UK Obstetric Surveillance System Research Articles

Planning for a cohort study to investigate the impact and management of influenza in pregnancy in a future pandemic

BackgroundEvidence from the 2009 A/H1N1 influenza pandemic demonstrated that pregnant women are particularly vulnerable to infection and at an increased risk of death. Active data collection through the UK Obstetric Surveillance System (UKOSS) about women admitted to hospital during the 2009 A/H1N1 pandemic was used to inform ongoing clinical guidance regarding the use of antiviral treatment for pregnant women and demonstrated that, in addition to an increased risk of maternal morbidity, influenza infection in pregnancy is associated with poor perinatal outcomes, including an increased risk of stillbirth and preterm birth. This evidence influenced the decision to offer routine influenza immunisation to pregnant women. Even in a non-epidemic period, pregnant women continue to die from influenza.ObjectiveTo establish, and then to put into hibernation, the study mechanisms needed to mount a rapid investigation of the impact of pandemic influenza in pregnancy in the event of a newly emerging pandemic strain.DesignA new UKOSS cohort study was designed, based on the 2009–10 study, and following consultation with the Pandemic Flu Planning Group at the Royal College of Obstetricians and Gynaecologists and the UKOSS Steering Committee, to identify potential previously unanswered questions.SettingUK maternity units.ParticipantsAll pregnant women admitted to hospital with influenza in a future pandemic.Main outcome measuresManagement of pregnant women with influenza infection, intervention rates, treatment and pregnancy outcome for both the mother and fetus.ResultsThe study was designed and approved by the UKOSS Steering Committee and then placed into hibernation for activation in the event of an influenza pandemic.ConclusionsPregnant women, as a result of their changed immunological status, appear to be particularly susceptible to infection, including from influenza. The existence of the UKOSS enabled us to rapidly mount a study of pregnant women who were hospitalised with 2009 A/H1N1 influenza. Minor modifications to incorporate previously unanswered questions and our previous study enabled us to design, and then put into hibernation, a new study ready to investigate the impact and management of influenza in pregnancy, which is poised for activation in the event of a newly emerging pandemic strain. This will enable real-time data to be available on which to base rapid changes in clinical management as the as-yet-unforeseen pandemic unfolds. In the event of an influenza pandemic the study will be available to be immediately activated following expedited regulatory approvals.Trial registrationCurrent Controlled Trials ISRCTN44137563.FundingThe National Institute for Health Research Health Services and Delivery Research programme.

Incidence, risk factors, management and outcomes of amniotic-fluid embolism: a population-based cohort and nested case-control study.

To describe the incidence, risk factors, management and outcomes of amniotic-fluid embolism (AFE) over time. A population-based cohort and nested case-control study using the UK Obstetric Surveillance System (UKOSS). All UK hospitals with obstetrician-led maternity units. All women diagnosed with AFE in the UK between February 2005 and January 2014 (n=120) and 3839 control women. Prospective case and control identification through UKOSS monthly mailing. Amniotic-fluid embolism, maternal death or permanent neurological injury. The total and fatal incidence of AFE, estimated as 1.7 and 0.3 per 100000, respectively, showed no significant temporal trend over the study period and there was no notable temporal change in risk factors for AFE. Twenty-three women died (case fatality 19%) and seven (7%) of the surviving women had permanent neurological injury. Women who died or had permanent neurological injury were more likely to present with cardiac arrest (83% versus 33%, P<0.001), be from ethnic-minority groups (adjusted odds ratio [OR] 2.85, 95% confidence interval [95% CI] 1.02-8.00), have had a hysterectomy (unadjusted OR 2.49, 95% CI 1.02-6.06), had a shorter time interval between the AFE event and when the hysterectomy was performed (median interval 77minutes versus 248minutes, P=0.0315), and were less likely to receive cryoprecipitate (unadjusted OR 0.30, 95% CI 0.11-0.80). There is no evidence of a temporal change in the incidence of or risk factors for AFE. Further investigation is needed to establish whether earlier treatments can reverse the cascade of deterioration leading to severe outcomes.

One size does not fit all. Management of the laparoscopic adjustable gastric band in pregnancy: a national prospective cohort study

BackgroundPregnancies are increasingly seen in women with a gastric band, but no guidance exists on band management during pregnancy. Although band inflation can prevent excessive gestational weight gain and its associated complications, it might have detrimental effects on fetal growth. We compared maternal and perinatal outcomes according to band management strategy—keeping the band inflated throughout pregnancy versus deflation. MethodsData were collected by means of the UK Obstetric Surveillance System (UKOSS) on all pregnancies in women with a laparoscopic adjustable gastric band, booking in UK maternity units (Nov 1, 2011, to Oct 31, 2012). Maternal and perinatal outcomes were compared according to band management strategy, with women in a control group who had not undergone the procedure and with national data. Multivariable regression analyses were used to adjust for potential confounders. Findings109 cases were reported (prevalence 1·7 per 10 000 maternities), of whom 42 underwent band deflation and 54 had inflation maintained (remainder unknown). Mean weight gain was higher with deflation than inflation (15·4 kg [95% CI 10·8–20·0] vs 7·6 [3·7–11·5], p=0·047). Some evidence of a higher risk of gestational hypertension with deflation than with inflation was noted (relative risk [RR] 6·86, p=0·07). There was strong evidence of a high risk of gestational hypertension with deflation compared with controls and national data (RR 4·74, p=0·001). Mean birth weight was significantly lower in the inflation group than in the deflation group (3380 g [95% CI 3255–3505] vs 3712 [3572–3851], p=0·002). Infants of women with deflation had a high risk of macrosomia compared with controls (adjusted RR 0·40, p=0·002) and national data (RR 2·04, p=0·01). InterpretationPregnant women with a laparoscopic adjustable gastric band are high risk; the monitoring of both fetal and maternal wellbeing is essential. Maintainance of band inflation during pregnancy reduces gestational weight gain and associated complications, but affects fetal growth. Therefore, maintainance of band inflation throughout pregnancy cannot be recommended. However, inflation for part of the pregnancy might improve some maternal outcomes. Further studies are needed to define the optimum timing of band adjustment. FundingBristol Bariatric Pregnancy Research Hub.

Maternal near-miss case reviews: the UK approach.

The UK has a well-established programme of Confidential Enquiries into Maternal Deaths and a national system for research into near-miss maternal morbidities, the UK Obstetric Surveillance System. The addition of a programme of near-miss case reviews, the Confidential Enquiries into Maternal Morbidity, permits a complete examination of the incidence, risk factors, care and outcomes of the severest complications in pregnancy, and enables the lessons learnt to improve future care to be identified more quickly. This in turn allows for more rapid inclusion of recommendations into national guidance and hence the potential of better health for both women and babies.

6.4 Transfusion management and haemostatic changes in major obstetric haemorrhage in the UK

Blood transfusion is fundamental to improving outcomes during major obstetric haemorrhage (MOH). Current guidelines recommend that fresh frozen plasma (FFP), cryoprecipitate and platelets are transfused when PT/APTT is >1.5 ×...

Managing cardiovascular disease during pregnancy: best practice to optimize outcomes.

Cardiac disease is the most common cause of death in pregnancy in the U.K. Optimal management requires an understanding of the physiological changes of the cardiovascular system during pregnancy, and their impact on existing or developing heart disease. Pregnancy itself is associated with the onset of cardiomyopathy, and a potential risk factor for ischemic heart disease and aortic dissection. Women with valvular disease and aortopathy require regular follow-up in specialized centers, and those requiring long-term anticoagulation face difficult challenges to balance maternal and fetal risks. In the UK, the Confidential Enquiries into maternal deaths and the UK Obstetric Surveillance system are examples of existing systems for identifying clinical risks and provide examples of potential improvements in care.

Hepatology highlights

Hepatology highlights

Association of severe intrahepatic cholestasis of pregnancy with adverse pregnancy outcomes: A prospective population‐based case‐control study

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease, characterized by maternal pruritus and raised serum bile acids. Our objectives were to describe the epidemiology and pregnancy complications associated with severe ICP and to test the hypothesis that adverse perinatal outcomes are increased in these women. A prospective population-based case-control study with national coverage was undertaken using the UK Obstetric Surveillance System (UKOSS). Control data for comparison were obtained from women with healthy pregnancy outcome through UKOSS (n = 2,232), St Mary’s Maternity Information System (n = 554,319), and Office for National Statistics (n = 668,195). The main outcome measures investigated were preterm delivery, stillbirth, and neonatal unit admission. In all, 713 confirmed cases of severe ICP were identified, giving an estimated incidence of 9.2 per 10,000 maternities. Women with severe ICP and a singleton pregnancy (n = 669) had increased risks of preterm delivery (164/664; 25% versus 144/2200; 6.5%; adjusted odds ratio [OR] 5.39, 95% confidence interval [CI] 4.17 to 6.98), neonatal unit admission (80/654; 12% versus 123/2192; 5.6%; adjusted OR 2.68, 95% CI 1.97 to 3.65), and stillbirth (10/664; 1.5% versus 11/2205; 0.5%; adjusted OR 2.58, 95% CI 1.03 to 6.49) compared to controls. Seven of 10 stillbirths in ICP cases were associated with coexisting pregnancy complications. These differences remained significant against national data. Risks of preterm delivery, meconium-stained amniotic fluid, and stillbirth rose with increasing maternal serum bile acid concentrations. Conclusion: In the largest prospective cohort study in severe ICP to date, we demonstrate significant increased risks of adverse perinatal outcomes, including stillbirth. Our findings support the case for close antenatal monitoring of pregnancies affected by severe ICP. (Hepatology 2014;59:1482-1491)

Pregnancy Outcomes in Liver and Cardiothoracic Transplant Recipients: A UK National Cohort Study

IntroductionThere are an increasing number of reports of pregnancy in transplant recipients but many questions remain regarding the effect of the transplant on pregnancy outcome, the pregnancy on the graft and the medication on the fetus. The majority of studies reporting outcomes in transplant recipients have focused on women with kidney transplants, and have included retrospective, voluntary registries or single centre studies.MethodsThe UK Obstetric Surveillance System (UKOSS) was used to prospectively identify all pregnant women with a liver or cardiothoracic transplant in the United Kingdom, between January 2007 and January 2012. Data were collected on demographics, transplant characteristics, immunosuppression regimens, antenatal care, maternal, graft and neonatal outcomes. In an exploratory analysis, we tested for associations between “poor fetal outcome” and medications used before or during pregnancy.Results and conclusionsWe report 62 pregnancies in 56 liver transplant recipients and 14 pregnancies in 14 cardiothoracic transplant recipients (including 10 heart, three lung and one heart-lung recipient). Liver transplant recipients, in comparison to cardiothoracic, had similar livebirth rates (92% vs. 87%) but better fetal outcomes (median gestational age 38 weeks vs. 35 weeks; median birthweight 2698 g vs. 2365 g), fewer caesarean deliveries (47% vs. 62%), fewer maternal intensive care (ICU) admissions (19% vs. 29%) and fewer neonatal ICU admissions (25% vs. 54%). Nine women (12%) were taking mycophenolate mofetil at conception, which was associated with adverse fetal outcomes. Pregnancy in transplant recipients may have successful outcomes, but complication rates are high, emphasising the role of pre-conception counselling and further research into the long-term effect on maternal and graft survival rates.

Serum bile acids in intrahepatic cholestasis of pregnancy: Not just a diagnostic test

Serum bile acids in intrahepatic cholestasis of pregnancy: Not just a diagnostic test

Editorial

Editorial

The management and outcomes of placenta accreta, increta, and percreta in the UK: a population‐based descriptive study

Objective To describe the management and outcomes of placenta accreta, increta, and percreta in the UK.Design A population-based descriptive study using the UK Obstetric Surveillance System (UKOSS).Setting All 221 UK hospitals with obstetrician-led maternity units.Population All women diagnosed with placenta accreta, increta, and percreta in the UK between May 2010 and April 2011.Methods Prospective case identification through the monthly mailing of UKOSS.Main outcome measures Median estimated blood loss, transfusion requirements.Results A cohort of 134 women were identified with placenta accreta, increta, or percreta: 50% (66/133) were suspected to have this condition antenatally. In women with a final diagnosis of placenta increta or percreta, antenatal diagnosis was associated with reduced levels of haemorrhage (median estimated blood loss 2750 versus 6100 ml, P = 0.008) and a reduced need for blood transfusion (59 versus 94%, P = 0.014), possibly because antenatally diagnosed women were more likely to have preventative therapies for haemorrhage (74 versus 52%, P = 0.007), and were less likely to have an attempt made to remove their placenta (59 versus 93%, P < 0.001). Making no attempt to remove any of the placenta, in an attempt to conserve the uterus or prior to hysterectomy, was associated with reduced levels of haemorrhage (median estimated blood loss 1750 versus 3700 ml, P = 0.001) and a reduced need for blood transfusion (57 versus 86%, P < 0.001).Conclusions Women with placenta accreta, increta, or percreta who have no attempt to remove any of their placenta, with the aim of conserving their uterus, or prior to hysterectomy, have reduced levels of haemorrhage and a reduced need for blood transfusion, supporting the recommendation of this practice.

PP082. Eclampsia in flanders: A comparative study between flanders, United Kingdom and The Netherlands

Eclampsia fulfills the European criteria of "uncommon medical conditions". To describe eclampsia in Flanders and compare the results with data of United Kingdom Obstetric Surveillance System (UKOSS) and a similar study in the Netherlands. Methods Between January and December 2012 each maternity hospital in Flanders was contacted monthly to learn whether a case of eclampsia had occurred. For each reported case an extensive questionnaire was completed. The obtained data were analyzed using the IBM-SPSSvs20 and BMJ-CIA programs. Over 95% of all maternity hospitals in Flanders participated. In 2012, 16 eclampsia cases were reported (incidence 2.3/10,000). Data of 14/16 cases could be used for analysis. No maternal or perinatal death occurred. In 71.4% (10/14;95%CI:45.4-88.3%) the gestational age at time of delivery was <37 weeks; in 28.6% (4/14;95%CI:11.7-54.6%) the insult occurred after the delivery; 50.00% (7/14;95%CI:26.8-73.2%) of the patients was primigravida and 28.6% (4/14;95%CI:11.7-54.6%) was negroid. Data presented in the table below summarize the findings of the last medical examination preceding the insult (n=13, insufficient data in 1 case). The incidence of eclampsia in Flanders is comparable to that of the UK (2.7/10,000) and is 2.7 times smaller than that of the Netherlands (6.2/10.000). Proteinuria was not tested in 9. In 5 of 14 no clear alert sign was seen at the last observation compared to 10.8% and 21% in Ndl and UK.

PM.01 Management and Outcomes of HELLP Syndrome in the UK

ObjectiveTo describe the current management and outcomes of HELLP (haemolysis, elevated liver enzymes and low platelet count) syndrome in the UK.MethodsA national descriptive study using the UK Obstetric Surveillance System,...

2.1 Incidence, Causes and Outcomes of Severe Maternal Sepsis Morbidity in the UK

BackgroundThe incidence of severe genital-tract sepsis has increased in the UK and is now the leading cause of direct maternal death. Underlying this trend is a larger number of severe...

The UK Obstetric Surveillance System: Impact on patient safety

The UK Obstetric Surveillance System is a national system that allows for the collection of information on a range of rare disorders of pregnancy, enabling national descriptive, case-control and cohort studies. The population-based nature of the studies conducted renders them less susceptible to the biases typically associated with observational studies. Data collected using The UK Obstetric Surveillance System and similar systems can be used to address a range of patient safety issues. These include assessing the safety of different treatment options, using the data as an aid to service planning, as part of ongoing quality-improvement initiatives, as a benchmark against which to compare hospital-level disease incidence and outcomes, to inform and audit national guidelines, and to monitor the effect of changes in practice or policy. Studies can be introduced rapidly in response to newly arising safety concerns. International comparisons can further enhance the utility of these data for improving patient safety.

Failed tracheal intubation in obstetric anaesthesia: 2 yr national case–control study in the UK

There are few national figures on the incidence of failed tracheal intubation during general anaesthesia in obstetrics. Recent small studies have quoted a rate of one in 250 general anaesthetics (GAs). The aim of this UK national study was to estimate this rate and identify factors that may be predictors. Using the UK Obstetric Surveillance System (UKOSS) of data collection, a survey was conducted between April 2008 and March 2010. Incidence and associated risk factors were recorded in consultant-led UK delivery suites. Units reported the details of any failed intubation (index case) and the two preceding GA cases (controls). Predictors were evaluated using multivariable logistic regression, significance P<0.05 (two-sided). We received 57 completed reports (100% response). The incidence using a unit-based estimation approach was one in 224 (95% confidence interval 179-281). Univariate analyses showed the index cases to be significantly older, heavier, with higher BMI, with Mallampati score recorded and score >1. Multivariate analyses showed that age, BMI, and a recorded Mallampati score were significant independent predictors of failed tracheal intubation. The classical laryngeal mask airway was the most commonly used rescue airway (39/57 cases). There was one emergency surgical airway but no deaths or hypoxic brain injuries. Gastric aspiration occurred in four (8%) index cases. Index cases were more likely to have maternal morbidities (P=0.026) and many babies in both groups were admitted to the neonatal intensive care unit: 21 (37%) vs 29 (27%) (NS). Three babies died--all in the control group.

Variation in severe maternal morbidity according to socioeconomic position: a UK national case–control study

ObjectivesThis study aimed to explore the independent association between socioeconomic position, defined by occupation, and severe maternal morbidity among women in the UK.DesignCase–control study.SettingThe analysis was conducted as a case–control...

Incidence and Risk Factors for Placenta Accreta/Increta/Percreta in the UK: A National Case-Control Study

BackgroundPlacenta accreta/increta/percreta is associated with major pregnancy complications and is thought to be becoming more common. The aims of this study were to estimate the incidence of placenta accreta/increta/percreta in the UK and to investigate and quantify the associated risk factors.MethodsA national case-control study using the UK Obstetric Surveillance System was undertaken, including 134 women diagnosed with placenta accreta/increta/percreta between May 2010 and April 2011 and 256 control women.ResultsThe estimated incidence of placenta accreta/increta/percreta was 1.7 per 10,000 maternities overall; 577 per 10,000 in women with both a previous caesarean delivery and placenta praevia. Women who had a previous caesarean delivery (adjusted odds ratio (aOR) 14.41, 95%CI 5.63–36.85), other previous uterine surgery (aOR 3.40, 95%CI 1.30–8.91), an IVF pregnancy (aOR 32.13, 95%CI 2.03–509.23) and placenta praevia diagnosed antepartum (aOR 65.02, 95%CI 16.58–254.96) had raised odds of having placenta accreta/increta/percreta. There was also a raised odds of placenta accreta/increta/percreta associated with older maternal age in women without a previous caesarean delivery (aOR 1.30, 95%CI 1.13–1.50 for every one year increase in age).ConclusionsWomen with both a prior caesarean delivery and placenta praevia have a high incidence of placenta accreta/increta/percreta. There is a need to maintain a high index of suspicion of abnormal placental invasion in such women and preparations for delivery should be made accordingly.

Pregnancy in Renal Transplant Recipients

In this issue of CJASN , Bramham et al. identified pregnant kidney transplant recipients being managed by practitioners participating in the UK Obstetric Surveillance System, comparing their outcomes with those of a cohort consisting of two women without kidney transplants that had delivered at the