Anal Sphincter Injury Associated with Vaginal Twin Delivery.

OBJECTIVE: Obstetric anal sphincter injury remains the most common cause of fecal incontinence in women, and research in twin pregnancies is sparse. This study aimed to examine risk factors for sphincter injury in twin deliveries over a 10-year period. STUDY DESIGN: This was a retrospective study of twin vaginal deliveries in a tertiary-level hospital over 10 years. We examined the demographics of women who had a vaginal delivery of at least one twin. Logistic regression analysis was used to examine risk factors. RESULTS: There were 1,783 (2.1%) twin pregnancies, of which 556 (31%) had a vaginal delivery of at least one twin. Sphincter injury occurred in 1.1% (6/556) women with twins compared with 2.9% (1720/59,944) singleton vaginal deliveries. Women with sphincter injury had more instrumental deliveries (83.3 vs. 27.6%; p = 0.008). On univariate analysis, only instrumental delivery was a significant risk factor (odds ratio: 2.93; p = 0.019). CONCLUSION: Sphincter injury occurs at a lower rate in vaginal twin pregnancies than in singletons. No twin-specific risk factors were identified. Discussion of the risk of sphincter injury should form part of patient counseling with regard to the mode of delivery.

Use of the Robson Ten Group Classification System to categorise operative vaginal delivery.

BACKGROUND: Operative vaginal delivery (OVD), either vacuum or forceps, can be used to expedite vaginal delivery. While rates of OVD have been reducing worldwide, rates in Ireland remain high. The Robson Ten Group Classification System (TGCS) was originally created to compare rates of caesarean delivery between healthcare units, although no similar system exists for the analysis of OVD. AIMS: We sought to examine rates of OVD using the TGCS in an effort to understand which patient groups make significant contributions to the overall rate of OVD. MATERIALS AND METHODS: This is a retrospective cohort study of all women delivering in a tertiary-level university institution in Dublin, Ireland, from 2007 to 2016. Mode of delivery for all patients was extracted from contemporaneously recorded hospital records. Rates of OVD were analysed according to the TGCS, and the contribution of each group to the overall hospital population was calculated. RESULTS: There were 86 191 deliveries of women in our institution, of which 19.3% (16 673/86 191) had an OVD. Women in Group 1 (singleton, cephalic, nulliparous women at term in spontaneous labour) contributed the most to the overall rate of OVD, accounting for almost half of all OVDs (46.1% (7679/16 673)). Nulliparous women with a singleton, cephalic fetus at term who were induced (Group 2) were more likely to have an OVD than similar patients who laboured spontaneously (Group 1). CONCLUSION: OVD accounts for almost one in five deliveries in our population and is predominately performed in nulliparous women. These groups may be the subject of interventions to lower rates of OVD. The Robson TGCS is a freely available tool to hospitals and birthing centres to facilitate comparison of rates of OVD on local and national levels.

Antecedents of red cell transfusion in a large contemporary obstetric cohort.

Background Hemorrhage is a critical contributor to maternal morbidity but estimation of blood loss at delivery is frequently inaccurate. Due to this inaccuracy we sought to examine blood transfusion as a surrogate marker for morbidity in a large non-population based consecutive cohort. Methods A retrospective analysis of prospectively gathered data was carried out at two university institutions serving a heterogeneous urban obstetric population from January to December 2016. Data were analyzed to determine whether individual characteristics were associated with perinatal transfusion. Hematological indices and requirement for other blood products were also characterized. Results A total of 16,581 deliveries were recorded during the study and 1.7% (289/16,581) of the cohort required red cell transfusion. Those who received transfusion were more likely to be nulliparous, and to deliver <37 weeks' or >42 weeks' gestation. They were also more likely to have a macrosomic infant (birthweight >4 kg) and to have had a multiple pregnancy. Characteristics not associated with risk of transfusion included obesity [18% (52/289) vs. 15% (2445/16,292); P=0.18], and maternal age ≥35 years [28% (82/289) vs. 33% (5537/16,292); P=0.05]. Additional blood products were necessary in a small number of patients who received red cells. Conclusion The rate of transfusion in a contemporary Irish cohort has risen compared with previous data. Several variables associated with transfusion are consistent with older studies but importantly; maternal obesity and advanced maternal age are not associated with transfusion. These data may encourage the investment of resources in a population previously considered low-risk and, following future studies, to improve strategies aimed at limiting blood transfusion.

Cesarean delivery in the United States 2005 through 2014: a population-based analysis using the Robson 10-Group Classification System.

BACKGROUND: Cesarean delivery has increased steadily in the United States over recent decades with significant downstream health consequences. The World Health Organization has endorsed the Robson 10-Group Classification System as a global standard to facilitate analysis and comparison of cesarean delivery rates. OBJECTIVE: Our objective was to apply the Robson 10-Group Classification System to a nationwide cohort in the United States over a 10-year period. STUDY DESIGN: This population-based analysis applied the Robson 10-Group Classification System to all births in the United States from 2005 through 2014, recorded in the 2003 revised birth certificate format. Over the study 10-year period, 27,044,217 deliveries met inclusion criteria. Five parameters (parity including previous cesarean, gestational age, labor onset, fetal presentation, and plurality), identifiable on presentation for delivery, were used to classify all women included into 1 of 10 groups. RESULTS: The overall cesarean rate was 31.6%. Group-3 births (singleton, term, cephalic multiparas in spontaneous labor) were most common, while group-5 births (those with a previous cesarean) accounted for the most cesarean deliveries increasing from 27% of all cesareans in 2005 through 2006 to >34% in 2013 through 2014. Breech pregnancies (groups 6 and 7) had cesarean rates >90%. Primiparous and multiparous women who had a prelabor cesarean (groups 2b and 4b) accounted for over one quarter of all cesarean deliveries. CONCLUSION: Women with a previous cesarean delivery represent an increasing proportion of cesarean deliveries. Use of the Robson criteria allows standardized comparisons of data and identifies clinical scenarios driving changes in cesarean rates. Hospitals and health organizations can use the Robson 10-Group Classification System to evaluate quality and processes associated with cesarean delivery.

The presentation and management of platelet disorders in pregnancy.

Thrombocytopenia, defined as a platelet count less than 150 000 per microlitre, occurs in 7%-12% of all pregnancies. Apart from anaemia, it is the most common haematological disorder in pregnancy. Despite its frequent occurrence, thrombocytopenia often leads to difficulties of diagnosis and management in pregnancy. Typically, a pregnant woman will have platelet counts of 150 000 to 450 000 per microlitre and platelet counts may be slightly lower than those of healthy, non-pregnant controls. Approximately, 8% of pregnant women will develop mild thrombocytopenia (100 000-150 000 per microlitre) and while 65% of these women will have no underlying pathology, all pregnant women with platelet counts of less than 100 000 per microlitre should undergo further clinical and laboratory assessment. Thrombocytopenia in pregnancy occurs as a result of multiple distinct conditions, we present four cases of thrombocytopenia in pregnancy encountered in our unit over a 12-month period. These include gestational thrombocytopenia, immune thrombocytopenic purpura (ITP), thrombotic thrombocytopenic purpura (TTP) and thrombocytopenia absent radius (TAR) syndrome. The literature review of these cases highlights the significance of identification, understanding pathophysiology and a multidisciplinary approach to these conditions. We refresh knowledge on these conditions and emphasise the importance of thrombocytopenia in pregnancy.

Anal sphincter injury in vaginal deliveries complicated by shoulder dystocia.

INTRODUCTION AND HYPOTHESIS: Shoulder dystocia is an obstetric emergency that occurs in 0.2-3% of all cephalic vaginal deliveries. We hypothesized that because of the difficult nature of deliveries complicated by shoulder dystocia, the condition may be associated with anal sphincter injury. We sought to identify risk factors for obstetric anal sphincter injury in women with shoulder dystocia. METHODS: This retrospective analysis included all cases of shoulder dystocia from 2007 to 2011 at two large tertiary referral centers, in the USA and Ireland. Details of maternal demographics, intrapartum characteristics, and delivery outcomes in cases of shoulder dystocia were analyzed. Univariate and multivariate analyses were used to describe the association between shoulder dystocia and anal sphincter injury. RESULTS: There were 685 cases of shoulder dystocia, and the rate of shoulder dystocia was similar at both institutions. The incidence of anal sphincter injury was 8.8% (60 out of 685). The rate was 14% (45 out of 324) in nulliparas and 4.2% (15 out of 361) in multiparas. Women with sphincter injury were more likely to be nulliparous (75% [45 out of 60] vs 45% [279 out of 625]; p < 0.0001), have had an operative vaginal delivery (50% [30 out of 60] vs 36% [226 out of 625]; p = 0.03) and require internal maneuvers (50% [30 out of 60] vs 32% [198 out of 625], p = 0.004) than those with an intact sphincter. On multivariate regression analysis, these predictors of sphincter injury remained significant when adjusted for other risk factors. Episiotomy was negatively associated with sphincter injury on multivariate regression analysis. CONCLUSIONS: In a retrospective cohort of 685 women with shoulder dystocia, the risk of anal sphincter injury is 9%. Risk factors include nulliparity, operative vaginal delivery, and use of internal maneuvers, whereas episiotomy was found to have a protective effect against anal sphincter injury during cases of shoulder dystocia.

Severe maternal morbidity and comorbid risk in hospitals performing <1000 deliveries per year.

BACKGROUND: While research has demonstrated increasing risk for severe maternal morbidity in the United States, risk at lower volume hospitals remains poorly characterized. More than half of all obstetric units in the United States perform <1000 deliveries per year and improving care at these hospitals may be critical to reducing risk nationwide. OBJECTIVE: We sought to characterize maternal risk profiles and severe maternal morbidity at low-volume hospitals in the United States. STUDY DESIGN: We used data from the Nationwide Inpatient Sample to evaluate trends in severe maternal morbidity and comorbid risk during delivery hospitalizations in the United States from 1998 through 2011. Comorbid maternal risk was estimated using a comorbidity index validated for obstetric patients. Severe maternal morbidity was defined as the presence of any 1 of 15 diagnoses representative of acute organ injury and critical illness. RESULTS: A total of 2,300,279 deliveries occurred at hospitals with annual delivery volume <1000, representing 20% of delivery hospitalizations overall. There were 7849 cases (0.34%) of severe morbidity in low-volume hospitals and this risk increased over the course of the study from 0.25% in 1998 through 1999 to 0.49% in 2010 through 2011 (P < .01). The risk in hospitals with ≥1000 deliveries increased from 0.35-0.62% during the same time periods. The proportion of patients with the lowest comorbidity decreased, while the proportion of patients with highest comorbidity increased the most. The risk of severe morbidity increased across all women including those with low comorbidity scores. Risk for severe morbidity associated with obstetric hemorrhage, infection, hypertensive diseases of pregnancy, and medical conditions all increased during the study period. CONCLUSION: Our findings demonstrate increasing maternal risk at hospitals performing <1000 deliveries per year broadly distributed over the patient population. Rates of morbidity in centers with ≥1000 deliveries have also increased. These findings suggest that maternal safety improvements are necessary at all centers regardless of volume.

Prenatal prediction of significant intertwin birthweight discordance using standard second and third trimester sonographic parameters.

INTRODUCTION: Our study aim was to evaluate standard ultrasound-derived fetal biometric parameters in the prediction of clinically significant intertwin birthweight discordance defined as ≥18%. MATERIAL AND METHODS: This was a secondary analysis of a prospective cohort study of 1028 unselected twin pairs recruited over a two-year period. Dichorionic twins underwent two-weekly ultrasonographic surveillance from 24 weeks' gestation, with surveillance of monochorionic twins two-weekly from 16 weeks. Ultrasonographic biometric data from 24 to 36 weeks were evaluated for the prediction of an intertwin birthweight discordance threshold ≥18%. Umbilical artery Doppler waveform data was also analyzed to evaluate whether it was predictive of birthweight discordance. RESULTS: Of the 956 twin pairs analyzed for discordance, 208 pairs were found to have a clinically significant birthweight discordance ≥18%. All biometric parameters were predictive of significant inter-twin birthweight discordance at low cut-offs, with low discriminatory powers when ROC curves were analyzed. Discordance in estimated fetal weight was predictive of a significant birthweight discordance at all gestational categories with cut-offs between 8 and 11%. A low-discriminatory power and poor sensitivity and specificity were also observed. An abnormal umbilical artery Doppler was predictive of birthweight discordance ≥18% between 28 and 32 weeks' gestation, although with poor sensitivity and specificity. CONCLUSIONS: Calculation of estimated fetal weight and birthweight discordance between twins allows minimal margin for error. These margins make it difficult to accurately predict those who are at or above the discordance threshold of 18%. These findings highlight that small intertwin discrepancies in weight and biometry should not be overlooked and merit further investigation.

Perinatal death associated with umbilical cord prolapse.

OBJECTIVE: Umbilical cord prolapse occurs when the cord prolapses ahead of or alongside the presenting part. It is an acute obstetric emergency with potential catastrophic effects. We set out to assess incidence of cord prolapse, as well as rates and characteristics of perinatal death associated with the condition. STUDY DESIGN: This was a retrospective cohort study. All recorded cases of cord prolapse were included, and rates of perinatal death and encephalopathy, as well as intrapartum and maternal characteristics were examined. RESULTS: There were 156,130 deliveries at the hospital over the 20-year study period. Three hundred and seven cases of cord prolapse were identified (1.9/1000 deliveries). There was a decrease in the incidence of cord prolapse over the course of the study. The rate peaked in 1999 at 3.9/1000 and was just 0.8/1000 of all deliveries in 2007. The majority of cases (216/307, 70%) occurred in multiparas; however, nulliparous parturients were more likely to have a perinatal death [12% (11/91) vs. 4.6% (10/216)]. The rate of perinatal death in cases of cord prolapse was 6.8% (21/307). Over half of perinatal deaths (11/21) occurred in infants of mothers who presented with ruptured membranes, seven of these infants were already dead on reaching hospital. There was just one case of neonatal encephalopathy associated with cord prolapse, giving an incidence of 0.32%. CONCLUSION: Cord prolapse carries a significant risk of perinatal death, approximately 7%. The corresponding rate of encephalopathy is low. A significant number of deaths were diagnosed on presentation to hospital and were not deemed preventable.

Paeoniflorin, a novel heat-shock protein inducing compound, and human myometrial contractility in vitro.

AIM: Heat shock proteins (HSPs) are synthesized in virtually all organisms in response to increases in temperature. They are associated with a relaxant effect on the human myometrium and are present in decreased concentration in the myometrium at the time of labor. Paeoniflorin is derived from Paeonia lactiflora and has been shown to induce the synthesis of HSPs in cultured mammalian cells. The purpose of the study was to evaluate the effect of paeoniflorin on human uterine contractility. MATERIAL AND METHODS: Samples of human myometrium were taken at lower segment cesarean section. Dissected muscle strips were suspended under isometric conditions and exposed to cumulative additions of paeoniflorin in concentrations ranging from 1 nmol/L to 10 mol/L. Control experiments were simultaneously performed. RESULTS: Paeoniflorin was found to exert an inhibitory effect on spontaneous and agonist-induced contractions compared to control strips. The mean maximal inhibition values were: 42.21% ± 9.26 for spontaneous contractions (n = 6; P < 0.0001) and 47.84% ± 9.05 for oxytocin-induced contractions (n = 6; P < 0.0001). CONCLUSION: The HSP inducing compound, paeoniflorin, had a relaxant effect on human uterine contractility in vitro. These results reinforce the fact that HSPs may play a physiological role in the onset of labor and may also provide future targets for novel tocolytic treatments.

Improved Perinatal Mortality in Twins--Changing Practice and Technologies.

OBJECTIVE: We set out to examine rates of perinatal mortality in twin pregnancies over a 17-year study period. Changes in mode of delivery were also examined as well as causes of death in twin mortalities. STUDY DESIGN: This retrospective cohort study was performed at three large tertiary referral centers from 1996 to 2012. It included all normally formed twin infants with a birth weight more than 500 g. All cases of perinatal mortality in twin pregnancies (infants more than 500 g who suffered an intrauterine or early neonatal (≤ 7 days of age) death were recorded. The changing rate of cesarean delivery as well as varying causes of death in twins over the course of the study were also examined. RESULTS: During the study period, there were 395,830 pregnancies across the three institutions, this included 6,727 twin gestations. The perinatal mortality rate was 21.5/1,000 twin infants. The perinatal mortality rate in twins decreased over the study period (p = 0.0006; R (2) = 0.55; slope = -1.2). Rates of cesarean delivery in twin gestations were found to have increased over the course of the study (p < 0.0001; R (2) = 0.84; slope = 1.7). There were 288 intrauterine and early neonatal deaths in twin infants, 50% (147/288) occurred in twins born extremely premature (< 26 weeks). Prematurity was the leading cause of mortality in twins, followed by twin-to-twin transfusion syndrome (TTTS). TTTS was found to have a decreasing contribution to perinatal mortality during the study (p = 0.008; R (2) = 0.38; slope = -1.5). CONCLUSION: The perinatal mortality rate in twins improved during the study. The rate of cesarean delivery increased by 1.7% for each year of the study, culminating in a cesarean delivery rate of 62% in 2012. TTTS made a decreasing contribution to the mortality rate in twins during the study.

Gestational hypertensive disease in twin pregnancy: Influence on outcomes in a large national prospective cohort.

OBJECTIVE: Gestational hypertensive disease (GHD) is associated with pregnancy-related complications and poor maternal and fetal outcomes in singleton pregnancies. We sought to examine the influence of GHD in a large prospective cohort of twin pregnancies. STUDY DESIGN: The ESPRIT study was a national multicenter observational cohort study of 1028 structurally normal twin pregnancies. Each pregnancy underwent sonographic surveillance with two-week ultrasound from 24 weeks for dichorionic and from 16 weeks for monochorionic gestations. Characteristics and demographics as well as labour and delivery outcome data were prospectively recorded. Perinatal mortality, admission to the neonatal intensive care unit (NICU) and a composite of morbidity of respiratory distress syndrome, hypoxic ischaemic encephalopathy, periventricular leukomalacia, necrotising enterocolitis and sepsis were documented for all cases. Outcomes for patients with documented GHD (pre-eclampsia and gestational hypertension) were compared with those without GHD. RESULTS: Perinatal outcome data were recorded for 977 patients. Women with GHD had a higher body mass index (27.1 ± 6.4 vs 25.2 ± 4.5, P < 0.0001) than those without and were more likely to be nulliparous (65% (59/92) vs 46% (407/885), P = 0.001). Both groups had similar mean birthweights, but those with GHD were more likely to have a birthweight discordance ≥18% (35% (32/92) vs 20% (179/885), P = 0.001). Rates of caesarean delivery were higher in those twin pregnancies affected by GHD, and while the rate of composite morbidity was similar in both groups, twins in the GHD group had higher rates of NICU admission. CONCLUSION: In twin gestations, gestational hypertension independently confers an increased risk for emergency caesarean delivery, birthweight discordance and NICU admission, such that intensive maternal-fetal monitoring is justified when hypertension develops in a twin pregnancy.

Extreme macrosomia--obstetric outcomes and complications in birthweights >5000 g.

OBJECTIVE: Management of extremely large birthweight infants presents challenges during the period of labour and delivery. We sought to examine outcomes in infants with extreme macrosomia (birthweight > 5000 g), at an institution where the management of labour is standardised. MATERIALS AND METHODS: This is a retrospective analysis of prospectively gathered data on all infants with a birthweight >5000 g delivered at a tertiary level institution from 2008 to 2012. Details of labour characteristics and outcomes were examined; these were compared according to parity. RESULTS: During the study period, there were 46 128 deliveries at the hospital and 182 infants with a birthweight >5000 g, giving an incidence of 0.4%. The majority of women (133/182) were multiparous. Among nulliparas, 47% (23/49) had a vaginal delivery, while 53% (26/49) had a caesarean delivery. 86% (97/113) of multiparas had a vaginal delivery, and 14% (16/113) had a caesarean delivery. 43% (69/162) required induction of labour. This was more common in nulliparous compared with multiparous women (58% [29/49] vs 30% [40/133], P = 0.005, OR = 3.4, 95% CI = 1.7-6.6). A total of 30% (49/162) of women had their labour accelerated with oxytocin. There were higher rates of oxytocin use in nulliparas than in multiparas (55% [27/49] vs 16.5% [22/133], P < 0.0001, OR = 6.2, 95% CI = 3-12.8). Seventeen of the 120 infants delivered vaginally had a shoulder dystocia (14.2%), with three suffering an Erbs palsy, all of which had resolved before 6 months of age. One baby had a clavicular fracture. CONCLUSION: Extreme macrosomia affects 0.4% of pregnancies in contemporary practice. Multiparas have a low rate of caesarean section. Infants delivered vaginally are at increased risk of shoulder dystocia and associated complications.

Maternal and neonatal morbidity during off peak hours in a busy obstetric unit. Are deliveries after midnight more complicated?

OBJECTIVE: We sought to compare maternal and neonatal outcomes in deliveries occurring overnight with those in daylight hours. DESIGN: Prospective observational study. SETTING: Large national tertiary referral center. POPULATION: All singleton laboring nulliparous parturients delivering infants >500 g over a 2-year period, 1 January 2008 to 31 December 2009. METHODS: Details of intrapartum characteristics and neonatal outcomes of deliveries occurring between midnight and 08.00 h were compared with deliveries occurring outside of these hours. MAIN OUTCOME MEASURES: Maternal and neonatal morbidity. RESULTS: During the study period there were 8450 nulliparous deliveries. 2668 (31.6%) delivered between midnight and 08.00 h, and 5782 (68.4%) outside of these hours. There was a significant difference between the time periods in the number of babies born with a cord pH <7.1: 10.8% (44/406) of babies were born between midnight and 08.00 h, and 6.3% (63/1007) of babies were born outside these hours (p = 0.003). There was no significant difference in terms of Apgar score <7 at 5 min (p = 0.17). There was a trend toward a larger number of anal sphincter injuries occurring between midnight and 08.00 h (3% vs. 2.3%; p = 0.05). CONCLUSION: Our findings suggest that infants are more likely to be born with a pH <7.1 and there was a trend toward an increased rate of anal sphincter injury during time periods when staffing levels are low and clinician fatigue may play a role in decision-making and patient management. This may play a role in service provision planning and staff recruitment.

Eclampsia: trends in incidence and outcomes over 30 years.

OBJECTIVE: This study set out to describe the incidence, mortality rates, and treatment of eclampsia over a 30-year period in a large urban population. STUDY DESIGN: A detailed report of all pregnancies delivered in the Dublin area from 1977 to 2006 was reviewed for incidence, mortality, and treatment of eclampsia. Almost all pregnancies in this area are managed at one of three major obstetric hospitals. All offer comprehensive antenatal care and operate a restrictive policy to magnesium sulfate prophylaxis, in which MgSO4 is reserved for patients with severe preeclampsia or who have already had an eclamptic seizure. RESULTS: During the 30-year study period, there were a total of 626,929 deliveries. Of the 247 cases of eclampsia (3.9/10,000 deliveries) and four maternal deaths (0.63/100,000 deliveries) attributed to eclampsia, none received MgSO4. The mortality rate due to eclampsia was 1.6% (4/247). The use of MgSO4 increased significantly from 11% (13/115) in the first decade of the study to 88.1% (67/76) in the last decade (p < 0.001). The incidence of eclampsia decreased from 5.4/10,000 in the first decade to 3.5/10,000 in the final decade of the study (p < 0.0001). CONCLUSION: Over the study period, MgSO4 has become the leading antiseizure medication used, and this has led to a significant decrease in rates of eclampsia.

Outcomes of Uterine Rupture in the Setting of the Unscarred Compared With the Scarred Uterus.

Uterine rupture is a rare obstetric complication that is associated with maternal and neonatal morbidity and mortality. The aim of this study was to examine uterine rupture and its outcomes in the setting of the unscarred compared with the scarred uterus. A retrospective observational cohort study was performed examining all cases of uterine rupture in three tertiary care hospitals in Dublin, Ireland, over a 20-year period. The primary outcome was perinatal mortality rate with uterine rupture, which was 11.02% (95% CI 6.5-17.3). There was no significant difference in perinatal mortality between cases of scarred and unscarred uterine rupture. Unscarred uterine rupture was associated with higher maternal morbidity , defined as major obstetric hemorrhage or hysterectomy.

The adipokine apelin and human uterine contractility.

OBJECTIVE: Obesity is an increasing problem in obstetric practice. Apelin, secreted by adipocytes, is present in increased serum concentrations in an obese state. Our group has previously highlighted that the adipokines leptin and ghrelin have a potential role in metabolic modulation of uterine contractility in obese women. The aim of this study was to evaluate the effects of apelin on human uterine contractility in vitro. STUDY DESIGN: Biopsies of human myometrium were obtained at elective cesarean section. Myometrial strips suspended under isometric conditions, undergoing spontaneous and oxytocin-induced contractions, were exposed to cumulative additions of apelin in the concentration range of 1 nmol/L to 1 µmol/L. Control experiments were performed simultaneously. RESULTS: Apelin exerted an inhibitory effect on spontaneous and oxytocin induced contractions in human myometrium. The mean maximal inhibition values were 36.8 ± 6.4% for spontaneous (n = 6; P = .002) and 30.4 ± 4.6% for oxytocin-induced contractions (n = 6; P < .0001). CONCLUSION: Apelin inhibits human uterine contractility in vitro, raising the possibility that such metabolic modulation may play a physiological role in obese parturients.

Changes in vaginal breech delivery rates in a single large metropolitan area.

OBJECTIVE: Vaginal breech delivery rates have been accepted widely to be in decline and the Term Breech Trial (TBT) has recommended delivery of a breech-presenting infant by elective cesarean section delivery. Our aim was to examine the rate of vaginal delivery of term breech pregnancies in the 8 years before and after the publication of the TBT. STUDY DESIGN: We retrospectively examined vaginal delivery rates of breech presentations over a 16-year period in 3 large tertiary maternity hospitals that serve a single large metropolitan population. All 3 hospitals are of similar size and serve a population with similar risk profile. We also examined rates of perinatal mortality in the 3 hospitals over the study period. RESULTS: During the 16-year study period, there were 344,259 deliveries among the 3 hospitals; 11,913 of which were breech deliveries. There were 5655 breech deliveries in the 8 years before the publication of the TBT, with a cesarean delivery rate of 76.9%. There were 6258 breech deliveries in the 8 years since publication of the TBT, and the cesarean delivery rate increased to 89.7% (P < .0001). During the 8 years since publication, the rate of vaginal delivery in nulliparous women decreased from 15.3-7.2% (P < .0001). The vaginal breech delivery rate in multiparous women decreased from 32.6-14.8% (P < .0001). The rates of corrected perinatal mortality showed a significant decrease in the last 4 years of the study. CONCLUSION: Our study demonstrates that the results and recommendations of the TBT have contributed to decreasing vaginal breech delivery rates, which were already in decline before its publication.