Mode of birth in twins: data and reflections.

Our primary objective was to compare neonatal and maternal outcomes in women with twin pregnancies, beyond 32 weeks, having a planned vaginal birth or a planned caesarean section (CS). This was a retrospective cohort study from a single tertiary centre over nine years. 534 sets of twins ≥32 + 0 weeks of gestation were included. 401 sets were planned vaginally and 133 sets were planned by CS. We compared a composite adverse perinatal outcome (perinatal mortality or serious neonatal morbidity; five minute APGAR score ≤4, neurological abnormality and need for intubation) and a composite maternal adverse outcome (major haemorrhage, trauma or infection) between the groups. There were no significant differences. Given the similarity of these results with several other larger studies of twin birth, we sought to look at reasons why there is still a rising rate of CS for twin births. We further make suggestions for keeping this rate to a sensible minimum. Impact statement What is already known on this subject? The largest randomised controlled study comparing planned vaginal birth with planned CSs for lower risk twins between 32 and 39 weeks of gestation, showed no added safety from planned CS. However, in most of the Western countries this conclusion has failed to increase the number of planned vaginal births for lower risk twins. What do the results of this study add? This observational study from a single tertiary centre provides external validation of the twin trial results in a practical day-to-day setting. It also provides insights as to how planned vaginal birth can be developed and maintained, with a key focus on safety and maternal participation in decision making. It does focus on consent and providing accurate data. What are the implications of these findings for clinical practice and/or further research? There are good grounds to encourage vaginal birth for low-risk twin pregnancies. The trend of rising caesarean rates in low-risk twin pregnancies worldwide will erode important skills for the conduct of vaginal births without any clear benefit for mothers or babies. The current situation demands careful thought about implementing innovative training opportunities for younger obstetricians. Finally, we need intelligent responses to many non-evidence-based factors which can drive clinical practice.

This baby is not for turning: Women's experiences of attempted external cephalic version.

BACKGROUND: Existing studies regarding women's experiences surrounding an External Cephalic Version (ECV) report on women who have a persistent breech post ECV and give birth by caesarean section, or on women who had successful ECVs and plan for a vaginal birth. There is a paucity of understanding about the experience of women who attempt an ECV then plan a vaginal breech birth when their baby remains breech. The aim of this study was to examine women's experience of an ECV which resulted in a persistent breech presentation. METHODS: A qualitative descriptive exploratory design was undertaken. In-depth semi-structured interviews were conducted and analysed thematically. RESULTS: Twenty two (n = 22) women who attempted an ECV and subsequently planned a vaginal breech birth participated. Twelve women had a vaginal breech birth (55 %) and 10 (45 %) gave birth by caesarean section. In relation to the ECV, there were five main themes identified: 'seeking an alternative', 'needing information', 'recounting the ECV experience', 'reacting to the unsuccessful ECV' and, 'reflecting on the value of an ECV'. CONCLUSIONS: ECV should form part of a range of options provided to women, rather than a default procedure for management of the term breech. For motivated women who fit the safe criteria for vaginal breech birth, not being subjected to a painful experience (ECV) may be optimal. Women should be supported to access services that support vaginal breech birth if this is their choice, and continuity of care should be standard practice.

A placental clock controlling the length of human pregnancy.

We report the existence of a 'placental clock', which is active from an early stage in human pregnancy and determines the length of gestation and the timing of parturition and delivery. Using a prospective, longitudinal cohort study of 485 pregnant women we have demonstrated that placental secretion of corticotropin-releasing hormone (CRH) is a marker of this process and that measurement of the maternal plasma CRH concentration as early as 16-20 weeks of gestation identifies groups of women who are destined to experience normal term, preterm or post-term delivery. Further, we report that the exponential rise in maternal plasma CRH concentrations with advancing pregnancy is associated with a concomitant fall in concentrations of the specific CRH binding protein in late pregnancy, leading to a rapid increase in circulating levels of bioavailable CRH at a time that coincides with the onset of parturition, suggesting that CRH may act directly as a trigger for parturition in humans.

Barriers and facilitators for vaginal breech births in Australia: Clinician's experiences.

BACKGROUND: Since the Term Breech Trial in 2000, few Australian clinicians have been able to maintain their skills to facilitate vaginal breech births. The overwhelming majority of women with a breech presentation have been given one birth option, that is, caesarean section. The aim of this study was to explore clinician's experiences of caring for women when facilitating a vaginal breech birth. METHODS: A descriptive exploratory design was undertaken. Nine clinicians (obstetricians and midwives) from two tertiary hospitals in Australia who regularly facilitate vaginal breech birth were interviewed. The interviews were analysed thematically. RESULTS: Participants were five obstetricians and four midwives. There were two overarching themes that arose from the data: Facilitation of and Barriers to vaginal breech birth. A number of sub-themes are described in the paper. CONCLUSIONS: In order to facilitate vaginal breech birth and ensure it is given as an option to women, it is necessary to educate, upskill and support colleagues to increase their confidence and abilities, carefully counsel and select suitable women, and approach the option in a calm, collaborative way.

Care during the decision-making phase for women who want a vaginal breech birth: Experiences from the field.

BACKGROUND: few women are given the option of a vaginal breech birth in Australia, unless the clinicians feel confident and have the skills to facilitate this mode of birth. Few studies describe how clinicians provide care during the decision-making phase for women who choose a vaginal breech birth. The aim of this study was to explore how experienced clinicians facilitated decisions about external cephalic version and mode of birth for women who have a breech presentation. METHODS: a descriptive exploratory design was undertaken with nine experienced clinicians (obstetricians and midwives) from two tertiary hospitals in Australia. Data were collected through face to face interviews and analysed thematically. FINDINGS: five obstetricians and four midwives participated in this study. All were experienced in caring for women having a vaginal breech birth and were currently involved in providing such a service. The themes that arose from the data were: Pitching the discussion, Discussing safety and risk, Being calm and Providing continuity of care. CONCLUSIONS: caring for women who seek a vaginal breech birth includes careful selection of appropriate women, full discussions outlining the risks involved, and undertaking care with a calm manner, ensuring continuity of care. Health services considering establishing a vaginal breech service should consider that these elements are included in the establishment and implementation processes.

U46619-mediated vasoconstriction of the fetal placental vasculature in vitro in normal and hypertensive pregnancies.

OBJECTIVES: To measure in-vitro responses to the thromboxane A2 (TxA2) mimetic U46619 in the fetal placental vasculature of human placentae from normotensive women and those with pre-eclampsia. Furthermore, to compare fetal vascular responses to endothelin-1,5-hydroxytryptamine, potassium chloride (KCl) and prostacyclin (PGI2) in placentae from normal or pre-eclamptic pregnancies. METHODS: Single placental lobules of intact placentae were bilaterally perfused in situ (fetal and maternal) with constant flows of Krebs' solution. Changes in fetal arterial perfusion pressure during intra-arterial infusion of vasoactive agents were recorded. Fetal placental vasoconstrictor concentration response curves were obtained to U46619 (0.01-300 nmol/l), endothelin-1 (0.4-160 nmol/l), KCl (3-300 mmol/l) and 5-hydroxytryptamine (0.03-30 mumol/l). In addition, vasodilator concentration response curves were obtained for PGI2 (1.2-350 nmol/l) in the fetal placental circulation during submaximal increases in perfusion pressure with prostaglandin F2 alpha (PGF2 alpha; 0.7-2.0 mumol/l). RESULTS: The maximum increase in perfusion pressure caused by U46619 in placentae from normotensive women was 194 +/- 25 mmHg. The maximum response to U46619 was significantly reduced in the placentae from women with pre-eclampsia (104 +/- 21 mmHg). In contrast, there were no differences in constrictor responses to endothelin-1,5-hydroxytryptamine and KCl, or in dilator responses to PGI2 in placentae obtained from either normotensive women or those with pre-eclampsia. CONCLUSION: TxA2 receptor-mediated vasoconstriction is reduced in the fetal vasculature of placentae from women with pre-eclampsia, possibly to compensate for the increased levels of TxA2 seen in these conditions.

Vasoactive effects of 8-epi-prostaglandin F(2alpha)in isolated human placental conduit and resistance blood vessels in vitro.

The effects of 8-epi-prostaglandin F(2alpha)(8-epi-PGF(2alpha)) and the thromboxane A(2)-mimetic U46619 were examined on isolated human fetal placental arteries obtained from normal pregnancies and from those complicated by pre-eclampsia. The effects of these agents were examined on both conduit and resistance arteries. 8-epi-PGF(2alpha)was found to be markedly less potent than U46619 in constricting both size vessels. Vasoconstrictor EC(50)s for 8-epi PGF(2alpha)were 4.10x10(-7) m (2.02-8.35x10(-7) m) (mean, 95 per cent CI and 2.05x10(-6) m (0.43-9.89 x10(-6) m) in conduit and resistance arteries, respectively. The maximum vasoconstriction produced by 8-epi-PGF(2alpha)(112+/-17 per cent), (relative to maximum KCl induced vasoconstriction) in conduit vessels was significantly less than that caused by U46619 (152+/-20 per cent). In resistance vessels the maximum vasoconstrictor effects to 8-epi-PGF(2alpha)(208+/-10 per cent) and U46619 (201+/-19 per cent) were similar, and in both cases significantly greater than the maximal effects seen in conduit vessels. U46619 displayed a similar vasoconstrictor potency in both conduit (EC(50)=1.21x10(-9) m, 0.58-2.51x10(-9) m) and resistance arteries [EC(50)=5.95x10(-9) m, (0.81-43.60x10(-9) m] as was found for 8-epi PGF(2alpha). 8-epi-PGF(2alpha)was equipotent in resistance arteries obtained from women with severely pre-eclamptic pregnancies (EC(50)=1.25x10(-6) m, 0.25-6.17x10(-6) m) compared with normotensive controls. However, the maximum vasoconstrictor effect induced by 8-epi-PGF(2alpha)in placental resistance arteries was significantly reduced (99+/-20 per cent) in vessels obtained from severely pre-eclamptic compared with normal pregnancies. These results indicate that 8-epi-PGF(2alpha)displays differential vasoconstrictor activity in the fetal-placental vasculature. Furthermore the vasoconstrictor effects of 8-epi-PGF(2alpha)are reduced in pre-eclampsia, the effect being selective to placental resistance vessels. This reduction may occur as a result of more serious disturbances in the placental microcirculation with the disease process in pre-eclampsia.

Renal abscess with paranephric extension in a gravid woman: ultrasound and magnetic resonance imaging findings.

We present a case of renal abscess with perinephric and paranephric extension. Ultrasonography showed an intrarenal lesion. The extension into the perinephric and paranephric space was better defined on MRI.

Laparoscopic surgical treatment of ectopic pregnancy: salpingectomy or salpingostomy?

There is a widespread belief that salpingostomy is the treatment of choice for ectopic pregnancy. The ability to treat most ectopic pregnancies via a laparoscopic approach has been a major advance in gynaecological surgery. Despite the well publicized benefits of laparoscopy over laparotomy only 50% of patients with ectopic pregnancies in Australia presently benefit from this surgical advance. Although it is clear that laparoscopic treatments are preferable to laparotomy there is no consensus on whether salpingectomy or salpingostomy should be performed, despite over 40 years of research since the introduction of conservative tubal treatment. A systematic review of laparoscopic surgical treatment is needed and could be incorporated into the Cochrane Collaboration. A prospective clinical study, with long-term follow-up, needs to be performed to evaluate fertility prognosis and complications after laparoscopic salpingectomy versus salpingostomy.

Clinical use of Doppler ultrasound in pregnancy: information from six randomised trials.

The objective of this report was to undertake an overview of the clinical utility of umbilical Doppler ultrasound in the management of high-risk pregnancies. The study is designed as a formal meta-analysis of 6 randomised trial reports selected by predetermined criteria and was performed at the Division of Reproductive Medicine, Newcastle University, Australia. A total of 6 randomised controlled trials amounted to 2,102 patients in the experimental (Doppler) group and 2,133 patients in the control group. All patients had high-risk pregnancies. The management of pregnancies with Doppler was compared to those with standard obstetric management (i.e. excluding Doppler). Main outcome measures were perinatal mortality in the form of intrauterine deaths as well as obstetric performance indicators including caesarean section, elective delivery, fetal distress in labour, antenatal admissions and admissions to Neonatal Intensive Care Unit. The meta-analysis shows a significant reduction in perinatal mortality in the groups in which Doppler was used. Typical odds ratio was 0.5 [95% confidence intervals (CI) 0.34, 0.73]. The specific reduction in perinatal mortality occurred in intrauterine deaths in otherwise normally formed fetuses. The typical odds ratio was 0.54 with 95% CI 0.32, 0.89. This meta-analysis shows a significant reduction in overall perinatal mortality, specifically in the form of intrauterine deaths in otherwise normally formed babies.

Delayed ectopic pregnancies after sterilization.

Female sterilization as an interval, postabortal or postpartum procedure, is one of the most widely employed contraceptive techniques on a global basis. The short-term complications of sterilization, which include intra- and extrauterine pregnancies, are well researched and documented. The figures for long-term complications, including ectopic pregnancy, are much less reliable as the follow-up rates diminish as time passes after sterilization. Three cases of tubal pregnancy that occurred long after interval sterilization are presented as a warning against the assumption that long-term complications cannot occur.

Examination of a low-cost pocket Doppler device for fetal assessment.

The objective of this study was to evaluate a pocket Doppler device (Multi Dopplex II) for the waveform analysis of umbilical artery systolic/diastolic (S/D) ratios and resistance index (RI). A prospective, paired study was undertaken in a perinatal ultrasound unit in a tertiary referral hospital. Forty-three high-risk pregnant women beyond 16 weeks' gestation had fetal umbilical artery flow velocity waveforms recorded with both Multi Dopplex II and duplex Doppler devices and the waveform analyses were calculated. The Multi Dopplex II falsely indicated absent diastolic flow in two cases and failed to produce a flow velocity waveform in the presence of maternal obesity, polyhydramnios and some cases of anterior placenta (n = 8). As well as this, the limits of agreement overall for both S/D ratio and RI were wide (for S/D ratio, -1.6 to 2.2 and for RI, -0.20 to 0.20). Even though the levels of agreement were better for the third trimester (for S/D ratio, -0.8 to 1.1 and for RI, -0.10 to 0.20), we concluded that the limits of agreement were too wide for clinical use.

A systematic review of single-dose intramuscular methotrexate for the treatment of ectopic pregnancy.

The use of single-dose intramuscular methotrexate for the primary treatment of ectopic pregnancy is increasing in frequency in many countries. We performed a systematic review of all available studies and case reports of intramuscular methotrexate to examine the therapeutic efficacy, side-effects and complication rates of this new treatment approach. The pooled data show a successful resolution rate of 71% (95% confidence interval 58% to 81%) after a single dose of intramuscular methotrexate and 84% (95% confidence interval 77% to 90%) after 1 or 2 doses. Side-effects were experienced by 24% (95% confidence interval 9% to 47%) of patients and 10% (95% confidence interval 7% to 14%) had a ruptured ectopic pregnancy. The pooled data show that single-dose intramuscular methotrexate is associated with a high failure rate. Follow-up is prolonged and there is a significant incidence of minor side-effects. Serious complications and side-effects have occurred. The use of intramuscular methotrexate should be confined to clinical trials until more evidence is obtained to support its more widespread use.

The effect of fetal fibronectin testing on admissions to a tertiary maternal-fetal medicine unit and cost savings.

OBJECTIVE: Fetal fibronectin bedside testing has been proposed as a diagnostic tool for the accurate diagnosis of preterm labor. The study objective was to determine whether the introduction of routine fetal fibronectin bedside testing affected costs and transfer rates from referral district hospitals to a tertiary obstetric hospital, as well as direct admissions to a tertiary referral hospital. STUDY DESIGN: We performed an 18-month prospective audit of fetal fibronectin use in 9 referral hospitals and one university maternal-fetal medicine unit. Data collected were delivery details and cervical dilatation at admission. Cost savings in terms of transport costs for patients with a negative fetal fibronectin result who were not transferred or admitted to the tertiary center were calculated for interhospital transfer (road ambulance or fixed-wing retrieval). RESULTS: One hundred fifty-one patients had a presumptive diagnosis of threatened preterm labor. Forty-five patients had a positive fetal fibronectin result and 106 had a negative fetal fibronectin result (3 with cervical dilatation >/=3 cm). Eleven (24%) patients with a positive fetal fibronectin result were delivered within 7 days, and 5 (5%) with a negative fetal fibronectin result were delivered within 7 days. One patient was delivered at 34 weeks, and the remaining patients were delivered at or after 36 weeks' gestation. All 3 patients with negative fetal fibronectin results with cervical dilatation of >/=3 cm were delivered within 5 days, leaving 2 (1.9%) patients (with closed cervices and negative fetal fibronectin results) being delivered 5 days after the fetal fibronectin testing. Ninety percent of the patients admitted to a referral hospital with threatened preterm labor who had a negative fetal fibronectin result were not transferred; thus an unnecessary transfer was avoided, with cost savings ranging from $30,297 for road and fixed-wing transport. CONCLUSION: A negative fetal fibronectin result is not helpful if cervical dilatation is present, and these patients should be treated as having a high risk of preterm delivery. The use of a fetal fibronectin test was associated with a 90% reduction in maternal transfer and can substantially reduce the costs and inconvenience associated with unnecessary transfer.

Corticotropin-releasing hormone: a biochemical predictor of preterm delivery in a pilot randomized trial of the treatment of preterm labor.

OBJECTIVE: We assessed the ability of maternal plasma corticotropin-releasing hormone measurements to predict preterm delivery in the setting of a pilot study comparing transdermal glyceryl trinitrate with standard beta-mimetic therapy for preterm labor and to determine the effect of these tocolytics on maternal plasma corticotropin-releasing hormone concentrations. STUDY DESIGN: Twenty-six consecutive patients with preterm labor were randomized to tocolytic treatment with transdermal glyceryl trinitrate (n=13) or intravenous albuterol (n=13). RESULTS: Plasma corticotropin-releasing hormone immunoreactivity levels were higher in women who were delivered within 7 days (41.4+/-13.5 pmol/L) than in those continuing to term (14.2+/-2.4 pmol/L, p=0.011) and were not altered by treatment. Two women in each of the treatment groups delivered within 7 days of the initiation of treatment, two women in the glyceryl trinitrate group were changed to albuterol because of persistence of contractions. Glyceryl trinitrate treatment was associated with significantly fewer maternal side effects. Neither treatment altered umbilical artery Doppler ultrasonographic findings. CONCLUSION: Transdermal glyceryl trinitrate is better tolerated than intravenous albuterol but may be no more efficacious than albuterol for the treatment of preterm labor. Biologic markers such as plasma corticotropin-releasing hormone levels may be an important method of identifying women at high risk of preterm delivery.

Predicting risk of preterm delivery by second-trimester measurement of maternal plasma corticotropin-releasing hormone and alpha-fetoprotein concentrations.

OBJECTIVE: Many women who have preterm labor have abnormally high plasma concentrations of the placental peptide corticotropin-releasing hormone and the fetal product alpha-fetoprotein in early pregnancy. This study was designed to evaluate the ability of these biochemical tests and a clinical risk factor score to prospectively discriminate pregnancies at high risk for preterm delivery. STUDY DESIGN: Eight hundred sixty women were studied prospectively from the early second trimester until delivery. A risk factor score for preterm delivery was calculated from the clinical history and maternal plasma corticotropin-releasing hormone and alpha-fetoprotein concentrations were measured by radioimmunoassay between 17 and 30 weeks' gestation. The risk factor score, corticotropin-releasing hormone concentration, and alpha-fetoprotein concentration for each woman were expressed as individual odds or likelihood ratios for preterm delivery and as a combined risk estimate derived from the 3 tests. RESULTS: Sixty women had preterm deliveries (n = 37 spontaneous labor, n = 23 planned deliveries), and these women had significantly higher concentrations of corticotropin-releasing hormone (median 1.92 multiples of the median) and alpha-fetoprotein (median 1.32 multiples of the median) than did women with term deliveries (median 1.00 multiples of the median, P <.001 for both tests), with these abnormalities being evident from early in the second trimester. The risk factor score was >/=10 in 28% of women with preterm delivery and 7% of women with term delivery. The combination of all 3 markers resulted in a higher detection rate and a higher positive predictive value than the risk factor score, corticotropin-releasing hormone concentration, or alpha-fetoprotein concentration alone, correctly discriminating 37% of women who would have preterm deliveries with a false-positive rate of 5%. The positive predictive value was also 37% (odds of being affected given a positive result were 1:1.7). CONCLUSIONS: The combination of measurement of maternal plasma corticotropin-releasing hormone and alpha-fetoprotein concentrations in the second trimester with risk factor scoring provides a more accurate indicator of the risk of preterm delivery than does risk factor scoring alone. This method of risk assessment may therefore be of use in targeting prevention strategies.

Alterations of placental vascular function in asthmatic pregnancies.

Asthma during pregnancy is associated with low-birthweight neonates at term but the mechanisms that cause this outcome are presently unknown. Changes in placental vascular function resulting from asthma or its treatment could contribute to altered fetal growth. We have prospectively followed women with asthma and a control group of women without asthma during their pregnancies, classified them based on asthma severity and glucocorticoid intake, and monitored fetal development and placental blood flow using Doppler ultrasound at 18 and 30 wk gestation. The placentae from these women were collected after delivery and vascular responses to dilator and constrictor agonists assessed using an in vitro placental perfusion method. At 18 wk gestation, umbilical artery flow velocity waveforms were significantly reduced in the moderate and severe asthmatic groups and in those women using high-dose inhaled glucocorticoid for the treatment of their asthma (ANOVA, p < 0.05). However, at 30 wk gestation there were no significant differences in umbilical artery flow velocity between control and asthmatic women (ANOVA, p > 0.05). Corticotropin-releasing hormone (CRH), a potent vasodilator that acts via the nitric oxide pathway, caused a dose-dependent vasodilatory response in all placentae in vitro. However, CRH-induced dilation was significantly reduced in moderate and severe asthmatics (ANOVA, p < 0.05). Vasoconstrictor responses to potassium chloride and prostaglandin F(2alpha) were reduced in placentae from moderate and severe asthmatic women (ANOVA, p < 0.05). These studies demonstrate significant differences in placental vascular function in pregnancies complicated by asthma, which may relate directly to the asthma or be a consequence of the associated glucocorticoid treatment. These changes in vascular function in asthmatic pregnancies may contribute to the low-birthweight outcome observed in this condition.

The Randomized Nitric Oxide Tocolysis Trial (RNOTT) for the treatment of preterm labor.

OBJECTIVE: This study was undertaken to assess the effectiveness of glyceryl trinitrate (GTN) patches in comparison with beta2 sympathomimetics (beta2) for the treatment of preterm labor. STUDY DESIGN: A multicenter, multinational, randomized controlled trial was conducted in tertiary referral teaching hospitals. Women in threatened preterm labor with positive fetal fibronectin or ruptured membranes between 24 and 35 weeks' gestation were recruited and randomly assigned to either beta2 or GTN with rescue beta2 tocolysis if moderate-to-strong contractions persisted at 2 hours. Obstetric and neonatal outcomes were assessed. RESULTS: Two hundred thirty-eight women were recruited and randomly assigned, 117 to beta2 and 121 to GTN. On a strict intention-to-treat basis, there was no significant difference in the time to delivery using Kaplan-Meier curves (P = .451). At 2 hours, 27% of women receiving beta2 had moderate or stronger contractions compared with 53% in the GTN group (P < .001). This led to 35% of women in the GTN group receiving rescue treatment. If delivery or requirement for beta2 rescue are regarded as treatment failure, then a significant difference was observed between the 2 arms (P = .0032). There were no significant differences in neonatal outcomes. CONCLUSION: GTN is a less efficacious tocolytic compared with ss2 sympathomimetics.