Elective Deliveries and Neonatal Outcomes in Full-Term Pregnancies.

Cesarean and induced delivery rates have risen substantially in recent decades and currently account for over one-third and one-fourth of US births, respectively. Initiatives to encourage delaying deliveries until a gestational age of 39 weeks appear to have slowed the increases but have not led to declines. The rates are at historic highs and the consequences of these interventions when not medically necessary have not been systematically explored at the population level. In this study, we used population-level data on births in New Jersey (1997-2011) to document trends in elective deliveries (induced vaginal delivery, cesarean delivery with no labor trial, and cesarean delivery after induction) and estimate logistic and linear regression models of associations between delivery method and neonatal morbidities and cost-related outcomes in low-risk pregnancies. We found that elective deliveries more than doubled during the observation period and were associated with neonatal morbidities and cost-related outcomes even at gestational ages of 39 and 40 weeks. Findings suggest that delaying beyond 39 weeks and avoiding delivery interventions when not medically necessary would improve infant health and reduce health-care costs.

Exploring Multilevel Factors for Family Engagement in Home Visiting Across Two National Models.

The associations of family, home visitor and site characteristics with family engagement within the first 6 months were examined. The variation in family engagement was also explored. Home visiting program participants were drawn from 21 Healthy Families America sites (1707 families) and 9 Nurse-Family Partnership sites (650 families) in New Jersey. Three-level nested generalized linear mixed models assessed the associations of family, home visitor and site characteristics with family receipt of a high dose of services in the first 6 months of enrollment. A family was considered to have received a high dose of service in the first 6 months of enrollment if they were active at 6 months and had received at least 50% of their expected visits in the first 6 months. In general, both home visiting programs engaged, at a relatively high level (Healthy Families America (HFA) 59%, Nurse-Family Partnership (NFP) 64%), with families demonstrating high-risk characteristics such as lower maternal education, maternal smoking, and maternal mental health need. Home visitor characteristics explained more of the variation (87%) in the receipt of services for HFA, while family characteristics explained more of the variation (75%) in the receipt of services for NFP. At the family level, NFP may improve the consistency with which they engage families by increasing retention efforts among mothers with lower education and smoking mothers. HFA sites seeking to improve engagement consistency should consider increasing the flexible in home visitor job responsibilities and examining the current expected-visit policies followed by home visitors on difficult-to-engage families.

The Epidemiology of Infant Mortality in the Greater Newark, New Jersey Area: A New Look at an Old Problem.

REVIEW: This research had institutional review board approval from the University of Medicine and Dentistry of New Jersey and the State of New Jersey Department of Health and Senior Services. IRB #0120110286 BACKGROUND: The death rate during the first year of life, or infant mortality rate (IMR), is a key indicator of a nation's health. Many factors affect IMR in the United States, including race and ethnicity. The 2020 U.S. Healthy People IMR target goal has been revised to 6.0 deaths per 1,000 births. In 2006, the IMR in New Jersey was 5.5 deaths per 1,000 births, ranging from 4.4 for Caucasians, to 11.5 for African Americans. OBJECTIVE: This study is designed to determine whether IMRs vary by zip code in the greater Newark region and identify maternal/infant characteristics associated with elevated IMRs. METHODS: A descriptive study was conducted using New Jersey Department of Health (NJDOH) birth certificate data and U.S. Census data by zip code in the greater Newark area. IMRs were analyzed by zip code and by characteristics of mothers and infants. RESULTS: IMRs vary by zip code of residence. The lowest and highest IMRs were in zip codes 07105 and 07102, respectively, both located within the city of Newark. Maternal characteristics associated with high IMR, in multivariable analysis, include: lack of prenatal care, single marital status, and non-Hispanic black race. Demographic characteristics associated with high IMRs were: low mean household income and a large percentage of the population living below poverty level. CONCLUSIONS: Race/ethnicity, marital status, and zip code of residence show significant impact upon infant mortality. Poverty and race/ethnicity are associated with increased IMRs and track to ZIP code.

Does ambient air pollution trigger stillbirth?

OBJECTIVE: We previously reported an increased risk of stillbirth associated with increases in trimester-specific ambient air pollutant concentrations. Here, we consider whether sudden increase in the mean ambient air pollutant concentration immediately before delivery triggers stillbirth. METHODS: We used New Jersey linked fetal death and hospital discharge data and hourly ambient air pollution measurements from particulate matter ≤ 2.5 mm (PM2.5), carbon monoxide (CO), nitrogen dioxide (NO2), and sulfur dioxide (SO2) monitors across New Jersey for the years 1998-2004. For each stillbirth, we assigned the concentration of air pollutants from the closest monitoring site within 10 km of the maternal residence. Using a time-stratified case-crossover design and conditional logistic regression, we estimated the relative odds of stillbirth associated with interquartile range (IQR) increases in the mean pollutant concentrations on lag day 2 and lag days 2 through 6 before delivery, and whether these associations were modified by maternal risk factors. RESULTS: The relative odds of stillbirth increased with IQR increases in the mean concentrations of CO (odds ratio [OR] = 1.20, 95% confidence interval [CI] = 1.05-1.37), SO2 (OR = 1.11, 95% CI = 1.02-1.22), NO2 (OR = 1.11, 95% CI = 0.97-1.26), and PM2.5 (OR = 1.07, 95% CI = 0.93-1.22) 2 days before delivery. We found similar associations with increases in pollutants 2 through 6 days before delivery. These associations were not modified by maternal risk factors. CONCLUSION: Short-term increases in ambient air pollutant concentrations immediately before delivery may trigger stillbirth.

Ambient air pollution and the risk of stillbirth.

The purpose of the present study was to examine the risk of stillbirth associated with ambient air pollution during pregnancy. Using live birth and fetal death data from New Jersey from 1998 to 2004, the authors assigned daily concentrations of air pollution to each birth or fetal death. Generalized estimating equation models were used to estimate the relative odds of stillbirth associated with interquartile range increases in mean air pollutant concentrations in the first, second, and third trimesters and throughout the entire pregnancy. The relative odds of stillbirth were significantly increased with each 10-ppb increase in mean nitrogen dioxide concentration in the first trimester (odds ratio (OR) = 1.16, 95% confidence interval (CI): 1.03, 1.31), each 3-ppb increase in mean sulfur dioxide concentration in the first (OR = 1.13, 95% CI: 1.01, 1.28) and third (OR = 1.26, 95% CI: 1.03, 1.37) trimesters, and each 0.4-ppm increase in mean carbon monoxide concentration in the second (OR = 1.14, 95% CI: 1.01, 1.28) and third (OR = 1.14, 95% CI: 1.06, 1.24) trimesters. Although ambient air pollution during pregnancy appeared to increase the relative odds of stillbirth, further studies are needed to confirm these findings and examine mechanistic explanations.

Using mixture models with linear predictors to identify incorrect gestational age in state birth records.

BACKGROUND: Birthweight distributions for early last-menstrual-period-based gestational ages are bimodal, and some birthweights in the right-side distribution are implausible for the specified gestational age. Mixture models can be used to identify births in the right-side distribution. The objective of this study was to determine which maternal and infant factors to include in the mixture models to obtain the best fitting models for New Jersey state birth records. METHODS: We included covariates in the models as linear predictors of the means of the component distributions and the proportion of births in each component. This allowed both the means and the proportions to vary across levels of the covariates. RESULTS: The final model included maternal age and timing of entry into prenatal care. The proportion of births in the right-side distribution was lowest for older mothers who entered prenatal care early, higher for teen mothers who entered prenatal care early, higher still for older mothers who entered prenatal care late, and highest for teens who entered prenatal care late. Over 44% of births were classified as incorrect reported gestational age. CONCLUSION: These results suggest that (1) including these two covariates as linear predictors of the means and mixing proportions gives the best model for identifying births with incorrect reported gestational age, (2) late entry into prenatal care is a mechanism by which erroneously short last-menstrual-period-based gestational ages are generated, and (3) including linear predictors of the mixing proportions in the model increases the validity of the classification of incorrect reported gestational age.

Risk of peripartum hysterectomy by mode of delivery and prior obstetric history: data from a population-based study.

PURPOSE: To provide an estimate of the incidence of peripartum hysterectomy in the state of New Jersey and calculate the effect of mode of delivery and prior obstetric history. METHODS: A perinatal-linked dataset provided by the Maternal Child Health Epidemiology Program in the New Jersey Department of Health was used to obtain information from birth certificates and hospital discharge records. Using multivariate logistic regression, various demographic and clinical factors were assessed for association with peripartum hysterectomy. RESULTS: A total of 1,004,116 births were identified between 1997 and 2005 and 853 peripartum hysterectomies were performed (0.85/1,000 deliveries). Parity increased the risk of hysterectomy with nulliparous women having approximately half the risk compared to multiparous women. Cesarean delivery with no previous c-section almost doubled the risk (OR 2.20, CI 1.80-26.69) while in the presence of a previous c-section the risk was almost four times higher (OR 4.51, CI 3.76-5.40). Operative vaginal delivery did not result in any increase in the risk. CONCLUSIONS: Mode of delivery and prior obstetric history are major risk factors for peripartum hysterectomy. Patients desiring cesarean delivery need to be counseled on the risk of this serious complication.

Municipality-Level Variation in Severe Maternal Morbidity and Association With Municipal Expenditures in New Jersey.

Importance: Severe maternal morbidity (SMM) is a major risk factor for maternal mortality, yet little is known about geographic variation in SMM or factors associated with geographical variation at the local level. Municipal governments incur substantial expenditures providing services that are an essential part of residents' lives, but associations between municipal expenditures and SMM have not been previously examined. Objective: To investigate variation in rates of SMM across municipalities in New Jersey, the contributions of individual-level characteristics and municipal expenditures to that variation, and associations between municipal expenditures and SMM. Design, Setting, and Participants: This cross-sectional study analyzed 2008 to 2018 New Jersey birth files linked to maternal hospital discharge records and US Census municipal expenditures data. The birth files contain all birth records for New Jersey, and hospital discharge records contain information from all in-patient hospitalizations in New Jersey over the study period. Birth records were matched to maternal discharge records and expenditures data. Data were analyzed from August 2020 to August 2021. Exposures: Individual-level characteristics and per capita municipal expenditures on education; public health; fire and ambulance; parks, recreation, and natural resources; housing and community development; public welfare; police; transportation; and libraries. Main Outcomes and Measures: SMM was identified using diagnosis and procedure codes developed by the Centers for Disease Control and Prevention to measure SMM. Results: Of 1 001 410 individuals (mean [SD] age, 29.8 [5.9] years; 108 665 Asian individuals [10.9%]; 147 910 Black individuals [14.8%]; 280 697 Hispanic individuals [28.0%]; 447 442 White individuals [44.7%]) who gave birth in New Jersey hospitals from 2008 to 2018, 19 962 individuals (2.0%) had SMM. There was substantial municipality-level variation in SMM that was not fully explained by demographic characteristics. Municipal expenditures on fire and ambulance, transportation, health, housing, and libraries were negatively associated with SMM; $1000 higher annual expenditures per capita in these categories were associated with 35.4% to 67.3% lower odds of SMM (odds ratios, 0.33 [95% CI, 0.15-0.72] to 0.65 [95% CI, 0.46-0.91]). Expenditures on police were positively associated with SMM (odds ratio, 1.15 [95% CI, 1.04-1.28]). Conclusions and Relevance: The findings in this study regarding associations between spending on various types of services at the municipal level and SMM, holding constant overall spending, population size, and socioeconomic status at the municipal level, indicate that municipal budget allocation decisions were associated with SMM rates and point to the importance of future research investigating potential causal connections.

Disparities in asthma hospitalizations among children seen in the emergency department.

We examined the race/ethnicity variation in the risk of hospitalization among children seen in the emergency department (ED) for asthma. ED and hospitalization records for children 1 to 19 years of age in New Jersey for 2004 and 2005 were linked. The dataset identified 47,548 ED and hospitalizations among 37,216 children. ED and hospitalization rates indicated persistent disparities in pediatric asthma. ED admission rates were similar across race/ethnic groups, suggesting similar management of pediatric asthma patients once they are seen in the ED. Integrating existing ED and hospitalization records will enhance asthma surveillance and the targeting of interventions to reduce race/ethnicity disparities.

Physician cesarean delivery rates and risk-adjusted perinatal outcomes.

OBJECTIVE: To compare perinatal outcomes in obstetric practices with high and low cesarean delivery rates. METHODS: We conducted a population-based study based on 171295 singleton births in New Jersey in 1996 and 1997. Vital certificate data for each birth were linked to the corresponding hospital discharge records. Nonsubspecialist obstetricians were divided into three groups based on their cesarean delivery rates during the study period: low (less than 18%), medium (18-27%), and high (greater than 27%). Perinatal mortality, rates of birth injury, and uterine rupture were compared among the physician groups after adjustment for differences in patient risks. RESULTS: Physicians in the frequent cesarean delivery group performed more cesarean deliveries for all major indications. Perinatal mortality rates were comparable among the three physician groups. Low and very low birth weight infants delivered by the high-rate physicians did not have a lower risk of mortality. The risk of intracranial hemorrhage was significantly higher for infants delivered by low-rate physicians than for those delivered by medium-rate physicians (adjusted relative risk [RR] 1.53; 95% confidence interval [CI] 1.07, 2.19). Relative to deliveries by medium-rate physicians, deliveries by low-rate physicians were associated with a lower overall risk of uterine rupture (adjusted RR 0.56; 95% CI 0.34, 0.92). Medium- and high-rate groups had similar occurrences of birth injury and uterine rupture. CONCLUSION: Low cesarean delivery rates reduced the rate of uterine rupture and were not associated with increased perinatal mortality. The data suggest a small increase in intracranial hemorrhages in infants delivered by physicians who perform relatively few cesarean deliveries.

Pediatric hospitalizations for asthma: use of a linked file to separate person-level risk and readmission.

INTRODUCTION: Disparities in asthma hospitalization by gender, age, and race/ethnicity are thought to be driven by a combination of 2 factors: disease severity and inadequate health care. Hospitalization data that fail to differentiate between numbers of admissions and numbers of individuals limit the ability to derive accurate conclusions about disparities and risks. METHODS: Hospitalization records for pediatric asthma patients (aged one to 14 years) were extracted from New Jersey Hospital Discharge Files (for the years 1994 through 2000) and then linked by patient identifiers using a probabilistic matching algorithm. The analysis file contained 30,400 hospital admissions for 21,016 children. Hospitalization statistics were decomposed into persons hospitalized and number of hospitalizations. Analysis of readmission within 180 days of discharge used additional records from 2001 to avoid bias due to truncated observation. RESULTS: Overall, 22.9% of children in our analysis had repeat asthma admissions within the same age interval, accounting for 30.9% of all hospitalizations. Also among all children, 11.7% had at least one readmission within 180 days of a prior discharge. The risk of hospitalization was higher for boys, decreased by age for both genders, was lowest for white children and highest for black children. Readmission rates were higher for black and Hispanic girls than boys in older age groups, but were otherwise relatively uniform by gender and age. CONCLUSION: Decomposition of ratios of total hospitalizations to population illuminates components of risk and suggests specific causes of disparity.

Breastfeeding initiation rates derived from electronic birth certificate data in New Jersey.

Increasing breastfeeding initiation has been a national goal since Healthy People targets were first set in 1979. Sensitive methods used to measure incidence of breastfeeding initiation are important in the evaluation of breastfeeding trends. The authors used the statewide electronic birth certificate (EBC) as a surveillance system to measure breastfeeding initiation rates in New Jersey from 1997 to 2000. Overall breastfeeding initiation rates rose over the 4 years surveyed, yet exclusive breastfeeding rates remained stable. Trends demonstrated persistent racial and ethnic disparities in breastfeeding practices. The EBC was a valuable tool for monitoring breastfeeding initiation rates and evaluating the statewide goal of increasing exclusive breastfeeding.

Prenatal care and subsequent birth intervals.

CONTEXT: Prenatal care generally includes contraceptive and health education that may help women to control their subsequent fertility. However, research has not examined whether receipt of prenatal care is associated with subsequent birthspacing. METHODS: Longitudinally linked birth records from 113,662 New Jersey women who had had a first birth in 1996-2000 were used to examine associations between the timing and adequacy of prenatal care prior to a woman's first birth and the timing of her second birth. Multinomial logistic regression analyses adjusted for social and demographic characteristics, hospital and year of birth. RESULTS: Most women (85%) had initiated prenatal care during the first trimester. Women who had not obtained prenatal care until the second or third trimester, or at all, were more likely than those who had had first-trimester care to have a second child within 18 months, rather than in 18-59 months (odds ratios, 1.2-1.6). Similarly, women whose care had been inadequate were more likely than those who had had adequate care to have a short subsequent birth interval (1.2). The associations were robust to alternative measures of prenatal care and birth intervals, and were strongest for mothers with less than 16 years of education. CONCLUSIONS: Providers should capitalize on their limited encounters with mothers who initiate prenatal care late or use it sporadically to ensure that these women receive information about family planning.

Trends and risk factors of stillbirth in New Jersey 1997-2005.

INTRODUCTION: The purpose of this study was to examine the trends in the rates of stillbirth by race and ethnicity and to determine the risk factors of stillbirth. METHODS: We used New Jersey data (1997-2005) for live births and fetal deaths. Cox proportional hazards model was used to estimate the risk of stillbirth associated with maternal risk factors and pregnancy complications. RESULTS: The rate of stillbirth was 4.4/1000 total births (3.4 for white and 7.9 for black non-Hispanics and 4.4 for Hispanics/1000 total births). The rates of stillbirth decreased from 3.8 in 1997 to 2.7/1000 total births in 2005 for white non-Hispanics but remained unchanged for other race/ethnicity groups. Adjusted relative risks for the risk factors associated with stillbirth were 1.3 (95% CI, 1.2-1.4) for maternal age ≥ 35 years, 1.9 (95% CI, 1.7-2.1) for black non-Hispanics, 2.8 (95% CI, 2.4-3.3) for no prenatal care, 40.2 (95% CI, 36.9-43.9) for placental abruption, 5.3 (95% CI, 3.4-8.2) for eclampsia, 3.5 (95% CI, 2.8-4.3) for diabetes mellitus and 1.7 (95% CI, 1.3-2.2) for preeclampsia. CONCLUSION: There was a decline in the rate of stillbirth but there were persistent racial disparities with the highest rates of stillbirth for black non-Hispanics.

Impact of mode of delivery on neonatal complications: trends between 1997 and 2005.

OBJECTIVE: This study examined whether rates of selected neonatal complications vary by mode of delivery and whether these rates are changing as a result of the increasing cesarean delivery rate. METHOD: Birth certificates in New Jersey from 1997 to 2005 were matched to hospital discharge records for mothers and newborns. RESULTS: In New Jersey, the total cesarean section rate for 2005 was 35.3%, a relative increase of 46% since 1997 (from 24.2%). Rates of transient tachypnea of the newborn (TTN) and respiratory distress syndrome (RDS), regardless of mode of delivery, increased between 1997 and 2005 from 3.3 to 3.9% and 2.1 to 2.4%, respectively. Newborn injuries declined sharply (from 4.1 to 2.6%), whereas intra-ventricular hemorrhage (IVH) rates remained stable. The rates of RDS, TTN and IVH were highest for cesarean delivery without trial of labor, while the rate of injuries was highest for instrumental vaginal delivery. CONCLUSION: Neonatal complication rates varied by mode of delivery and decreased with gestational age.

Amniotic fluid embolism-risk factors, maternal and neonatal outcomes.

OBJECTIVE: To investigate demographic characteristics, risk factors, maternal and neonatal outcomes of all cases of amniotic fluid embolism that occurred in New Jersey during 1997-2005. METHODS: Information was derived from a perinatal linked dataset provided by the MCH-Epidemiology Program in the New Jersey Department of Health. Bivariate analysis for dichotomous variables used the Chi-square test. Stepwise logistic regression models were created to assess the influence of potential risk factors and p value < 0.05 considered statistically significant. RESULTS: Forty-five cases of amniotic fluid embolism were identified among 1,004,116 deliveries, for a prevalence rate of 1 in 22,313 pregnancies. Statistically, significant association was found with multifetal pregnancy, caesarean section, placenta previa, placental abruption, eclampsia and cervical laceration. The rate of maternal complications such as coagulopathy, seizures, neurological damage, shock and cardiac arrest were significantly greater in the cases as compared with the overall study population. Neonatal morbidity was significant as demonstrated by higher NICU admissions and neonatal intubation rates and lower 5-min Apgar scores. CONCLUSIONS: Significant correlation was identified between historically reported risk factors and amniotic fluid embolism. The fetal and maternal mortality rates were lower compared with previous studies, attributed both to improvements in perinatal healthcare and reporting of 'milder' cases.

Delayed diagnosis of critical congenital cardiovascular malformations (CCVM) and pulse oximetry screening of newborns.

OBJECTIVE: Congenital cardiovascular malformations (CCVMs) are relatively common with a prevalence of 5-10 per 1000 live births. Pulse oximetry screening is proposed to identify newborns with critical CCVMs which are missed by routine prenatal ultrasound and by pre-discharge physical examinations. The purpose of this study was to identify the number of infants with a delayed diagnosis of critical CCVMs potentially detectable by pre-discharge pulse oximetry screening. PATIENTS AND METHODS: Hospital Discharge records in New Jersey from 199-2004 for infants with critical CCVMs were identified using ICD-9 codes. These records were matched to the Electronic Birth Certificate records to identify newborns who were discharged as normal newborns and were later admitted with a diagnosis of critical CCVMs. Chart review was completed on these cases to confirm a delay in diagnosis. RESULTS: Chart reviews confirmed delayed diagnosis of critical CCVM in 47 infants out of 670,245 births. Coarctation of the Aorta was the most common delayed diagnosis. The age at final diagnosis varied from 3 days to 6.5 months. CONCLUSIONS: Further examination of pulse oximetry as a routine newborn screening service is warranted. Implementation of pre-discharge pulse oximetry screening for newborns may improve the timely detection of asymptomatic critical CCVMs.

Maternal obesity: can pregnancy weight gain modify risk of selected adverse pregnancy outcomes?

Reports by the Institute of Medicine (IOM) recommend that gestational weight gain goals should be modified according to prepregnancy body mass index (BMI), which could result in better maternal and infant outcomes. The authors assessed whether the risk of the pregnancy outcomes such as rate of cesarean section to primiparous and multiparous women, macrosomia, and breastfeeding at 10 weeks postpartum can be modified by following the IOM guidelines for gestational weight gain irrespective of prepregnancy BMI. Staff from the New Jersey Pregnancy Risk Assessment Monitoring System interviewed a sample of women who delivered live births in New Jersey during 2002 through 2005 (n = 7661). In New Jersey, 18% of mothers were obese, 13% were overweight, and 16% were underweight. In logistic regression analyses, after controlling for maternal characteristics, the effect of prepregnancy obesity and weight gain more than 34 lb independently and significantly increased the risk of all four adverse outcomes. For no outcomes was the 25- to 34-pound weight gain category significantly distinguishable from the 16- to 24-pound reference category. These results strongly support the idea that the IOM weight gain recommendation (education during preconception regarding the importance of optimal BMI at the start of pregnancy) will help to achieve better pregnancy outcomes in obese and overweight women.

Surveillance of cesarean section deliveries, New Jersey, 1999-2004.

BACKGROUND: Nationally and in New Jersey, the cesarean delivery rate has been increasing steadily for nearly a decade, and especially since 1999. The purpose of this study was to describe recent trends in cesarean section delivery in New Jersey. METHODS: Data on delivery method, medical indications and patient characteristics were extracted from electronic birth certificate files. RESULTS: Cesarean section deliveries increased as a proportion of live births by 6 percent annually. Growth was roughly uniform across Robson's clinical classification. Repeat cesareans contributed only proportionately to the overall trend. The greatest acceleration was observed for procedures without trial of labor, and in medical situations where cesarean delivery had been relatively rare. CONCLUSIONS: Medical indications recorded on the birth certificate explained little of the rapid growth in utilization of cesarean delivery, since trends were comparable in most categories we examined. A sustained autonomous shift in practice patterns, patient preferences, or both seems the most likely driver of the overall trend.

Shoulder dystocia at noninstrumental vaginal delivery.

This study examines the relationship between episiotomy and the occurrence of shoulder dystocia among noninstrumental vaginal deliveries. Analysis of data from a retrospective database was used to study noninstrumental vaginal deliveries in New Jersey during the years 1996 to 2001. The episiotomy group and nonepisiotomy group were analyzed separately using univariate and multivariate analysis. Among 358,664 deliveries, rate of shoulder dystocia was 1.0% (n = 3596). Thirty-five percent of deliveries were assisted by episiotomy. Rate of dystocia was 1.42% with the use of episiotomy, and 0.81% when episiotomy was not used. This increased rate with episiotomy was noted across all of the racial groups, all birthweight categories, and all of the risk factor subgroups analyzed. There was a gradual decrease in the use of episiotomy from 37.30 to 26.03% without a corresponding increase in the rate of dystocia. Among noninstrumental deliveries, the rate of shoulder dystocia is higher in the episiotomy group. Decrease in the use of episiotomy has not resulted in an increase in the occurrence of dystocia.