Antenatal screening for Down's syndrome.
Explore the source record for details and available documents.
Biomarkers↗
Biomedical subjects
Zarko Alfirevic
Publications and source records attributed to Zarko Alfirevic.
The impact of delivery suite guidelines on intrapartum care in 'standard primigravida'.
OBJECTIVE: To compare intrapartum interventions and outcomes in low-risk primiparous women and identify factors which may contribute to the variations between different maternity units. DESIGN: Prospective observational study. PARTICIPANTS: Ten maternity units in England. METHODS: Participating units provided data on 11 clinical indicators for all 'standard primigravidae' delivered between January and December 2000 and provided information on written delivery suite policies operational during July 2000. RESULTS: There was a significant inter-unit variation in the use of intrapartum foetal blood sampling, use of syntocinon for augmentation of labour, mode of delivery, type of perineal damage, postpartum haemorrhage, low Apgar score and admission to SCBU. Units with guidelines for intrapartum foetal heart monitoring had higher rate of normal vaginal deliveries (odds ratio (OR): 1.34; 99% confidence interval (CI): 1.05-1.70) and lower rate of Caesarean section for foetal distress (OR: 0.57; 99% CI: 0.34-0.96). Units with partogram guidelines also had lower rates of Caesarean section for foetal distress (OR: 0.49; 99% CI: 0.30-0.81). Units with guidelines on the management of episiotomy had higher episiotomy rates (OR: 1.54; 99% CI: 1.15-2.06) while units with guidelines on the involvement of neonatal staff recorded less babies with Apgar score <7 at 5 min (OR: 0.37; 99% CI: 0.17-0.76). CONCLUSIONS: Written delivery suite guidelines have significant impact on the type of intrapartum care and outcome of pregnancy in low-risk women. Their availability suggests more active role of interested clinicians in the provision of intrapartum care. There is an urgent need to identify other factors that influence quality and quantity of clinical input into the care of low-risk pregnant women.
Apgar Score↗
Cervical cerclage for prevention of preterm delivery in women with short cervix: randomised controlled trial.
BACKGROUND: Cervical cerclage has been widely used in the past 50 years to prevent early preterm birth and its associated neonatal mortality and morbidity. Results of randomised trials have not generally lent support to this practice, but this absence of benefit may be due to suboptimum patient selection, which was essentially based on obstetric history. A more effective way of identifying the high-risk group for early preterm delivery might be by transvaginal sonographic measurement of cervical length. We undertook a multicentre randomised controlled trial to investigate whether, in women with a short cervix identified by routine transvaginal scanning at 22-24 weeks' gestation, the insertion of a Shirodkar suture reduces early preterm delivery. METHODS: Cervical length was measured in 47?123 women. The cervix was 15 mm or less in 470, and 253 (54%) of these women participated in the study and were randomised to cervical cerclage (127) or to expectant management (126). Primary outcome was the frequency of delivery before 33 completed weeks (231 days) of pregnancy. FINDINGS: The proportion of preterm delivery before 33 weeks was similar in both groups, 22% (28 of 127) in the cerclage group versus 26% (33 of 126) in the control group (relative risk=0.84, 95% CI 0.54-1.31, p=0.44), with no significant differences in perinatal or maternal morbidity or mortality. INTERPRETATION: The insertion of a Shirodkar suture in women with a short cervix does not substantially reduce the risk of early preterm delivery. Routine sonographic measurement of cervical length at 22-24 weeks identifies a group at high risk of early preterm birth.
Adult↗
Thrombin activatable fibrinolysis inhibitor and its fibrinolytic effect in normal pregnancy.
We investigated changes in both thrombin activatable fibrinolysis inhibitor (TAFI) antigen levels and its functional effect on in vitro fibrinolysis in normal pregnancy. 152 pregnant women and 31 women in the immediate postpartum period were studied, with pregnancy divided into 6 windows at 4 weekly intervals. As TAFI influences and is in turn influenced by components of the protein C (PC) pathway, its measurements were correlated with levels of soluble thrombomodulin, PC, protein S (PS) and the overall phenotype of activated PC resistance (APCR). Compared with mean TAFI levels at booking gestation (6.6 +/- 1.2 microg/ml), levels peaked at 35-39 weeks gestation (9.6 +/- 2 microg/ml, p = 0.001), followed by a significant drop within 24 hours of delivery (7.2 +/- 1.1 microg/ml). In functional terms, the mean clot lysis time (CLT) (101 +/- 13 min at booking) also peaked at 35-39 weeks gestation (141 +/- 42 min, p = 0.007) and dropped after delivery (99 +/- 33 min), and was significantly correlated with gestational age (r = 0.410, p = 0.001) and could be abrogated in the presence of an inhibitor to TAFI activation. A significant negative correlation was found between TAFI levels and APCR (r = -0.478, p <0.001), APCRV (r = -0.598; p <0.001), PS (r = -0.490, P <0.001) and PC (r = -0.198, p = 0.02). In summary, there is a significant increase in TAFI levels, which translates into increased CLT during pregnancy. Furthermore, changes in TAFI contribute to the increasing APCR of pregnancy.
Activated Protein C Resistance↗
The influence of needle and syringe size on chorionic villus sampling of term placentae: a randomised trial.
OBJECTIVE: To determine the effect of needle and syringe size on the amount of tissue obtained at chorionic villus sampling METHODS: Two needle sizes, 18 and 20 gauge, and two syringe sizes 5 mL and 20 mL, were used to assess samples from term post-partum placentae. Each of the four combinations was tested by 25 aspirations. The placentae were divided into 100 grid spaces and each grid space was randomly allocated to a needle/syringe combination. The resulting samples were cleaned to separate the chorionic villi (CV), centrifuged and then weighed. RESULTS: Significantly more tissue was obtained with an 18-g needle compared with a smaller 20-g needle (median weight difference 1.5 mg, 95% CI 0.8-2.3 mg). More tissue was also obtained with the larger 20-mL syringe though the impact of the syringe size was less than that of the needle size (median difference 0.8 mg, 95% CI 0-1.6). CONCLUSION: A larger syringe and needle size yields a larger quantity of chorionic villi from the post-partum term placenta.
Chorionic Villi Sampling↗
Cervical cerclage for prevention of preterm delivery: meta-analysis of randomized trials.
OBJECTIVE: To estimate the effectiveness of prophylactic and therapeutic cerclage by meta-analysis of randomized clinical trials. DATA SOURCES: We searched the Cochrane Pregnancy and Childbirth Group specialized register of clinical trials (May 2002). Congress proceedings of international society meetings of fetal-maternal and reproductive medicine were searched by hand. METHODS OF STUDY SELECTION: Meta-analysis of randomized clinical trials comparing cervical cerclage with expectant management during pregnancy was performed. Further clarification was sought from trial authors when required. TABULATION, INTEGRATION, AND RESULTS: Six trials describing a total of 2175 women were analyzed. Prophylactic cerclage was compared with no cerclage in four trials. Pooled results failed to show a statistically significant reduction in pregnancy loss and preterm delivery rates, although a small reduction in births less than 33 weeks' gestation was seen in the largest trial (relative risk [RR] 0.75; 95% confidence interval [CI] 0.58 to 0.98). Cervical cerclage was associated with mild pyrexia, increased use of tocolytic therapy, and hospital admission but no serious morbidity. Two trials examined the role of therapeutic cerclage when ultrasound examination revealed a short cervix. Pooled results failed to show a reduction in total pregnancy loss, early pregnancy loss, or preterm delivery before 28 and 34 weeks in women assigned to cervical cerclage. CONCLUSION: The effectiveness of prophylactic cerclage in preventing preterm delivery in women at low or medium risk for second-trimester pregnancy loss has not been proven. The role of cerclage in women whose ultrasound reveals short cervix remains uncertain.
Adult↗
Impact of rising caesarean rate on stillbirths in Merseyside.
Explore the source record for details and available documents.
Cesarean Section↗
Management of unscarred ruptured uterus.
AIMS AND OBJECTIVES: Rupture of an unscarred gravid uterus is a rare and dangerous event. We carried out a postal questionnaire survey of the Fellows of the Royal College of Obstetricians and Gynaecologists (United Kingdom), to ascertain the past and present management policies in such an event. 210 Fellows responded (43.5%) and 85 of them managed at least one case of uterine rupture in previously unscarred gravid uterus. RESULTS: A total of 108 cases were reported of which 74 (68.5%) were diagnosed during labor. The tear was repaired and the uterus conserved in 56.5% cases. Maternal mortality was 10.2% (95% CI 5.2, 17.5) and perinatal mortality was 34.3% (95% CI 25.4, 44). When asked how they would manage such a case in the absence of life threatening circumstances in future, 80.8% of Fellows would opt for uterine repair. Fellows with previous hands-on experience of uterine rupture would involve urologists more often in operative management (22% v 8%, OR 3.4, 95% CI 1.2, 10.1). 48% of Fellows felt that in-patient management is indicated in subsequent pregnancies and 91% would perform an elective cesarean section in subsequent pregnancy.
Female↗
Differences in episiotomy technique between midwives and doctors.
OBJECTIVES: To examine the practice of making an episiotomy and to determine any differences in practice between professional groups. DESIGN: A prospective survey. SETTING: A large tertiary referral obstetric hospital and the obstetric department of a district general hospital. POPULATION: All staff routinely involved in the care of women in labour. METHODS: A novel validated pictorial questionnaire was designed, validated and distributed to the study population. Differences in outcome measures were compared by profession and by seniority. MAIN OUTCOME MEASURES: Measurements taken from the questionnaire: the length of episiotomy drawn; the distance from the sagittal plane at which the episiotomy was begun; and the angle of the episiotomy from the sagittal plane. RESULTS: Fifty doctors and 78 midwives completed the forms. Median distance of the episiotomy from the midline was 0 mm (-2 to 11). Episiotomies drawn by doctors were significantly longer and more angled than those drawn by midwives (P = 0.002 and P = 0.001). Sixteen percent of doctors and 1% of midwives drew an episiotomy longer than 20 mm (difference 15%, 95% CI 6 to 24). Twenty-three percent of midwives and 2% of doctors drew an episiotomy angled 30 degrees or less (difference 21%, 95% CI 9 to 34). CONCLUSIONS: This study has demonstrated differences in the reporting of episiotomy practice by doctors and midwives. Theoretically, the differences demonstrated could predispose to a greater risk of anal sphincter injuries. These data need to be confirmed by observational studies of actual practice and by studies to investigate the mechanics of sphincter injury during childbirth.
Episiotomy↗
How strong is the association between maternal thrombophilia and adverse pregnancy outcome? A systematic review.
OBJECTIVE: To determine whether inherited and acquired thrombophilias are associated with adverse obstetric complications. STUDY DESIGN: A systematic review; studies where women with adverse obstetric complications were tested for one or more acquired and inherited thrombophilias were included. MAIN OUTCOME MEASURES: Prevalence of thrombophilia in women with severe pre-eclampsia/eclampsia, severe placental abruption, intrauterine growth restriction or unexplained stillbirth. RESULTS: Compared with controls, placental abruption was more often associated with homozygous and heterozygous factor V Leiden mutation, heterozygous G20210A prothrombin gene mutation, homocysteinaemia, activated protein C resistance or anticardiolipin IgG antibodies. Women with pre-eclampsia/eclampsia were more likely to have heterozygous factor V Leiden mutation, heterozygous G20210A prothrombin gene mutation, homozygous MTHFR C677T mutation, protein C deficiency, protein S deficiency or activated protein C resistance compared with controls. Unexplained stillbirth, when compared with controls, was more often associated with heterozygous factor V Leiden mutation, protein S deficiency, activated protein C resistance, anticardiolipin IgG antibodies or lupus anticoagulant. Women with intrauterine growth restriction had a higher prevalence of heterozygous G20210A prothrombin gene mutation, homozygous MTHFR C677T gene mutation, protein S deficiency or anticardiolipin IgG antibodies than controls. There was wide heterogeneity in the prevalence of thrombophilia between the studies. CONCLUSIONS: Women with adverse pregnancy outcome are more likely to have a positive thrombophilia screen but studies published so far are too small to adequately assess the true size of this association. Screening for thrombophilia should not become standard practice until clear evidence emerges that thromboprophylaxis during pregnancy improves perinatal outcome. Further research into the link between the observed association, causality and heterogeneity is required.
Abruptio Placentae↗
Major postpartum hemorrhage: survey of maternity units in the United Kingdom.
BACKGROUND: To determine current clinical practice among different maternity units in the United Kingdom for the management of major postpartum hemorrhage. METHODS: A postal questionnaire was sent to 258 maternity units in the UK. It was developed to identify the definition of major postpartum hemorrhage, and to identify the medical and surgical interventions used for postpartum hemorrhage, as considered by each unit, and the type and use of thromboprophylaxis following surgery for major hemorrhage after delivery. RESULTS: A total of 212 (82%) returned the questionnaire, but 13 units indicated that the questionnaire was not applicable to them, leaving 199 (82%) for analysis. There was a lack of agreement between the different units regarding the definition and interventions for major postpartum hemorrhage. The majority of the units use oxytocin, ergometrine and carboprost as a 'first-line' for the treatment of postpartum hemorrhage. Hysterectomy was the most common surgical procedure (89% of units had performed at least one hysterectomy for major hemorrhage in the last 5 years). There was a lack of agreement regarding the use and choice of thromboprophylaxis following surgery for major hemorrhage. CONCLUSIONS: Current management of major postpartum hemorrhage varies considerably. There is an urgent need to identify protocols that will reduce the need for hysterectomy in women with major hemorrhage who are unresponsive to conventional medical therapy.
Adult↗