Experiences with maternal and perinatal death reviews in the UK--the MBRRACE-UK programme.

Established in 1952, the programme of surveillance and Confidential Enquiries into Maternal Deaths in the UK is the longest running such programme worldwide. Although more recently instituted, surveillance and confidential enquiries into perinatal deaths are also now well established nationally. Recent changes to funding and commissioning of the Enquiries have enabled both a reinvigoration of the processes and improvements to the methodology with an increased frequency of future reporting. Close engagement with stakeholders and a regulator requirement for doctors to participate have both supported the impetus for involvement of all professionals leading to greater potential for improved quality of care for women and babies.

Interventions for twin-twin transfusion syndrome: a Cochrane review.

We performed a Cochrane review to assess which of the treatments for twin-twin transfusion syndrome (TTTS) improves fetal, childhood and maternal outcomes. This article represents a version of the review which includes additional data to the published version. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2007) and the Cochrane Central Register of Controlled Trials (The Cochrane Library, October 2007) for randomized and quasi-randomized studies of amnioreduction, laser coagulation and septostomy and compared their outcomes. We also searched conference proceedings and contacted the authors of published trials for clarification and additional data. No trials compared intervention with no intervention. Three studies (253 women) were included. Laser coagulation resulted in less overall death (48% vs. 59%; relative risk (RR), 0.81; 95% CI, 0.65-1.01 adjusted for clustering; two trials, 364 fetuses), perinatal death (26% vs. 44%; RR, 0.59; 95% CI, 0.40-0.87 adjusted for clustering; one trial, 284 fetuses) and neonatal death (8% vs. 26%; RR, 0.29; 95% CI, 0.14-0.61 adjusted for clustering; one trial, 284 fetuses) when compared with amnioreduction. There was no difference in perinatal outcome between amnioreduction and septostomy. More babies were alive without neurological abnormality at the age of 6 months in the laser group than in the amnioreduction group (52% vs. 31%; RR, 1.66; 95% CI, 1.17-2.35 adjusted for clustering; one trial). There was no difference in the proportion of babies alive at 6 months that had undergone treatment for major neurological abnormality between the laser coagulation and the amnioreduction groups (4% vs. 7%; RR, 0.58; 95% CI, 0.18-1.86 adjusted for clustering; one trial). The results suggest that endoscopic laser coagulation of anastomotic vessels should be considered in the treatment of all stages of TTTS to improve perinatal and neonatal outcome.

Interventions for the treatment of twin-twin transfusion syndrome.

BACKGROUND: Twin-twin transfusion syndrome, a condition affecting monochorionic twin pregnancies, is associated with a high risk of perinatal mortality and morbidity. A number of treatments have been introduced to treat the condition but it is unclear which intervention improves maternal and fetal outcome. OBJECTIVES: The objective of this review was to evaluate the impact of treatment modalities in twin-twin transfusion syndrome. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (October 2007) and the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 4). We also searched conference proceedings and made personal contact with experts active in the area of the review. SELECTION CRITERIA: Randomised and quasi-randomised studies of amnioreduction versus laser coagulation, septostomy versus laser coagulation or septostomy versus amnioreduction. DATA COLLECTION AND ANALYSIS: One review author assessed eligibility and extracted data, which were checked by a second author. We contacted study authors for additional information. MAIN RESULTS: Two studies (213 women) were included. This review shows that laser coagulation of anastomotic vessels results in less death of both infants per pregnancy (relative risk (RR) 0.33; 95% confidence interval (CI) 0.16 to 0.67, one trial), less perinatal death (RR 0.59; 95% CI 0.0.40 to 0.87 adjusted for cluster, one trial) and less neonatal death (RR 0.29; 95% CI 0.14 to 0.61 adjusted for cluster, one trial) than in pregnancies treated with amnioreduction. There is no difference in perinatal outcome between amnioreduction and septostomy. A third study is awaiting assessment. More babies were alive without neurological abnormality at the age of six months in the laser group than the amnioreduction groups (RR 1.66; 95% CI 1.17 to 2.35 adjusted for clustering, one trial). This difference did not persist beyond six months of age. There was no significant difference in the babies alive at six months with neurological abnormality treated by laser coagulation or amnioreduction (RR 0.58; 95% CI 0.18 to 1.86 adjusted for clustering, one trial). AUTHORS' CONCLUSIONS: Endoscopic laser coagulation of anastomotic vessels should be considered in the treatment of all stages of twin-twin transfusion syndrome to improve perinatal outcome. Further research on the effect of treatment on milder forms of twin-twin transfusion syndrome (Quintero stage 1 and 2) are required. The long-term outcomes of survivors from the studies included in this review are required.

Probiotics for preventing preterm labour.

BACKGROUND: Preterm birth causes 60% to 80% of neonatal deaths. Survivors can experience life-long complications. The risk of preterm labour in the presence of maternal infection is thought to be 30% to 50%. Probiotics are defined as live micro-organisms which, when administered in an adequate amount, confer a health benefit on the host. They have been shown to displace and kill pathogens and modulate the immune response by interfering with the inflammatory cascade that leads to preterm labour and delivery. During pregnancy, local treatment restoring normal vaginal flora and acidity without systemic effects could be preferable to other treatment in preventing preterm labour. OBJECTIVES: To evaluate the effectiveness and the safety of probiotics for preventing preterm labour and birth. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (June 2006). SELECTION CRITERIA: All randomised controlled trials assessing the prevention of preterm birth in pregnant women and women planning pregnancy through the use of probiotics to treat or prevent urogenital infections. DATA COLLECTION AND ANALYSIS: We extracted data using the prepared form and analysed with the Review Manager software. MAIN RESULTS: We assessed four trials for inclusion in the review. One trial started in February 2005 and is still ongoing. We excluded one trial because there were no data to be extracted from the article. Of the two trials included in the review, one enrolled women after 34 weeks of pregnancy using oral fermented milk as probiotic, while the other study utilised commercially available yogurt to be used vaginally by women diagnosed with bacterial vaginosis in early pregnancy. Reduction in genital infection was the only prespecified clinical outcome for which the data were available; pooled results showed an 81% reduction in the risk of genital infection with the use of probiotics (risk ratio 0.19; 95% confidence interval 0.08 to 0.48). AUTHORS' CONCLUSIONS: Although the use of probiotics appears to treat vaginal infections in pregnancy, there are currently insufficient data from trials to assess impact on preterm birth and its complications.

WITHDRAWN: Routine Doppler ultrasound in pregnancy.

BACKGROUND: Doppler ultrasound study of umbilical artery waveforms helps identify the compromised fetus in 'high risk' pregnancies and, therefore, deserves assessment as a screening test in 'low risk' pregnancies. One of the main aims of routine antenatal care is to identify the 'at risk' fetus in order to apply clinical interventions which could result in reduced perinatal morbidity and mortality. OBJECTIVES: To assess the effects on obstetric practice and pregnancy outcome of routine Doppler ultrasound in unselected and low risk pregnancies. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group Specialised Register of Controlled Trials and the Cochrane Controlled Trials Register were searched. Date of last search: September 1999 SELECTION CRITERIA: Acceptably controlled trials of routine Doppler ultrasound (umbilical circulation and/or uterine circulation) in unselected or low risk pregnancies. DATA COLLECTION AND ANALYSIS: Both reviewers assessed trial quality and extracted data. Authors of two trials were contacted for additional information. MAIN RESULTS: Five trials were included which recruited 14,338 women. The methodological quality of the trials was generally good. Based on existing evidence, routine Doppler ultrasound examination in low risk or unselected populations did not result in increased antenatal, obstetric and neonatal interventions, and no overall differences were detected for substantive short term clinical outcomes such as perinatal mortality. There is no available evidence to assess the effect on substantive long term outcomes such as childhood neurodevelopment. There is no available evidence to assess maternal outcomes, particularly psychological effects. In two studies there were unexpected findings suggesting possible harmful effects, but the explanation for this is not clear, and further evaluation regarding the safety of Doppler ultrasound is required. AUTHORS' CONCLUSIONS: Based on existing evidence, routine Doppler ultrasound in low risk or unselected populations does not confer benefit on mother or baby. Future research should be powerful enough to address small changes in perinatal outcome, and should include evaluation of maternal psychological effects, long term outcomes such as neurodevelopment, and issues of safety.

WITHDRAWN: Routine ultrasound in late pregnancy (after 24 weeks' gestation).

BACKGROUND: Diagnostic ultrasound is used selectively in late pregnancy where there are specific clinical indications. However, the value of routine late pregnancy ultrasound screening in unselected populations is controversial. The rationale for such screening would be the detection of clinical conditions which place the fetus or mother at high risk, which would not necessarily have been detected by other means such as clinical examination, and for which subsequent management would improve perinatal outcome. OBJECTIVES: To assess the effects on obstetric practice and pregnancy outcome of routine late pregnancy ultrasound, defined as greater than 24 weeks gestation, in women with either unselected or low risk pregnancies. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group Specialised Register of Controlled Trials and the Cochrane Controlled Trials Register were searched. SELECTION CRITERIA: All acceptably controlled trials of routine ultrasound in late pregnancy (defined as after 24 weeks). DATA COLLECTION AND ANALYSIS: The principal reviewer assessed trial quality and extracted data, under supervision of the co-reviewer. MAIN RESULTS: Seven trials recruiting 25,036 women were included. The quality of trials overall was satisfactory. There was no difference in antenatal, obstetric and neonatal intervention or morbidity in screened versus control groups. Routine late pregnancy ultrasound was not associated with improvements in overall perinatal mortality. Placental grading as an adjunct to third trimester examination scan was associated with a significant reduction in the stillbirth rate in the one trial that assessed it. There is a lack of data with regard to long term substantive outcomes such as neurodevelopment. There is a lack of data on maternal psychological effects. AUTHORS' CONCLUSIONS: Based on existing evidence, routine late pregnancy ultrasound in low risk or unselected populations does not confer benefit on mother or baby. There is a lack of data about the potential psychological effects of routine ultrasound in late pregnancy, and the effects on both short and long term neonatal and childhood outcome. Placental grading in the third trimester may be valuable, but whether reported results are reproducible remains to be seen, and future research of late pregnancy ultrasound should include evaluation of placental textural assessment.

Fetal electrocardiogram (ECG) for fetal monitoring during labour.

BACKGROUND: Hypoxaemia during labour can alter the shape of the fetal electrocardiogram (ECG) waveform, notably the relation of the PR to RR intervals, and elevation or depression of the ST segment. Technical systems have therefore been developed to monitor the fetal ECG during labour as an adjunct to continuous electronic fetal heart rate monitoring with the aim of improving fetal outcome and minimising unnecessary obstetric interference. OBJECTIVES: To compare the effects of analysis of fetal ECG waveforms during labour with alternative methods of fetal monitoring. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2006). SELECTION CRITERIA: Randomised trials comparing fetal ECG waveform analysis with alternative methods of fetal monitoring during labour. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were performed by the review author, without blinding. MAIN RESULTS: Four trials including a total of 9829 women were included. In comparison to continuous electronic fetal heart rate monitoring alone, the use of adjunctive ST waveform analysis (three trials, 8872 women) was associated with fewer babies with severe metabolic acidosis at birth (cord pH less than 7.05 and base deficit greater than 12 mmol/L) (relative risk (RR) 0.64, 95% confidence interval (CI) 0.41 to 1.00, data from 8108 babies), fewer babies with neonatal encephalopathy (three trials, RR 0.33, 95% CI 0.11 to 0.95) although the absolute number of babies with encephalopathy was low (n = 17), fewer fetal scalp samples during labour (three trials, RR 0.76, 95% CI 0.67 to 0.86) and fewer operative vaginal deliveries (three trials, RR 0.87, 95% CI 0.78 to 0.96). There was no statistically significant difference in caesarean section (three trials, RR 0.97, 95% CI 0.84 to 1.11), Apgar score less than seven at five minutes (three trials, RR 0.80, 95% CI 0.56 to 1.14), or admissions to special care unit (three trials, RR 0.90, 95% CI 0.75 to 1.08). Apart from a trend towards fewer operative deliveries (one trial, RR 0.87, 95% CI 0.76 to 1.01), there was little evidence that monitoring by PR interval analysis conveyed any benefit. AUTHORS' CONCLUSIONS: These findings provide some support for the use of fetal ST waveform analysis when a decision has been made to undertake continuous electronic fetal heart rate monitoring during labour. However, the advantages need to be considered along with the disadvantages of needing to use an internal scalp electrode, after membrane rupture, for ECG waveform recordings.

Medical treatment for early fetal death (less than 24 weeks).

BACKGROUND: In most pregnancies that miscarry, arrest of embryonic or fetal development occurs some time (often weeks) before the miscarriage occurs. Ultrasound examination can reveal abnormal findings during this phase by demonstrating anembryonic pregnancies or embryonic or fetal death. Treatment before 14 weeks has traditionally been surgical but medical treatments may be effective, safe, and acceptable, as may be waiting for spontaneous miscarriage. OBJECTIVES: To assess the effectiveness, safety and acceptability of any medical treatment for early pregnancy failure (anembryonic pregnancies or embryonic and fetal deaths before 24 weeks). SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group Trials Register (30 November 2005). SELECTION CRITERIA: Randomised trials comparing medical treatment with another treatment (e.g. surgical evacuation), or placebo, or no treatment for early pregnancy failure. Quasi-random studies were excluded. DATA COLLECTION AND ANALYSIS: Data were extracted unblinded. MAIN RESULTS: Twenty four studies (1888 women) were included. Vaginal misoprostol hastens miscarriage (complete or incomplete) when compared with placebo: e.g. miscarriage less than 24 hours (two trials, 138 women, relative risk (RR) 4.73, 95% confidence interval (CI) 2.70 to 8.28), with less need for uterine curettage (two trials, 104 women, RR 0.40, 95% CI 0.26 to 0.60) and no significant increase in nausea or diarrhoea. Lower-dose regimens of vaginal misoprostol tend to be less effective in producing miscarriage (three trials, 247 women, RR 0.85, 95% CI 0.72 to 1.00) with similar incidence of nausea. There seems no clear advantage to administering a 'wet' preparation of vaginal misoprostol or of adding methotrexate, or of using laminaria tents after 14 weeks. Vaginal misoprostol is more effective than vaginal prostaglandin E in avoiding surgical evacuation. Oral misoprostol was less effective than vaginal misoprostol in producing complete miscarriage (two trials, 218 women, RR 0.90, 95% CI 0.82 to 0.99). Sublingual misoprostol had equivalent efficacy to vaginal misoprostol in inducing complete miscarriage but was associated with more frequent diarrhoea. The two trials of mifepristone treatment generated conflicting results. There was no statistically significant difference between vaginal misoprostol and gemeprost in the induction of miscarriage for fetal death after 13 weeks. AUTHORS' CONCLUSIONS: Available evidence from randomised trials supports the use of vaginal misoprostol as a medical treatment to terminate non-viable pregnancies before 24 weeks. Further research is required to assess effectiveness and safety, optimal route of administration and dose. Conflicting findings about the value of mifepristone need to be resolved by additional study.

Caesarean section for non-medical reasons at term.

BACKGROUND: Caesarean section rates are progressively rising in many parts of the world. One suggested reason is increasing requests by women for caesarean section in the absence of clear medical indications, such as placenta praevia, HIV infection, contracted pelvis and, arguably, breech presentation or previous caesarean section. The reported benefits of planned caesarean section include greater safety for the baby, less pelvic floor trauma for the mother, avoidance of labour pain and convenience. The potential disadvantages, from observational studies, include increased risk of major morbidity or mortality for the mother, adverse psychological sequelae, and problems in subsequent pregnancies, including uterine scar rupture and greater risk of stillbirth and neonatal morbidity. An unbiased assessment of advantages and disadvantages would assist discussion of what has become a contentious issue in modern obstetrics. OBJECTIVES: To assess, from randomised trials, the effects on perinatal and maternal morbidity and mortality, and on maternal psychological morbidity, of planned caesarean delivery versus planned vaginal birth in women with no clear clinical indication for caesarean section. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (December 2005), MEDLINE (1974 to April 2005), EMBASE (1974 to April 2005), CINAHL (1982 to April 2005) and PsycINFO (1887 to April 2005). We also performed a manual search of the references of all retrieved articles, sought unpublished papers and abstracts submitted to international conferences and contacted expert informants. SELECTION CRITERIA: All comparisons of intention to perform caesarean section and intention for women to give birth vaginally; random allocation to treatment and control groups; adequate allocation concealment; women at term with single fetuses with cephalic presentations and no clear medical indication for caesarean section. DATA COLLECTION AND ANALYSIS: We identified no studies that met the inclusion criteria. MAIN RESULTS: There were no included trials. AUTHORS' CONCLUSIONS: There is no evidence from randomised controlled trials, upon which to base any practice recommendations regarding planned caesarean section for non-medical reasons at term. In the absence of trial data, there is an urgent need for a systematic review of observational studies and a synthesis of qualitative data to better assess the short- and long-term effects of caesarean section and vaginal birth.

Placental regulation of insulin-like growth factor axis in monochorionic twins with chronic twin-twin transfusion syndrome.

To test the hypothesis that severe growth restriction (intrauterine growth retardation) in donor twins with chronic twin-twin transfusion syndrome (TTTS), a common complication of monochorionic twin pregnancy, is due to an aberration in the insulin-like growth factor (IGF) axis, we studied 25 sets of monochorionic twins with (n = 13) and without (n = 12) TTTS. Maternal and cord blood samples were collected at birth and analyzed for IGF-I, IGF-II, IGF-binding protein-1 (IGFBP-1), and IGFBP-1 phosphorylation status. Fetal IGF-II levels in the recipient twins with TTTS were higher than those in the donor twins (829 +/- 45 vs. 543 +/- 60 ng/mL; P < 0.001), but were comparable with those in the non-TTTS twin pairs. IGF-I levels in recipient and donor twin pairs were similar. The total IGFBP-1 concentration was higher in the donor twins than in the recipients (1153 +/- 296 vs. 419 +/- 108 ng/mL; P < 0.001) and non-TTTS twin pairs (P < 0.01). The percent less phosphorylated IGFBP-1 was higher in the recipients than in the donor twins (P < 0.05). There were no differences in IGF-I, IGF-II, and IGFBP-1 levels between non-TTTS twin pairs. Maternal levels of IGFs were comparable in the two groups. In the TTTS group, fetal birth weight gave a positive correlation with serum IGF-II levels (y = 0.25x + 361.1; r = 0.47; P < 0.05), and a negative association with IGFBP-1 levels (y = -0.72x + 1593.6; r = 0.58; P < 0.01). Our data argue against intertwin transfusion as the cause of intrauterine growth retardation in the donor twin and provide evidence that the placenta is the key regulator of the fetal IGF axis, especially when fetal genotype and maternal environments are similar.

Fetal growth retardation and second trimester maternal serum human chorionic gonadotrophin levels.

Second trimester maternal serum human chorionic gonadotrophin (hCG) levels in women who remained normotensive but delivered an unexplained growth retarded infant were compared with those from a control group and a group of women who developed pre-eclampsia in a retrospective observational study. Our hypothesis was that the similar placental pathological changes shared by unexplained normotensive IUGR and pre-eclampsia would be reflected by elevated maternal serum hCG levels in the second trimester. Normotensive women delivering unexplained singleton growth retarded infants were identified (n=43) and their second trimester hCG levels, taken as part of antenatal screening for Down's syndrome, were obtained. These were compared with a control group of 625 women, and a group of 48 women who subsequently developed pre-eclampsia. There was no significant difference in the hCG levels expressed as multiples of the median (MOM) between the women who delivered growth retarded fetuses (median MOM 0.96) and the control group (median MOM 0.97). The levels of hCG in the women who subsequently developed pre-eclampsia were significantly higher (median MOM 1.3, P=0.008). There were no significant differences in AFP levels in the three groups; however, the trend was towards a higher level of AFP in the fetal growth retardation group. Maternal serum hCG in the second trimester does not appear to be elevated in normotensive women who later produce a growth retarded fetus, although human chorionic gonadotrophin levels are significantly higher in women who subsequently develop pre-eclampsia.

The Neu-Laxova syndrome in female sibs: clinical and pathological features with prenatal diagnosis in the second sib.

We report on affected sisters with the Neu-Laxova syndrome. Prenatal diagnosis of the condition was achieved by serial ultrasound examinations which demonstrated abnormal fetal growth in the second affected fetus before 24 weeks gestation.

Interleukin-6, interferon-gamma, interleukin-8, and granulocyte-macrophage colony stimulating factor levels in human amniotic fluid at term.

Cytokines contribute to the maintenance of successful pregnancy and have also been implicated in the initiation of labour. This study has examined those cytokines which may be involved in normal term parturition. IL-6, IFN-gamma, IL-8 and GM-CSF levels were measured by ELISA in samples of amniotic fluid, peripheral and uterine venous blood plasma, and umbilical artery blood plasma from non-labouring women undergoing elective caesarean section at term and from women in spontaneous labour. IFN-gamma and IL-6 were detected only in amniotic fluid and not in blood plasma samples, unlike IL-8 which was found in all amniotic fluid and plasma samples from both labouring and non-labouring women; GM-CSF was undetectable in all samples examined. Levels of IL-6 were significantly raised in the amniotic fluid of women in labour compared with the control group (P = 0.008). IFN-gamma was detected in the amniotic fluid of both labouring women and the control group, and there was also a significant correlation (P = 0.003) between IFN-gamma and IL-6 levels in individual amniotic fluid samples. The presence of both IFN-gamma and IL-8 in amniotic fluid, as well as IL-6, suggests these cytokines are involved in important immunobiological events relevant to the latter half of gestation.

Preterm labor in twin pregnancies: prediction by cervical assessment.

Patients attending a twin pregnancy antenatal clinic underwent cervical palpation at each visit to calculate a cervical score by subtracting dilatation from length. Prediction of the onset of labor by cervical assessment was studied in 223 already parous women with twin pregnancies who ultimately labored spontaneously. The lower the score, the shorter was the mean time until delivery, although there existed a subgroup of patients who had ripe cervices for several weeks before the onset of labor. The cervical score itself appeared to give better prediction of labor than did changes in the score. Cervical assessment identified a group of twin pregnancies at especially high risk of preterm labor, in that 76% of patients with a score of -2 or less at or before 34 weeks delivered preterm. There was no evidence that labor was precipitated by vaginal examination, although this requires further study.

Prediction of the small for gestational age twin fetus by Doppler umbilical artery waveform analysis.

In 89 consecutive twin pregnancies, monthly Doppler ultrasound measurements were made of the umbilical artery blood flow velocity waveforms of each fetus. In total, 453 Doppler studies were performed. Of the 178 infants, 32 were small for gestational age (SGA); only 24 of the 82 SGA Doppler studies were abnormal, giving an overall sensitivity of the test in the prediction of the SGA fetus of 29% and a positive predictive value of 34%. Furthermore, neither the sensitivities nor the positive predictive values were above 50% in any of the gestational-age intervals individually studied. We conclude that Doppler study of umbilical artery flow velocities is not of much value in the prediction of SGA infants in twin pregnancies, although persistently absent end-diastolic velocities were associated with poor outcome.

Spiral artery blood flow in the central and peripheral areas of the placental bed in the second trimester.

OBJECTIVE: To assess impedance to blood flow through spiral arteries in the central and peripheral areas of the placental bed, to determine if in vivo findings are in concordance with histologic observations of cytotrophoblast invasion. METHODS: This study was cross-sectional, using transabdominal color flow and pulsed Doppler imaging in 64 women with normal, singleton pregnancies at 17-20 weeks' gestation. Spiral arteries were visualized by color Doppler in the central and peripheral parts of the placental bed, and blood flow was analyzed using pulsed Doppler to calculate the resistance index (RI) and the pulsatility index (PI). RESULTS: Visualization of flow in the spiral arteries was achieved in 100% of cases in the central area and in 95% in the periphery. Both the RI and PI were significantly lower in the center compared with the periphery (P < .001). There was no significant difference in the peak systolic velocities between the two areas. Regression analysis showed no significant difference in RI or PI at the different weeks of gestation in the central and peripheral areas of the placental bed. CONCLUSION: Impedance to blood flow through spiral arteries in the second trimester is lower in the central area of the placental bed, and is in agreement with previous histologic data. Physiologic change of the spiral arteries is functionally complete around 17 weeks' gestation.

The relationship between asymptomatic human immunodeficiency virus infection and the prevalence and severity of anemia in pregnant Malawian women.

The relationship between asymptomatic human immunodeficiency virus (HIV) infection and blood hemoglobin (Hb) concentration was examined in anemic pregnant women from a population with high prevalence of both anemia (60%) and HIV seropositivity (30%). Sera from 155 pregnant women with Hb levels < 10.5 g/dL were tested for HIV status, C-reactive protein (CRP), vitamin B12, retinol, and folate levels. The observed prevalence of HIV seropositivity in the group of women with anemia was 47.1% (95% confidence interval=39.2-55.0%). This is significantly higher than the HIV prevalence in the whole population (30.1%; P < 0.001). Median Hb values in HIV-seropositive and -seronegative women with anemia were 8.40 g/dL and 8.95 g/dL, respectively. Serum retinol, vitamin B12, and folate levels were not significantly different in the HIV-seropositive and -seronegative groups. In women who were HIV-seropositive with normal levels of CRP, a median decrease in Hb of 0.4 g/dL was observed. For those with serum CRP levels > 25 mg/l, the median decrease in Hb was 0.7 g/dL. Results indicate that asymptomatic HIV infection is associated with increased prevalence and severity of anemia in pregnancy in this population.

Biochemical tests of placental function for assessment in pregnancy.

BACKGROUND: Biochemical tests of placental or feto-placental function were widely used in the 1960s and 1970s in high-risk pregnancies to try to predict, and thus try to avoid, adverse fetal outcome. OBJECTIVES: To assess the effects of performing biochemical tests of placental function in high-risk, low-risk, or unselected pregnancies. SEARCH STRATEGY: Comprehensive electronic search of the Cochrane Pregnancy and Childbirth Group trials register (February 2003). SELECTION CRITERIA: Controlled trials (randomized or 'quasi-randomized') that compare the use of biochemical tests of placental function in pregnancy with non-use. DATA COLLECTION AND ANALYSIS: Trial quality was assessed and data were extracted by the reviewer. MAIN RESULTS: A single eligible trial of poor quality was identified. It involved 622 women with high-risk pregnancies who had had plasma (o)estriol estimations. Women were allocated to have their (o)estriol results revealed or concealed on the basis of hospital record number (with attendant risk of selection bias). There were no obvious differences in perinatal mortality (relative risk (RR) 0.88, 95% confidence interval (CI) 0.36 to 2.13) or planned delivery (RR 0.97, 95% CI 0.81 to 1.15) between the two groups. REVIEWER'S CONCLUSIONS: The available trial data do not support the use of (o)estriol estimation in high-risk pregnancies. The single small trial available does not have the power to exclude a beneficial effect but this is probably of historical interest since biochemical testing has been superseded by biophysical testing in antepartum fetal assessment.

Fetal electrocardiogram (ECG) for fetal monitoring during labour.

BACKGROUND: Animal and human studies have shown that fetal hypoxaemia during labour can alter the shape of the fetal electrocardiogram (ECG) waveform, notably (1) the relation of the PR to RR intervals and (2) elevation or depression of the ST segment. Technical systems have therefore been developed to monitor the fetal ECG during labour as an adjunct to continuous electronic fetal heart rate monitoring with the aim of improving fetal outcome and minimising unnecessary obstetric interference. OBJECTIVES: To compare the effects of analysis of fetal ECG waveforms during labour with alternative methods of fetal monitoring. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register was searched (September 2002). SELECTION CRITERIA: Randomised trials comparing fetal ECG waveform analysis with alternative methods of fetal monitoring during labour. DATA COLLECTION AND ANALYSIS: Trial quality assessment and data extraction were performed by the reviewer, without blinding. MAIN RESULTS: Three trials including a total of 8357 pregnant women were included. The trials were of sound methodological quality. All three trials assessed the use of the fetal ECG as an adjunct to continuous electronic fetal heart rate monitoring during labour. One study assessed PR intervals; two assessed the ST segment. The use of ST waveform analysis (7400 women) was associated with fewer babies with severe metabolic acidosis at birth (cord pH less than 7.05 and base deficit greater than 12 mmol/L) (relative risk (RR) 0.44, 95% confidence interval (CI) 0.26 to 0.75, data from 6672 babies). This was achieved along with fewer fetal scalp samples during labour (RR 0.86, 95% CI 0.76 to 0.98) and fewer operative deliveries (RR 0.89, 95% CI 0.82 to 0.97). Apart from a trend (that did not achieve statistical significance) towards fewer operative deliveries (RR 0.87, 95% CI 0.76 to 1.01), there was little evidence that monitoring by PR interval analysis conveyed any benefit. This may reflect limitations of the technique or, alternatively, the smaller numbers available for analysis from the single trial (957 women). REVIEWER'S CONCLUSIONS: These findings support the use of fetal ST waveform analysis when a decision has been made to undertake continuous electronic fetal heart rate monitoring during labour. However, in most labours, technically satisfactory cardiotocographic traces can be obtained by external ultrasound monitors which are less invasive than internal scalp electrodes (which are required for electrocardiographic (ECG) analysis). A better approach might be to restrict fetal ST waveform analysis to those fetuses demonstrating disquieting features on cardiotocography.

Interventions for suspected placenta praevia.

BACKGROUND: Because placenta praevia is implanted unusually low in the uterus, it may cause major, and/or repeated, antepartum haemorrhage. The traditional policy of care of women with symptomatic placenta praevia includes prolonged stay in hospital and delivery by caesarean section. OBJECTIVES: To assess the impact of any clinical intervention applied specifically because of a perceived likelihood that a pregnant woman might have placenta praevia. SEARCH STRATEGY: A comprehensive electronic search was performed to identify relevant literature. Searched databases included the Trials Register maintained by the Cochrane Pregnancy and Childbirth Group (August 2002), and the Cochrane Controlled Trials Register (The Cochrane Library, Issue 2, 2002). SELECTION CRITERIA: Any controlled clinical trial that has assessed the impact of an intervention in women diagnosed as having, or being likely to have, placenta praevia. DATA COLLECTION AND ANALYSIS: Data were extracted, unblinded, by the author without consideration of results. MAIN RESULTS: Three trials were included, involving a total of 114 women. Both tested interventions (home versus hospitalisation and cervical cerclage versus no cerclage) were associated with reduced lengths of stay in hospital antenatally: weighted mean difference (WMD) respectively -18.50 days (95% confidence interval (CI) -26.83 to -10.17), -4.80 days (95% CI -6.37 to -3.23). Otherwise, there was little evidence of any clear advantage or disadvantage to a policy of home versus hospital care. The one woman who had a haemorrhage severe enough to require immediate transfusion and delivery was in the home care group. Cervical cerclage may reduce the risk of delivery before 34 weeks: relative risk (RR) 0.45 (95% CI 0.23 to 0.87), or the birth of a baby weighing less than two kilograms RR 0.34 (0.14 to 0.83) or having a low five minute Apgar score RR 0.19 (0.04 to 1.00). In general, these possible benefits were more evident in the trial of lower methodological quality. REVIEWER'S CONCLUSIONS: There are insufficient data from trials to recommend any change in clinical practice. Available data should, however, encourage further work to address the safety of more conservative policies of hospitalisation for women with suspected placenta praevia, and the possible value of insertion of a cervical suture.