Use of natural language processing to uncover racial bias in obstetrical documentation

Natural Language Processing (NLP), a form of Artificial Intelligence, allows free-text based clinical documentation to be integrated in ways that facilitate data analysis, data interpretation and formation of individualized medical and obstetrical care. In this cross-sectional study, we identified all births during the study period carrying the radiology-confirmed diagnosis of fibroid uterus in pregnancy (defined as size of largest diameter of >5 cm) by using an NLP platform and compared it to non-NLP derived data using ICD10 codes of the same diagnosis. We then compared the two sets of data and stratified documentation gaps by race. Using fibroid uterus in pregnancy as a marker, we found that Black patients were more likely to have the diagnosis entered late into the patient's chart or had missing documentation of the diagnosis. With appropriate algorithm definitions, cross referencing and thorough validation steps, NLP can contribute to identifying areas of documentation gaps and improve quality of care.

Investigation of health inequities in maternal and neonatal outcomes of patients with placenta accreta spectrum: a multicenter study

BACKGROUND

Placenta accreta spectrum (PAS) is associated with significant maternal and neonatal morbidity and mortality. There is limited established data on healthcare inequities in outcomes of patients with PAS.

OBJECTIVE

To investigate health inequities in maternal and neonatal outcomes of pregnancies with PAS.

STUDY DESIGN

This multicentered retrospective cohort study included patients with histopathological diagnosis of PAS at four regional perinatal centers between 1/1/2013 - 6/30/2022. Maternal race and/or ethnicity were categorized as either Hispanic, non-Hispanic Black, non-Hispanic White, or Asian or Pacific Islander. Primary outcome was a composite adverse maternal outcome: transfusion of 4+ units of packed red blood cells, vasopressor use, mechanical ventilation, bowel or bladder injury or mortality. Secondary outcomes were composite adverse neonatal outcome (APGAR < 7 at 1-minute, morbidity, or mortality), gestational age at PAS diagnosis, and planned delivery by a multidisciplinary team. Multivariable logistic regression was used to estimate the associations of race/ethnicity with maternal and neonatal outcomes.

RESULTS

408 pregnancies with PAS were included. In 218 patients (53%), the diagnosis of PAS was made antenatally. Patients predominantly self-identified as non-Hispanic White (31.6%) or non-Hispanic Black (24.5%). After adjusting for institution, age, BMI, income and parity, there was no difference in composite adverse maternal outcome among racial and ethnic groups. Similarly, adverse neonatal outcomes, gestational age at prenatal diagnosis, rate of planned delivery by a multidisciplinary team and cesarean hysterectomy were similar between groups.

CONCLUSION

In our multicenter PAS cohort, race and/or ethnicity were not associated with inequities in composite maternal or neonatal morbidity, timing of diagnosis and planned multi-disciplinary care. We hypothesize that comparable incidence of individual risk factors for perinatal morbidity as well as geographic proximity reduce potential inequities that may exist in the larger population.

The case for making the first-trimester anatomical survey a standard of care post Dobbs

Currently, 11- to 14-week-detailed anatomic surveys are generally reserved for at-risk populations because of the lower incidence of major fetal anomalies in low-risk populations. Until recently, such standard reflects, in part, the fact that pregnant persons retain the option of abortion even if the initial anatomy scan was in the second trimester of pregnancy. However, on June 24, 2022, the US Supreme Court overturned Roe, and many states subsequently lowered the gestational age at which abortions can legally be performed. Here, we argue for a reconsideration of limitations on first-trimester scans to preserve pregnant persons' reproductive options, particularly in those states that have imposed laws limiting access to abortion. Moreover, we acknowledge and discuss some of the challenges that will be associated with this approach.

Use of Machine Learning to Identify Clinical Variables in Pregnant and Non-pregnant Women with SARS-CoV-2 Infection

OBJECTIVE

 The aim of the study is to identify the important clinical variables found in both pregnant and non-pregnant women who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, using an artificial intelligence (AI) platform.

MATERIALS AND METHODS

 This was a retrospective cohort study of all women between the ages of 18 to 45, who were admitted to Maimonides Medical Center between March 10, 2020 and December 20, 2021. Patients were included if they had nasopharyngeal PCR swab positive for SARS-CoV-2. Safe People Artificial Intelligence (SPAI) platform, developed by Gynisus, Inc., was used to identify key clinical variables predicting a positive test in pregnant and non-pregnant women. A list of mathematically important clinical variables was generated for both non-pregnant and pregnant women.

RESULTS

 Positive results were obtained in 1,935 non-pregnant women and 1,909 non-pregnant women tested negative for SARS-CoV-2 infection. Among pregnant women, 280 tested positive, and 1,000 tested negative. The most important clinical variable to predict a positive swab result in non-pregnant women was age, while elevated D-dimer levels and presence of an abnormal fetal heart rate pattern were the most important clinical variable in pregnant women to predict a positive test.

CONCLUSION

 In an attempt to better understand the natural history of the SARS-CoV-2 infection we present a side-by-side analysis of clinical variables found in pregnant and non-pregnant women who tested positive for COVID-19. These clinical variables can help stratify and highlight those at risk for SARS-CoV-2 infection and shed light on the individual patient risk for testing positive.

A Novel Partogram for Stages 1 and 2 of Labor Based on Fetal Head Station Measured by Ultrasound: A Prospective Multicenter Cohort Study

OBJECTIVE

This study was aimed to describe continuous labor curves, including second stage, based on fetal head station.

STUDY DESIGN

We performed a prospective multicenter cohort study. The inclusion criteria were women with singleton uncomplicated cephalic term pregnancies in labor, who delivered vaginally. We used a device that combines ultrasound imaging with position-tracking technology to monitor the head station noninvasively throughout labor. We collected data on demographics, labor parameters, and delivery and neonatal outcomes.

RESULTS

A total of 613 women delivered vaginally, 327 (53.3%) were nulliparous, while 286 (46.7%) were multiparous. Time to delivery (TTD) diminished progressively with descent of the fetal head. When the head is engaged, the labor curve of multiparous women demonstrated a more prominent downward shift in curve as compared with nulliparous women. When comparing multipara and nullipara at engagement level, the median TTD was 1 and 1.62 hours, respectively. In 95% of women with unengaged head during the second stage, TTD of nulliparous and multiparous women were less than 3.8 and 3 hours, respectively.

CONCLUSION

While current labor curves end at full dilatation, the described curves were developed throughout stages 1 and 2 of labor. The TTD, according to the station curves, shows an acceleration of labor, once passed the engagement level, especially in multiparous women.

A Novel and Precise Profiling Tool to Predict Gestational Diabetes

BACKGROUND

There is a trend in healthcare for developing models for predictions of disease to enable early intervention and improve outcome.

INSTRUMENT

We present the use of artificial intelligence algorithms that were developed by Gynisus Ltd. using mathematical algorithms.

EXPERIENCE

Data were retrospectively collected on pregnant women that delivered at a single institution. Hundreds of parameters were collected and found to have different importance and correlation with the likelihood to develop gestational diabetes mellitus (GDM). We highlight 3 of 29 specific parameters that were important in pregestation and in early pregnancy, which have not been previously correlated with GDM.

CONCLUSION

This predictive tool identified parameters that are not currently being used as predictors in GDM, even before pregnancy. This tool opens the possibility of intervening on patients identified at risk for GDM and its complications. Future prospective studies are needed.

The Relationship between Status at Presentation and Outcomes among Pregnant Women with COVID-19

OBJECTIVE

This study was aimed to compare maternal and pregnancy outcomes of symptomatic and asymptomatic pregnant women with novel coronavirus disease 2019 (COVID-19).

STUDY DESIGN

This is a retrospective cohort study of pregnant women with COVID-19. Pregnant women were divided into two groups based on status at admission, symptomatic or asymptomatic. All testing was done by nasopharyngeal swab using polymerase chain reaction (PCR) for severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Initially, nasopharyngeal testing was performed only on women with a positive screen (symptoms or exposure) but subsequently, testing was universally performed on all women admitted to labor and delivery. Chi-square and Wilcoxon's rank-sum tests were used to compare outcomes between groups.

RESULTS

Eighty-one patients were tested because of a positive screen (symptoms [n = 60] or exposure only [n = 21]) and 75 patients were universally tested (all asymptomatic). In total, there were 46 symptomatic women and 22 asymptomatic women (tested based on exposure only [n = 12] or as part of universal screening [n = 10]) with confirmed COVID-19. Of symptomatic women (n = 46), 27.3% had preterm delivery and 26.1% needed respiratory support while none of the asymptomatic women (n = 22) had preterm delivery or need of respiratory support (p = 0.007 and 0.01, respectively).

CONCLUSION

Pregnant women who presented with COVID19-related symptoms and subsequently tested positive for COVID-19 have a higher rate of preterm delivery and need for respiratory support than asymptomatic pregnant women. It is important to be particularly rigorous in caring for COVID-19 infected pregnant women who present with symptoms.

KEY POINTS

· Respiratory support is often needed for women who present with symptoms.. · Low rate of severe disease in women who present without symptoms.. · There were no neonatal infections on day 0 of life..

Caring for Pregnant Patients with COVID-19: Practical Tips Getting from Policy to Practice

Novel coronavirus disease 2019 (COVID-19) is a pandemic with most American cases in New York. As an institution residing in a high-prevalence zip code, with over 8,000 births annually, we have cared for over 80 COVID-19-infected pregnant women, and have encountered many challenges in applying new national standards for care. In this article, we review how to change outpatient and inpatient practices, develop, and disseminate new hospital protocols, and we highlight the psychosocial challenges for pregnant patients and their providers. KEY POINTS: · Novel coronavirus disease 2019 (COVID-19) information rapidly changes.. · Multidisciplinary communication is key.. · This study addresses psychosocial challenges..

The effect of maternal position on fetal middle cerebral artery Doppler indices and its association with adverse perinatal outcomes: a pilot study

Objective The aim of this study was to compare position-related changes in fetal middle cerebral artery (MCA) Doppler pulsatility indices (PI). Methods A prospective study of 41 women with conditions associated with placental-pathology (chronic hypertension, pregestational diabetes, and abnormal analytes) and 34 women without those conditions was carried out. Fetal MCA Doppler velocity flow waveforms were obtained in maternal supine and left lateral decubitus positions. MCA PI Δ was calculated by subtracting the PI in the supine position from the PI in the left lateral position. Secondary outcomes included a composite of adverse perinatal outcomes (fetal growth restriction, oligohydramnios, and preeclampsia). χ2 and Student t-tests and repeated-measures analysis of variance were used. Results MCA PI Δ was significantly less for high-risk pregnant women ([P = 0.03]: high risk, left lateral PI, 1.90 ± 0.45 vs. supine PI, 1.88 ± 0.46 [Δ = 0.02]; low risk, left lateral PI, 1.90 ± 0.525 vs. supine PI, 1.68 ± 0.40 [Δ = 0.22]). MCA PI Δ was not significantly different between women who had a composite adverse outcome and women who did not have a composite adverse outcome (P = 0.843). Conclusion Our preliminary study highlights differences in position-related changes in fetal MCA PI between high-risk and low-risk pregnancies. These differences could reflect an attenuated ability of women with certain risk factors to respond to physiologic stress.

Predicting Preeclampsia with Noninvasive Measures of Endothelial Dysfunction: A Pilot Study

Objective  This study evaluates the assessment of endothelial function and its prediction for preeclampsia among women with high-risk factors. Study Design  A prospective cohort study of 107 pregnant women at 20 weeks or greater gestation with risk factors for developing preeclampsia. Endothelial dysfunction was assessed using peripheral arterial tonometry by generating a reactive hyperemia index (RHI) score. An index score of <1.67 was defined as endothelial dysfunction. The primary outcome was preeclampsia. Logistic regression was used to predict preeclampsia from RHI scores, body mass index, gestational age at RHI evaluation, history of preeclampsia, history of pregestational diabetes mellitus, chronic hypertension, and fetal number. A receiver operating characteristic plot was constructed to predict preeclampsia from the RHI score. Results  Among 107 women, 99 had interpretable RHI scores. Among those with an abnormal RHI ( n  = 61), 17 (28%) developed preeclampsia. Among women with a normal score ( n  = 38), six (16%) developed preeclampsia ( p  = 0.166). After logistic regression, there was no significant association. A receiver operating characteristic plot also revealed no association between RHI score and preeclampsia. Conclusion  An abnormal RHI score using peripheral arterial tonometry indicating endothelial dysfunction was not predictive of developing preeclampsia in this cohort. Future studies are needed to further evaluate this relationship.

Same-day confirmation of intrauterine pregnancy failure in women with first- and early second-trimester bleeding

OBJECTIVE

To determine if alpha-fetoprotein (AFP) concentration in vaginal blood, in the setting of dissolved fetal tissue, is significantly higher than its concentration in the maternal serum.

DESIGN

A prospective cohort study.

SETTING

Medical center.

PATIENT(S)

Four groups of women were evaluated: 1) with missed/incomplete miscarriage with vaginal bleeding; 2) with threatened miscarriage; 3) with vaginal bleeding during cerclage placement; and 4) undergoing dilation and curettage (D&C).

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

In each patient, AFP concentration in the vaginal blood or in the liquid component of the evacuated products of conception (POC; D&C group) was compared with the AFP concentration in the maternal serum.

RESULT(S)

The median (range) concentration ratios of AFP in vaginal blood (or POC) to AFP in maternal serum were 24.5 (5.1-8,620) and 957 (4.6-24,216) for the missed/incomplete (n = 30) and the D&C (n = 22) groups, respectively, whereas they were only 1.2 (0.4-13.4) and 1.01 (0.7-1.5) for the threatened miscarriage (n = 15) and cerclage (n = 9) groups, respectively. Receiver operating characteristic (ROC) analysis demonstrated 100% sensitivity and 86.7% specificity for the detection of the passage of fetal tissue (ratio 4.3, area under the ROC curve 0.96).

CONCLUSION(S)

Higher concentrations of AFP in vaginal blood than in maternal serum may indicate the presence of dissolved fetal tissue (i.e., confirming a failed pregnancy).

Maternal magnesium therapy, neonatal serum magnesium concentration and immediate neonatal outcomes

OBJECTIVE

The fetus is exposed to magnesium administered to the pregnant mother. However, there is controversy regarding magnesium-related neonatal adverse outcomes, largely driven by a limited understanding of the factors that influence neonatal serum magnesium concentrations and associated outcomes. The objective of this study was to examine the relationship between antenatal maternal magnesium dose and serum concentrations, neonatal serum magnesium concentration and immediate neonatal outcomes.

STUDY DESIGN

A retrospective study was conducted at a community-based teaching hospital. Neonatal serum magnesium concentrations within 48 h of birth were used to stratify magnesium-exposed neonates into three groups: group 1: <2.5 mg dl^-1, group 2: ⩾2.5 to <4.5 mg dl^-1, and group 3:⩾4.5 mg dl^-1. Immediate neonatal outcomes were compared between the three groups. Total maternal magnesium dose and serum magnesium concentrations before the delivery were correlated with neonatal serum magnesium concentrations and outcomes.

RESULTS

Of the 304 mother-baby dyads between 24 and 34 weeks gestation, 237 received antenatal magnesium. Neonatal serum magnesium concentration was 3.14±0.83 mg dl^-1 in exposed and 1.96±0.42 mg dl^-1 in unexposed neonates (P<0.001). Compared with group 2, neonates had higher odds of grade 3 or 4 intraventricular hemorrhage in group 1 (adjusted odds ratio (AOR) 5.95 (95% confidence interval (CI) 1.05 to 33.66)) and group 3 (AOR 8.42 (95% CI 1.35 to 52.54)). Group 3 neonates also had increased odds of periventricular leukomalacia (AOR: 5.37 (95% CI 1.02 to 28.28) compared with group 2 neonates. Predictors of neonatal serum magnesium concentrations included maternal magnesium dose (r=0.66, P<0.0001), duration of therapy (r=0.70, P<0.0001) and serum concentration (r=0.72, P<0.001).

CONCLUSION

The between-group differences highlight that there is a therapeutic range of neonatal serum magnesium concentrations for neuroprotective effects of antenatal magnesium sulfate, while concentrations outside of this range may be associated with adverse neonatal outcomes. Further studies are needed to determine the optimal dose and duration of maternal magnesium to minimize adverse neonatal outcomes.

Sonographic Measurement of Cervical Volume in Pregnant Women at High Risk of Preterm Birth Using a Geometric Formula for a Frustum Versus 3-Dimensional Automated Virtual Organ Computer-Aided Analysis

OBJECTIVES

To compare cervical volume measurements by 3-dimensional (3D) sonography using Virtual Organ computer-aided analysis (VOCAL; GE Healthcare, Milwaukee, WI) versus a manual method using a geometric formula for a frustum.

METHODS

We included 142 asymptomatic pregnant women at 16 to 24 weeks gestation at high risk for preterm birth. With a Voluson 730 Expert system (GE Healthcare), they underwent 2-dimensional (2D) transvaginal sonographic cervical length measurements and 3D cervical volume acquisition. The stored volumes were processed by VOCAL on a surface tablet. Cervical volume was manually calculated from the 2D images by using the formula V = 1/3 × π × h × (r1²  + r2²  + r1 × r2), where V represents cervical volume; π was approximated as 3.14159; h, cervical length; r1, radius at the internal os; and r2, radius at the external os.

RESULTS

Cervical volume was lower when obtained manually than by VOCAL, with a coefficient of variation of 30%, a mean difference of 10.1 ± 14.9 cm³ (P < .0001), and a poor interclass correlation coefficient of 0.62 (95% confidence interval [CI], 0.31 to 0.78). Both methods had good reproducibility; however, VOCAL had wider limits of agreement. A positive correlation was found between both methods (r = 0.63; P < .0001). No correlation was found between cervical length by 2D transvaginal ultrasound and cervical volume by the VOCAL technique (r = 0.06; 95% CI, -0.10 to 0.22) or cervical volume by the manual method (r = 0.2; 95% CI, 0.08 to 0.39).

CONCLUSIONS

The cervix represents a frustum (truncated cone, r1 is not equal to r2) in shape rather than a cylinder. Both methods are reproducible; VOCAL is less reliable but provides higher values of cervical volume.

Fetal proximal humeral epiphysis as an indicator of term gestation in different ethnic groups. J Matern Fetal Neonatal Med 2016;30:2505-2509. [PMID: 27819180 DOI: 10.1080/14767058.2016.1254184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

OBJECTIVES

Accurate pregnancy dating is critical for appropriate clinical management. Our aim was to determine the time of appearance of proximal humeral epiphysis (PHE), consistency of its appearance among ethnic groups and whether 3D imaging helps with its visualization.

METHODS

A cross-sectional study was done on 360 patients with 563 scans in different ethnic groups between August 2013 and July 2015. Inclusion criteria were singleton pregnancies (34-40+  weeks of gestation), well dated by <20 weeks sonogram.

RESULTS

PHE was not seen at 34 (n = 44) or 35 weeks (n = 36) and was present at gestational ages 36 (n = 3), 37 (n = 126), 38 (n = 96), 39 (n = 100) and 40 weeks (n = 28) in 2%, 12%, 51%, 75% and 100%, respectively. PHE was seen in 20 of 50 (60%) African-Americans, 22 of 61 (64%) south Asians, 41 of 72 (57%) Caucasians, 45 of 86 (48%) Hispanics and 41 of 80 (49%) Asians.

CONCLUSION

Appearance of PHE did increase with gestational age, prior to 40 weeks, it was not uniformly present and was seen as early as 36 weeks independent of ethnic group.

Uterine tachysystole in spontaneous labor at term

OBJECTIVES

The objective of this study is to determine the incidence of uterine tachysystole and its association with spontaneous labor at term.

METHODS

A retrospective cohort study of 8008 women in spontaneous labor (without prostaglandins or oxytocin). Fetal heart tracings and uterine activity were recorded every 15 min.

PRIMARY OUTCOME

occurrence of tachysystole (> 5 uterine contractions /10 min over 30 min periods).

SECONDARY OUTCOMES

non-reassuring fetal heart tracings (NRFHT), NICU admissions, and cesarean deliveries.

RESULTS

About 890 patients (11.1 %) had at least one episode of tachysystole. Non-whites have higher incidence of uterine tachysystole; adjusted odds ratio (aOR) was 1.66 for Hispanics (95% CI 1.28-2.05), 1.58 for African Americans (95% CI 1.05-2.38), and 1.51 for Asians (95% CI = 1.13-2.0). The use of epidural analgesia was higher in the tachysystole group (62.2% versus 40.9%, aOR 1.89, CI 1.58-2.26; p < 0.001). Tachysystole was more frequent among nulliparous women and in women carrying higher weight fetuses. Oligohydramnios (aOR 1.62, CI 0.70-3.72; p < 0.004), and NRFHT were more common in the tachysystole group (4.2% versus 2.5%, p = 0.002). Newborns in the tachysystole group were two times more likely to be admitted to NICU (30 /890 [3.4%] versus 122 /7118 [1.7%], OR = 2, p=0.001). There was no difference in the frequency of meconium-stained amniotic fluid or Apgar scores <7 at 5 min.

CONCLUSION

Uterine tachysystole occurs in more than 10% of spontaneous labors and is associated with NRFHR, increased rate of caesarean deliveries and NICU admissions. It is not associated with low Apgar scores or meconium-stained amniotic fluid.

Carcinoembryonic antigen as a biomarker for meconium-stained amniotic fluid

OBJECTIVE

To assess whether elevated carcinoembryonic antigen (CEA) concentration in amniotic fluid can indicate meconium-stained amniotic fluid (MSAF).

METHODS

In a prospective cohort study, women with a term singleton pregnancy who were in labor but had intact membranes were recruited at a center in Israel over a 5-month period in 2013. Only women who subsequently underwent artificial rupture of membranes following a clear medical indication were included. Samples of amniotic fluid, urine, and serum were collected. Amniotic fluid was examined by sight and classified as clear, MSAF, or undetermined. CEA concentration in the samples was measured.

RESULTS

Among 81 participants, 45 had clear amniotic fluid, 28 had MSAF, and eight had undetermined amniotic fluid. Mean CEA concentration was more than 10 times higher in MSAF (2658 μg/L, standard error 250) than in clear amniotic fluid (238 μg/L, standard error 29; P<0.001). Receiver operating characteristic curve analysis demonstrated a sensitivity of 96% and a specificity of 100% for distinguishing MSAF from clear amniotic fluid at a CEA cutoff of 799.2 μg/L. CEA concentrations in urine and serum were all within the normal range (≤5 μg/L), irrespective of amniotic fluid status.

CONCLUSION

High CEA concentrations in amniotic fluid can assist in the diagnosis of MSAF. These findings could provide the basis for a bedside test to detect MSAF following rupture of membranes.

Prospective multicenter study of ultrasound-based measurements of fetal head station and position throughout labor

OBJECTIVES

To assess the relationship between fetal head position and head station during labor, as measured using an ultrasound-based system, and the occurrence of occiput posterior (OP) position at delivery.

METHODS

This was an international prospective observational study including women who delivered between January 2009 and September 2013 in four centers: one in Brooklyn, NY, USA; one in Haifa, Israel; and two in Paris, France. We used an ultrasound-based system (LaborPro) to monitor fetal head station and position non-invasively throughout labor. We collected data on demographics, labor parameters and outcome.

RESULTS

A total of 595 women were included. In 563 (94.6%) women, fetal head position at delivery was occiput anterior (OA), in 31 (5.2%) it was OP and in one (0.2%) it was occiput transverse. In 89% of pregnancies with intrapartum OP when fetal head station was above -2, the head position turned to OA at delivery; the equivalent figures were 74% and 63% OA at delivery when intrapartum OP was diagnosed at head stations of -2 to < 0, and 0 and below, respectively. Cesarean delivery was performed in 35% of pregnancies with fetal head in OP position at delivery, as opposed to 10% of those with non-OP position at delivery. On retrospective analysis, all deliveries in OP were already in OP at station -2 and below.

CONCLUSIONS

In this first assessment of fetal head position at delivery according to fetal head position at various station levels, our data show that 100% of OP positions at delivery were already in OP position at station -2 and below. We did not observe rotation from a non-OP to an OP position from station -2 and below. Nearly two-thirds of fetuses in OP at station 0 and below will rotate to an OA position for delivery.

Neonatal morbidities among full-term infants born to obese mothers

INTRODUCTION

Impact of maternal obesity on full-term neonates is not known.

OBJECTIVE

We hypothesized increased incidence of neonatal morbidities requiring NICU admission in full-term neonates of obese women compared to neonates of normal-weight women.

METHODS

Data from full-term pregnancies collected in the Consortium of Safe Labor study were analyzed. Maternal BMI was classified using the WHO criteria. Incidence of neonatal outcomes including sepsis, PDA, NEC, respiratory distress, or their combination were compared between newborns of obese and normal-weight women.

RESULTS

Of the 109 488 women included in the study, 17.7% were obese. Maternal co-morbidities (diabetes, gestational diabetes, hypertension, and preeclampsia) increased with increasing maternal BMI. Both maternal obesity and its related co-morbidities were associated with higher incidence of neonatal morbidities. After adjusting for maternal comorbidities, there was a higher incidence of sepsis (AOR 1.91(1.45-2.50)), and combination of any of the neonatal outcomes (AOR 1.66(1.32-2.09)) among newborns of obese women than those of normal-weight women, along with an increased trend for incidence of PDA (Cochran-Armitage Test (CA) = 23.1, p < 0.0001) and NEC (CA = 7.2, p = 0.007).

CONCLUSION

Maternal obesity is independently associated with increased incidence of neonatal sepsis and a combination of neonatal morbidities in full-term newborns with an increased trend for PDA and NEC.

Neonatal serum magnesium concentrations are determined by total maternal dose of magnesium sulfate administered for neuroprotection

BACKGROUND

Antenatal magnesium in preterm labor for neuroprotection decreases the incidence of cerebral palsy. However, there are no guidelines on the dose and duration of magnesium infusion for neuroprotection. As increased neonatal serum magnesium concentrations may be related to higher risk of morbidity and mortality, the role of total amount of magnesium and maternal serum magnesium concentrations associated with safe neonatal serum magnesium concentrations is not known.

METHODS

A retrospective study was conducted on 289 mothers who received antenatal magnesium for neuroprotection as a loading dose of 4-6 g infused over 30 min, followed by a maintenance infusion of 1-2 g/h. Total magnesium dose infused to the mother and maternal serum magnesium concentrations were correlated with neonatal serum magnesium concentrations.

RESULTS

Of the 289 mothers, 192 mother/baby dyads had all three measurements (maternal total magnesium dose, and maternal and neonatal serum magnesium concentrations). Magnesium infusion was continued beyond 24 h in 60 mothers. Total maternal magnesium dose at 24 and 48 h of infusion correlated with neonatal serum magnesium concentrations (r=0.55, P<0.0001 and r=0.35, P<0.0001, respectively), but not with maternal serum magnesium concentrations (r=0.004, P=0.98 and r=0.14, P=0.21). However, there was no correlation between the maternal and neonatal serum magnesium concentrations (r=0.10, P=0.15).

CONCLUSION

Total dose of magnesium infused to the mother correlates with neonatal serum magnesium concentrations. To keep neonatal serum magnesium concentrations within a range that is effective for neuroprotection and safe for the neonates, the total dose received by the mother needs to be monitored and limited.

Nonclinical parameters affecting primary cesarean rates in the United States

OBJECTIVE

Cesarean is the single most common operation in United States and has reached epidemic proportions in recent decades. Our objective was to study the effect of nonclinical parameters on primary cesarean rates in a large contemporary population.

STUDY DESIGN

We designed a retrospective multicenter study using data obtained from electronic medical records from 19 U.S. hospitals between 2005 and 2007 (Consortium on Safe Labor Database), which included 145,764 term, singleton, nonanomalous, vertex, live births that included labor. The impact of nonclinical parameters (patient and provider characteristics, time of delivery, institutional policies, and insurance type) was investigated using modified Poisson regression methodology and classification and regression tree analysis.

RESULTS

There were 125,517 vaginal and 20,247 cesarean deliveries. Using the multivariable model, the nonclinical parameters with statistical significance for primary cesarean were delivery during evening hours, a male provider, public insurance, and nonwhite race (p < 0.001).

CONCLUSIONS

Cesarean rates are associated with several nonclinical factors. Further investigation into these factors might help to develop strategies to reduce their influence and hence the rates of cesarean.

Association between ultrasound-based assessment of fetal head station and clinically assessed cervical dilatation

OBJECTIVES

To describe the association between ultrasound-based determination of fetal head station and clinical assessment of cervical dilatation during active labor.

METHODS

From 427 women with singleton uncomplicated term pregnancies we obtained, during the active phase of labor, 907 pairs of measurements. Fetal head station and position were determined using the LaborPro system, based on position tracking and ultrasound imaging technology, and degree of cervical dilatation was determined by digital vaginal examination. The association between them was analyzed.

RESULTS

The overall correlation between cervical dilatation and fetal head station was 0.64 (P < 0.001). Complete dilatation was observed in 78% of women with fetal head engagement, and in all women with a fetal head station of + 1.5 or more.

CONCLUSIONS

There is good association between non-invasive ultrasound-based determination of fetal head station and clinically assessed cervical dilatation.

A comparison of obstetric maneuvers for the acute management of shoulder dystocia

OBJECTIVE

To assess the efficacy of obstetric maneuvers for resolving shoulder dystocia and the effect that these maneuvers have on neonatal injury when shoulder dystocia occurs.

METHODS

Using an electronic database encompassing 206,969 deliveries, we identified all women with a vertex fetus beyond 34 0/7 weeks of gestation who incurred a shoulder dystocia during the process of delivery. Women whose fetuses had a congenital anomaly and women with an antepartum stillbirth were excluded. Medical records of all cases were reviewed by trained abstractors. Cases involving neonatal injury (defined as brachial plexus injury, clavicular or humerus fracture, or hypoxic-ischemic encephalopathy or intrapartum neonatal death attributed to the shoulder dystocia) were compared with those without injury.

RESULTS

Among 132,098 women who delivered a term cephalic liveborn fetus vaginally, 2,018 incurred a shoulder dystocia (1.5%), and 101 (5.2%) of these incurred a neonatal injury. Delivery of the posterior shoulder was associated with the highest rate of delivery when compared with other maneuvers (84.4% compared with 24.3-72.0% for other maneuvers; P<.005 to P<.001) and similar rates of neonatal injury (8.4% compared with 6.1-14.0%; P=.23 to P=.7). The total number of maneuvers performed significantly correlated with the rate of neonatal injury (P<.001).

CONCLUSION

Delivery of the posterior shoulder should be considered following the McRoberts maneuver and suprapubic pressure in the management of shoulder dystocia. The need for additional maneuvers was associated with higher rates of neonatal injury.

Contemporary patterns of spontaneous labor with normal neonatal outcomes

OBJECTIVE

To use contemporary labor data to examine the labor patterns in a large, modern obstetric population in the United States.

METHODS

Data were from the Consortium on Safe Labor, a multicenter retrospective study that abstracted detailed labor and delivery information from electronic medical records in 19 hospitals across the United States. A total of 62,415 parturients were selected who had a singleton term gestation, spontaneous onset of labor, vertex presentation, vaginal delivery, and a normal perinatal outcome. A repeated-measures analysis was used to construct average labor curves by parity. An interval-censored regression was used to estimate duration of labor, stratified by cervical dilation at admission and centimeter by centimeter.

RESULTS

Labor may take more than 6 hours to progress from 4 to 5 cm and more than 3 hours to progress from 5 to 6 cm of dilation. Nulliparous and multiparous women appeared to progress at a similar pace before 6 cm. However, after 6 cm, labor accelerated much faster in multiparous than in nulliparous women. The 95 percentiles of the second stage of labor in nulliparous women with and without epidural analgesia were 3.6 and 2.8 hours, respectively. A partogram for nulliparous women is proposed.

CONCLUSION

In a large, contemporary population, the rate of cervical dilation accelerated after 6 cm, and progress from 4 cm to 6 cm was far slower than previously described. Allowing labor to continue for a longer period before 6 cm of cervical dilation may reduce the rate of intrapartum and subsequent repeat cesarean deliveries in the United States.

Contemporary cesarean delivery practice in the United States

OBJECTIVE

To describe contemporary cesarean delivery practice in the United States.

STUDY DESIGN

Consortium on Safe Labor collected detailed labor and delivery information from 228,668 electronic medical records from 19 hospitals across the United States, 2002-2008.

RESULTS

The overall cesarean delivery rate was 30.5%. The 31.2% of nulliparous women were delivered by cesarean section. Prelabor repeat cesarean delivery due to a previous uterine scar contributed 30.9% of all cesarean sections. The 28.8% of women with a uterine scar had a trial of labor and the success rate was 57.1%. The 43.8% women attempting vaginal delivery had induction. Half of cesarean for dystocia in induced labor were performed before 6 cm of cervical dilation.

CONCLUSION

To decrease cesarean delivery rate in the United States, reducing primary cesarean delivery is the key. Increasing vaginal birth after previous cesarean rate is urgently needed. Cesarean section for dystocia should be avoided before the active phase is established, particularly in nulliparous women and in induced labor.

The maternal body mass index: a strong association with delivery route

OBJECTIVE

We sought to assess body mass index (BMI) effect on cesarean risk during labor.

STUDY DESIGN

The Consortium on Safe Labor collected electronic data from 228,668 deliveries. Women with singletons > or = 37 weeks and known BMI at labor admission were analyzed in this cohort study. Regression analysis generated relative risks for cesarean stratifying for parity and prior cesarean while controlling for covariates.

RESULTS

Of the 124,389 women, 14.0% had cesareans. Cesareans increased with increasing BMI for nulliparas and multiparas with and without a prior cesarean. Repeat cesareans were performed in > 50% of laboring women with a BMI > 40 kg/m(2). The risk for cesarean increased as BMI increased for all subgroups, P < .001. The risk for cesarean increased by 5%, 2%, and 5% for nulliparas and multiparas with and without a prior cesarean, respectively, for each 1-kg/m(2) increase in BMI.

CONCLUSION

Admission BMI is significantly associated with delivery route in term laboring women. Parity and prior cesarean are other important predictors.

Respiratory morbidity in late preterm births

CONTEXT

Late preterm births (340/7-366/7 weeks) account for an increasing proportion of prematurity-associated short-term morbidities, particularly respiratory, that require specialized care and prolonged neonatal hospital stays.

OBJECTIVE

To assess short-term respiratory morbidity in late preterm births compared with term births in a contemporary cohort of deliveries in the United States.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective collection of electronic data from 12 institutions (19 hospitals) across the United States on 233,844 deliveries between 2002 and 2008. Charts were abstracted for all neonates with respiratory compromise admitted to a neonatal intensive care unit (NICU), and late preterm births were compared with term births in regard to resuscitation, respiratory support, and respiratory diagnoses. A multivariate logistic regression analysis compared infants at each gestational week, controlling for factors that influence respiratory outcomes.

MAIN OUTCOME MEASURES

Respiratory distress syndrome, transient tachypnea of the newborn, pneumonia, respiratory failure, and standard and oscillatory ventilator support.

RESULTS

Of 19,334 late preterm births, 7055 (36.5%) were admitted to a NICU and 2032 had respiratory compromise. Of 165,993 term infants, 11,980 (7.2%) were admitted to a NICU, 1874 with respiratory morbidity. The incidence of respiratory distress syndrome was 10.5% (390/3700) for infants born at 34 weeks' gestation vs 0.3% (140/41,764) at 38 weeks. Similarly, incidence of transient tachypnea of the newborn was 6.4% (n = 236) for those born at 34 weeks vs 0.4% (n = 155) at 38 weeks, pneumonia was 1.5% (n = 55) vs 0.1% (n = 62), and respiratory failure was 1.6% (n = 61) vs 0.2% (n = 63). Standard and oscillatory ventilator support had similar patterns. Odds of respiratory distress syndrome decreased with each advancing week of gestation until 38 weeks compared with 39 to 40 weeks (adjusted odds ratio [OR] at 34 weeks, 40.1; 95% confidence interval [CI], 32.0-50.3 and at 38 weeks, 1.1; 95% CI, 0.9-1.4). At 37 weeks, odds of respiratory distress syndrome were greater than at 39 to 40 weeks (adjusted OR, 3.1; 95% CI, 2.5-3.7), but the odds at 38 weeks did not differ from 39 to 40 weeks. Similar patterns were noted for transient tachypnea of the newborn (adjusted OR at 34 weeks, 14.7; 95% CI, 11.7-18.4 and at 38 weeks, 1.0; 95% CI, 0.8-1.2), pneumonia (adjusted OR at 34 weeks, 7.6; 95% CI, 5.2-11.2 and at 38 weeks, 0.9; 95% CI, 0.6-1.2), and respiratory failure (adjusted OR at 34 weeks, 10.5; 95% CI, 6.9-16.1 and at 38 weeks, 1.4; 95% CI, 1.0-1.9).

CONCLUSION

In a contemporary cohort, late preterm birth, compared with term delivery, was associated with increased risk of respiratory distress syndrome and other respiratory morbidity.

Maternal and neonatal outcomes by labor onset type and gestational age

OBJECTIVE

We sought to determine maternal and neonatal outcomes by labor onset type and gestational age.

STUDY DESIGN

We used electronic medical records data from 10 US institutions in the Consortium on Safe Labor on 115,528 deliveries from 2002 through 2008. Deliveries were divided by labor onset type (spontaneous, elective induction, indicated induction, unlabored cesarean). Neonatal and maternal outcomes were calculated by labor onset type and gestational age.

RESULTS

Neonatal intensive care unit admissions and sepsis improved with each week of gestational age until 39 weeks (P < .001). After adjusting for complications, elective induction of labor was associated with a lower risk of ventilator use (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.28-0.53), sepsis (OR, 0.36; 95% CI, 0.26-0.49), and neonatal intensive care unit admissions (OR, 0.52; 95% CI, 0.48-0.57) compared to spontaneous labor. The relative risk of hysterectomy at term was 3.21 (95% CI, 1.08-9.54) with elective induction, 1.16 (95% CI, 0.24-5.58) with indicated induction, and 6.57 (95% CI, 1.78-24.30) with cesarean without labor compared to spontaneous labor.

CONCLUSION

Some neonatal outcomes improved until 39 weeks. Babies born with elective induction are associated with better neonatal outcomes compared to spontaneous labor. Elective induction may be associated with an increased hysterectomy risk.

How reliable is the determination of cervical dilation? Comparison of vaginal examination with spatial position-tracking ruler

OBJECTIVE

The purpose of this study was to evaluate the accuracy of clinical measurement of cervical dilation with a position-tracking system during vaginal examination.

STUDY DESIGN

This prospective study that was conducted in Poissy, France, Brooklyn, NY, and Haifa, Israel, included 333 measurements that were performed in 188 women with term singleton vertex uncomplicated pregnancies during the active stage of labor. Ninety measurements with clinical diagnosis of full dilation were excluded from analysis. Measurements were performed with a sensor attached to the midwife's index fingertip and a position-tracking system that was based on a low magnetic field. Evaluations were done when cervical examinations were clinically indicated.

RESULTS

Results were similar in all centers. Mean error was 10.2 +/- 8.4 mm and ranged from 7.5 +/- 7.3 mm, when cervical dilation was > 8 cm, to 12.5 +/- 8.7 mm when cervical dilation was between 6.1 and 8 cm.

CONCLUSION

This first evaluation of cervical assessment accuracy during vaginal examination with a position-tracking system shows limited precision.

Determination of fetal head station and position during labor: a new technique that combines ultrasound and a position-tracking system

OBJECTIVE

The purpose of this study was to compare the ultrasound-based LaborPro (Trig Medical Ltd, Yokneam, Israel) system determination of fetal head station and position with routine vaginal examination.

STUDY DESIGN

This prospective study, which was conducted in 3 centers included 311 measurements that were performed in 166 singleton term pregnancies during the active phase of vertex, uncomplicated labor. Ultrasound-based position-tracking system calculations of fetal head station and position were compared with routine vaginal examination measurements.

RESULTS

Comparison of vaginal examination with the system head station results revealed a mean absolute difference of 5.5 +/- 6.1 mm (n = 311). Vaginal examination head-position evaluation, within a 45 degrees interval, complied with the system in 35 of 87 cases (40.2%).

CONCLUSION

Our data show that an ultrasound-based system can determine fetal head station and position during labor, when compared with vaginal examination, and requires minimal ultrasound skills. The limits of vaginal examination assessment of the head position are in agreement with published data.