A Review of Ectopic Pregnancies in Southern Tasmania

Summary: Over the 10-year period 1968–1977, 131 patients with ectopic pregnancy were treated at the Royal Hobart Hospital. The clinical features of these patients are discussed. Using data on the number of ectopic pregnancies confirmed in Southern Tasmania in the period 1973–1977, it was shown that in terms of the ratio of ectopic pregnancies to total births, the incidence of ectopic gestation in the essentially stable population has risen from 1:130 to 1:72; possible reasons for this increase are discussed. The difficulty in diagnosis of the condition is emphasised.     

Number and gestational age of prior preterm births does not modify the predictive value of a short cervix

OBJECTIVE: This study was undertaken to determine whether the number and gestational age of prior preterm deliveries modifies the significance of endovaginal sonographic cervical length less than 25 mm for the prediction of recurrent preterm birth less than 35 weeks' gestation. STUDY DESIGN: Secondary analysis of a multicenter, blinded, observational study. Endovaginal ultrasonographic examinations were scheduled at 2-week intervals between 16 and 23 weeks' gestation in singleton pregnancies of 181 gravid women with at least 1 prior spontaneous preterm birth between 16 and 32 weeks' gestation. RESULTS: The earliest prior preterm birth occurred before 23 weeks in 61 women and at 23.0 to 31 weeks in 115; 5 had missing gestational age data. Cervical length was not different between these 2 groups both at the initial scan (median 38 vs 37 mm, P=.54) and considering the shortest ever observed cervical length over the entire study period (median 30 vs 30 mm, P=.97). Cervical length less than 25 mm was associated with spontaneous preterm birth less than 35 weeks for both groups (positive predictive value 80% vs 71%, P>.99). There were 134 women with 1 prior preterm delivery (74%) and 47 with 2 or more. Cervical lengths were not different between these 2 groups at the initial scan (median 36.5 vs 37 mm, P=.52) or over the entire study period (median 30 vs 32 mm, P=.31). The positive predictive value of cervical length less than 25 mm for subsequent spontaneous premature birth was not significantly higher in gravid women with multiple prior preterm births (100% vs 73%, P>.99). CONCLUSION: Neither the number nor the gestational age of prior preterm births modify the predictive value of a cervical length less than 25 mm at 16 to 19 weeks for recurrent spontaneous preterm birth.     

Outcome of pregnancies progressing beyond 28 weeks gestation in women with a history of recurrent miscarriage

Ninety-seven women who had had three or more miscarriages had also had at least one pregnancy with a singleton birth that had reached 28 weeks gestation. Information was available on these 118 babies: 30% were small-for-gestational age (birthweight less than or equal to 10th centile using figures from Scotland 1973-79), 28% were born preterm, and the perinatal mortality rate (excluding babies of less than 28 weeks gestation) was 161/1000 births, all of which are significantly increased above the prevalence for a normal obstetric population. These observations may serve to alert the clinician to the increased risk of these complications when dealing with women who have a history of recurrent miscarriage.     

Do Birth Certificate Data Accurately Reflect the Number of CNM‐Attended Births? An Exploratory Study

The number of midwife-attended births is increasing as reported on birth certificates in the United States. However, there is some evidence that births attended by certified nurse-midwives (CNMs) may not be accurately recorded. In this exploratory study, data on birth attendants for those clients giving birth during the study period were compared by using four sources: the client's hospital chart, the CNM birth log, hospital birth certificate records, and state vital statistics records. Researchers sought to determine the accuracy of birth attendant data as reflected in these four sources and whether other providers were listed as the birth attendant for actual CNM-attended births. During the study period, the CNM birth log showed that CNMs attended 97 vaginal births, whereas the client hospital charts for these same births noted 92 births as attended by CNMs (the other five were operative vaginal births). Hospital birth certificate and state vital statistics data during the study time period credited 88 and 82 of the client's births, respectively, to the CNMs. Exploration of the inaccurately reported birth attendant data, implications for practice, and recommendations for accurately recording birth certificate data are discussed.     

Validation of an Online Data Registry for Midwifery Practices: A Pilot Project

Introduction: The value of a data registry for research, benchmarking, and quality improvement activities depends on the underlying quality of the data. This pilot study was conducted to design and implement a validation process assessing data quality in the American Association of Birth Centers’ online data registry, the Uniform Data Set (UDS). Methods: Site visits were conducted in 5 midwifery practices attending births in freestanding birth centers and hospitals to compare data from health records with data in the registry. Practices meeting the inclusion criteria and representative of the overall population of midwifery practices contributing data to the UDS were audited. Between 2% and 5% of each practice's total UDS records were randomly selected and then compared with their matched health records for 29 key variables from the 189 variables in the UDS. Results: A total of 3966 variables were reviewed for 152 records. There were 126 records for which complete maternity care was provided; thus, all 4 parts of the UDS were expected. There were 26 records for women who left care during pregnancy; thus, only parts 1 and 2 of the UDS were expected. Quality of the UDS data was evaluated, with the health records serving as the criterion standard, and the 2 sources were found to be consistent for 97.1% of the variables. Discussion: Results from the study suggest that the data registry can provide valid data for use in research describing the process and outcomes of midwifery care and for benchmarking and quality improvement activities.     

Birth outcomes of planned home births in Missouri: a population-based study

We evaluated the birth outcomes of planned home births. We conducted a retrospective cohort study using Missouri vital records from 1989 to 2005 to compare the risk of newborn seizure and intrapartum fetal death in planned home births attended by physicians/certified nurse midwives (CNMs) or non-CNMs with hospitals/birthing center births. The study sample included singleton pregnancies between 36 and 44 weeks of gestation without major congenital anomalies or breech presentation ( N?=?859,873). The adjusted odds ratio (aOR) of newborn seizures in planned home births attended by non-CNMs was 5.11 (95% confidence interval [CI]: 2.52, 10.37) compared with deliveries by physicians/CNMs in hospitals/birthing centers. For intrapartum fetal death, aORs were 11.24 (95% CI: 1.43, 88.29), and 20.33 (95% CI: 4.98, 83.07) in planned home births attended by non-CNMs and by physicians/CNMs, respectively, compared with births in hospitals/birthing centers. Planned home births are associated with increased likelihood of adverse birth outcomes.     

Outcomes of planned home births in Washington State: 1989-1996

OBJECTIVE: To determine whether there was a difference between planned home births and planned hospital births in Washington State with regard to certain adverse infant outcomes (neonatal death, low Apgar score, need for ventilator support) and maternal outcomes (prolonged labor, postpartum bleeding). METHODS: We examined birth registry information from Washington State during 1989-1996 on uncomplicated singleton pregnancies of at least 34 weeks' gestation that either were delivered at home by a health professional (N = 5854) or were transferred to medical facilities after attempted delivery at home (N = 279). These intended home births were compared with births of singletons planned to be born in hospitals (N = 10,593) during the same years. RESULTS: Infants of planned home deliveries were at increased risk of neonatal death (adjusted relative risk [RR] 1.99, 95% confidence interval [CI] 1.06, 3.73), and Apgar score no higher than 3 at 5 minutes (RR 2.31, 95% CI 1.29, 4.16). These same relationships remained when the analysis was restricted to pregnancies of at least 37 weeks' gestation. Among nulliparous women only, these deliveries also were associated with an increased risk of prolonged labor (RR 1.73, 95% CI 1.28, 2.34) and postpartum bleeding (RR 2.76, 95% CI 1.74, 4.36). CONCLUSION: This study suggests that planned home births in Washington State during 1989-1996 had greater infant and maternal risks than did hospital births.     

Triplet births in the United States. An epidemic of high-risk pregnancies

OBJECTIVE: To more precisely understand the changes in triplet births in recent years. STUDY DESIGN: Analysis of recent government and medical publications pertaining to triplets. RESULTS: Triplet births are at much greater risk than singletons of poor birth outcomes. More than 9 of 10 triplet births are born preterm (< 37 completed weeks of gestation) as compared with < 1 of 10 singleton infants. The average weight of a triplet newborn (1,698 g) is one-half that of a singleton newborn (3,358 g). The infant death rate for triplet and other higher-order multiple births is 12 times higher than that for singletons (93.7 as compared with 7.8 infant deaths per 1,000 live births). CONCLUSION: Based on their frequency of preterm birth, low birth weight and infant death rate, it is appropriate to characterize all triplet pregnancies as high risk.     

The Cesarean Section Rate in Sweden: The End of the Rise

ABSTRACT: This nationwide study examined the annual changes in cesarean section rates in relation to perinatal mortality, the condition of the newborn at birth, and different indications for the procedure in Sweden. Since 1973 all obstetric units have sent copies of medical birth registration forms for newborns to the National Board of Health and Welfare. Information about the cesarean section rate, indications for the surgery, Apgar scores, and perinatal mortality between 1973 and 1990 was obtained from this data base. The cesarean section rate increased from 5 percent in 1973 to 12.3 percent in 1983, and thereafter declined steadily to 10.84 percent in 1990. Perinatal mortality was halved from 14.2 to 6.3 per 1000 live births, and the number of newborns with low Apgar scores (<4 at 1 min and/or <7 at 5 min) decreased from 20 to 14 per 1000 live births. We conclude that it is possible to lower the cesarean section rate on a nationwide basis without increasing risks to newborn infants.     

Choosing wisely for the other 80%: What we need to know about the more mature newborn and NICU care

Although neonatal intensive unit (NICU) care is envisioned as the care of very immature infants, more than 95% of births and 80% of NICU admissions are of more mature newborns—infants born at 34 or more weeks’ gestation. In spite of the size of this population there are important gaps in the understanding of their needs and optimal management as reflected by remarkably large unexplained variation in their care. The goal of this article is to describe what is known about the more mature, higher birth weight newborn population's use of NICU care and highlight important gaps in knowledge and obstacles to research. Research priorities are identified: including (1) the need for birth population based rather than NICU based studies, and (2) population specific data elements.Summary: More mature newborns—infants of 34 or more weeks’ gestation—account for most NICU admissions. There are large gaps in the understanding of their needs and optimal management as reflected by large unexplained variation in their care. We enumerate these gaps in current knowledge and suggest research priorities to address them.     

Customised birthweight: coefficients for an Australian population and validation of the model

BACKGROUND: Published birthweight references in Australia do not fully take into account constitutional factors that influence birthweight and therefore may not provide an accurate reference to identify the infant with abnormal growth. Furthermore, studies in other regions that have derived adjusted (customised) birthweight references have applied untested assumptions in the statistical modelling. AIMS: To validate the customised birthweight model and to produce a reference set of coefficients for estimating a customised birthweight that may be useful for maternity care in Australia and for future research. METHODS: De-identified data were extracted from the clinical database for all births at the Mater Mother's Hospital, Brisbane, Australia, between January 1997 and June 2005. Births with missing data for the variables under study were excluded. In addition the following were excluded: multiple pregnancies, births less than 37 completed week's gestation, stillbirths, and major congenital abnormalities. Multivariate analysis was undertaken. A double cross-validation procedure was used to validate the model. RESULTS: The study of 42,206 births demonstrated that, for statistical purposes, birthweight is normally distributed. Coefficients for the derivation of customised birthweight in an Australian population were developed and the statistical model is demonstrably robust. CONCLUSIONS: This study provides empirical data as to the robustness of the model to determine customised birthweight. Further research is required to define where normal physiology ends and pathology begins, and which segments of the population should be included in the construction of a customised birthweight standard.     

Late-preterm birth: does the changing obstetric paradigm alter the epidemiology of respiratory complications?

OBJECTIVE: To analyze the effect of gestational age, delivery mode, and maternal-fetal risk factors on rates of respiratory problems among infants born 34 or more weeks of gestation over a 9-year period. METHODS: Retrospective analysis of prospectively collected maternal and neonatal data on all inborn births at 34 or more weeks of gestation at a single tertiary care center for the years 1990-1998. Specific diagnostic criteria were concurrently applied by a single investigator. RESULTS: Over the 9-year period, late-preterm births increased by 37%, whereas births at more than 40 weeks decreased by 39%, resulting in a decrease in median age at delivery from 40 weeks to 39 weeks (P<.001). Respiratory problems occurred in 705 term or late-preterm infants (4.9%), with clinically significant morbidity (respiratory distress syndrome, meconium aspiration syndrome, or pneumonia) least common at 39-40 weeks of gestation. Respiratory morbidity was greater among infants born by cesarean delivery or complicated vaginal delivery compared with uncomplicated cephalic vaginal delivery. The rate of respiratory morbidity did not change over time (1990-1992 1.3%, 1993-1995 1.5%, 1996-1998 1.4%, P=.746). The etiologic fraction for respiratory morbidity did not change over time for infants 34-36 weeks but decreased twofold for infants born after 40 weeks. CONCLUSION: Over the 9-year study period, reduced respiratory morbidity associated with decreased births after 40 weeks were offset by the adverse respiratory effect of increased cesarean delivery rates and increased late-preterm birth rates.     

Preterm birth in Sweden 1973-2001: rate, subgroups, and effect of changing patterns in multiple births, maternal age, and smoking

BACKGROUND: The objectives of this report are to evaluate changes in the preterm birth rate in Sweden 1973-2001. Furthermore, describe the proportion of spontaneous and indicated preterm births and assess risk factors for the subgroups of preterm birth during the period from 1991 to 2001. METHODS: A population-based register study of all births occurring in Sweden from 1973 to 2001 registered in the Swedish Medical Birth Register was designed. The analysis of subgroups was restricted to the period 1991-2001. Gestational age was calculated using last menstrual period and best estimate. Odds ratio for preterm birth related to risk factors was calculated for the subgroups' spontaneous and indicated preterm birth. RESULTS: After an increase in the beginning of the 1980s, the preterm birth rate has decreased from 6.3% in 1984 to 5.6% in 2001 (P < 0.0001). The proportion of multiple births born preterm of the total birth rate increased from 0.34% in 1973 to 0.71% in 2001 (P < 0.0001). Spontaneous preterm births account for 55.2% and iatrogenic preterm births for 20.2% of all preterm births. The strongest association with maternal smoking in early pregnancy was found at gestational age <28 weeks and spontaneous preterm birth [odds ratio (OR) smoking versus no smoking: 1.55, 95% confidence intervals (CI): 1.42-1.69]. The strongest association for maternal age was found between gestational age <28 weeks and indicated preterm birth (OR 5-year increase: 1.34, 95% CI: 1.21-1.47). CONCLUSIONS: The preterm birth rate in Sweden has decreased since the mid 1980s. The composition of different subtypes of preterm birth in a Scandinavian low-risk population seems to be similar to populations with higher incidence of preterm birth and perinatal infections.     

Twins and triplets: the effect of plurality and growth on neonatal outcome compared with singleton infants

OBJECTIVE: Information on outcome by gestational age from large numbers of twins and triplets is limited and is important for counseling and decision-making in obstetric practice. We reviewed one of the largest available neonatal databases to describe mortality and morbidity rates and growth in newborn infants from multiple gestations and compared these data with data for singletons. STUDY DESIGN: Data from a large prospectively recorded neonatal database that incorporated neonatal records from January 1997 to July 2002 were reviewed. We evaluated birth weight and neonatal mortality and morbidity rates that affected long-term outcome for each week of gestational age from 23 to 35 weeks of gestation for all nonanomolous inborn twins and triplets who were admitted to the neonatal intensive care unit and compared these data to all singletons who met similar criteria during the same time period. RESULTS: There were 12,302 twin and 2155 triplet births that met the entry criteria. The data for these newborn infants were compared with 36,931 singletons. Average birth weights at each gestational week were similar for all gestational ages until 29 weeks of gestation for triplets and 32 weeks of gestation for twins. After these gestational ages, the entire difference between twins and singletons was due to the weight of the smaller twin; the larger twins' mean weights were similar to singletons at all weeks that were studied. Birth order at each week also did not affect neonatal mortality rates, even when corrected for route of delivery and antenatal steroids. Neonatal morbidities associated with adverse long-term outcomes (intraventricular hemorrhage, retinopathy of prematurity, necrotizing enterocolitis) were also not different between multiple infants and singletons. Intrauterine growth restriction (IUGR) was associated with increased mortality rates at all gestational ages, but in the absences of IUGR, discordance was not. CONCLUSION: Data on a large number of twins and triplets provide reassurance that neonatal outcome at all viable premature weeks of gestation are similar to singletons. Intrauterine growth restriction and prematurity are therefore the principal issues that drive neonatal mortality and morbidity rates in multiple gestations. These data are important for obstetric decision-making and patient counseling.     

Missing hospital records: a confounding variable in retrospective studies

In retrospective chart reviews there are often a certain number of missing hospital records. To elucidate this variable we compared the outcomes of very low birth weight breech infants with respect to the method of collecting data. A prospective sampling, during the hospital stay, of data was performed in 1979 to 1980 and in 1983 to 1984, and the frequencies of very low birth weight were 1.89 and 1.90, respectively, per 1000 live births. For 1981 to 1982 a retrospective record search was performed with the use of the ordinary medical record search system at this institution. For this period 39 of 52 (75%) hospital records were recovered, giving an apparent frequency of 1.32/1000 live births, which differed significantly from either period studied prospectively. An analysis of demographic data of the three groups revealed that the mean gestational age and the mean birth weights were higher in the period studied retrospectively compared with both periods studied prospectively and that the neonatal mortality rates were higher in the periods studied prospectively (74.1% and 57.1%, respectively) than in the period studied retrospectively (28.2%). It is concluded that the more complicated a clinical case is, the more likely the record will not be found for retrospective chart review. This problem should be kept in mind, and it ought to be a requirement that the number of missing charts be stated in retrospective observational studies.     

Population‐Based Study of Cesarean Section After In Vitro Fertilization in Australia

Abstract: Background: Decisions about method of birth should be evidence based. In Australia, the rising rate of cesarean section has not been limited to births after spontaneous conception. This study aimed to investigate cesarean section among women giving birth after in vitro fertilization (IVF). Methods: Retrospective population‐based study was conducted using national registry data on IVF treatment. The study included 17,019 women who underwent IVF treatment during 2003 to 2005 and a national comparison population of women who gave birth in Australia. The outcome measure was cesarean section. Results: Crude rate of cesarean section was 50.1 percent versus 28.9 percent for all other births. Single embryo transfer was associated with the lowest (40.7%) rate of cesarean section. Donor status and twin gestation were associated with significantly higher rates of cesarean section (autologous, 49.0% vs donor, 74.9%; AOR: 2.20, 95% CI: 1.80, 2.69) and (singleton, 45.0% vs twin gestations, 75.7%; AOR: 3.81, 95% CI: 3.46, 4.20). The gestation‐specific rate (60.1%) of cesarean section peaked at 38 weeks for singleton term pregnancies. Compared with other women, cesarean section rates for assisted reproductive technology term singletons (27.8% vs 43.8%, OR: 2.02 [95% CI: 1.95–2.10]) and twins (62.0% vs 75.7%, OR: 1.92 [95% CI: 1.74–2.11]) were significantly higher. Conclusions: Rates for cesarean section appear to be disproportionately high in term singleton births after assisted reproductive technology. Vaginal birth should be supported and the indications for cesarean section evidence based. (BIRTH 37:3 September 2010)     

Changes in frequency and indications for cesarean section in Norway 1967-1984

We have studied the cesarean section frequencies and changing spectrum of indications in Norway during six consecutive 3-year periods from 1967 to 1984. The data set consists of 1,046,162 births notified to the Medical birth registry of Norway, of which 52,426 were specified as cesarean sections, the frequency rising from 1.9% in 1967-69 to 9.7% in 1982-84. A check for completeness of cesarean section notification was made against the birth protocols of the largest obstetrical unit in Norway. The error rate was about 3%. Information on the indication for performing cesarean section was missing in 11.4% of the cases. We grouped thirty-one specified indications under seven headings. In 1967-69 the operation was most often performed for 'maternal' reasons, followed by 'mechanical', 'abnormalities of fetal presentation' and 'acute placental' conditions. Throughout the study period, 'mechanical' (which can also be labelled 'dystocia') accounted for about one third of the indications for cesarean section, while 'maternal' (including high maternal age and pre-eclampsia) and 'acute placental' (placenta praevia and placental abruption) decreased in relative importance. 'Fetal presentation' (including twins) doubled its relative share, while increasing from 2.4 per 1000 births in 1967-69 to 24.8 per 1000 births in 1982-84. A steep rise in the group 'fetal asphyxia' corresponded to the period when the mass of electronic monitoring devices was introduced, in the early 1970s. 'Fetal asphyxia' had a higher relative share of the indications among para 0 mothers than in the total birth population.     

Survival rates of monoamniotic twins do not decrease after 30 weeks' gestation

A search of pathology records from the years 1967 to 1988 at Women and Infants' Hospital of Rhode Island (138,232 live births) revealed 24 sets of histologically confirmed monoamniotic twins. All records were available for review. Among the 17 sets of monoamniotic twins that reached 30 weeks' gestation with at least one twin still alive, there were no further fetal deaths. The risks of early delivery in these pregnancies appear to outweigh the risk of fetal death as a result of monoamniotic status alone. These data do not show an advantage to early delivery.     

The cost of prematurity: quantification by gestational age and birth weight

OBJECTIVE: To determine gestational age- and birth weight-related pregnancy outcomes and resource use associated with prematurity in surviving neonates. METHODS: A data set linking birth certificates with maternal and newborn hospital discharge records from hospitals in California (from January 1, 1996, to December 31, 1996) was examined for all singleton deliveries by gestational age (weekly, from 25 to 38 weeks) and birth weight (by 250-g increments from 500 to 3000 or more g). Records were examined for respiratory distress syndrome (RDS), use of mechanical ventilation, length of hospital stay in days, and hospital costs. RESULTS: As expected, RDS, ventilation, length of hospital stay, and costs per case decreased exponentially with increasing gestational age and birth weight. Specifically, neonatal hospital costs averaged 202,700 dollars for a delivery at 25 weeks, decreasing to 2600 dollars for a 36-week newborn and 1100 dollars for a 38-week newborn. Neonatal costs were 224,400 dollars for a newborn at 500-700 g, decreasing to 4300 dollars for a newborn at 2250-2500 g and 1000 dollars for a birth weight greater than 3000 g. For each gestational age group from 25 to 36 weeks, total neonatal costs were similar, despite increasing case numbers with advancing gestational age. Neonatal RDS and need for ventilation were significant at 7.4% and 6.3%, respectively, at 34 weeks' gestation. Significant "excess" costs were found for births between 34 and 37 weeks' gestational age when compared with births at 38 weeks. CONCLUSION: Prematurity, whether examined by gestational age or birth weight, is associated with significant neonatal hospital costs, all of which decrease exponentially with advancing gestational age. Because total costs for each gestational age group from 25 to 36 weeks were roughly the same (38,000,000 dollars), opportunity for intervention to prevent preterm delivery and decrease costs is potentially available at all preterm gestational ages.     

Gestational trophoblastic neoplasia in American Indians

OBJECTIVE: To analyze gestational trophoblastic neoplasia (GTN) trends among American Indians (AI) using population-based data. STUDY DESIGN: GTN incidence, by race and age, was calculated using data collected by the New Mexico Tumor Registry over 29 years (1973-2001). Live birth, pregnancy and women at risk were tabulated using data derived from the state's vital record annual reports and from the registry. Statistical methods included trends analysis and Poisson regression. There is no national registry in the United States for all GTN. Therefore, the Surveillance, Epidemiology and End Results (SEER) database was used to identify choriocarcinoma cases in American Indians between 1973 and 1999. RESULTS: Within New Mexico, 1,082 cases of GTN were identified among 752,374 live births and 904,831 pregnancies, with ratios of 1:695 and 1:836, respectively, affecting 234 AI, 355 non-Hispanic whites (NHW), 463 Hispanic whites (HW) and 30 other nonwhites. Ratios per live births (pregnancy), respectively, were significantly higher in AI (AI 1:439 [1:487], NHW 1:739 [1:949], HW 1:783 [1:903]), as was age-adjusted incidence per 100,000 woman-years (AI 10.62, NHW 3.53, HW 5.15; all P<.0001). Using Poisson models with live birth and woman-year denominators, AI were found to be at increased risk for all GTN histologic subsets (complete, partial and invasive hydatidiform mole and choriocarcinoma). Of 524 total gestational choriocarcinoma cases identified within SEER, 8 (1.8%) affected American Indians; of them, 7 were from New Mexico. CONCLUSION: In New Mexico, AI continue to be at higher risk of GTN than are other groups. Given the rarity of choriocarcinoma within SEER, especially among AI, the New Mexico dataset provides the best available estimate of trends in U.S. AI GTN risk.