ObjectiveAntenatal education aims to provide women with the knowledge and support they need to make informed decisions in labor. Theoretically, a formal prelabor birth plan should reduce misunderstanding, facilitate discussion between women and their care providers, and ultimately optimize birth outcomes. Anecdotally however, many obstetric care providers have the perception that the existence of a formal birth plan often leads to increased obstetric intervention. We aimed to assess whether development of a formal prelabor birth plan has an impact on obstetric interventions in a large population of nulliparous women.Study DesignThe Genesis Study recruited 2,336 nulliparous patients with a vertex presentation between 39+0 and 40+6 weeks’ gestation in a prospective multi-center study to examine predictors of cesarean delivery (CD). Information regarding attendance at antenatal classes and preparation of a formal prelabor birth plan was collected prospectively and correlated with obstetric outcomes including induction of labor and mode of delivery.ResultsAlmost 40% of our cohort of 2336 nulliparous patients had a birth plan (932,39.8%). Women with formal prelabor birth plans were significantly older (30.5 vs 29.5, p<0.001)and were more likely to have attended university (75% vs 64%, p<0.001). There were similar rates of labor induction, oxytocin use, operative vaginal delivery, episiotomy and 3rd and 4th degree tears in both cohorts (Table 1). Patients with a formal prelabor birth plan had a significantly more prolonged labor (16% vs 9%, p<0.001) and a higher incidence of cesarean delivery (23% vs 19%, p=0.022).Conclusion ObjectiveAntenatal education aims to provide women with the knowledge and support they need to make informed decisions in labor. Theoretically, a formal prelabor birth plan should reduce misunderstanding, facilitate discussion between women and their care providers, and ultimately optimize birth outcomes. Anecdotally however, many obstetric care providers have the perception that the existence of a formal birth plan often leads to increased obstetric intervention. We aimed to assess whether development of a formal prelabor birth plan has an impact on obstetric interventions in a large population of nulliparous women. Antenatal education aims to provide women with the knowledge and support they need to make informed decisions in labor. Theoretically, a formal prelabor birth plan should reduce misunderstanding, facilitate discussion between women and their care providers, and ultimately optimize birth outcomes. Anecdotally however, many obstetric care providers have the perception that the existence of a formal birth plan often leads to increased obstetric intervention. We aimed to assess whether development of a formal prelabor birth plan has an impact on obstetric interventions in a large population of nulliparous women. Study DesignThe Genesis Study recruited 2,336 nulliparous patients with a vertex presentation between 39+0 and 40+6 weeks’ gestation in a prospective multi-center study to examine predictors of cesarean delivery (CD). Information regarding attendance at antenatal classes and preparation of a formal prelabor birth plan was collected prospectively and correlated with obstetric outcomes including induction of labor and mode of delivery. The Genesis Study recruited 2,336 nulliparous patients with a vertex presentation between 39+0 and 40+6 weeks’ gestation in a prospective multi-center study to examine predictors of cesarean delivery (CD). Information regarding attendance at antenatal classes and preparation of a formal prelabor birth plan was collected prospectively and correlated with obstetric outcomes including induction of labor and mode of delivery. ResultsAlmost 40% of our cohort of 2336 nulliparous patients had a birth plan (932,39.8%). Women with formal prelabor birth plans were significantly older (30.5 vs 29.5, p<0.001)and were more likely to have attended university (75% vs 64%, p<0.001). There were similar rates of labor induction, oxytocin use, operative vaginal delivery, episiotomy and 3rd and 4th degree tears in both cohorts (Table 1). Patients with a formal prelabor birth plan had a significantly more prolonged labor (16% vs 9%, p<0.001) and a higher incidence of cesarean delivery (23% vs 19%, p=0.022). Almost 40% of our cohort of 2336 nulliparous patients had a birth plan (932,39.8%). Women with formal prelabor birth plans were significantly older (30.5 vs 29.5, p<0.001)and were more likely to have attended university (75% vs 64%, p<0.001). There were similar rates of labor induction, oxytocin use, operative vaginal delivery, episiotomy and 3rd and 4th degree tears in both cohorts (Table 1). Patients with a formal prelabor birth plan had a significantly more prolonged labor (16% vs 9%, p<0.001) and a higher incidence of cesarean delivery (23% vs 19%, p=0.022). Conclusion

A large neonatal head circumference is associated with prolonged labor, operative vaginal delivery (OVD), cesarean delivery (CD) and oxytocin use. The Fetal Head Circumference (FHC) has not been assessed as a potential risk factor for these outcomes. In this prospective observational blinded study, we sought to ascertain if a large FHC was associated with CD, OVD, prolonged labor, oxytocin use and a composite outcome of ‘complicated labor’ (all OVD, CD and prolonged labors). The Genesis Study recruited 2,336 nulliparous patients with a vertex presentation between 39+0 and 40+6 weeks’ gestation in a prospective multi-center study to examine the association between the FHC and cesarean delivery. At recruitment, a detailed clinical evaluation and ultrasound assessment were performed. Patients and their managing clinicians were blinded to the ultrasound details. An analysis of pre-defined outcomes, including CD, CD at full dilation, OVD, prolonged labor (>12hours) and oxytocin use was performed, dividing the cohort into two groups according to whether the FHC was greater or less than the 90th centile. From a total cohort of 2,336 nulliparous patients, there were 491(21%) cesarean deliveries, 62 (3%) of which were CD at full dilation; 404 (17%) operative vaginal deliveries; 279 (12%) cases of prolonged labor; and 1,178 (50%) cases of oxytocin use. The results according to the two FHC categories are shown in Table 1, with adjusted p-values and controlling for maternal age, BMI, height, AC and EFW. Table 1 also includes the composite outcome of ‘complicated labor’. CD was 20% in the group with FHC 90th centile (adjusted p < 0.0001). The Genesis Study shows that a FHC >90th centile is associated with a significantly increased risk of CD, CD at full dilatation, prolonged labor, oxytocin use and complicated labor, but is not associated with a significantly increased risk of operative vaginal delivery. Fetal biometry at term should be considered as a clinical aid for predicting complicated birth.

Induction of labor (IOL) has traditionally been associated with an increased risk of cesarean delivery (CD). Advancing maternal age and high body mass index (BMI) are possible indications for IOL: both are risk factors for CD. In this analysis, we sought to evaluate the effect of IOL on the CD rate in nulliparous patients at term in different demographic profiles. The Genesis Study recruited 2,336 nulliparous patients with a cephalic presentation between 39+0 and 40+6 weeks’ gestation in a prospective multi-center study to examine predictors of CD. At recruitment, a detailed clinical evaluation and ultrasound assessment were performed. Patients and their managing clinicians were blinded to the ultrasound details. The cohort was analyzed according to age and BMI. The CD rate for spontaneous labor (SOL) and IOL were calculated and presented as relative risk. In this cohort of 2,336 patients, 940 (40.2%) were induced and 491 had a CD (21%). The rate of CD in the induced cohort was 31.6% (297/940) compared to 13.9% (194/1396) in the SOL group. Table 1 shows the CD rates according to onset of labor, stratified in sub-groups according to age and BMI. In the BMI groups, there was an increasing rate of CD (p-values for trend: 0.002 for SOL and <0.001 for IOL). For the age groups, there was an increasing rate of CD for the IOL group only (p-value 0.02). There was an elevated risk of CD with IOL compared to SOL across all demographic profiles. IOL is a risk factor for CD across all maternal age and BMI profiles. Regardless of onset of labor, the CD rate increases with BMI but it does not increase with maternal age in those with SOL. The sub-population with the highest relative risk for CD when induced are those with age < 25 plus BMI <25 i.e. those who have the lowest rates of CD in absolute terms (and are most likely to have further pregnancies). This is important information to consider when making a decision to induce a nulliparous patient.

The rising cesarean delivery rate continues to generate concern. While many studies have tried to predict cesarean delivery (CD) by prenatal diagnosis of cephalopelvic disproportion or fetal macrosomia, neither strategy has proved particularly useful in the clinical setting. In this primary analysis of the Genesis Study we sought to prospectively assess the use of a range of demographic, clinical and ultrasound features to develop a predictive tool for CD in nulliparous, singleton pregnancies. The Genesis Study recruited 2,336 nulliparous patients with a vertex presentation between 39+0 and 40+6 weeks' gestation in a prospective multi-center national study to examine predictors of CD. At recruitment a detailed clinical evaluation and ultrasound assessment were performed. Patients and their managing clinicians were blinded to the ultrasound details, to reduce bias from knowledge of this data potentially influencing mode of delivery. All hypothetical prenatal risk factors for unplanned CD were assessed individually and as a composite to eliminate confounding factors. Multiple logistic regression analysis was used to develop a risk evaluation tool for CD in nulliparous patients. From a cohort of 2,336 nulliparous patients, 491 (21%) had an unplanned CD. In a multivariate analysis, five parameters (maternal age, maternal height, BMI, fetal AC and fetal HC) were determined to be the best combined predictors of CD. These five parameters are listed in Table 1 along with their respective odds ratios when calculated at different time points during pregnancy. Individual Z scores were calculated for demographic and biometric data to determine these odds ratios and a risk score. Z scores can be calculated from Table 1. The totaled Z scores for the five parameters can then be applied to Figure 1 to give a personalized risk of CD. Five parameters (maternal age, BMI, height, fetal AC and fetal HC) can be used to better determine the overall risk of cesarean delivery in nulliparous patients at term. A risk score can be used to better inform patients of their individualized risk of CD in early gestation and again from 39 weeks' gestation. This risk tool may be useful for planning service needs as well as for individual patient's decisions on place and mode of delivery.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

To compare perinatal outcomes of twin pregnancies conceived by assisted conception with those of natural conception. Evaluation of Sonographic Predictors of Restricted growth in Twins (ESPRiT) is a multicentric prospective observational study conducted in eight maternity centres in Ireland, by the Perinatal Ireland Research consortium. Of 1001 twin pregnancies completing the study over a 24 month period, method of conception was available for 874 twins. Statistical comparisons were made between methods of conception and types of artificial reproductive techniques (ARTs) for demographics, baseline characteristics and perinatal outcomes. There were 636 (73%) spontaneously conceived twins and 238 (27%) conceived by ART in the study. Nearly all (97%) of the ART twins were dichorionic as compared to 74% dichorionic twins of those conceived naturally. The ART group was older with a maternal age of 35 years as compared to 31 years for the spontaneous conception group (p < 0.0001). The ART group was also more likely to be nulliparous (70% vs 40%, p<0.0001) and were less likely to be smokers (4% versus 15%, p <0.0001). There were no significant differences between the obstetric features such as preeclampsia, gestational diabetes, antepartum haemorrhage or preterm delivery. There were 16(1%) neonatal deaths in the naturally conceived group and 3(0.6%) in the assisted conception group (p=0.124) We found no difference (p-value > 0.05) in gestational age at delivery for the ART group (median 37.0 vs 36.9 weeks), birth weights (median 2538g vs. 2523g), birth weight discordance (median 10% vs. 9% discordance) or neonatal admission rates (44% vs. 46%). Other perinatal outcomes were compared and found not to be statistically significant, including hypoxic ischemic encephalopathy, periventricular leukomalacia, necrotising enterocolitis, respiratory distress syndrome, sepsis and a composite of these outcomes including neonatal deaths (total 15% vs. 19%, p > 0.05). We compared perinatal outcomes between the different types assisted conception groups (composed of 1% artificial insemination, 72% in vitro fertilization 10% intracytoplasmic sperm injection and 17% ovulation induction conception) and found no evidence of a difference in perinatal outcomes. This study found maternal, neonatal, and perinatal outcomes in twins conceived naturally and by assisted conception were comparable.