Expanding midwifery care in the United States: Implications for clinical outcomes and cost.

BACKGROUND: This study compared clinical and financial outcomes for low-risk birthing people between those attended by midwives and those attended by obstetricians during hospital births. METHODS: We conducted a retrospective cohort analysis of births from January 1, 2016 to December 31, 2020 at hospitals participating in a perinatal quality improvement collaborative, Obstetrical Care Outcomes Assessment Program (OB COAP), in the Northwest region of the United States and estimated risk ratios using a multivariate regression approach with a modified Poisson binomial for mode of delivery, labor interventions, and newborn outcomes comparing midwife-led to obstetrician-led care. Using publicly available data on average costs of vaginal and cesarean births, we then extrapolated the cost differences in care between midwives and obstetricians. RESULTS: Births in the midwife group were less likely to be associated with induction (17.6% vs. 20.3% RR 0.74; 95% CI 0.70-0.78), epidural use (58.9% vs. 76.3% RR 0.78; 95% CI 0.77-0.80), and episiotomy (2.2% vs. 3.4% RR 0.68; 95% CI 0.58-0.81). Cesarean birth was also lower in the midwifery group (7.8% vs. 12.3% RR 0.68, 95% CI 0.62-0.73), without a corresponding increase in risk in adverse neonatal outcomes. We estimated that expanding midwifery care to 100% of low-risk births across the United States could save as much as $340 million per year. CONCLUSIONS: Midwifery care is associated with a lower risk of cesarean birth and other interventions versus care provided by obstetricians and is therefore likely lower-cost.

The impact of the Antenatal Late Preterm Steroids trial on the administration of antenatal corticosteroids.

BACKGROUND: In 2016 the Antenatal Late Preterm Steroids study was published, demonstrating that antenatal corticosteroid therapy given to women at risk of late preterm delivery reduces respiratory morbidity in infants. However, the administration of antenatal corticosteroid therapy in late-preterm infants remains controversial. Late-preterm infants do not suffer from the same rates of morbidity as early-preterm infants, and the short-term benefits of antenatal corticosteroid therapy are less pronounced; consequently, the risk of possible harm is more difficult to balance. OBJECTIVE: This study aimed to evaluate the association between the publication of the Antenatal Late Preterm Steroids study or the subsequent changes in guidelines and the rates of antenatal corticosteroid therapy administration in late-preterm infants in the United States. STUDY DESIGN: Data analyzed were publicly available US birth certificate data from January 1, 2016 to December 31, 2018. An interrupted time series design was used to analyze the association between publication of the Antenatal Late Preterm Steroids study and changes in monthly rates of antenatal corticosteroid administration in late preterm gestation (34+0 to 36+6 weeks). Births at 28+0 to 31+6 weeks' gestation were used as a control. Antenatal corticosteroid therapy administration in women with births at 32+0 to 34+6 weeks was explored to analyze whether the intervention influenced antenatal corticosteroid therapy administration in women in the subgroup approaching 34 weeks' gestation. Antenatal corticosteroid therapy administration in women with term births (>37 weeks' gestation) was analyzed to explore if the intervention influenced the number of term babies exposed to antenatal corticosteroid therapy. Our regression model allowed analysis of both step and slope changes. February 2016 was chosen as the intervention period. RESULTS: Our sample size was 18,031,950 total births. Of these, 1,056,047 were births at 34+0 to 36+6 weeks' gestation, 123,788 at 28+0 to 31+6 weeks, 153,708 at 32 to 33 weeks, and 16,602,699 were term births. There were 95,708 births at <28 weeks' gestation. There was a statistically significant increase in antenatal corticosteroid therapy administration rates in late preterm births following the online publication of the Antenatal Late Preterm Steroids study (adjusted incidence rate ratio, 1.48; 95% confidence interval, 1.36-1.61; P=.00). A significant increase in antenatal corticosteroid therapy administration rates was also seen in full-term births following the online publication of the Antenatal Late Preterm Steroids study. No significant changes were seen in antenatal corticosteroid administration rates in gestational age groups of 32+0 to 33+6 weeks or 28+0 to 31+6 weeks. CONCLUSION: Online publication of the Antenatal Late Preterm Steroids study was associated with an immediate and sustained increase in the rates of antenatal corticosteroid therapy administration in late preterm births across the United States, demonstrating a swift and successful implementation of the Antenatal Late Preterm Steroids study guidance into clinical practice. However, there is an unnecessary increase in full-term infants receiving antenatal corticosteroid therapy. Given that the long-term consequences of antenatal corticosteroid therapy are yet to be elucidated, efforts should be made to minimize the number of infants unnecessarily exposed to antenatal corticosteroid therapy.

Antepartum and intrapartum stillbirth rates across gestation: a cross-sectional study using the revised foetal death reporting system in the U.S.

BACKGROUND: There is a renewed call to address preventable foetal deaths in high-income countries, especially where progress has been slow. The Centers for Disease Control and Prevention released publicly, for the first time, the initiating cause and estimated timing of foetal deaths in 2014. The objective of this study is to describe risk and characteristics of antepartum versus intrapartum stillbirths in the U.S., and frequency of pathological examination to determine cause. METHODS: We conducted a cross-sectional study of singleton births (24-43 weeks) using 2014 U.S. Fetal Death and Natality data available from the National Center for Health Statistics. The primary outcome was timing of death (antepartum (n = 6200), intrapartum (n = 453), and unknown (n = 5403)). Risk factors of interest included maternal sociodemographic, behavioural, medical and obstetric factors, along with foetal sex. We estimated gestational week-specific stillbirth hazard, risk factors for intrapartum versus antepartum stillbirth using multivariable log-binomial regression models, conditional probabilities of intrapartum and antepartum stillbirth at each gestational week, and frequency of pathological examination by timing of death. RESULTS: The gestational age-specific stillbirth hazard was approximately 2 per 10,000 foetus-weeks among preterm gestations and > 3 per 10,000 foetus-weeks among term gestations. Both antepartum and intrapartum stillbirth risk increased in late-term and post-term gestations. The risk of intrapartum versus antepartum stillbirth was higher among those without a prior live birth, relative to those with at least one prior live birth (RR 1.32; 95% CI 1.08-1.61) and those with gestational hypertension, relative to those with no report of gestational hypertension (RR 1.47; 95% CI 1.09-1.96), and lower among Black, relative to white, individuals (RR 0.70; 95% CI 0.55-0.89). Pathological examination was not performed/planned in 25% of known antepartum stillbirths and 29% of known intrapartum stillbirths. CONCLUSION: These findings suggest greater stillbirth risk in the late-term and post-term periods. Primiparous mothers had greater risk of intrapartum than antepartum still birth, suggesting the need for intrapartum interventions for primiparous mothers in this phase of pregnancy to prevent some intrapartum foetal deaths. Efforts are needed to improve understanding, prevention and investigation of foetal deaths as well as improve stillbirth data quality and completeness in the United States.

Effects of the ARRIVE (A Randomized Trial of Induction Versus Expectant Management) Trial on Elective Induction and Obstetric Outcomes in Term Nulliparous Patients.

OBJECTIVE: To evaluate the effect of publication of the ARRIVE (A Randomized Trial of Induction Versus Expectant Management) trial on perinatal outcomes in singleton, term, nulliparous patients. METHODS: An interrupted time series analysis was performed using clinical data for nulliparous singleton births at 39 weeks of gestation or later at 13 hospitals in the Northwest region of the United States (January 2016-December 2020). A modified Poisson regression was used to model time trends and changes after the ARRIVE trial (August 9, 2018). Outcomes of interest were elective induction, unplanned cesarean births, hypertensive disorders of pregnancy, a composite of perinatal adverse outcomes, and neonatal intensive care unit admissions. RESULTS: The analysis included 28,256 births (15,208 pre-ARRIVE and 13,048 post-ARRIVE). The rate of elective labor induction was 3.6% during the pre-ARRIVE period (January 2016-July 2018) and 10.8% post-ARRIVE (August 2018-December 2020). In the interrupted time series analysis, elective induction increased by 42% (relative risk [RR] 1.42; 95% CI 1.18-1.71) immediately after the ARRIVE trial publication. Thereafter, the trend was unchanged compared with the pre-ARRIVE period. There was no statistically significant change in cesarean birth (RR 0.96; 95% CI 0.89-1.04) or hypertensive disorders of pregnancy (RR 0.91; 95% CI 0.79-1.06) immediately after the trial, and no change in trend. After the ARRIVE trial, there was no immediate change in adverse perinatal outcomes, but a statistically significant increase in trend of adverse perinatal events (1.03; 95% CI 1.01-1.05) when compared with a declining trend observed in the pre-ARRIVE period. CONCLUSION: Publication of the ARRIVE trial was associated with an increase in elective induction, and no change in cesarean birth or hypertensive disorders of pregnancy in singleton nulliparous patients giving birth at 39 weeks or later. There was a flattening of the pre-ARRIVE decreasing trend in perinatal adverse events.

Cesarean delivery rates and indications in pregnancies complicated by diabetes.

OBJECTIVE: Rates of pregestational (PGDM) and gestational diabetes (GDM), and their associated pregnancy complications, are rising. Pregnancies complicated by diabetes have increased cesarean delivery (CD) rates; however, there are limited data regarding the current rates of, and contributing factors to, these deliveries. The Robson Ten Group Classification System (TGCS) is a clinically relevant, standardized framework that can be used to evaluate and analyze cesarean rates. The objective of this study was to evaluate rates of, and indications for, intrapartum, unplanned CD among pregnancies complicated by diabetes, compared to normoglycemic (NG) pregnancies, in a large United States birth cohort. METHODS: This retrospective cohort study used chart-abstracted data on births between 24 and 42 weeks' gestation at 17 hospitals that contributed to the Obstetrical Care Outcome Assessment Program database between 01/2016 and 03/2019. The CD rate for NG pregnancies, and pregnancies complicated by gestational and PGDM was calculated and compared using the Robson TGCS. The indications for intrapartum CD in patients with term, singleton, vertex gestations without a prior cesarean were then analyzed. Univariate and multivariate logistic regression models were used to compare the cesarean rate and indications for CD, between the diabetic groups and the NG group. Results were adjusted for maternal age, BMI, neonatal birth weight, and insurance status, as well as clustering by hospital. RESULTS: A total of 86,381 pregnant people were included in the study cohort. Of these 76,272 (88.3%) were NG, 8591 (9.9%) had GDM, and 1518 (1.8%) had PGDM. Compared to NG patients, overall cesarean rates were higher in patients with GDM (40.3% vs. 29.7%; aOR 1.25, 95%CI 1.18-1.31) and PGDM (60.0% vs. 29.7%; aOR 2.53, 95%CI 2.04-3.13). This finding remained true when the cohort was restricted to term, singleton, vertex laboring patients without a prior cesarean; compared to NG patients, the cesarean rate was higher in patients with GDM (17.4% vs. 12.2%, aOR 1.37, 95%CI 1.29-1.45) and PGDM (26.0% vs. 12.2%, aOR 2.55, 95%CI 2.00-3.25). The cesarean rate for fetal indications was similar in the GDM (5.7%) and NG (4.4%) groups, while those patients with PGDM had a significantly higher rate (10.4%; aOR 2.01, 95%CI 1.43-2.83). Similarly, the rate of cesarean for labor dystocia in patients with PGDM was significantly higher than in NG patients (16.9% vs. 7.0%, and aOR 2.28, 95%CI 1.66-3.13) while patients with GDM had an intermediate rate (10.6% vs. 7.0%, aOR 1.49, 95%CI 1.40-1.57). CONCLUSIONS: The CD rate is significantly higher in pregnancies complicated by diabetes, particularly pregestational, compared to NG pregnancies. Despite controlling for maternal factors and birth weight, pregnancies complicated by diabetes are more likely to undergo an unplanned intrapartum cesarean secondary to labor dystocia than their NG counterparts, but only pregnancies complicated by PGDM have an increased risk of cesarean for fetal indications. More research is needed to understand whether this higher cesarean rate is due to factors intrinsic to diabetes in laboring patients or is due to a difference in the way clinicians manage diabetics in labor.

Institutional prevalence of class III obesity modifies risk of adverse obstetrical outcomes.

BACKGROUND: Women with prepregnancy class III obesity (body mass index ≥40 kg/m2) are at an increased risk of perinatal complications and adverse obstetrical outcomes. Estimates of the magnitude of risk that these women face vary widely, which may reflect differences in institutional experience caring for women with obesity. OBJECTIVE: We sought to characterize the relationship between institutional prevalence of prepregnancy class III obesity and the risk of adverse perinatal outcomes among these women, hypothesizing that higher-prevalence institutions would have lower rates of adverse maternal and perinatal outcomes among this population. STUDY DESIGN: We conducted a retrospective cohort study using chart-abstracted data on births in Washington state from Jan. 1, 2012, to Dec. 31, 2017. The analysis was restricted to hospitals that delivered at least 1 patient per month with prepregnancy class III obesity. Institutional prevalence of prepregnancy class III obesity was calculated, and hospitals were classified as either high or low prevalence. We included nulliparous women with vertex-presenting singleton pregnancies at ≥37 weeks of gestation. We excluded births with missing initial body mass index. The primary outcome was the incidence of cesarean delivery. Secondary outcomes were induction of labor, postpartum complications, postpartum readmission, and neonatal intensive care unit admissions. We compared outcomes between women with prepregnancy class III and all obesity at high- and low-prevalence hospitals using the χ2 test or the Fishers exact test as appropriate. Binary logistic regression was performed to compare outcomes at high- and low-prevalence hospitals. A hospital-adjusted multivariable regression model that controlled for baseline institutional rates of each outcome and compared outcomes between high- and low-prevalence hospitals was developed. A final multivariable logistic regression that controlled for both baseline institutional variation as well as potential clinical confounders was performed. RESULTS: A total of 20,556 women at 6 hospitals were eligible for inclusion; the prevalence of prepregnancy class III obesity was 6.2% and 2.1% in high- and low-prevalence hospitals, respectively. Obese women, including those with class III obesity in a high-prevalence hospital, were more likely to be Latina and less likely to be of advanced maternal age and carry private insurance. After adjusting for the institutional cesarean delivery rate, women with prepregnancy class III obesity had significantly increased odds of cesarean delivery (odds ratio, 1.53, 95% confidence interval, 1.12-2.10); however, after adjusting for significant covariates, the association no longer achieved significance (odds ratio, 1.68, 95% confidence interval, 0.97-2.94). The hospital-adjusted odds of postpartum readmission were significantly increased for women with prepregnancy class III obesity when delivering in low-prevalence institutions (odds ratio, 6.61, 95% confidence interval, 1.93-22.56), and the association was further strengthened after controlling for significant covariates (odds ratio, 15.20, 95% confidence interval, 2.32-99.53). None of the models demonstrated significantly different odds of induction of labor, postpartum complications, or neonatal intensive care unit admission by institutional prevalence of prepregnancy class III obesity. CONCLUSION: Even after controlling for underlying hospital and subject characteristics, women with prepregnancy class III obesity had significantly increased odds of postpartum readmission, and a trend toward increased odds of cesarean delivery, when delivering in institutions with less experience caring for women with obesity.

Cervical Dilation on Admission in Term Spontaneous Labor and Maternal and Newborn Outcomes.

OBJECTIVE: To examine associations between cervical dilation on admission and maternal and newborn outcomes in term spontaneous labor. METHODS: This is a retrospective cohort study of 11,368 singleton, term (37-43 6/7 weeks of gestation) spontaneously laboring women delivering in 14 hospitals in Washington State between 2012 and 2014 using chart abstracted data from the Obstetrics Clinical Outcomes Assessment Program. Women with prior cesarean delivery or ruptured membranes on admission were excluded. Pregnancy history, cervical dilation on admission, and outcomes were analyzed. Associations between early (less than 4 cm cervical dilation) and late (4 cm or greater cervical dilation) admission and outcomes were examined using general linear models with a log-link stratifying by parity. Results were reported as adjusted relative risks (RRs) with 95% confidence intervals (CIs). RESULTS: Early admission compared with late admission was associated with increased epidural use of 84.8% compared with 71.8% in nulliparous women and 66.3% compared with 53.1% in multiparous women (nulliparous RR 1.18, 95% CI 1.13-1.24; multiparous RR 1.25, 95% CI 1.18-1.32); oxytocin augmentation in 58.5% compared with 36.6% in nulliparous women and 45.9% compared with 20.7% in multiparous women (nulliparous RR 1.56, 95% CI 1.50-1.63; multiparous RR 2.14, 95% CI 1.87-2.44); and cesarean delivery of 21.8% compared with 14.5% in nulliparous women and 3.7% compared with 1.9% in multiparous women (nulliparous RR 1.50, 95% CI 1.32-1.70; multiparous women RR 1.95, 95% CI 1.47-2.57). Early admission was associated with increased neonatal intensive care unit admission for newborns of nulliparous women only (RR 1.38, 95% CI 1.01-1.89). Between 2012 and 2014, late admission increased 14.6% for nulliparous patients and 10.1% for multiparous patients, and the cesarean delivery rate decreased from 10.5% to 7.9% (P<.001) for all. CONCLUSION: Early admission (less than 4 cm cervical dilation) is a risk factor for increased medical intervention and cesarean delivery.

Use of genetic sonography for adjusting the risk for fetal Down syndrome.

Systematic evaluation of ultrasound findings known to be associated with trisomy 21, at an appropriate gestational age, has been referred to as a genetic sonogram. A number of high-risk centers performing genetic sonography have reported detection of ultrasound abnormalities in the majority of fetuses with fetal Down syndrome. However, nonspecific markers are more commonly observed than structural abnormalities, which are detected in less than 20% of cases in a nonselected population. Also, the actual sensitivity of a genetic sonogram will depend on various factors including the markers sought, gestational age, reasons for referral, and of course the quality of the ultrasound. Appropriate use of a genetic sonogram can help to modify the risk of fetal Down syndrome by decreasing the risk when the ultrasound is normal, or increasing the risk when specific ultrasound markers are detected. The postultrasound risk can be estimated by applying specific likelihood ratios, reflecting the strength of individual markers, with the a priori risk based on maternal age alone, or combined with biochemical markers when known. We review this approach of age-adjusted ultrasound risk assessment for fetal Down syndrome and illustrate how the risk can be estimated. Individual sonographic markers are also discussed.

A case of true hermaphroditism reveals an unusual mechanism of twinning.

Traditionally twins are classified as dizygous or fraternal and monozygous or identical (Hall Twinning, 362, 2003 and 735-743). We report a rare case of 46,XX/46,XY twins: Twin A presented with ambiguous genitalia and Twin B was a phenotypically normal male. These twins demonstrate a third, previously unreported mechanism for twinning. The twins underwent initial investigation with 17-hydroxyprogesterone and testosterone levels, pelvic ultrasound and diagnostic laparoscopy. Cytogenetic analysis was performed on peripheral blood cells and skin fibroblasts. Histological examination and Fluorescence in situ hybridization studies on touch imprints were performed on gonadal biopsies. DNA analysis using more than 6,000 DNA markers was performed on skin fibroblast samples from the twins and on peripheral blood samples from both parents. Twin A was determined to be a true hermaphrodite and Twin B an apparently normal male. Both twins had a 46,XX/46,XY chromosome complement in peripheral lymphocytes, skin fibroblasts, and gonadal biopsies. The proportion of XX to XY cells varied between the twins and the tissues evaluated. Most significantly the twins shared 100% of maternal alleles and approximately 50% of paternal alleles in DNA analysis of skin fibroblasts. The twins are chimeric and share a single genetic contribution from their mother but have two genetic contributions from their father thus supporting the existence of a third, previously unreported type of twinning.

Correlation of ultrasound findings and biochemical markers in the second trimester of pregnancy in fetuses with trisomy 21.

OBJECTIVE: The aim of the present study was to assess possible correlations between ultrasound findings and maternal serum biochemical ('triple test') markers among fetuses with trisomy 21 in the second trimester of pregnancy. METHODS: The study was a retrospective cohort study of 72 pregnancies affected by trisomy 21 who had a second trimester ultrasound and biochemical screen performed at a single center between 1990 and 1999. The biochemical screen consisted of alpha-fetoprotein (AFP), total beta human chorionic gonadotrophin (hCG) and estriol (uE(3)). Marker levels were expressed in multiples of the median (MoM). The ultrasound findings assessed were major structural anomalies, short humerus length, short femur length, increased nuchal fold thickness (NF), hyperechoic bowel, echogenic intracardiac focus (EIF), ventriculomegaly, choroid plexus cysts and renal pyelectasis. RESULTS: Second trimester maternal serum biochemical markers and ultrasound findings appeared to be largely independent of each other. However, some significant correlations were observed. Estriol was significantly lower when a fetal cystic hygroma was detected on ultrasound compared to those with no cystic hygroma (0.40 vs. 0.70 MoM, p<0.05). The median hCG level was significantly lower in those pregnancies with a normal second trimester fetal ultrasound compared to those with positive ultrasound findings (2.07 vs. 2.87 MoM, p<0.05). Median hCG levels were also significantly higher in those cases with NF> or =5 mm as compared to those with NF<5 mm (2.99 vs. 2.49 MoM, p<0.05). This difference persisted after exclusion of the five cases with cystic hygromas (2.99 vs. 2.49 MoM, p<0.05). A significant positive correlation was observed between log(10) hCG and log(10) NF MoM (Spearman's rho=0.252, p<0.05). NF was significantly greater among fetuses with an identifiable cardiac defect compared with those without a detectable cardiac defect (median of 7.0 mm vs. 3.8 mm, p<0.01). This difference persisted when expressed as multiples of the median (2.8 vs. 1.3 MoM, p<0.01). CONCLUSION: Second trimester ultrasound and biochemical markers are largely independent in fetuses with trisomy 21, however significant correlations between the two were observed in the present series. These may be important in screening protocols that combine second trimester ultrasound and biochemical markers.

Correlation of second-trimester sonographic and biochemical markers.

OBJECTIVES: To investigate correlations between sonographic soft markers and biochemical markers (human chorionic gonadotrophin, alpha-fetoprotein, and estriol) for Down syndrome in the second trimester of pregnancy. METHODS: A total of 2183 women with apparently normal singleton fetuses who underwent second-trimester sonography (14-22 weeks) and maternal serum biochemical testing (triple test) were identified. Seven sonographic markers were recorded: nuchal fold thickness, humerus length, femur length, renal pyelectasis, hyperechoic bowel, echogenic intracardiac focus, and choroid plexus cysts. RESULTS: Weak negative but statistically significant correlations were observed between human chorionic gonadotropin (multiples of the median) and both femur length (multiples of the median; Spearman p = -0.073; P < .01) and humerus length (multiples of the median; Spearman p = -0.083; P < .01). No other correlations significant at the 1% level were observed between femur length (multiples of the median) or humerus length (multiples of the median) and the biochemical markers. There were no significant correlations between nuchal fold thickness and any of the 3 biochemical markers. At the 5% (P < .05) level, the median human chorionic gonadotropin level (multiples of the median) was lower when an echogenic intracardiac focus was detected. Hyperechoic bowel also tended to be associated with higher median human chorionic gonadotropin (multiples of the median) and alpha-fetoprotein (multiples of the median) levels (P < .05). CONCLUSIONS: We found that sonographic and biochemical markers for trisomy 21 are largely independent in unaffected pregnancies. For accurate risk estimation, correlations in both affected and unaffected pregnancies need to be considered. No or minimal correlation between sonographic markers and serum screening tests indicates that they can be used as independent modifiers of the maternal age-specific risk for Down syndrome.