Risk factors and outcome of failure to progress during the first stage of labor: a population-based study

BACKGROUND: One of the major indications for Cesarean section (CS) is failure of labor to progress. This study was aimed at defining obstetric risk factors for failure of labor to progress during the first stage, and to determine pregnancy outcome. METHODS: A population-based study comparing all singleton, vertex, term deliveries between the years 1988 and 1999 with an unscarred uterus, complicated with failure of labor to progress during the first stage with deliveries without non-progressive labor (NPL). Multiple logistic regression analysis was performed to investigate independent obstetric risk factors associated with failure of labor to progress during the first stage. RESULTS: Failure to progress during the first stage of labor complicated 1.3% (n = 1197) of all deliveries included in the study (n = 92 918), and resulted in CS. Independent risk factors for failure of labor to progress during the first stage, using a multivariable analysis, were premature rupture of membranes (PROM; OR = 3.8, 95% CI 3.2-4.5), nulliparity (OR = 3.8, 95% CI 3.3-4.3), labor induction (OR = 3.3, 95% CI 2.9-3.7), maternal age > 35 years (OR = 3.0, 95% CI 2.6-3.6), birth weight > 4 kg (OR = 2.2, 95% CI 1.8-2.7), hypertensive disorders (OR = 2.1, 95% CI 1.8-2.6), hydramnios (OR = 1.9, 95% CI 1.5-2.3), fertility treatment (OR = 1.8, 95% CI 1.4-2.4), epidural analgesia (OR = 1.6, 95% CI 1.4-1.8) and gestational diabetes (OR = 1.4, 95% CI 1.1-1.7). Although newborns delivered after failure of labor to progress during the first stage had significantly higher rates of Apgar scores lower than 7 at 1 and 5 min as compared with the controls (18.2% vs. 2.1%; P < 0.001 and 1.3% vs. 0.2%; P < 0.001, respectively), no significant differences were noted between the groups regarding perinatal mortality (0.3% vs. 0.4%; P = O.329). Maternal anemia and accordingly packed cells transfusion (47.4% vs. 22.8%; P < 0.001 and 5.6% vs. 1.0%; P < 0.001, respectively) were higher among pregnancies complicated with failure of labor to progress during the first stage as compared with the controls. CONCLUSIONS: Major risk factors for failure of labor to progress during the first stage were PROM, nulliparity, induction of labor and older maternal age. Indications for labor induction should be carefully evaluated in order to decrease the rate of operative deliveries.     

Umbilical cord prolapse and perinatal outcomes.

OBJECTIVES: To determine obstetric risk factors and perinatal outcomes of pregnancies complicated by umbilical cord prolapse. METHODS: A population-based study was performed comparing all deliveries complicated by cord prolapse to deliveries without this complication. Statistical analysis was performed using multiple logistic regression models. RESULTS: Prolapse of the umbilical cord complicated 0.4% (n=456) of all deliveries included in the study (n=121,227). Independent risk factors for cord prolapse identified by a backward, stepwise multivariate logistic regression model were: malpresentation (OR=5.1; 95% CI 4.1-6.3), hydramnios (OR=3.0; 95% CI 2.3-3.9), true knot of the umbilical cord (OR=3.0; 95% CI 1.8-5.1), preterm delivery (OR=2.1; 95% CI 1.6-2.8), induction of labor (OR=2.2; 95% CI 1.7-2.8), grandmultiparity (>five deliveries, OR=1.9; 95% CI 1.5-2.3), lack of prenatal care (OR=1.4; 95% CI 1.02-1.8), and male gender (OR=1.3; 95% CI 1.1-1.6). Newborns delivered after umbilical cord prolapse graded lower Apgar scores, less than 7, at 5 min (OR=11.9, 95% CI 7.9-17.9), and had longer hospitalizations (mean 5.4+/-3.5 days vs. 2.9+/-2.1 days; P<0.001). Moreover, higher rates of perinatal mortality were noted in the cord prolapse group vs. the control group (OR=6.4, 95% CI 4.5-9.0). Using a multiple logistic regression model controlling for possible confounders, such as preterm delivery, hydramnios, etc., umbilical cord prolapse was found to be an independent contributing factor to perinatal mortality. CONCLUSIONS: Prolapse of the umbilical cord is an independent risk factor for perinatal mortality.     

Precipitate labor: higher rates of maternal complications

OBJECTIVE: The study was aimed to identify risk factors and to elucidate pregnancy outcome following precipitate labor, i.e. expulsion of the fetus within less than 3 h of commencement of contractions. METHODS: A comparison of patients with and without precipitate labor, delivered during the years 1988-2002, was conducted. Patients who underwent cesarean deliveries were excluded from the analysis. A multiple logistic regression model, with backward elimination, was performed to investigate independent risk factors for precipitate labor. RESULTS: The number of vaginal deliveries that occurred during the study period was 137,171. Of these, 99 were precipitate. Independent risk factors for precipitate labor, using a backward, stepwise multivariate analysis were: placental abruption (odds ratio (OR) = 30.9, 95% confidence interval (CI) 15.9-60.4, P < 0.001); fertility treatments (OR = 3.9, 95% CI 1.7-9.0, P = 0.002); chronic hypertension (OR = 3.1, 95% CI 1.2-7.8, P = 0.015); intrauterine growth restriction (IUGR) (OR = 2.9, 95% CI 1.2-6.8, P = 0.014); prostaglandin E2 induction (OR = 1.9, 95% CI 1.1-3.5, P = 0.045); birth weight < 2,500 g (OR = 1.8, 95% CI 1.1-3.1, P = 0.020); and nulliparity (OR = 1.7, 95% CI 1.1-2.6, P = 0.014). No significant differences were noted between the groups regarding perinatal complications such as meconium stained amniotic fluid, perinatal mortality and low Apgar scores. However, there were higher rates of maternal complications in the precipitate labor group such as cervical tears and grade 3 perineal tears (18.2% versus 0.3%, P < 0.001; and 2.0% versus 0.1%, P < 0.001, respectively), post-partum hemorrhage (13.1% versus 0.4%, P < 0.001); retained placenta (2.0% versus 0.5%, P = 0.02); the need for revision of uterine cavity and packed-cells transfusions (34.3% versus 4.9%, P < 0.001; and 11.1% versus 1.1%, P < 0.001, respectively) and prolonged hospitalization (27.6% versus 19.2%, P = 0.035) as compared to the controls. CONCLUSION: Precipitate labor is associated with higher rates of maternal complications.     

Obstetric characteristics and perinatal outcome of pregnancies with uterine leiomyomas

OBJECTIVE: To determine the rate, obstetric characteristics and perinatal outcome of pregnancies with uterine leiomyomas. STUDY DESIGN: A population-based study comparing all singleton deliveries between the years 1988 and 1999 in women with and without uterine leiomyomas was performed. Patients lacking prenatal care were excluded from the analysis. Multivariable analysis, adjusting for possible confounders, such as maternal age, parity and gestational age, was performed to investigate associations between uterine leiomyomas and selected outcomes. RESULTS: There were 105,909 singleton deliveries with 690 (0.65%) complicated by uterine leiomyomas during the study period. Using a multivariable analysis, the following conditions were significantly associated with uterine leiomyomas: nulliparity (odds ratio [OR]=4.0, 95% confidence interval [CI] 3.3-4.7, P<.001), chronic hypertension (OR=1.9, 95% CI 1.6-2.4, P<.001), hydramnios (OR=1.5, 95% CI 1.2-2.0, P<.001), diabetes mellitus (OR=1.4, 95% CI 1.1-1.7, P=.001) and advanced maternal age (OR=1.2, 95% CI 1.1-1.2, P<.001). Higher rates of perinatal mortality (2.2% vs. 1.2%, OR=1.8, 95% CI 1.1-3.2, P<.001) were found in the uterine leiomyoma group as compared to the control group. While adjusting for maternal age, parity, gestational age and malpresentation, pregnancies with uterine leiomyomas had higher rates of cesarean deliveries (OR=6.7, 95% CI 5.5-8.1, P<.001), placental abruption (OR=2.6, 95% CI 1.6-4.2, P<.001) and preterm deliveries (<36 weeks' gestation, OR=1.4, 95% CI 1.1-1.7, P=.009) as compared to pregnancies without uterine leiomyomas. Conversely, no significant differences were noted regarding perinatal mortality (OR=1.4, 95% CI 0.7-2.8, P=.351) after controlling for maternal age, parity and gestational age using a multivariable analysis. CONCLUSION: Uterine leiomyomas increase the risk of adverse pregnancy outcomes, thus emphasizing the importance of appropriate intrapartum management of these high-risk pregnancies.     

Hydramnios and small for gestational age are independent risk factors for neonatal mortality and maternal morbidity

Objective The objective was to evaluate the contribution of hydramnios and small for gestational age (SGA) as a combined pathology to maternal and neonatal morbidity and mortality.Methods The study population consisted of 192 SGA neonates with hydramnios, 5,515 SGA neonates with a normal amount of amniotic fluids, 3,714 appropriate for gestational age (AGA) neonates with polyhydramnios and 83,763 AGA neonates with a normal amount of amniotic fluid. A cross-sectional population based study was designed between the four study groups. Multiple logistic regression analysis was used to assess the contribution of these abnormalities and different risk factors to maternal and perinatal complications.Results The combination of hydramnios/SGA was found to be an independent risk factor for perinatal mortality (OR 20.55; CI 12.6–33.4). Congenital anomalies, prolapse of cord, hydramnios, SGA and grand multiparity were also independent risk factors for perinatal mortality. Independent risk factors for neonatal complications were prolapse of umbilical cord (OR 4.13; 95% CI 1.48–11.5), hydramnios/SGA (OR 2.72; 95% CI 1.81–4.07), chronic hypertension (OR 2.45; 95% CI 1.02–5.9), congenital malformations (OR 1.93; 95% CI 1.14–3.24) and SGA (OR 1.47; 95% CI 1.07–2). Significant independent risk factors for medical interventions during labor were fetal distress (OR 198.46; 95% CI 47.27–825.27), GDM Class B–R (OR 21.22; 95% CI 2.34–192.25), GDM class A (OR 4.64; 95% CI 2.62–8.21), severe pregnancy-induced hypertension (PIH; OR 7.74; 95% CI 2.35–25.42), hydramnios (OR 1.95; 95% CI 1.3–2.91), hydramnios/SGA (OR 1.84; 95% CI 1.12–3.02) and malpresentation (OR 1.56; 95% CI 1.32–1.84).Conclusion The combination of hydramnios and SGA is an independent risk factor for perinatal mortality and maternal complications. We suggest that the growth restriction of these fetuses is responsible for the neonatal complications, while the hydramnios contributes mainly to maternal complications.     

Short stature--an independent risk factor for Cesarean delivery

OBJECTIVE: The present study was aimed to investigate pregnancy outcome of patients with short stature (height<155 cm), and specifically to elucidate if patients with short stature are at an increased risk for Cesarean section (CS) even after controlling for labor dystocia. METHODS: A population-based study comparing pregnancy outcome of patients with and without short stature, was performed. Deliveries occurred during the years 1988-2002, in a tertiary medical center. Stratified analyses, using the Mantel-Haenszel technique, and a multiple logistic regression model were performed to control for confounders. RESULTS: During the study period, 159,210 deliveries occurred. Of these, 5822 (3.65%) were of patients with short stature. Patients with short stature had statistically significant higher rates of CS compared with patients>or=155 cm (21.3% versus 11.9%, odds ratio (OR)=2.0; 95% confidence interval (CI): 1.9-2.1; P<0.001). Furthermore, there patients had higher rated of previous deliveries by CS (17.5% versus 10.3%, OR=1.8; 95% CI: 1.7-2.0; P<0.001), intrauterine growth restriction (IUGR, 3.2% versus 1.9%, OR=1.7; 95% CI: 1.4-1.9; P<0.001), premature rupture of membranes (PROM, 7.1% versus 5.6%, OR=1.3; 95% CI: 1.2-1.4; P<0.001), failed induction (0.7% versus 0.4%, OR=2.0; 95% CI: 1.5-2.8; P<0.001), labor dystocia (6.1% versus 3.5%, OR=1.8; 95% CI: 1.6-2.0; P<0.001), mal-presentations (7.6% versus 6.1%, OR=1.3; 95% CI: 1.1-1.4; P<0.001), and cephalopelvic disproportion (CPD, 0.9% versus 0.3%, OR=2.6; 95% CI: 1.9-3.4; P<0.001). No significant differences were noted between the groups regarding perinatal complications such as low birth-weight, meconium-stained amniotic fluid, perinatal mortality, and low Apgar scores at 5 min. Controlling for possible confounders such as previous CS, IUGR, PROM, failed induction, labor dystocia, mal-presentations and CPD, using the Mantel-Haenszel technique, did not change the significant association between short stature and CS. Moreover, a multiple logistic regression model was constructed with CS as the outcome variable, controlling for all these confounders. The model found short stature to be an independent risk factor for CS (OR=1.7; 95% CI: 1.6-1.9; P<0.001). CONCLUSION: Short stature is an independent risk factor for Cesarean delivery. Further studies investigating the actual indication for CS should be performed in order to make an informed recommendation regarding the preferred mode of delivery in short parturient women.     

Idiopathic bleeding during the second half of pregnancy as a risk factor for adverse perinatal outcome.

OBJECTIVE: To investigate pregnancy outcome in women suffering from idiopathic vaginal bleeding (IVB) during the second half of pregnancy. METHODS: A comparison between patients admitted to the hospital due to bleeding during the second half of pregnancy and patients without bleeding was performed. Patients lacking prenatal care as well as multiple gestations were excluded from the analysis. Stratified analyses using the Mantel-Haenszel technique and a multiple logistic regression model were performed to control for confounders. RESULTS: During the study period, 173,621 singleton deliveries occurred at our institute. Of these, 2077 (1.19%) were complicated with bleeding upon admission during the second half of pregnancy. After excluding cases with bleeding due to placental abruption, placenta previa, cervical problems, etc., 67 patients were classified as having IVB (0.038%). Independent risk factors associated with IVB, using a backward, stepwise multivariable analysis were oligohydramnios (OR=6.2; 95% CI 3.1-12.7; p < 0.001), premature rupture of membranes (OR=3.4; 95% CI 1.8-6.2; p < 0.001), intrauterine growth restriction (IUGR, OR 5.6; 95% CI 2.5-12.2; p < 0.001), and Jewish ethnicity (OR=1.9; 95% CI 1.0-3.5; p=0.036). These patients subsequently were more likely to deliver preterm (<37 weeks, 56.7% vs. 7.3%; mean gestational age of 33.6+/-5.7 weeks vs. 39.2+/-2.1 weeks; p < 0.001) and by cesarean delivery (CD, 35.8% vs. 12.1%, OR=4.0; 95% CI 2.4-6.6; p < 0.001). Higher rates of low Apgar scores (<7) at 1 and 5 minutes were noted in these patients (OR=10.3; 95% CI 5.9-17.8; p < 0.001 and OR=17.8; 95% CI 7.1-44.5; p < 0.001, respectively). Moreover, perinatal mortality rate among patients admitted due to idiopathic bleeding was significantly higher as compared to patients without bleeding (9.6% vs. 1.2%, OR=8.4; 95% CI 3.3-21.2; p < 0.001). However, when controlling for preterm delivery, using the Mantel-Haenszel technique, the association lost its significance. CONCLUSION: Idiopathic vaginal bleeding during the second half of pregnancy is a risk factor for adverse perinatal outcome, mostly due to its significant association with preterm delivery. Careful surveillance, including fetal monitoring, is suggested in these cases in order to reduce the adverse perinatal outcome.     

Pregnancy outcome among obese women: a prospective study

We investigated pregnancy outcome among obese women using a prospective cohort study comparing consecutive deliveries of obese and nonobese patients. Stratified analysis, using the Mantel-Haenszel technique, was done to assess the association between obesity and the risk for cesarean delivery (CD) while controlling for confounding variables. Complete data were abstracted for 376 women, of whom 21% ( N = 79) were obese. CD rate was significantly higher among obese women (32.9% versus 18.9%; P = 0.006). Maternal obesity was associated with multiparity (odds ratio [OR] 2.97, 95% confidence interval [CI] 1.27 to 6.97; P = 0.012), fertility treatments (OR 11.3, 95% CI 2.84 to 44.89; P = 0.001), insulin-treated gestational diabetes (OR 24.55, 95% CI 2.28 to 264.08; P = 0.008), and hydramnios (OR 20.46, 95% CI 2.17 to 192.89; P = 0.008). When controlling for possible confounders, the association between maternal obesity and CD remained significant (weighted OR 2.2, 95% CI 1.2 to 4.1; P = 0.018). No significant differences were noted between the groups regarding neonatal complications. Both first and second stages of labor were longer in obese women. Obesity is a risk factor for developing gestational hypertension, insulin-treated gestational diabetes, and hydramnios. Moreover, maternal obesity is an independent risk factor for CD. Additional independent risk factors for CD were fertility treatments, insulin-treated gestational diabetes, and hydramnios. However, neonatal outcome of obese women is comparable to women with normal prepregnancy body mass index.     

Uterine rupture: risk factors and pregnancy outcome

OBJECTIVES: This study aimed at determining risk factors and pregnancy outcome in women with uterine rupture. STUDY DESIGN: We conducted a population-based study, comparing all singleton deliveries with and without uterine rupture between 1988 and 1999. RESULTS: Uterus rupture occurred in 0.035% (n=42) of all deliveries included in the study (n=117,685). Independent risk factors for uterine rupture in a multivariable analysis were as follows: previous cesarean section (odds ratio [OR]=6.0, 95% CI 3.2-11.4), malpresentation (OR=5.4, 95% CI 2.7-10.5), and dystocia during the second stage of labor (OR=13.7, 95% CI 6.4-29.3). Women with uterine rupture had more episodes of postpartum hemorrhage (50.0% vs 0.4%, P<.01), received more packed cell transfusions (54.8% vs 1.5%, P<.01), and required more hysterectomies (26.2% vs 0.04%, P<.01). Newborn infants delivered after uterine rupture were more frequently graded Apgar scores lower than 5 at 5 minutes and had higher rates of perinatal mortality when compared with those without rupture (10.3% vs 0.3%, P<.01; 19.0% vs 1.4%, P<.01, respectively). CONCLUSION: Uterine rupture, associated with previous cesarean section, malpresentation, and second-stage dystocia, is a major risk factor for maternal morbidity and neonatal mortality. Thus, a repeated cesarean delivery should be considered among parturients with a previous uterine scar, whose labor failed to progress.     

Moderate to severe thrombocytopenia during pregnancy

OBJECTIVE: The objective was to investigate obstetric risk factors, complications, and outcomes of pregnancies complicated by moderate to severe thrombocytopenia. MATERIALS AND METHODS: A retrospective case-control study comparing 199 pregnant women with moderate to severe thrombocytopenia (platelet count below 100x10(9)/l) with 201 pregnant women without thrombocytopenia, who delivered between January 2003 to April 2004. Stratified analysis, using the Mantel-Haenszel procedure was performed in order to control for confounders. RESULTS: The main causes of thrombocytopenia were gestational thrombocytopenia (GT) (59.3%), immune thrombocytopenic purpura (ITP) (11.05%), preeclampsia (10.05%), and HELLP (Hemolysis, elevated liver enzymes and low platelet count) syndrome (12.06%). Women with thrombocytopenia were significantly older (30.7+/-5.9 versus 28.7+/-5.7; p=0.001) compared with patients without thrombocytopenia, and had higher rates of labor induction (OR=4.0, 95% CI=2.2-7.6, p<0.001) and preterm deliveries (OR=3.5, 95% CI=1.9-6.5, p<0.001). Even after controlling for labor induction, using the Mantel-Haenszel technique, thrombocytopenia was significantly associated with preterm delivery (weighted OR=3.14, 95% CI=1.7-6.0, p<0.001). Higher rates of placental abruption were found in pregnant women with thrombocytopenia (OR=6.2, 95% CI=1.7-33.2, p=0.001). In a comparison of perinatal outcomes, higher rates of Apgar scores <7 at 5 min were noted in infants of mothers with thrombocytopenia (OR=6.3, 95% CI=1.8-33.8, p=0.001), intrauterine growth restriction (IUGR; OR=4.6, 95% CI=1.5-19.1, p=0.003), and stillbirth (65/1000 versus 0 p<0.001). These adverse perinatal outcomes were found in rare causes of thrombocytopenia such as disseminated intravascular coagulation (DIC), familial thrombotic thrombocytopenic purpura (TTP), anti-phospholipid antibodies (APLA) syndrome, and myeloproliferative disease, and not among patients with GT. CONCLUSIONS: Moderate to severe maternal thrombocytopenia points to a higher degree of severity of the primary disease, which increases perinatal complications. However, the adverse outcome is specifically attributed to preeclampsia, HELLP syndrome, and rare causes, while the perinatal outcome of GT and ITP is basically favorable. Special attention should be given to patients with thrombocytopenia due to preeclampsia, HELLP syndrome, and rarer causes during pregnancy.     

Second trimester placental location as a predictor of an adverse pregnancy outcome.

OBJECTIVE: To determine if the second trimester placental location is associated with perinatal outcomes. MATERIALS AND METHODS: Observational study of placental location and the subsequent risk of an adverse pregnancy outcome. Placental location was divided into three categories, low, high lateral and high fundal. RESULTS: There were 3336 pregnancies analyzed in this study. Low implantation sites had a greater risk of preterm labor (odds ratio (OR) 1.70, 95% confidence interval (CI) 1.38 to 2.90, P<0.001), preterm delivery (OR 1.86, 95% CI 1.36 to 2.54, P<0.001), fewer fetuses with macrosomia (OR 0.56, 95% CI 0.38 to 0.83, P=0.010) and reduced risk of postpartum hemorrhage (OR 0.56, 95% CI 0.46 to 0.95, P=0.026). High lateral implantations had a greater risk of low 1-min (OR 1.80, 95% CI 1.11 to 2.93, P=0.017) and 5-min (OR 3.49, 95% CI 1.46 to 8.36, P=0.005) Apgar scores. CONCLUSIONS: Low placental implantation was associated with an increased risk of preterm labor, preterm delivery and a reduced risk of postpartum hemorrhage, and of a macrosomic fetus. High lateral implantation was associated with low Apgar scores.     

Factors Associated With Non‐Normal Birth Outcomes for Low‐Risk Women in an Inner‐City Hospital

Introduction: The purpose of this study was to examine factors associated with normal versus non‐normal birth outcomes for low‐risk women who were admitted for care in spontaneous labor. Methods: The birth records of 93 women were reviewed. Results: At the completion of the fourth stage of labor, 61% of births (n = 57) met the criteria for normal, while 39% of births (n = 36) had non‐normal outcomes. On bivariate analysis, variables associated with non‐normal outcomes included nulliparity (odds ratio [OR], 9.10; 95% confidence interval [CI], 3–28; P <.0001), lower average centimeters of dilation at admission (t‐score 4.422; P <.001), use of pharmacologic pain relief, including narcotics and epidural anesthesia (OR, 5.03; 95% CI, 2–16; P = .005), and birth attended by a physician versus a certified nurse‐midwife (OR, 3.60; 95% CI, 2–9; P = .004). In a multivariate analysis, nulliparity (OR, 6.07; 95% CI, 2–19; P = .002) and lower average centimeters of dilation at admission (OR, 0.63; 95% CI, 0.5–0.9; P = .005) were independently associated with non‐normal outcome. Discussion: The development of clinical guidelines aimed at reducing admissions of women in early labor may reduce non‐normal outcomes, particularly for nulliparous women.     

Abnormal fetal heart rate tracing patterns during the first stage of labor: effect on perinatal outcome

OBJECTIVE: The purpose of this study was to evaluate perinatal outcomes of infants who had pathologic fetal heart rate tracings during the first stage of labor, in comparison with pregnancies with normal tracings. STUDY DESIGN: The perinatal outcomes of 301 infants born at 37 to 42 weeks of gestation with pathologic fetal heart rate patterns during the first stage of labor were compared with 300 infants with normal fetal heart rate tracing patterns. The data were collected prospectively. Tracings were interpreted with the use of the National Institute of Child Health and Human Development fetal heart rate monitor guidelines. RESULTS: Hydramnios (odds ratio, 7.68; 95% CI, 1.75%-33.63%), oligohydramnios (odds ratio, 2.74; 95% CI, 1.01%-7.39%), and the presence of meconium-stained amniotic fluid (odds ratio, 1.91; 95% CI, 1.03%-3.3%) were independent factors that were associated with pathologic fetal heart rate monitoring during the first stage of labor in a multivariable analysis. The occurrences of umbilical arterial pH of <7.20, a 1-minute Apgar score of <7, a base deficit of 12 mmol/L or higher, and operative deliveries were significantly higher in the study group as compared with subjects with normal fetal heart rate monitoring. Late decelerations and severe variable decelerations (<70 bpm) during the first stage of labor were independent risk factors (odds ratio, 17.5; 95% CI, 1.61%-185.7% and odds ratio, 3.9; 95% CI, 1.36%-11.7%, respectively) that were associated with fetal acidosis (determined by both pH of <7.2 and a base deficit of 12 mmol/L or higher) in a multiple logistic model, controlled for hydramnios, oligohydramnios, meconium-stained amniotic fluid, augmentation by oxytocin, nulliparity, duration of first stage of labor, and birth weight. CONCLUSION: The operative delivery rate was higher among patients with abnormal first-stage fetal heart rate patterns. Late decelerations and severe variable decelerations were significant factors associated with fetal acidosis.     

The contribution of assisted conception,chorionicity and other risk factors to very low birthweight in a twin cohort

Objectives To investigate the contribution of assisted conception (assisted reproductive technology and ovulation induction), chorionicity and selected maternal risk factors for very low birthweight.
Design Retrospective twin cohort study.
Setting Staff model Colorado Health Maintenance Organization.
Sample Five hundred and sixty-two twin gestations [assisted = 193 (34%); unassisted = 369 (66%)].
Methods Data were collected from a perinatal database and medical record review. Data were analysed using univariate and multivariable logistic regression analysis.
Main outcome measure Very low birthweight.
Results Women with assisted twin gestation were more likely to be older, nulliparous, non-smokers, married, have a prior history of a miscarriage and a dichorionic placentation. There was no difference in the distribution of low and very low birthweight, discordant growth or preterm delivery between assisted and unassisted twin gestations. Significant risk factors for very low birthweight were: a prior preterm birth (odds ratio, OR, 3.8, 95% confidence interval, CI, 2, 7), monochorionicity (OR 3, 95% CI 2, 4.7), nulliparity (OR 2, 95% CI 1.3, 3), cigarette smoking (OR 1.8, 95% CI 1, 3) and prior miscarriage (OR 1.6, 95% CI 1, 2). Monochorionicity was significantly associated with adverse perinatal outcomes.
Conclusion Assisted conception did not play a significant role in the occurrence of very low birthweight in this cohort. A history of preterm birth and a monochorionic twin gestation were the leading risk factors for very low birthweight. Associated risk factors for very low birthweight were nulliparity, cigarette smoking and a prior miscarriage.     

Gender does matter in perinatal medicine

OBJECTIVE: To investigate complications and outcome of pregnancies with male and female fetuses. METHODS: A population-based study comparing all singleton deliveries between the years 1988 and 1999 was performed. We compared pregnancies with male vs. female fetuses. Patients with a previous cesarean section (CS) were excluded from the study. Statistical analyses with the Mantel-Haenszel technique and multiple logistic regression models were performed to control for confounders. RESULTS: During the study period there were 55,891 deliveries of male and 53,104 deliveries of female neonates. Patients carrying male fetuses had higher rates of gestational diabetes mellitus (OR = 1.1; 95% CI 1.01-1.12; p = 0.012), fetal macrosomia (OR = 2.0; 95% CI 1.8-2.1; p < 0.001), failure to progress during the first and second stages of labor (OR = 1.2; 95% CI 1.1-1.3; p < 0.001 and OR = 1.4; 95% CI 1.3-1.5; p < 0.001, respectively), cord prolapse (OR = 1.3; 95% CI 1.1-1.6; p = 0.014), nuchal cord (OR = 1.2; 95% CI 1.1-1.2; p < 0.001) and true umbilical cord knots (OR = 1.5; 95% CI 1.3-1.7; p < 0.001). Higher rates of CS were found among male compared with female neonates (8.7 vs. 7.9%; OR = 1.1; 95% CI 1.06-1.16; p < 0.001). Using three multivariate logistic regression models and controlling for birth weight and gestational age, male gender was significantly associated with non-reassuring fetal heart rate patterns (OR = 1.5; 95% CI 1.4-1.6; p < 0.001), low Apgar scores at 5 min (OR = 1.5; 95% CI 1.3-1.8; p < 0.001) and CS (OR = 1.2; 95%CI 1.2-1.3; p < 0.001). Controlling for possible confounders like gestational diabetes, cord prolapse, failed induction, nonprogressive labor, fetal macrosomia, nuchal cord and true umbilical cord knots using the Mantel-Haenszel technique did not change the significant association between male gender and CS. CONCLUSION: Male gender is an independent risk factor for adverse pregnancy outcome.     

Manejo expectante del período expulsivo frente a actitud activa en gestantes usuarias de analgesia epidural

ObjectiveTo determine the influence of epidural analgesia on the expulsion period when a policy of delayed pushing was used by analyzing its effect on type of delivery and perinatal outcomes.Material and methodsWe performed a retrospective observational study comparing a group of women without epidural analgesia (238) who were advised to commence pushing at full dilatation with a second group of women with epidural analgesia (238) who were advised to wait 1-2 hours after full dilatation before starting to push. The variables measured included length of second stage, type of delivery, Apgar scores, and arterial cord pH values.ResultsThe second stage was longer in the group with passive fetal descent (MD = 39.61; 95% CI, 33.2-46.01). However, Apgar scores (OR = 1; 95% CI, 0.44-2.27), arterial cord pH values (MD = 0.0012; 95% CI, -0.011-0.013), and rates of cesarean (OR = 0.81; 95% CI, 0.42-1.55) and instrumental delivery (OR = 0.88; 95% CI, 0.41-1.91) were similar in both groups.ConclusionsDelayed pushing was not associated with higher rates of adverse outcome, although the second stage of labor was longer.     

Obstetric risk factors and outcome of pregnancies complicated with early postpartum hemorrhage: a population-based study.

OBJECTIVE: The study was aimed to identify obstetric risk factors for early postpartum hemorrhage (PPH) in singleton gestations and to evaluate pregnancy outcome. STUDY DESIGN: A comparison between consecutive singleton deliveries with and without early PPH was performed. Deliveries occurred during the years 1988-2002 in a tertiary medical center. A multivariate logistic regression model was constructed in order to define independent risk factors for PPH. RESULTS: Postpartum hemorrhage complicated 0.4% (n = 666) of all deliveries enrolled in the study (n = 154 311). Significant risk factors for PPH, identified using a multivariable analysis, were: retained placenta (OR 3.5, 95%CI 2.1-5.8), failure to progress during the second stage of labor (OR 3.4, 95%CI 2.4-4.7), placenta accreta (OR 3.3, 95%CI 1.7-6.4), lacerations (OR 2.4, 95%CI 2.0-2.8), instrumental delivery (OR 2.3, 95%CI 1.6-3.4), large for gestational age (LGA) newborn (OR 1.9, 95%CI 1.6-2.4), hypertensive disorders (OR 1.7, 95%CI 1.2-2.1), induction of labor (OR 1.4, 95%CI 1.1-1.7) and augmentation of labor with oxytocin (OR 1.4, 95%CI 1.2-1.7). Women were assigned into three different groups according to the assessed severity of PPH, assuming that the severe cases were handled by revision of the birth canal under anesthesia, and the most severe cases required in addition treatment with blood products. A significant linear association was found between the severity of bleeding and the following factors: vacuum extraction, oxytocin augmentation, hypertensive disorders as well as perinatal mortality, uterine rupture, peripartum hysterectomy and uterine or internal iliac artery ligation (p < 0.001 for all variables). CONCLUSION: Hypertensive disorder, failure to progress during the second stage of labor, oxytocin augmentation, vacuum extraction and LGA were found to be major risk factors for severe PPH. Special attention should be given after birth to hypertensive patients, and to patients who underwent induction of labor or instrumental delivery, as well as to those delivering LGA newborns.     

Placenta previa: obstetric risk factors and pregnancy outcome

Objective: To determine the incidence, obstetric risk factors and perinatal outcome of placenta previa. Study design: All singleton deliveries at our institution between 1990 and 1998 complicated with placenta previa were compared with those without placenta previa. Results: Placenta previa complicated 0.38% ( n = 298) of all singleton deliveries ( n = 78 524). A back-step multiple logistic regression model found the following factors to be independently correlated with the occurrence of placenta previa: maternal age above 40 years (OR 3.1, 95% CI 2.0-4.9), infertility treatments (OR 3.1, 95% CI 1.8-5.6), a previous Cesarean section (OR 1.8, 95% CI 1.4-2.4), a history of habitual abortions (OR 1.3, 95% CI 1.3-2.7) and Jewish ethnicity (OR 1.3, 95% CI 1.1-1.8). Pregnancies complicated with placenta previa had significantly higher rates of second-trimester bleeding (OR 156.0, 95% CI 87.2-277.5), pathological presentations (OR 7.6, 95% CI 5.7-10.1), abruptio placentae (OR 13.1, 95% CI 8.2-20.7), congenital malformations (OR 2.6, 95% CI 1.5-4.2), perinatal mortality (OR 2.6, 95% CI 1.1-5.6), Cesarean delivery (OR 57.4, 95% CI 40.7-81.4), Apgar scores at 5 min lower than 7 (OR 4.4, 95% CI 2.3-8.3), placenta accreta (OR 3.6, 95% CI 1.1-9.9) postpartum hemorrhage (OR 3.8, 95% CI 1.2-10.5), postpartum anemia (OR 5.5, 95% CI 4.4-6.9) and delayed maternal and infant discharge from the hospital (OR 10.9, 95% CI 7.3-16.1) as compared to pregnancies without placenta previa. In a multivariable analysis investigating risk factors for perinatal mortality, the following were found to be independent significant factors: congenital malformations, placental abruption, pathological presentations and preterm delivery. In contrast, placenta previa and Cesarean section were found to be protective factors against the occurrence of perinatal mortality while controlling for confounders. Conclusion: Although an abnormal implantation per se was not an independent risk factor for perinatal mortality, placenta previa should be considered as a marker for possible obstetric complications. Hence, the detection of placenta previa should encourage a careful evaluation with timely delivery in order to reduce the associated maternal and perinatal complications.     

Placenta previa: obstetric risk factors and pregnancy outcome.

OBJECTIVE: To determine the incidence, obstetric risk factors and perinatal outcome of placenta previa. STUDY DESIGN: All singleton deliveries at our institution between 1990 and 1998 complicated with placenta previa were compared with those without placenta previa. RESULTS: Placenta previa complicated 0.38% (n = 298) of all singleton deliveries (n = 78 524). A back-step multiple logistic regression model found the following factors to be independently correlated with the occurrence of placenta previa: maternal age above 40 years (OR 3.1, 95% CI 2.0-4.9), infertility treatments (OR 3.1, 95% CI 1.8-5.6), a previous Cesarean section (OR 1.8, 95% CI 1.4-2.4), a history of habitual abortions (OR 1.3, 95% CI 1.3-2.7) and Jewish ethnicity (OR 1.3, 95% CI 1.1-1.8). Pregnancies complicated with placenta previa had significantly higher rates of second-trimester bleeding (OR 156.0, 95% CI 87.2-277.5), pathological presentations (OR 7.6, 95% CI 5.7-10.1), abruptio placentae (OR 13.1, 95% CI 8.2-20.7), congenital malformations (OR 2.6, 95% CI 1.5-4.2), perinatal mortality (OR 2.6, 95% CI 1.1-5.6), Cesarean delivery (OR 57.4, 95% CI 40.7-81.4), Apgar scores at 5 min lower than 7 (OR 4.4, 95% CI 2.3-8.3), placenta accreta (OR 3.6, 95% CI 1.1-9.9) postpartum hemorrhage (OR 3.8, 95% CI 1.2-10.5), postpartum anemia (OR 5.5, 95% CI 4.4-6.9) and delayed maternal and infant discharge from the hospital (OR 10.9, 95% CI 7.3-16.1) as compared to pregnancies without placenta previa. In a multivariable analysis investigating risk factors for perinatal mortality, the following were found to be independent significant factors: congenital malformations, placental abruption, pathological presentations and preterm delivery. In contrast, placenta previa and Cesarean section were found to be protective factors against the occurrence of perinatal mortality while controlling for confounders. CONCLUSION: Although an abnormal implantation per se was not an independent risk factor for perinatal mortality, placenta previa should be considered as a marker for possible obstetric complications. Hence, the detection of placenta previa should encourage a careful evaluation with timely delivery in order to reduce the associated maternal and perinatal complications.