Impact of the Duration of the Second Stage of Labor on Postpartum Pelvic Floor Symptoms.

IMPORTANCE: The associated effect of duration of the second stage of labor (SSL) on pelvic floor symptoms development is not well studied. OBJECTIVE: This study aimed to examine the association between duration of SSL and pelvic floor symptoms at 6 months postpartum among primiparous women. STUDY DESIGN: A planned secondary analysis of a multicenter randomized trial evaluating the impact of immediate versus delayed pushing on vaginal delivery rates, maternal morbidity, and neonatal outcomes was conducted between 2014 and 2018. For pelvic floor arm participants, demographic, pelvic examination, and validated questionnaire data were collected postpartum. Primary outcome was change in Pelvic Floor Distress Inventory 20 (PFDI-20) score from immediate to 6 months postpartum. Secondary outcomes included changes in the Pelvic Floor Impact Questionnaire, Fecal Incontinence Severity Index, Modified Manchester Health Questionnaire scores, and Pelvic Organ Prolapse Quantification measurements at 6 months postpartum. Participants were analyzed by SSL duration ≤60 minutes or >60 minutes. RESULTS: Of the 2,414 trial participants, 767 (32%) completed pelvic floor assessments at 6 months. Pelvic Floor Distress Inventory 20 scores significantly improved at 6 months in the ≤60 minutes SSL group compared with >60 minutes SSL (-14.3 ± 48.0 and -3.2 ± 45.3, respectively; P = 0.04). Changes from immediate postpartum in total and subscale scores for other questionnaires at 6 months did not differ between groups. Prolapse stage did not differ between groups. Perineal body was significantly shorter in the >60 minutes SSL group (3.7 ± 0.7, 3.5 ± 0.8; P = 0.03). CONCLUSIONS: Women with SSL >60 minutes experience less improvement in PFDI-20 scores at 6 months. Greater tissue and innervation trauma in those with SSL >60 minutes may explain persistently less improvement in PFDI-20 scores.

Prostaglandins and cesarean delivery for nonreassuring fetal status in patients delivering small-for-gestational age neonates at term.

Objective: Growth-restricted fetuses have been excluded from many randomized trials of prostaglandins for labor induction. As prostaglandins, particularly misoprostol, are associated with increased rates of cesarean delivery for nonreassuring fetal heart tracing, it is important to assess their safety in pregnancies at higher risk of this complication. The objective of this study was to estimate the association between use of prostaglandins for labor induction in term singleton pregnancies complicated by delivery of small-for-gestational age (SGA) neonates and the risk of cesarean delivery for nonreassuring fetal status (NRFS).Materials and methods: Retrospective cohort study of singleton deliveries ≥37 weeks following induction of labor in patients with SGA (birthweight <10% percentile for gestational age). Patients with prior cesarean delivery or neonates with major congenital anomalies were excluded. Patients were categorized by exposure to prostaglandins. The primary outcome was cesarean delivery for NRFS. Secondary outcomes were any cesarean delivery, a composite of a 5-min Apgar score <7, admission to the neonatal intensive care unit, or neonatal death, and a composite of maternal morbidity (transfusion, postpartum hemorrhage, wound infection, endometritis, fever). Propensity scores for exposure were estimated using a logistic regression model, including parity, comorbidities, and Bishop score. Stabilized weights from inverse probability of treatment weighting were used. Outcomes were compared with relative risks (RRs) and 95% confidence intervals (CIs).Results: There were 1097 patients: 587 (53.5%) exposed to prostaglandins and 510 (46.5%) unexposed. Covariates were balanced in the stabilized sample. Overall, 166 (15.1%) patients had cesarean deliveries for NRFS. In unadjusted analysis, prostaglandin use was associated with an increased RR of cesarean for NRFS (18.3 versus 11.0%, RR: 1.71, 95% CI: 1.27-2.30). In propensity-score-weighted analysis, the RR for cesarean for NRFS was 1.22 (95% CI: 0.93-1.59). There was no significant association between prostaglandin exposure and all-cause cesarean delivery, maternal morbidity, or neonatal morbidity.Conclusion: In propensity score analysis, there was no association between the use of prostaglandins for labor induction at term and cesarean for NRFS in pregnancies complicated by SGA. However, given the retrospective nature of the study, these results should be interpreted with caution.

Association of abnormal first stage of labor duration and maternal and neonatal morbidity.

BACKGROUND: Contemporary guidelines for labor management do not characterize abnormal labor on the basis of maternal and/or neonatal morbidity. OBJECTIVE: In this study, we aimed to evaluate the association of abnormal duration of the first stage of term labor and the risk of maternal and neonatal morbidity. STUDY DESIGN: We conducted a retrospective analysis of prospectively collected data of all consecutive women admitted for delivery at a single center at ≥37 weeks and 0 to 7 days of gestation with singleton, nonanomalous, vertex infants from 2010 to 2015, who reached 10 cm cervical dilation. Multivariable logistic regression compared odds ratios for maternal and neonatal outcomes among women above and below the 90th, 95th, and 97th percentiles for first stage of labor duration. Receiver operating characteristic curves estimated the association between first stage of labor duration and maternal morbidity. Maternal morbidity was a composite of maternal fever, hemorrhage, transfusion, or endomyometritis; prolonged second stage of labor duration; and third- or fourth-degree perineal laceration. Neonatal morbidity was a composite of hypothermic therapy, need for mechanical ventilation, respiratory distress syndrome, meconium aspiration syndrome, birth injury or trauma, and neonatal seizure or sepsis. RESULTS: Of 6823 women included in this study, 682 were anticipated to have first stage of labor duration above the 90th percentile cutoff point, which was associated with an increased risk of composite maternal morbidity, maternal fever, postpartum transfusion, prolonged second stage of labor duration, third- or fourth-degree perineal laceration, and cesarean or operative vaginal delivery (P≤.02) and an increased risk of composite neonatal morbidity, respiratory distress syndrome, need for mechanical ventilation, and neonatal sepsis (P≤.03). Composite maternal morbidity was 2.2 (95% confidence interval, 1.8-2.7), 1.9 (95% confidence interval, 1.4-2.4), and 1.8 (95% confidence interval, 1.3-2.5) times more likely to occur among women above the 90th, 95th, and 97th percentile, respectively, for first stage of labor duration from 4 to 10 cm. Composite neonatal morbidity was 2.6 (95% confidence interval, 2.1-3.2), 2.2 (95% confidence interval, 1.7-2.9), and 1.9 (95% confidence interval, 1.3-2.8) times more likely to occur among infants delivered by women above the 90th, 95th, and 97th percentiles for first stage of labor duration from 4 to 10 cm. Receiver operating characteristic curves among all women from 4 to 10 cm and 6 to 10 cm, including when stratified by parity and type of labor onset, had an area under the curve of 0.51 to 0.62 and 0.53 to 0.71 for maternal and neonatal morbidity, respectively. Thus, duration of labor has moderate predictive ability, at best, for composite maternal or neonatal morbidity. No curve demonstrated a clear point at which adverse maternal or neonatal outcomes increased that could be used to define abnormal labor. CONCLUSION: The benefit of expectantly managing a prolonged first stage of labor with duration above the 90th percentile in anticipation of vaginal delivery must be weighed against the increased risk of composite maternal and neonatal morbidity. Risks associated with performing cesarean delivery as an alternative management for women with prolonged first stage of labor duration must also be considered.

First stage of labor progression in women with large-for-gestational age infants.

BACKGROUND: Women with suspected large-for-gestational age fetuses have higher rates of dysfunctional labor and labor arrest diagnoses and, consequently, higher rates of cesarean deliveries. The identification of the factors that significantly affect labor progression of women with large-for-gestational age infants may better inform expected duration of labor for certain subgroups of this population. OBJECTIVE: Because the standards for the first stage of labor when large-for-gestational age is present have not been defined clearly, the present study aims to evaluate labor progress of women with large-for-gestational age infants who complete the first stage of labor after 3-cm cervical dilation. STUDY DESIGN: We conducted a retrospective cohort study of patients who were admitted for labor from 2004-2014 with a term vertex singleton who achieved 10-cm cervical dilation. Labor curves were constructed with repeated measures regression and were compared between patients who delivered large-for-gestational age infants (actual birthweight, >90th percentile for gestational age) and those who delivered appropriate-for-gestational age infants (actual birthweight, 10-90th percentile for gestational age). Interval-censored regression estimated median duration of labor after 3-cm cervical dilation stratified by actual infant birthweight and further stratified by parity (nulliparity vs multiparity), labor onset (spontaneous [augmented and not augmented] and induced labor), pregestational diabetes mellitus or gestational diabetes mellitus status, and maternal body mass index (obese, ≥30 kg/m2 vs not obese, <30 kg/m2). Multivariate analysis adjusted for confounding factors that were identified by bivariate analysis. RESULTS: Among all 17,097 women who were included, 15,843 women (92.7%) had appropriate-for-gestational age infants; 1254 women (7.3%) had large-for-gestational age infants, of whom 387 (30.9%) were nulliparous; 464 women (37.0%) underwent induction of labor; 863 women (68.8%) were obese, and 158 women (12.6%) had diabetes mellitus or gestational diabetes mellitus. Women with large-for-gestational age infants had a slower progression from 3- to 10-cm cervical dilation compared with those with appropriate-for-gestational age infants (median, 8.57 hours [5th, 95th percentile, 2.95, 24.86] vs 6.46 hours [5th, 95th percentile, 2.23, 18.74]; P<.01). In the large-for-gestational age group, dilation from 6-10 cm progressed slower in nulliparous compared with multiparous women (3.28 hours [5th, 95th percentile, 0.71, 15.16] vs 2.03 hours [5th, 95th percentile, 0.44, 9.39]; P<.01) and in obese compared with not obese women (2.36 hours [5th, 95th percentile, 0.51, 10.91] vs 1.79 hours [5th, 95th percentile, 0.39, 8.31]; P<.01). Labor curves did not differ between large-for-gestational age and appropriate-for-gestational age groups when stratified by labor onset (nonaugmented spontaneous labor vs induced labor) or the presence of diabetes mellitus or gestational diabetes mellitus. CONCLUSION: After 3-cm cervical dilation, the time required to reach the second stage of labor is greater in women with large-for-gestational age infants compared with those with appropriate-for-gestational age infants; these differences are most pronounced in nulliparous and obese women with large-for-gestational age infants in the active phase of labor (6-10 cm). Among women with large-for-gestational age infants, labor onset and presence of diabetes mellitus or gestational diabetes mellitus have no apparent effect on the duration of the first stage of labor after 3-cm cervical dilation.

The transition from latent to active labor and adverse obstetrical outcomes.

BACKGROUND: Recommendations on preventing primary cesarean delivery removed the previously defined time limits for latent labor (defined as ending at 6 cm) and urged clinicians to avoid cesarean delivery for labor abnormalities in the latent phase. However, relatively little is known about the implications of labor curve abnormalities from 4 to 6 cm and subsequent outcomes. OBJECTIVE: To examine the association between length of time for dilation from 4 to 6 cm, delivery outcomes, and maternal and neonatal morbidity. STUDY DESIGN: This is a secondary analysis of a prospective cohort study of patients at ≥37 weeks presenting in spontaneous or induced labor with a nonanomalous living singleton in vertex presentation. Patients with a history of cesarean delivery or who did not achieve 6-cm dilation were excluded. We used interval censored regression to determine the 90th percentile for dilation time from 4 to 6 cm and used logistic regression to estimate the odds ratios and 95% confidence intervals for adverse outcomes for patients above this cutoff percentile compared with those at or below. Analyses were adjusted for obesity, nulliparity, race, hypertension, diabetes, and type of labor (induced vs spontaneous/augmented). Outcomes included cesarean delivery, maternal morbidity (composite of postpartum fever, wound infection, hemorrhage), and neonatal morbidity (composite of neonatal death, hypothermic therapy, mechanical ventilation, respiratory distress, meconium aspiration syndrome, seizure, or treatment of sepsis). In addition, we created receiver operator characteristic curves to predict cesarean delivery, and maternal and neonatal morbidity based on time to dilate from 4 to 6 cm. The cutoff for time for each outcome was identified using the Youden index to maximize sensitivity and specificity, and test characteristics were computed. RESULTS: There were 7355 patients eligible for analysis, 728 (10%) had dilation times from 4 to 6 cm >10.3 hours, which was the 90th percentile, and 6627 (90%) had dilation times ≤10.3 hours. Having dilation time from 4 to 6 cm above the 90th percentile (10.3 hours) was associated with cesarean delivery (adjusted odds ratio, 2.05; 95% confidence interval, 1.67-2.52), composite maternal morbidity (adjusted odds ratio, 1.48; 95% confidence interval, 1.10-2.00), and composite neonatal morbidity (adjusted odds ratio 1.92; 95% confidence interval 1.52-2.4). The area under the receiver operator characteristic curve for predicting cesarean delivery was 0.73 (95% confidence interval, 0.71-0.75). The test characteristics for the cutoff of 9.75 hours were sensitivity 68.3% (95% confidence interval, 64.8%-71.7%), specificity 66.2% (95% confidence interval, 55.0%-67.3%), positive predictive value 18.5% (95% confidence interval, 17.1%-20.0%), and negative predictive value 94.9% (95% confidence interval, 94.2%-95.5%). For composite maternal morbidity, the cutoff was 6.98 hours and the area under the curve was 0.62 (95% confidence interval, 0.59-0.65), whereas for composite neonatal morbidity it was 5.5 hours (area under the curve 0.69; 95% confidence interval, 0.67-0.71). CONCLUSIONS: Patients whose dilation time from 4 to 6 cm exceeds the 90th percentile have increased odds of cesarean delivery and postpartum complications. Prolonged dilation time has moderate predictive ability for adverse outcomes. Future studies should investigate at what point, if any, intervention is warranted during this period to reduce these risks.

Randomized Controlled Trial of Home-Based Lifestyle Therapy on Postpartum Weight in Underserved Women with Overweight or Obesity.

OBJECTIVE: This study aimed to assess the efficacy of a home-based lifestyle intervention delivered through Parents as Teachers (PAT), a national home-visiting organization, designed to minimize excessive weight gain through 12 months post partum in socioeconomically disadvantaged (SED) African American women with overweight or obesity. METHODS: This randomized controlled trial was conducted at a single center as part of the Lifestyle Interventions for Expectant Moms (LIFE-Moms) consortium. Analysis was conducted with 185 SED African American women (BMI 25.0-45.0 kg/m2 at pregnancy onset) retained from an original sample of 267 randomized to standard PAT or PAT+Lifestyle, which embedded lifestyle therapy within standard PAT delivered prenatally and for 12 months post partum. RESULTS: Compared with standard PAT, the PAT+Lifestyle group gained less weight (2.5 kg vs. 5.7 kg; P = 0.01) and were more likely to return to their baseline weight (38.0% vs. 21.5%; P = 0.01) from baseline to 12 months post partum. There were no differences between groups in cardiometabolic outcomes, indices of glycemic control and insulin sensitivity, and plasma lipid profile. The estimated cost of PAT+Lifestyle was $81 more to deliver per family than standard PAT. CONCLUSIONS: PAT+Lifestyle decreases weight gain during pregnancy through 12 months post partum in SED African American women with overweight or obesity at the start of pregnancy with minimal additional cost.

A Prediction Model for Severe Maternal Morbidity in Laboring Patients at Term.

OBJECTIVE: To determine the factors associated with severe maternal morbidity in a modern cohort of women laboring at term and to create a prediction model. STUDY DESIGN: This is a retrospective cohort study of all term, laboring patients with live births at a single tertiary care center from 2004 to 2014. The primary outcome was composite maternal morbidity including organ failure, amniotic fluid embolism, anesthesia complications, sepsis, shock, thrombotic events, transfusion, or hysterectomy. Multivariable logistic regression was used to identify independent risk factors. Antepartum, intrapartum, and combined risk scores were created and test characteristics were analyzed. RESULTS: Among 19,249 women delivering during the study period, 323 (1.68%) patients experienced severe morbidity, with blood transfusion the most common complication (286, 1.49%). Factors in the antepartum model included advanced maternal age, race, hypertension, nulliparity, history of cesarean delivery, smoking, and unfavorable Bishop score. Intrapartum factors included mode of delivery, use of cervical ripening agents or oxytocin, prolonged second stage, and macrosomia. The combined model had an area under the curve of 0.76 (95% confidence interval [CI], 0.73, 0.79). CONCLUSION: This three-part risk scoring system can help clinicians counsel patients and guide clinical decision making for anticipating severe maternal morbidity and necessary resources.

Effect of a Home-Based Lifestyle Intervention on Breastfeeding Initiation Among Socioeconomically Disadvantaged African American Women with Overweight or Obesity.

BACKGROUND: Socioeconomically disadvantaged (SED) African American women with overweight or obesity are less likely to breastfeed. OBJECTIVE: To test whether a home-based lifestyle intervention impacts breastfeeding initiation rates in SED African American women with overweight or obesity. STUDY DESIGN: This was a secondary analysis of a randomized controlled trial from October 2012 to March 2016 at a university-based hospital within the LIFE-Moms consortium. SED African American women with overweight or obesity and singleton gestations were randomized by 16 weeks to Parents as Teachers (PAT)-a home-based parenting support and child development educational intervention-or PAT+, PAT with additional content on breastfeeding. Participants completed a breastfeeding survey. Outcomes included breastfeeding initiation and reasons for not initiating or not continuing breastfeeding. RESULTS: One hundred eighteen women were included: 59 in PAT+; 59 in PAT. Breastfeeding initiation rates were similar in each group (78.00% in PAT+; 74.58% in PAT). On a one to four scale, with four denoting "very important," women in PAT+ and PAT were equally likely to rate their beliefs that formula was better than breast milk or breastfeeding would be too inconvenient as the most important reasons to not initiate breastfeeding. On the same scale, women similarly rated their difficulty latching or concern for low milk supply as the most important reasons for breastfeeding cessation. CONCLUSION: SED African American women with overweight or obesity who received a home-based educational intervention had higher breastfeeding rates than is reported nationally for black women (59%). However, the intervention with more breastfeeding content did not further increase breastfeeding rates or impact reasons for breastfeeding cessation. TRIAL REGISTRATION: ClinicalTrials.gov : NCT01768793.

Weight Control Program and Gestational Weight Gain in Disadvantaged Women with Overweight or Obesity: A Randomized Clinical Trial.

OBJECTIVE: This study aimed to evaluate the efficacy of a home-based lifestyle intervention delivered through Parents as Teachers (PAT) to reduce excessive gestational weight gain (GWG). METHODS: This was a single-blinded randomized controlled trial conducted as part of the LIFE-Moms consortium at a single university-based tertiary care institution from October 2012 to March 2016. There were 267 socioeconomically disadvantaged (SED) African American women with overweight or obesity (BMI 25.0-45.0 kg/m2 before pregnancy. Participants were randomized to therapy with standard PAT alone (n = 134) or PAT plus a lifestyle intervention program embedded within the standard PAT program (PAT+) (n = 133). Both interventions were delivered in 10 biweekly home visits during pregnancy. The primary outcome was the percentage of women whose GWG exceeded the Institute of Medicine guidelines, and secondary outcomes included both weekly and total GWG. RESULTS: Compared with the standard PAT group in the intent-to-treat analysis, the PAT + group gained less weekly (0.4 kg vs. 0.5 kg/wk; P = 0.04) and total (8.0 kg vs. 9.6 kg; P = 0.02) weight during gestation. Fewer participants in the PAT + group had excessive total GWG (36.1% vs. 45.9%), but the difference between groups was not statistically significant (P = 0.11). CONCLUSIONS: PAT + reduced the weekly and total GWG in SED African American women with overweight or obesity at the start of pregnancy.

Spontaneous Labor Onset and Outcomes in Obese Women at Term.

OBJECTIVE: The objective of this study was to compare the rates of spontaneous labor onset and its progression in obese and nonobese women after 37 weeks. STUDY DESIGN: We performed a secondary analysis of a retrospective cohort of all women who were admitted for delivery at ≥ 37 weeks of gestation at a university-based tertiary care center between 2004 and 2010. The cohort was stratified by weeks of gestation at which the patient presented for delivery. The rates of spontaneous labor, vaginal delivery, and augmentation with oxytocin were compared between obese (body mass index [BMI] ≥ 30) and nonobese (BMI < 30) women. RESULTS: Obese women had lower rates of spontaneous labor than nonobese women at every gestational week (37 weeks, 6.1 vs. 9.3%, p < 0.001; 38 weeks, 12.8 vs. 19.2%, p < 0.001; 39 weeks 26.0 vs. 37.0%, p < 0.001; 40 weeks, 39.6 vs. 50.2%, p < 0.001; 41 weeks, 30.8 vs. 38.0%, p < 0.012). Among women who presented in spontaneous labor, obesity was associated with higher rates of augmentation with oxytocin and lower rates of vaginal delivery. CONCLUSION: Obese women at or beyond 37 weeks are less likely to experience spontaneous labor compared with nonobese women. In addition, obese women presenting in spontaneous labor are less likely that nonobese women to have a vaginal delivery at 37 to 40 weeks, even after oxytocin augmentation.

New labor management guidelines and changes in cesarean delivery patterns.

BACKGROUND: In 2010 the Consortium on Safe Labor published labor curves. It was proposed that the rate of cesarean delivery could be lowered by avoiding the diagnosis of arrest of dilation before 6 cm. However, there is little information on the uptake of the guidelines and on changes in cesarean delivery rates that may have occurred. OBJECTIVE: The objective of the study was to test the following hypotheses: (1) among patients laboring at term, rates of arrest of dilation disorders have decreased, leading to a decrease in the rate of cesarean delivery; (2) in the second stage, pushing duration prior to diagnosis of arrest of descent has increased, also leading to a reduction in the rate of cesarean delivery for this indication. As a secondary aim, we investigated changes in maternal and neonatal morbidity. STUDY DESIGN: This was a secondary analysis of a prospective cohort study of all patients presenting at ≥37 weeks' gestation from 2010 through 2014 with a nonanomalous vertex singleton and no prior history of cesarean delivery. Rates of cesarean delivery, arrest of dilation, and changes in rates of maternal and neonatal morbidity were calculated in crude and adjusted models. Cervical dilation at diagnosis of the arrest of dilation, time spent at the maximal dilation prior to diagnosis of arrest of dilation, and time in the second stage prior to the diagnosis of arrest of descent were compared over the study period. RESULTS: There were 7845 eligible patients. The cesarean delivery rate in 2010 was 15.8% and, in 2014, 17.7% (P trend = .51). In patients undergoing cesarean delivery for the arrest of dilation, the median cervical dilation at the time of cesarean delivery was at 5.5 cm in 2010 and 6.0 cm in 2014 (P trend = .94). In these patients, there was an increase in the time spent at last dilation: 3.8 hours in 2010 to 5.2 hours in 2014 (P trend = .02). There was no change in the frequency of patients diagnosed with the arrest of dilation at <6 cm: 51.4% in 2010 and 48.6% in 2014 (P trend = .56). However, in these patients, the median time spent at the last cervical dilation was 4.0 hours in 2010 and 6.7 hours in 2014 (P trend = .046). There were 206 cesarean deliveries for the arrest of descent. The median pushing time in these patients increased in multiparous patients from 1.1 hours in 2010 to 3.4 hours in 2014 (P trend = .009); in nulliparous patients these times were 2.7 hours in 2010 and 3.8 hours in 2014 (P trend = .09). There was a significant trend toward increasing adverse neonatal and maternal outcomes (P < .001 for each). The adjusted odds ratio for adverse maternal outcome for 2014 compared with 2010 was 1.66 (95% confidence interval, 1.27-2.17); however, considering only transfusion, hemorrhage, or infection, there was no difference (P trend = .96). The adjusted odds ratio of adverse neonatal outcome in 2014 compared with 2010 was 1.80 (95% confidence interval, 1.36-2.36). CONCLUSION: Despite significant changes in labor management that have occurred over the initial years since publication of the new labor curves and associated guidelines, the primary cesarean delivery rate was not reduced and there has been an increase in maternal and neonatal morbidity in our institution. A randomized controlled trial is needed.

Predicting obstetric anal sphincter injuries in a modern obstetric population.

BACKGROUND: Perineal lacerations are common at the time of vaginal delivery and may predispose patients to long-term pelvic floor disorders, such as urinary incontinence and pelvic organ prolapse. Obstetric anal sphincter injuries, which are the most severe form of perineal lacerations, result in disruption of the anal sphincter and, in some cases, the rectal mucosa during vaginal delivery. Long-term morbidity, including pain, pelvic floor disorders, fecal incontinence, and predisposition to recurrent injury at subsequent delivery may result. Despite several studies that have reported risk factors for obstetric anal sphincter injuries, no accurate risk prediction models have been developed. OBJECTIVE: The purpose of this study was to identify risk factors and develop prediction models for perineal lacerations and obstetric anal sphincter injuries. STUDY DESIGN: This was a nested case control study within a retrospective cohort of consecutive term vaginal deliveries at 1 tertiary care facility from 2004-2008. Cases were patients with any perineal laceration that had been sustained during vaginal delivery; control subjects had no lacerations of any severity. Secondary analyses investigated obstetric anal sphincter injury (3rd- to 4(th)-degree laceration) vs no obstetric anal sphincter injury (0 to 2(nd)-degree laceration). Baseline characteristics were compared between groups with the use of the chi-square and Student t test. Adjusted odds ratios and 95% confidence intervals were calculated with the use of multivariable logistic regression. Prediction models were created and model performance was estimated with receiver-operator characteristic curve analysis. Receiver-operator characteristic curves were validated internally with the use of the bootstrap method to correct for bias within the model. RESULTS: Of the 5569 term vaginal deliveries that were recorded during the study period, complete laceration data were available in 5524 deliveries. There were 3382 perineal lacerations and 249 (4.5%) obstetric anal sphincter injuries. After adjusted analysis, significant predictors for laceration included nulliparity, non-black race, longer second stage, nonsmoking status, higher infant birthweight, and operative delivery. Private health insurance, labor induction, pushing duration, and regional anesthesia were not statistically significant in adjusted analyses. Significant risk factors for obstetric anal sphincter injury were similar to predictors for any laceration; nulliparity and operative vaginal delivery had the highest predictive value. Area under the curve for the predictive ability of the models was 0.70 for overall perineal laceration, and 0.83 for obstetric anal sphincter injury. When limited to primiparous patients, 1996 term vaginal deliveries were recorded. One hundred ninety-two women sustained an obstetric anal sphincter injury; 1796 women did not. After adjusted analysis, significant predictors for laceration included non-black race, age, obesity, and nonsmoking status. In secondary analyses, significant predictors for obstetric anal sphincter injury included non-black race, nonsmoking status, longer duration of pushing, operative vaginal delivery, and infant birthweight. Area under the curve for the predictive ability of the models was 0.60 for any laceration and 0.77 for obstetric anal sphincter injury. CONCLUSIONS: Significant risk factors for sustaining any laceration and obstetric anal sphincter injury during vaginal deliveries were identified. These results will help identify clinically at-risk patients and assist providers in counseling patients about modifications to decrease these risks.

Predictors of size for gestational age in St. Louis City and County.

OBJECTIVE: To identify social, behavioral, and physiological risk factors associated with small for gestational age (SGA) by gestational age category in St. Louis City and County. METHODS: A retrospective cohort study was conducted using birth certificate and fetal death records from 2000 to 2009 (n = 142,017). Adjusted associations of risk factors with SGA were explored using bivariate logistic regression. Four separate multivariable logistic regression analyses, stratified by gestational age, were conducted to estimate adjusted odds ratios. RESULTS: Preeclampsia and inadequate weight gain contributed significantly to increased odds for SGA across all gestational age categories. The point estimates ranged from a 3.41 increased odds among women with preeclampsia and 1.76 for women with inadequate weight gain at 24-28 weeks' gestational age to 2.19 and 2.11 for full-term infants, respectively. Among full-term infants, smoking (aOR = 2.08), chronic hypertension (aOR = 1.46), and inadequate prenatal care (aOR = 1.25) had the next most robust and significant impact on SGA. CONCLUSION: Preeclampsia and inadequate weight gain are significant risk factors for SGA, regardless of gestational age. Education on the importance of nutrition and adequate weight gain during pregnancy is vital. In this community, disparities in SGA and smoking rates are important considerations for interventions designed to improve birth outcomes.