cost analysis was assessed from a societal perspective, using a willingness-to-pay threshold of $100,000 per surviving infant. Outcomes and costs were considered throughout 1 year of postnatal life. Multiway sensitivity analysis was performed to address uncertainties in baseline assumptions.

RESULTS

In the base-case analysis, delivery at 38 weeks' gestation was the most cost-effective strategy. Planned delivery at 35 weeks was associated with the fewest stillbirths and deaths within 1 year of delivery, owing largely to a lower ongoing risk of stillbirth. In Monte Carlo simulation when every variable was varied over its entire range, delivery at 38 weeks was cost-effective compared to delivery at 39 weeks in 76% of trials and delivery at 37 weeks was cost-effective in 69% of trials. Delivery at 38 weeks resulted in three additional cases of RDS for every 100 stillbirths or deaths within 1 year that were prevented.

CONCLUSIONS

For pregnancies complicated by gastroschisis, the most cost-effective timing of delivery is at 38 weeks. Few additional cases of RDS are caused for every one stillbirth or death within 1 year that was prevented with delivery at 37-38 weeks compared with at 39 weeks.

Effect of Growth Restriction on Fetal Heart Rate Patterns in the Second Stage of Labor

OBJECTIVE

We aimed to estimate the effect of intrauterine growth restriction (IUGR) on electronic fetal monitoring (EFM) patterns in the second stage of labor.

STUDY DESIGN

We performed a 5-year retrospective cohort study of consecutive singleton, non-anomalous, term gestations. We compared IUGR infants, those with a birth weight less than the 10th percentile, with non-IUGR infants, those greater than or equal to the 10th percentile. Our primary outcome was the EFM patterns in the 30 minutes before delivery. A secondary analysis was performed excluding infants with composite morbidity. Logistic regression was used to adjust for body mass index, race, nulliparity, induction, and protracted labor.

RESULTS

Out of the 5,388 infants, 652 (12.1%) were IUGR. IUGR fetuses had less accelerations (29.0 vs. 35.9%, p < 0.01), even among apparently normal infants (29.0 vs. 36.4%, p < 0.01). IUGR fetuses had a higher risk of decelerations, and in all, IUGR accounted for 6% of late decelerations (attributable risk 0.06, 95% confidence interval 0.02-0.10). There was no significant association between IUGR and bradycardia or minimal variability.

CONCLUSION

Growth restriction at term confers an increased risk of late decelerations, even in the absence of neonatal morbidity. EFM patterns may require different interpretations based on a priori risk and clinical factors.

Evaluating the Optimal Definition of Abnormal First-Trimester Uterine Artery Doppler Parameters to Predict Adverse Pregnancy Outcomes

OBJECTIVES

To investigate the optimal definition of abnormal first-trimester uterine artery Doppler parameters associated with adverse pregnancy outcomes.

METHODS

A prospective cohort of women with singleton gestations between 11 and 14 weeks consented to uterine artery Doppler measurements. Doppler parameters were measured bilaterally, and mean pulsatility index (PI) and resistive index (RI) values were calculated. The presence of notching was also determined. Each parameter was evaluated for prediction of preeclampsia, early preeclampsia (<34 weeks), preterm birth (<37 weeks), early preterm birth (<34 weeks), and small for gestational age (SGA; birth weight <10th percentile). Descriptive statistics evaluated the association between abnormal Doppler indices and outcomes. A receiver operating characteristic (ROC) analysis was used to define the best cutoff points for mean PI and RI. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were calculated for bilateral notching and mean PI and RI percentiles.

RESULTS

Of 1192 patients with complete outcome data, preeclampsia was seen in 8.4%, early preeclampsia in 1.8%, preterm birth in 12.9%, early preterm birth in 5.6%, and SGA in 8.5%. A mean PI above the 75th percentile (>1.91) was the best index for predicting early preeclampsia (sensitivity, 45.0%; specificity, 75.5%; NPV, 98.7%; ROC area, 0.65). A mean PI above the 75th percentile was also the best index for predictive early preterm birth (sensitivity, 40.0%; specificity, 76.0%; NPV, 95.5%; ROC area, 0.65). None of the parameters were significant for predicting SGA.

CONCLUSIONS

A mean uterine PI above the 75th percentile is the most discriminative abnormal uterine artery Doppler parameter for predicting both early preeclampsia and early preterm birth.

Risk factors for serious morbidity in term nonanomalous neonates

OBJECTIVE

The purpose of this study was to identify ante- and intrapartum risk factors for serious morbidity in term nonanomalous neonates.

STUDY DESIGN

We analyzed the first 5000 subjects within an ongoing prospective cohort study of consecutive term births from 2010-2012. The primary outcome was a composite of serious neonatal morbidity defined as ≥1 cases of hypoxic ischemic encephalopathy, meconium aspiration with pulmonary hypertension, requirement of hypothermia therapy, respiratory distress syndrome, seizures, sepsis or suspected sepsis, or death. We calculated odds ratios for the composite morbidity that is associated with ante- and intrapartum factors. Multivariable logistic regression was used to estimate adjusted odds ratios.

RESULTS

Of 5000 term nonanomalous births, 393 had the composite morbidity. Significant risk factors for morbidity were nulliparity, presence of meconium, first stage of labor >95th percentile, second stage of labor >95th percentile, pregestational diabetes mellitus, chronic hypertension, obesity, maternal intrapartum fever, and cesarean delivery. In contrast, induction of labor and gestational age ≥41 weeks were not associated with significant morbidity.

CONCLUSION

We identified several significant risk factors for serious morbidity in term nonanomalous neonates. Clinicians may use these risk factors to help anticipate the potential need for additional neonatal support at delivery.

Time from uterine incision to delivery and hypoxic neonatal outcomes

OBJECTIVE

The objective of this study was to estimate the association between time from uterine incision to delivery and hypoxic neonatal outcomes in nonanomalous term infants.

METHODS

All women undergoing in-labor term cesarean deliveries (CDs) in the first 2 years of an ongoing prospective cohort study were included. The primary exposure was time in seconds from uterine incision to delivery. The primary outcome was a composite of hypoxia-associated neonatal outcomes, defined as at least one of: seizures, hypoxic ischemic encephalopathy, need for hypothermia treatment, and death within 7 days.

RESULTS

Of 812 patients who underwent in-labor CD, the composite hypoxia outcome occurred in 18 (2.2%) neonates. There was no significant difference in the rate of hypoxic morbidity with increasing increments of 60 seconds from uterine incision to delivery (p = 0.35). There was a significantly increased risk of hypoxic morbidity in those delivered in the highest quintile (>240 seconds) compared with those in the lowest quintile (≤ 60 seconds) in cesareans performed for an indication other than nonreassuring fetal status (relative risk, 5.58; 95% confidence interval, 1.30-23.91).

CONCLUSION

Overall, duration from uterine incision to delivery for in-labor cesareans of nonanomalous term infants was not associated with an increase in risk of hypoxia-associated morbidities.

Neonatal morbidity associated with shoulder dystocia maneuvers

OBJECTIVE

We sought to examine neonatal morbidity associated with different maneuvers used among term patients who experience a shoulder dystocia.

STUDY DESIGN

We conducted a retrospective cohort study of all women who experienced a clinically diagnosed shoulder dystocia at term requiring obstetric maneuvers at a single tertiary care hospital from 2005 through 2008. We excluded women with major fetal anomaly, intrauterine death, multiple gestation, and preterm. Women exposed to Rubin maneuver, Wood's screw maneuver, or delivery of the posterior arm were compared to women delivered by McRoberts/suprapubic pressure only, which served as the reference group. The primary outcome was a composite morbidity of neonatal injury (defined as clavicular or humeral fracture or brachial plexus injury) and neonatal depression (defined as Apgar <7 at 5 minutes, arterial cord pH <7.1, continuous positive airway pressure use, intubation, or respiratory distress). Logistic regression was used to adjust for nulliparity and duration of shoulder dystocia, defined as time from delivery of fetal head to delivery of shoulders.

RESULTS

Among the 231 women who met inclusion criteria, 135 were delivered by McRoberts/suprapubic pressure alone (57.9%), 83 women were exposed to Rubin maneuver, 53 women were exposed to Wood's screw, and 36 women were exposed to delivery of posterior arm. Individual maneuvers were not associated with composite morbidity, neonatal injury, or neonatal depression after adjusting for nulliparity and duration of shoulder dystocia.

CONCLUSION

We found no association between shoulder dystocia maneuvers and neonatal morbidity after adjusting for duration, a surrogate for severity. Our results demonstrate that clinicians should utilize the maneuver most likely to result in successful delivery.

Utility of magnetic resonance imaging for suspected appendicitis in pregnant women

OBJECTIVE

The purpose of this study was to estimate the rate and risk of appendix nonvisualization and alternative diagnoses made with magnetic resonance imaging (MRI) for suspected appendicitis in pregnant women.

STUDY DESIGN

We performed a retrospective cohort study of consecutive pregnant women who underwent MRI for suspected appendicitis at a single center from 2007-2012. Data on clinical presentation, imaging, and surgical pathologic evidence were extracted from electronic medical records. Odds ratios estimated risk factors for nondiagnosis. Radiologic diagnoses were identified, and rates of diagnoses were calculated. Subgroup analysis was performed among women who underwent initial imaging with ultrasound scanning.

RESULTS

Over the 5-year period, 171 pregnant women underwent MRI for suspected appendicitis. The rate of nonvisualization was 30.9% (n = 53). Of the remaining 118 women with a visualized appendix, 18 women had imaging findings that were consistent with appendicitis and underwent appendectomy. Twelve cases of appendicitis were confirmed on pathologic evaluation (66.7%). Women with nonvisualization of the appendix on MRI were more likely to be beyond the first trimester (odds ratio, 2.1; 95% confidence interval, 1.0-4.5). Seventy-four women had disease diagnosed on MRI (43.3%). In the group of 43 women who had a nondiagnostic ultrasound scanning before the MRI, the rate of subsequent diagnostic MRI was 65% (n = 28).

CONCLUSION

MRI yields a high diagnostic rate and accuracy in pregnant women with suspected appendicitis and provides alternative diagnoses to guide further management. Given the high rate of appendix nonvisualization on ultrasound scanning that has been reported in the literature, we recommend MRI as the imaging modality of choice for this population in settings in which MRI is readily available.

Are there differences in the first stage of labor between Black and White women?

OBJECTIVE

The objective of this study was to determine whether the duration and progress of the first stage of labor are different in black compared with white women.

STUDY DESIGN

Retrospective cohort study of labor progress among consecutive black (n = 3,924) and white (n = 921) women with singleton term pregnancies (≥ 37 weeks) who completed the first stage of labor. Duration of labor and progression from 1 cm to the next was estimated using interval-censored regression. Labor duration and progress among black and white women in the entire cohort, and stratified by parity, were compared in multivariable interval-censored regression models. Repeated-measures analysis with 9th-degree polynomial modeling was used to construct average labor curves.

RESULTS

There were no significant differences in duration of the first stage of labor in black compared with white women (median, 4-10 cm: 5.1 vs. 4.9 hours [p = 0.43] for nulliparous and 3.5 vs. 3.9 hours [p = 0.84] for multiparous women). Similarly, there were no significant differences in progression in increments of 1 cm. Average labor curves were also not significantly different.

CONCLUSION

Duration and progress of the first stage of labor are identical in black and white women. This suggests similar standards may be applied in the first stage of labor.