Epidemiological investigation of a temporal increase in atonic postpartum haemorrhage: a population-based retrospective cohort study

OBJECTIVE

Increases in atonic postpartum haemorrhage (PPH) have been reported from several countries in recent years. We attempted to determine the potential cause of the increase in atonic and severe atonic PPH.

DESIGN

Population-based retrospective cohort study.

SETTING

British Columbia, Canada, 2001-2009.

POPULATION

All women with live births or stillbirths.

METHODS

Detailed clinical information was obtained for 371 193 women from the British Columbia Perinatal Data Registry. Outcomes of interest were atonic PPH and severe atonic PPH (atonic PPH with blood transfusion ≥1 unit; atonic PPH with blood transfusion ≥3 units or procedures to control bleeding), whereas determinants studied included maternal characteristics (e.g. age, parity, and body mass index) and obstetrics practice factors (e.g. labour induction, augmentation, and caesarean delivery). Year-specific unadjusted and adjusted odds ratios for the outcomes were compared using logistic regression.

MAIN OUTCOME MEASURES

Atonic PPH and severe atonic PPH.

RESULTS

Atonic PPH increased from 4.8% in 2001 to 6.3% in 2009, atonic PPH with blood transfusion ≥1 unit increased from 16.6 in 2001 to 25.5 per 10 000 deliveries in 2009, and atonic PPH with blood transfusion ≥3 units or procedures to control bleeding increased from 11.9 to 17.6 per 10 000 deliveries. The crude 34% (95% CI 26-42%) increase in atonic PPH between 2001 and 2009 remained unchanged (42% increase, 95% CI 34-51%) after adjustment for determinants of PPH. Similarly, adjustment did not explain the increase in severe atonic PPH.

CONCLUSIONS

Changes in maternal characteristics and obstetric practice do not explain the recent increase in atonic and severe atonic PPH.

What is SNOMED CT and why should the ISSHP care?

SNOMED CT (Systematized NOmenclature of MEDicine Clinical Terms) is a standardized multilingual healthcare terminology. It was developed to meet the needs of our electronic world so that care can be documented and clinicians can retrieve and transmit data in electronic format. It is anticipated that SNOMED CT will provide the core general terminology for electronic health records and, as such, replace existing classification systems such as the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10). At present, there is no special interest group for the hypertensive disorders of pregnancy (HDP) within the SNOMED CT initiative. We believe that members of the ISSHP, and others interested in the HDP, should take a leadership role in this regard for a number of reasons.

Investigation of an increase in postpartum haemorrhage in Canada

OBJECTIVE

To investigate the cause of a recent increase in hysterectomies for postpartum haemorrhage in Canada.

DESIGN

Retrospective cohort study.

SETTING

Canada between 1991 and 2004.

POPULATION

All hospital deliveries in Canada as documented in the database of the Canadian Institute for Health Information (excluding incomplete data from Quebec, Manitoba and Nova Scotia).

METHODS

Deliveries with postpartum haemorrhage by subtype were identified using International Classification of Diseases codes, while hysterectomies were identified using procedure codes. Changes in determinants of postpartum haemorrhage (all postpartum haemorrhage and that requiring hysterectomy) were examined, and crude and adjusted period changes were assessed using logistic models.

MAIN OUTCOME MEASURES

Postpartum haemorrhage, postpartum haemorrhage with hysterectomy, postpartum haemorrhage with blood transfusion and postpartum haemorrhage by subtype.

RESULTS

Rates of postpartum haemorrhage increased from 4.1% in 1991 to 5.1% in 2004 (23% increase, 95% CI 20-26%), while rates of postpartum haemorrhage with hysterectomy increased from 24.0 in 1991 to 41.7 per 100,000 deliveries in 2004 (73% increase, 95% CI 27-137%). These increases were because of an increase in atonic postpartum haemorrhage, from 29.4 per 1000 deliveries in 1991 to 39.5 per 1000 deliveries in 2004 (34% increase, 95% CI 31-38%). Adjustment for temporal changes in risk factors did not explain the increase in atonic postpartum haemorrhage but attenuated the increase in atonic postpartum haemorrhage with hysterectomy.

CONCLUSIONS

There has been a recent, unexplained increase in the frequency, and possibly the severity, of atonic postpartum haemorrhage in Canada.

Maternal morbidity associated with cesarean delivery without labor compared with spontaneous onset of labor at term

OBJECTIVE

To estimate the maternal morbidity associated with cesarean deliveries performed at term without labor compared with morbidity associated with spontaneous labor.

METHODS

A 14-year, population-based, cohort study (1988-2001) using the Nova Scotia Atlee Perinatal Database compared maternal outcomes in nulliparous women at term undergoing spontaneous labor for planned vaginal delivery with singleton, cephalic presentation and nulliparous women delivering by cesarean without labor.

RESULTS

From a total of 18,435 pregnancies, which satisfied inclusion and exclusion criteria, 721 were cesarean deliveries without labor. There were no maternal deaths or transfers for intensive care. There was no difference in wound infection, blood transfusion, or intraoperative trauma. Women undergoing cesarean deliveries without labor were more likely to have puerperal febrile morbidity (relative risk [RR] 2.2; 95% confidence interval [CI] 1.1, 4.5; P=.03), but were less likely to have early postpartum hemorrhage (RR 0.6; 95% CI 0.4, 0.9; P=.01) compared with women entering spontaneous labor. Subgroup analyses of maternal outcomes in women delivering by spontaneous and assisted vaginal delivery and cesarean delivery in labor were also performed. The highest morbidity was found in the assisted vaginal delivery and cesarean delivery in labor groups.

CONCLUSION

The increased maternal morbidity in elective cesarean delivery compared with spontaneous onset of labor is limited to puerperal febrile morbidity. Maternal morbidity is increased after assisted vaginal delivery and cesarean delivery in labor compared with cesarean delivery without labor.

Impact of prenatal glucose screening on the diagnosis of gestational diabetes and on pregnancy outcomes

The authors examined the impact of universal screening on the diagnosis of gestational diabetes and its complications. All mothers and newborns registered by the Canadian Institute for Health Information from 1984 to 1996 (even-numbered fiscal years only) were included in the analysis. Over this time period, the proportion of women with gestational diabetes increased ninefold (from 0.3% to 2.7%) while the proportion with prepregnancy diabetes fell from 0.7% to 0.4%. As rates of gestational diabetes increased, a corresponding reduction in the risks of complications (polyhydramnios, amniotic cavity infection, cesarean delivery, and preeclampsia) occurred for women with gestational diabetes. The incidence of gestational diabetes fell in Metro-Hamilton (where screening was discontinued in 1989) but remained high in the rest of Ontario (where screening continued in most areas). No related temporal trends for fetal macrosomia, cesarean delivery, or other diabetes-related complications were observed, regardless of screening policy. The authors concluded that the substantial increase in gestational diabetes in Canada is an artifact caused by universal screening, with no evidence of beneficial effects on pregnancy outcomes.

Double-blind, randomized, controlled trial of atosiban and ritodrine in the treatment of preterm labor: a multicenter effectiveness and safety study

OBJECTIVE

This study was undertaken to compare the efficacy and safety of intravenous administration of atosiban versus ritodrine for the treatment of preterm labor.

STUDY DESIGN

Women with preterm labor and intact membranes diagnosed at 23 to 33 gestational weeks (n = 247) were randomly assigned to treatment arms and received atosiban (6.75 mg intravenous bolus, 300 microg/min for 3 hours, then 100 microg/min intravenously) or ritodrine (0.10-0.35 mg/min intravenously) for as long as 18 hours. Tocolytic effectiveness was assessed in terms of the numbers of women who had not been delivered after 48 hours and after 7 days. Safety was assessed in terms of maternal side effects and neonatal morbidity. Secondary outcomes included mean gestational age at delivery and mean birth weight. An intent-to-treat analysis was performed with the Cochran-Mantel-Haenszel test.

RESULTS

The proportion of women who had not been delivered at 48 hours was 84.9% (n = 107) in the atosiban group and 86.8% (n = 105) in the ritodrine group. At 7 days 92 women had still not been delivered in both the atosiban (73.0%) and ritodrine (76.0%) groups. Neither of these differences was statistically significant. The incidence of maternal cardiovascular side effects was substantially lower in the atosiban group (4.0% vs 84.3%, P <.001). In addition, intravenous therapy was terminated more frequently as a result of maternal adverse events in the ritodrine group (29.8%) than in the atosiban group (0.8%). The overall occurrences of fetal adverse events in the two treatment groups were comparable. Neonatal morbidity was similar between the treatment groups after adjustment for unbalanced enrollment of women with multiple pregnancies and for gestational ages within treatment groups.

CONCLUSION

Atosiban was comparable in clinical effectiveness to conventional ritodrine therapy but was better tolerated than ritodrine, with no evidence of significant maternal or fetal adverse events. Neonatal morbidity, which was similar between the two treatment arms, was apparently related to the gestational age of the infant rather than to the exposure to either tocolytic agent.

Effect of labour induction on rates of stillbirth and cesarean section in post-term pregnancies

BACKGROUND

Meta-analyses of randomized controlled trials suggest that elective induction of labour at 41 weeks' gestation, compared with expectant management with selective labour induction, is associated with fewer perinatal deaths and no increase in the cesarean section rate. The authors studied the changes over time in the rates of labour induction in post-term pregnancies in Canada and examined the effects on the rates of stillbirth and cesarean section.

METHODS

Changes in the proportion of total births at 41 weeks' and at 42 or more weeks' gestation, and in the rate of stillbirths at 41 or more weeks' (versus 40 weeks') gestation in Canada between 1980 and 1995 were determined using data from Statistics Canada. Changes in the rates of labour induction and cesarean section were determined using data from hospital and provincial sources.

RESULTS

There was a marked increase in the proportion of births at 41 weeks' gestation (from 11.9% in 1980 to 16.3% in 1995) and a marked decrease in the proportion at 42 or more weeks (from 7.1% in 1980 to 2.9% in 1995). The rate of stillbirths among deliveries at 41 or more weeks' gestation decreased significantly, from 2.8 per 1000 total births in 1980 to 0.9 per 1000 total births in 1995 (p < 0.001). The stillbirth rate also decreased significantly among births at 40 weeks' gestation, from 1.8 per 1000 total births in 1980 to 1.1 per 1000 total births in 1995 (p < 0.001). The magnitude of the decrease in the stillbirth rate at 41 or more weeks' gestation was greater than that at 40 weeks' gestation (p < 0.001). All hospital and provincial sources of data indicated that the rate of labour induction increased significantly between 1980 and 1995 among women delivering at 41 or more weeks' gestation. The associated changes in rates of cesarean section were variable.

INTERPRETATION

Between 1980 and 1995 clinical practice for the management of post-term pregnancy changed in Canada. The increased rate of labour induction at 41 or more weeks' gestation may have contributed to the decreased stillbirth rate but it had no convincing influence either way on the cesarean section rate.

Gestational diabetes mellitus. Risk factors, obstetric complications and infant outcomes

OBJECTIVE

To evaluate risk factors, obstetric complications and infant outcomes in women with gestational diabetes mellitus (GDM).

STUDY DESIGN

We performed a population-based, longitudinal study of 824 women diagnosed with GDM in Nova Scotia, Canada, between 1980 and 1993. Adjusted relative risks (RRs) with 95% confidence intervals (CIs) were estimated through logistic regression.

RESULTS

After controlling for confounding variables, the following were associated with an increased incidence of GDM: maternal age, prepregnancy weight, previous spontaneous or induced abortion (RR 1.41, 95% CI 1.18-1.68), previous stillbirth (RR 1.80, 95% CI 1.08-3.01), previous low birth weight infant (RR 1.48, 95% CI 1.03-2.14), previous high-birth-weight (HBW) infant (RR 1.51, 95% CI 1.18-1.93) and chronic hypertension (RR 2.03, 95% CI 1.19-3.44). The relationship between maternal age and prepregnancy weight with GDM was nonlinear; women over age 35 and with a prepregnancy weight < or = 49 kg or > 65 kg demonstrated an increased risk. Urinary tract infection, polyhydramnios, oligohydramnios, chronic hypertension with superimposed preeclampsia, mild preeclampsia and uterine bleeding of unknown origin occurred more frequently in women with GDM than in those in whom the diagnosis was not made. HBW infants were more likely to be born to women with GDM than to women without GDM. Finally, women with GDM were over twice as likely to undergo cesarean birth (RR 2.30, 95% CI 1.99-2.65).

CONCLUSION

The risk of developing GDM is greatest in women over age 35, when prepregnancy weight is < 49 kg or > 65 kg and in those with chronic hypertension. Pregnancies complicated by GDM are at risk and need to be monitored closely for obstetric complications and adverse infant outcomes.

Random protein-creatinine ratio for the quantitation of proteinuria in pregnancy

OBJECTIVE

To compare random urine protein-creatinine ratios with 24-hour urine protein excretion rates in patients hospitalized with hypertensive disorders in pregnancy.

METHODS

All hospitalized, hypertensive patients requiring 24-hour urine protein excretion collections were eligible for the study. During the 24-hour urine collection a separate 2-mL aliquot was taken for a protein and creatinine determination.

RESULTS

Seventy-one samples were collected from patients with the following diagnoses: gestational hypertension (n = 56), preexisting hypertension and superimposed gestational hypertension (n = 11), and syndrome of hemolysis, elevated liver enzymes and low platelets (n = 4). The correlation coefficient between the random protein-creatinine ratio and the 24-hour urine protein excretion was 0.94. Calculated excretion rates with at least 300 mg protein in 24 hours had a sensitivity of 0.93, specificity of 0.90, and positive and negative predictive values of 0.87 and 0.95, respectively. For those samples with calculated excretion rates at least 5 g protein in 24 hours, the sensitivity was 1.00, specificity was 0.99, and positive and negative predictive values were 0.75 and 0.99, respectively.

CONCLUSION

In nonambulatory hypertensive pregnant patients, there is a strong correlation between random voided protein-creatinine ratios and 24-hour urine protein excretions.

Monoamniotic twins delivered liveborn with a forked umbilical cord

Monoamniotic twins are rare and are associated with high intrauterine mortality rates. This case appears to represent the first report of liveborn monoamniotic monochorionic twins delivered with a bifurcated umbilical cord. Pathological and angiographic studies of the placenta demonstrated a marginally inserted two-vessel umbilical cord that bifurcated at 8.4 cm from the disk into three-vessel umbilical cords supplying each twin. This probably represents the last opportunity for cleavage of the embryo prior to the formation of conjoined twins. A review of eight prior reports of monoamniotic twins with a single, bifurcating umbilical cord is provided.

Asynchronous pulmonary hyperplasia associated with tracheal atresia: pathologic and prenatal sonographic findings

We describe a case of pulmonary hyperplasia associated with tracheal atresia and a complete obstruction to the egress of pulmonary secretions. In classical pulmonary hyperplasia associated with cartilagenous laryngeal atresia and a persistent pharyngotracheal duct, the histologic appearance of the lungs is normal but exhibits "synchronous" hypermaturity. The histologic pattern in our case is much less mature, resembles CAM type III, and exhibits "asynchronous" development. We suggest that these histologic patterns be distinguished and that pulmonary hyperplasia is probably underrecognized and not nearly as rare as previously thought.

The psychological effects of counting fetal movements

By identifying a change in fetal activity state, fetal movement counting may help to reduce the possibility of stillbirth. Concern has arisen that such a focus on fetal activity may cause undue maternal anxiety. A prospective, controlled trial was conducted to determine whether fetal movement counting induced anxiety or other deleterious psychological effects in low-risk primigravidas. A sample of 613 healthy pregnant women was randomly assigned at 28 weeks' gestation to fetal movement counting, sleep recording, or a nonrecording control group. State and trait of anxiety, belief in sources of personal control, and attitudes toward pregnancy and infant were assessed at 28 and 37 weeks' gestation. Participation rates were high (91.4%) across all groups. Most women (90%) assigned to count fetal movements did so on a daily basis (95% of days). No significant changes in psychological status occurred in the three groups as a result of self-monitoring conditions. Independent of group assignment, all women showed a slight increase in transient state and decrease in trait of anxiety from 28 to 37 weeks. Internal locus of control and positive attitudes toward the infant increased slightly, and feelings of well-being decreased slightly for all women. It was concluded that women are willing to record fetal activity, and that fetal movement counting does not cause deleterious psychological effects in low-risk pregnant women.

Hepatitis B prenatal screening survey, Nova Scotia, 1990-1991

We conducted a study in which 5,754 pregnant women who delivered at the Grace Maternity Hospital in Halifax were screened for HBsAg. There were five who were found to be seropositive for the first time (a screening yield for seropositivity of 8.7/10,000). Overall six were seropositive for a prevalence rate of 10.4/10,000. These rates are above the 6.0/10,000 level at which routine prenatal screening is considered to be cost-effective. Screening based upon risk factors would have identified only two of the five women who were found for the first time to be HBsAg seropositive. Based upon the results of this study, we recommend that routine screening for HBsAg be performed on all prenatal women in Nova Scotia.

Fetal movement monitoring: clinical application

Although many factors influence fetal movements, maternal perception of gross fetal movement appears to be an accurate reflection of fetal activity. Observation in humans and studies in animals indicate that the compromised fetus reduces its oxygen requirements by reducing activity. This fact has enabled perceived fetal movement to become a useful adjunctive test of fetal asphyxia in high-risk pregnancy. Its application to low-risk pregnancy has many attractions, particularly as approximately 50 per cent of stillbirths occur without obvious cause in normal pregnancies. Although studies suggest that such application would be beneficial, questions about acceptability, the burden of further testing precipitated by reports of diminished movement, and the perinatal implications of unwarranted early intervention need to be clarified before the universal application of fetal movement counting protocols can be recommended.

Amniotic fluid phosphatidylglycerol and phosphatidylcholine phosphorus as predictors of fetal lung maturity

The contents of phosphatidylglycerol and phosphatidylcholine phosphorus in amniotic fluid (10,000 X g pellets) were studied as predictors of fetal lung maturity. The presence of phosphatidylglycerol predicted the absence of neonatal respiratory distress syndrome with 99% probability. When phosphatidylglycerol was absent, phosphatidylcholine phosphorus was a reliable predictor if measured 3 to 7 days before delivery. The probability that respiratory distress syndrome would not occur was 94% when phosphatidylcholine phosphorus was greater than 6. When measurement was performed within 2 days of delivery, the probability that respiratory distress syndrome would not occur fell to 69%. As measured in amniotic fluid, phosphatidylglycerol and phosphatidylcholine phosphorus are reliable antenatal predictors of fetal pulmonary maturity and, therefore, are useful in the management of a number of obstetric conditions.

High-risk obstetrics. The three-year experience of four subspecialists

The development of maternal-fetal medicine as a subspecialty in obstetrics and gynecology is fairly new. The specialists involved in this area are usually hospital based and involved in multiple activities, including teaching, administration and research. The role of this subspecialist as a provider of primary care to a high-risk obstetric population is important but has not been reported on previously. In this context high-risk obstetrics refers to intercurrent obstetric problems, previous obstetric problems, previous medical problems, infertility and the supposedly high-risk group of physicians and physicians' wives.

Fetal-maternal bleeding associated with genetic amniocentesis: real-time versus static ultrasound

The incidence of fetal to maternal bleeding was studied in 773 consecutive patients having genetic amniocentesis by measuring maternal serum alpha-fetoprotein elevation following the procedure. The frequency of fetal to maternal bleeding was significantly lower in patients having amniocentesis immediately after real-time ultrasound (21 of 429 cases, 4.9%) when compared with patients having static B-mode ultrasound before the procedure (31 of 344 cases, 9.0%). A lower frequency of fetal to maternal bleeding was observed in the real-time group for anterior or partially anterior placentas (8.1%) and posterior or fundal posterior placentas (0%) when compared with the static B-mode group (12.9 and 5.2%, respectively). The rate of spontaneous abortion in patients with fetal to maternal bleeding (12.8%) was significantly higher than the rate in patients who did not demonstrate such bleeding (1.45%). The implications of these findings with regard to the safety of amniocentesis and the benefit of routine preliminary ultrasound evaluation are discussed.

Glycemic control in pregnant diabetic women using a continuous subcutaneous insulin infusion pump

Five insulin-dependent diabetics in the third trimester of pregnancy were first stabilized on morning and evening injections of both short- and long-acting insulin. Blood sugars were determined hourly from 7 A.M. to 7 P.M. and then every two hours from 7 P.M. to 7 A.M. After glycemic control was established, the patients were treated with continuous subcutaneous insulin infusion via a pump that administers a basal dosage at predetermined intervals and bolus doses preprandially. Mean blood sugar, glycemic excursions and intervals of hypoglycemia and hyperglycemia were calculated after three to five days of infusion therapy. The continuous subcutaneous insulin infusion with the pump did not improve glycemic control in the group as a whole, but in two of five patients there was a significant decrease in mean blood sugar. A trend towards a decrease in glycemic excursions as well as hypoglycemia and hyperglycemia was also obtained. Three patients were managed with long-term home and in-hospital use of the continuous subcutaneous insulin infusion pump. It proved to be efficacious and safe in establishing euglycemia. This study of a portable insulin infusion pump affirms its ability to maintain glycemic control and its safety for long-term therapy during pregnancy.