Patsy Spark

Cesarean Delivery and Peripartum Hysterectomy

OBJECTIVE: To estimate the national incidence of peripartum hysterectomy and quantify the risk associated with cesarean deliveries and other factors. METHODS: A population-based, matched case-control study using the United Kingdom Obstetric Surveillance System, including 318 women in the United Kingdom who underwent peripartum hysterectomy between February 2005 and February 2006 and 614 matched control women. RESULTS: The incidence of peripartum hysterectomy was 4.1 cases per 10,000 births (95% confidence interval [CI] 3.6–4.5). Maternal mortality was 0.6% (95% CI 0–1.5%). Previous cesarean delivery (odds ratio [OR] 3.52, 95% CI 2.35–5.26), maternal age over 35 years (OR 2.42, 95% CI 1.66–3.58), parity of three or greater (OR 2.30, 95% CI 1.26–4.18), previous manual placental removal (OR 12.5, 95% CI 1.17–133.0), previous myomectomy (OR 14.0, 95% CI 1.31–149.3), and twin pregnancy (OR 6.30, 95% CI 1.73–23.0) were all risk factors for peripartum hysterectomy. The risk associated with previous cesarean delivery was higher with increasing numbers of previous cesarean deliveries (OR 2.14 with one previous delivery [95% CI 1.37–3.33], 18.6 with two or more [95% CI 7.67–45.4]). Women undergoing a first cesarean delivery in the current pregnancy were also at increased risk (OR 7.13, 95% CI 3.71–13.7). CONCLUSION: Peripartum hysterectomy is strongly associated with previous cesarean delivery, and the risk rises with increasing number of previous cesarean deliveries, maternal age over 35 years, and parity greater than 3. LEVEL OF EVIDENCE: II

Perinatal outcomes after maternal 2009/H1N1 infection: national cohort study.

Objectives To follow up a UK national cohort of women admitted to hospital with confirmed 2009/H1N1 influenza in pregnancy in order to obtain a complete picture of pregnancy outcomes and estimate the risks of adverse fetal and infant outcomes. Design National cohort study. Setting 221 hospitals with obstetrician led maternity units in the UK. Participants 256 women admitted to hospital with confirmed 2009/H1N1 in pregnancy during the second wave of pandemic infection between September 2009 and January 2010; 1220 pregnant women for comparison. Main outcome measures Rates of stillbirth, perinatal mortality, and neonatal mortality; odds ratios for infected versus comparison women. Results Perinatal mortality was higher in infants born to infected women (10 deaths among 256 infants; rate 39 (95% confidence interval 19 to 71) per 1000 total births) than in infants of uninfected women (9 deaths among 1233 infants; rate 7 (3 to 13) per 1000 total births) (P<0.001). This was principally explained by an increase in the rate of stillbirth (27 per 1000 total births v 6 per 1000 total births; P=0.001). Infants of infected women were also more likely to be born prematurely than were infants of comparison women (adjusted odds ratio 4.0, 95% confidence interval 2.7 to 5.9). Infected women who delivered preterm were more likely to be infected in their third trimester (P=0.046), to have been admitted to an intensive care unit (P<0.001), and to have a secondary pneumonia (P=0.001) than were those who delivered at term. Conclusions This study suggests an increase in the risk of poor outcomes of pregnancy in women infected with 2009/H1N1, which reinforces the message from studies of maternal risk alone. The health of pregnant women is an important public health priority in future waves of this and other influenza pandemics.

A prospective national study of acute fatty liver of pregnancy in the UK

Objectives: To identify a national, population-based cohort of women with acute fatty liver of pregnancy (AFLP), to evaluate proposed diagnostic criteria and to document accurately the incidence, management and outcomes of the condition. Subjects and methods: This was a population-based descriptive study using the UK Obstetric Surveillance System, carried out in all 229 hospitals with consultant-led maternity units in the UK. The participants comprised 57 women in the UK diagnosed with AFLP between February 2005 and August 2006 in an estimated cohort of 1 132 964 maternities (women delivering). Results: The estimated incidence of AFLP was 5.0 cases per 100 000 maternities (95% CI 3.8 to 6.5 per 100 000). Fifty-five cases (90%) were confirmed by diagnostic criteria and clinical assessment, two (3%) by clinical assessment alone, representing 97% agreement (kappa statistic = 0.78). 18% of women had twin pregnancies and 20% were underweight (body mass index (BMI) <20). 60% of women were admitted to intensive care and 15% to a specialist liver unit. One woman received a liver transplant. One woman died (case fatality rate 1.8%, 95% CI 0% to 9.4%). There were seven deaths among 67 infants (perinatal mortality rate 104 per 1000 births, 95% CI 43 to 203). Conclusions: The largest population-based cohort of women with AFLP to date has been identified. Diagnostic criteria previously proposed agree substantially with clinical diagnosis. The incidence estimate from this study is lower than documented by earlier hospital-based studies, but maternal and neonatal outcomes are better than previously reported, possibly related to improved ascertainment. Women with twin pregnancies appear to be at higher risk, but further studies are needed to investigate the risk associated with low BMI.

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

To describe the management and outcomes of placenta accreta, increta, and percreta in the UK.

Extreme Obesity in Pregnancy in the United Kingdom

OBJECTIVE: To estimate the prevalence and describe on a national basis the management and outcomes of extreme obesity (body mass index [BMI] 50 kg/m2 or higher) in pregnancy in the United Kingdom. METHODS: A national cohort study was undertaken. Extremely obese women (BMI 50 or higher) and a comparison cohort were identified using the UK Obstetric Surveillance System. Prevalence estimates were calculated with 95% confidence intervals (CIs). Data for obese and comparison women were compared using the &khgr;2 test or the Wilcoxon rank sum test. Odds ratios were estimated throughout using unconditional logistic regression. RESULTS: There were 665 women with extreme obesity in an estimated 764,387 women delivering, representing an estimated prevalence of 8.7 cases per 10,000 deliveries (95% CI 8.1–9.4). Extremely obese women had more complications than did comparison women, including preeclampsia (9% of women in the case group, 2% of those in the comparison group), gestational diabetes (11% of women in the case group, 2% of those in the comparison group), preterm delivery (10% of women in the case group, 7% of those in the comparison group), general anesthesia (6% of women in the case group, 1% of those in the comparison group), and intensive care unit admission (3% of women in the case group, 1% of those in the comparison group). Fifty percent of extremely obese women had cesarean deliveries compared with 22% of women in the comparison group. No women died. CONCLUSION: Nearly 1 in every 1,000 women giving birth in the United Kingdom is extremely obese. These women have increased risks of poor outcomes. Basic equipment was not universally available for the care of these women, and this, together with the increase in prevalence of obesity, has important implications for maternity service provision. There is an urgent need to address prepregnancy care and weight management programs to prevent this increase in prevalence, as well as to ensure that appropriate services are in place to reduce the inequalities in pregnancy outcomes for these women. LEVEL OF EVIDENCE: II

Incidence and risk factors for amniotic-fluid embolism.

OBJECTIVE: To estimate the incidence of amniotic-fluid embolism and to describe risk factors, management, and outcomes. METHODS: Through a population-based cohort study and nested case-control analysis, using the UK Obstetric Surveillance System, we identified 60 women in the United Kingdom who had an amniotic-fluid embolism between February 2005 and February 2009 and 1,227 women for the control group. We investigated the potential factors underlying amniotic-fluid embolism using an exploratory logistic regression analysis to estimate odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Sixty cases of amniotic-fluid embolism were reported, an estimated incidence of 2.0 per 100,000 deliveries (95% CI 1.5–2.5). Amniotic-fluid embolism occurrence was significantly associated with induction of labor (adjusted OR 3.86, 95% CI 2.04–7.31) and multiple pregnancy (adjusted OR 10.9, 95% CI 2.81–42.7); an increased risk also was noted in older, ethnic-minority women (adjusted OR 9.85, 95% CI 3.57–27.2). Cesarean delivery was associated with postnatal amniotic-fluid embolism (adjusted OR 8.84, 95% CI 3.70–21.1). Twelve women died (case fatality 20%, 95% CI 11–32%); 5 of 37 newborns of women with antenatal amniotic-fluid embolism died (perinatal mortality 135 per 1,000 total births, 95% CI 45–288). Women who died were significantly more likely to be from ethnic-minority groups (adjusted OR 11.8, 95% CI 1.40–99.5). CONCLUSION: High-quality supportive care can result in good maternal outcomes after amniotic-fluid embolism. Clinicians should consider both the risks and benefits of induction and cesarean delivery because more restricted use may result in a decrease in the number of women suffering a potentially fatal amniotic-fluid embolism. The observed increased risk of fatality in ethnic-minority women may be associated with differences in underlying medical conditions or access to care, and clinicians should that ensure appropriate services are provided to minimize this risk. LEVEL OF EVIDENCE: II

Incidence and risk factors for placenta accreta/increta/percreta in the UK: a national case-control study.

Background Placenta 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. Methods A 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. Results The 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). Conclusions Women 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: A UK National Cohort Study

BACKGROUND AND OBJECTIVES Most reports of pregnancy outcome in women with kidney transplants are single-center, retrospective, and include small numbers and few are compared with controls. The aim of this study was to collect information about pregnancy outcomes among all kidney transplant recipients in the United Kingdom, managed with current antenatal and nephrologic care, and to compare these data with a contemporaneous control group. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Pregnant women with a kidney transplant were identified through the UK Obstetric Surveillance System (UKOSS) between January 1, 2007 and December 31, 2009. Data on a comparison cohort were obtained from the UKOSS database, containing information on comparison women identified in previous studies. Outcomes were also compared with national data. RESULTS There were 105 pregnancies identified in 101 recipients. Median prepregnancy creatinine was 118 μmol/L. Preeclampsia developed in 24% compared with 4% of the comparison group. Median gestation at delivery was 36 weeks, with 52% of women delivering at <37 weeks, significantly higher than the national rate of 8%. Twenty-four infants (24%) were small for gestational age (<10th centile). There were two (2%) cases of acute rejection. Potential predictive factors for poor pregnancy outcome included >1 previous kidney transplant (P=0.03), first trimester serum creatinine >125 μmol/L (P=0.001), and diastolic BP >90 mmHg in the second (P=0.002) and third trimesters (P=0.05). CONCLUSIONS Most pregnancies in the United Kingdom in women with kidney transplants are successful but rates of maternal and neonatal complications remain high.

Uterine Rupture by Intended Mode of Delivery in the UK: A National Case-Control Study

A case-control study using UK data estimates the risk of uterine rupture in subsequent deliveries amongst women who have had a previous caesarean section.

Influenza A/H1N1v in pregnancy: an investigation of the characteristics and management of affected women and the relationship to pregnancy outcomes for mother and infant

BACKGROUND In April 2009 a novel influenza A virus (AH1N1v) of swine origin (swine flu) emerged, spreading rapidly and achieving pandemic status in June 2009. Pregnant women were identified as being at high risk of severe influenza-related complications and as a priority group for vaccination against AH1N1v. Limited information was available about the maternal and fetal risks of AH1N1v infection or of antiviral drug or AH1N1v vaccine use in pregnancy. OBJECTIVES To assess rates of and risk factors for adverse outcomes following AH1N1v infection in pregnancy and to assess the adverse effects of the antiviral drugs and vaccines used in prevention and management. METHODS Prospective national cohort studies were conducted to identify pregnant women who were (1) suspected to be infected with AH1N1v or being treated with antiviral medication in primary care; (2) vaccinated against AH1N1v; and (3) admitted to hospital with confirmed AH1N1v. Characteristics of women with influenza-like illness (ILI) in primary care were compared with those of women without symptoms accepting or declining immunisation. Characteristics of women admitted to hospital with confirmed AH1N1v infection in pregnancy were compared with a historical cohort of over 1200 women giving birth in the UK who were uninfected with AH1N1v. Outcomes examined in hospitalised women included maternal death, admission to an intensive care unit, perinatal mortality and preterm birth. Risk factors for hospital and intensive care unit admission were examined in a full regression model. RESULTS The weekly incidence of ILI among pregnant women averaged 51/100,000 over the study period. Antiviral drugs were offered to 4.8% [95% confidence interval (CI) 4.0% to 5.9%] and vaccination to 64.8% (95% CI 64.7% to 68.9%) of registered pregnant women. Ninety pregnant women with ILI presenting in primary care were reported to the research team, 55 of whom were prescribed antiviral drugs and in 42 (76%) cases this was within 2 days of symptom onset. After comparison with 1329 uninfected pregnant women offered vaccination, pre-existing asthma was the only maternal factor identified as increasing risk of ILI presentation [adjusted odds ratio (OR) 2.0, 95% CI 1.0 to 3.9]. Maternal obesity and smoking during pregnancy were also associated with hospital admission with AH1N1v infection. Overall, 241 pregnant women were admitted to hospital with laboratory-confirmed AH1N1v infection. Eighty-three per cent of these women were treated with antiviral agents, but only 6% received antiviral treatment before hospital admission. Treatment within 2 days of symptom onset was associated with an 84% reduction in the odds of admission to an intensive therapy unit (OR 0.16, 95% CI 0.08 to 0.34). Women admitted to hospital with AH1N1v infection were more likely to deliver preterm; a three times increased risk was suggested compared with an uninfected population cohort (OR 3.1, 95% CI 2.1 to 4.5). CONCLUSIONS Earlier treatment with antiviral agents is associated with improved outcomes for pregnant women and further actions are needed in future pandemics to ensure that antiviral agents and vaccines are provided promptly to pregnant women, particularly in the primary care setting. Further research is needed on longer-term outcomes for infants exposed to AH1N1v influenza, antiviral drugs or vaccines during pregnancy.