Experience with fetal monitoring in a university teaching hospital.

Fetal monitoring during labour may be expected to decrease perinatal losses and the number of infants born with brain damage. In a prospective study of intrapartum fetal monitoring in selected high-risk pregnancies in a Winnipeg hospital the monitoring rate was 26.5% and the cesarean section rate in the monitored group was 22.0%. The fetal outcome in the monitored group was better than in the unmonitored group. The establishment of a fetal intensive care unit is believed to be strongly desirable in improving fetal surveillance during labour. Fetal monitors should be stationed in the delivery room as well as in the first-stage room.     

Time trends in twin perinatal mortality in northern England, 1982-94. Northern Region Perinatal Mortality Survey Steering Group.

The dynamics of perinatal mortality rates (PNMR) and causes of death in twin pregnancies over 13 years in the Northern Region of the National Health Service in England is described. All twin perinatal deaths occurring between 1982-1994 were identified from the Northern Region Perinatal Mortality Survey. The twinning rate increased from 9.9 per 1000 maternities in 1982 to 12.0 in 1994. There was a total of 10,734 twin pregnancies and of these 421 resulted in 530 perinatal deaths. The perinatal mortality rate in twins significantly decreased over time (1982-87, 55.4 per 1000; 1988-94, 44.4 per 1000; P = 0.01). The PNMR was significantly higher for twins from like-sexed than from unlike-sexed pairs (53.5 and 34.4 per 1000 respectively, P < 0.001). Despite no improvement in birthweight distribution in the twin population, birthweight-specific perinatal mortality rates for both like and unlike-sexed twins decreased for each birthweight category in 1988-94 compared with 1982-87. Twins with very low birthweight (< 1500 g) comprised 69%, and preterm twins (< 37 completed weeks of gestation) 74.9% of all twin perinatal deaths. The major immediate cause of early neonatal death was pulmonary immaturity (63%); antepartum anoxia caused 76.9% of antenatal deaths. Unexplained preterm labour and intrauterine death were the leading obstetric factors underlying death in twins. Despite a decrease over the 13 years, the perinatal mortality rate in twins in the Northern Region remains high. Continued monitoring of trends in twinning and mortality rates is needed to inform health care planning.     

Contribution of preterm delivery to perinatal mortality.

A detailed retrospective analysis was made of the records of 486 preterm infants, who accounted for 5-1% of all births during 1973 and 1974. Whereas preterm delivery did not contribute to perinatal mortality in terms of stillbirth, it outweighed all other causes in terms of early neonatal deaths. Preterm birth was responsible for 85% of the early neonatal deaths not due to lethal congenital deformities. Early neonatal mortality rates were closely linked both to gestational age and birth weight and to the reason for preterm birth. Early neonatal mortality was high (97 per 1000) when preterm labour was spontaneous, whether or not associated with material or fetal disease or with multiple pregnancy, but low (27 per 1000) when preterm delivery was elective. Preventing spontaneous preterm labour would considerably reduce neonatal mortality in our community.     

Classification of perinatal mortality

A classification based upon pathophysiological mechanisms has been applied to perinatal mortality. The approximate relevance of each group was: fetal insufficiency 40%, respiratory failure 30%, developmental abnormality 20%, and the specific mechanisms 10%. Secondary subclassification of each category according to the maturity of the gestation emphasizes the importance of prematurity in the total perinatal mortality (66%) and the relevance of each pathophysiological mechanism in each phase of maturity. The principal mechanism in the mature group is fetal insufficiency and in the premature group, particularly between 20 and 28 weeks, it is neonatal respiratory failure. Perinatal death due to developmental abnormalities occurs most frequently in the mature infant and due to specific mechanisms in the premature infant, particularly between 29 and 36 weeks. It is suggested that greater emphasis should be placed on perinatal mortality rather than the separate consideration of stillbirth and neonatal mortality.     

Evaluating perinatal mortality rates: effects of referral and case mix.

OBJECTIVE--To evaluate perinatal mortality rates as a method of auditing obstetric and neonatal care after account had been taken of transfer between hospitals during pregnancy and case mix. DESIGN--Case-control study of perinatal deaths. SETTING--Leicestershire health district. SUBJECTS--1179 singleton perinatal deaths and their selected live born controls among 114,362 singleton births to women whose place of residence was Leicestershire during 1978-87. MAIN OUTCOME MEASURE--Crude perinatal mortality rates and rates adjusted for case mix. RESULTS--An estimated 11,701 of the 28,750 women booked for delivery in general practitioner maternity units were transferred to consultant units during their pregnancy. These 11,701 women had a high perinatal mortality rate (16.8/1000 deliveries). Perinatal mortality rates by place of booking showed little difference between general practitioner units (8.8/1000) and consultant units (9.3-11.7/1000). Perinatal mortality rates by place of delivery, however, showed substantial differences between general practitioner units (3.3/1000) and consultant units (9.4-12.6/1000) because of the selective referral of high risk women from general practitioner units to consultant units. Adjustment for risk factors made little difference to the rates except when the subset of deaths due to immaturity was adjusted for birth weight. CONCLUSION--Perinatal mortality rates should be adjusted for case mix and referral patterns to get a meaningful result. Even when this is done it is difficult to compare the effectiveness of hospital units with perinatal mortality rates because of the increasingly small subset of perinatal deaths that are amenable to medical intervention.     

Osteocalcin is vitamin D-dependent during the perinatal period in the rat

The vitamin D-dependence of renal calbindin D-28K and osteocalcin during the perinatal period was studied in fetuses (days 18 and 21) and neonates (days 2, 12, 17 and 22) of rats fed either a standard diet (0.85% Ca-0.7% P; "high Ca-P diet" rats) or a mildly Ca-P restricted diet (0.2% Ca-0.2% P; "low Ca-P diet" rats). Body weight and plasma calcium levels were identical in both groups. Plasma 1,25(OH)2D concentrations were markedly higher in the low Ca-P diet rats at all stages of fetal and neonatal life (in 22-day-old neonates: 536 +/- 58 pg/ml versus 126 +/- 12 pg/ml). 1,25(OH)2D concentrations increased between day 18 and 21 of fetal life, remained constant between day 21 of fetal and day 12 of neonatal life, and increased sharply between day 12 and 17 in both groups; after day 17, 1,25(OH)2D concentrations increased further in pups fed the low Ca-P diet. Renal calbindin D-28K reached peak concentrations on day 12 of neonatal life; calbindin D-28K levels were similar in the high and low Ca-P diet rats at all stages of perinatal development. Plasma osteocalcin levels increased steadily during the perinatal period; at most stages of perinatal life, and already from the fetal period was osteocalcin higher in the low Ca-P diet rats than in the high Ca-P diet rats (in 22-day-old pups: 1106 +/- 47 ng/ml versus 429 +/- 14 ng/ml). Femoral osteocalcin concentrations were also increased in fetal and early neonatal (days 2 and 12) low Ca-P diet rats, while the femoral calcium content and concentration of these rats were decreased in the late neonatal period (days 12, 17 and 22). These studies indicate that osteocalcin is vitamin D-dependent in the fetal and neonatal rat.     

Short term outcome in babies refused perinatal intensive care.

OBJECTIVE--To compare the mortality in babies refused admission to a regional perinatal centre with that in babies accepted for intensive care in the centre. DESIGN--Retrospective study with group comparison. SETTING--Based at the Royal Maternity Hospital, Belfast, with follow up of patients in all obstetric units in Northern Ireland. PATIENTS--Requests for transfer of 675 babies to the regional perinatal centre (prenatally and postnatally) were made from hospitals in Northern Ireland between January 1984 and December 1986. In all, 343 babies were refused admission to the centre, and complete data were available for 332 of them. These babies were either admitted to other neonatal intensive care units (261 babies) or remained in hospitals with only special care cots (71 babies). MAIN OUTCOME MEASURE--Short term mortality. RESULTS--Seventy of the 332 babies refused admission to the centre died compared with 51 of the 333 who were admitted. Multivariate analysis based on a logistic model showed a non-significant increase in mortality among babies treated in other intensive care units compared with babies treated in the centre (relative odds 1.2; 95% confidence interval 0.7 to 1.9). The increase in mortality in babies who remained in a special care baby unit, however, was significant (3.5; 1.7 to 7.0). This increase was particularly significant in babies born at less than or equal to 32 weeks'' gestation and who weighed less than 1500 g (8.4; 2.5 to 28.1). CONCLUSIONS--The results of the study confirm the benefits of neonatal intensive care and its particular value in improving survival in babies of low birth weight. As the babies were refused admission to the regional perinatal centre because intensive care cots were not available this deficiency should be corrected.     

Influence of maternal age, parity and social class on perinatal mortality in Scotland: 1960-82

This study examines secular changes in the influence of maternal age, parity and social class on perinatal mortality in Scotland. Using cross-sectional national data on all Scottish legitimate births the effects of these factors are estimated on the risk of stillbirths, neonatal and perinatal deaths, and the extent to which the current pattern of relative risks in the early 1980s has changed over the past 2 decades is investigated. Social class is used as a crude measure of relative as opposed to absolute differences in socioeconomic conditions which may influence reproductive outcomes. The effects of age, parity and social class are estimated using logistic models. The most parsimonious model adequately describing the data is provided by a main effects model without interactions. Despite changes in reproductive behavior, improved access to maternity services and more effective perinatal care, the influence of maternal age and social class on perinatal mortality remained unchanged between 1960 and 1982. Although the absolute risks of stillbirths and neonatal deaths declined in all maternal age groups, this improvement was not accompained by a significant change in the relative risks traditionally associated with age. Despite no significant changes in the traditional J-shaped association between parity and stillbirths, cross-sectional analysis shows that in the early 1980s the risk of both neonatal and perinatal deaths decreased as parity increased. This finding is consistent with the pattern of risks observed in longitudinal studies and retrospective surveys of reproductive histories. In view of the stability of age, parity and social class effects on the risk of perinatal mortality, little if any of the overall decrease in Scottish stillbirth and neonatal death rates can be attributed to a significant narrowing of relative risks. The results suggest that the attributable risk of high maternal age or low social class on perinatal mortality is negligible. Future improvements in perinatal mortality are thus likely to result from a continuation of the uniform decrease in perinatal mortality for women of all ages, parities and social classes and not from a diminishing of differences in relative risks which are now virtually identical for a large and growing % of women in Scotland.     

The physiologic and medical rationale for intrapartum fetal monitoring

In the United States and most industrialized countries, intrapartum fetal surveillance is performed primarily by electronic fetal heart rate monitoring. Following implementation of this technology into clinical practice, a reduction in perinatal mortality has been accompanied by a concomitant increase in the cesarean section rate to concerning levels. Although these trends are not solely due to one factor such as electronic fetal heart rate monitoring, it is well-recognized that this method of surveillance is hampered by subjectivity in interpretation and by a high false-positive (falsely nonreassuring) rate. The purpose of this review is to assess the physiologic rationale for intrapartum assessment, the significant limitations of current primary and ancillary monitoring methods, and the development of new technologies such as fetal oxygen saturation monitoring (pulse oximetry) that potentially hold great promise for the future.     

Perinatal outcome of singletons and twins after assisted conception: a systematic review of controlled studies

Objective To compare the perinatal outcome of singleton and twin pregnancies between natural and assisted conceptions.Design Systematic review of controlled studies published 1985-2002.Studies reviewed 25 studies were included of which 17 had matched and 8 had non-matched controls.Main outcome measures Very preterm birth, preterm birth, very low birth weight, low birth weight, small for gestational age, caesarean section, admission to neonatal intensive care unit, and perinatal mortality.Results For singletons, studies with matched controls indicated a relative risk of 3.27 (95% confidence interval 2.03 to 5.28) for very preterm (< 32 weeks) and 2.04 (1.80 to 2.32) for preterm (< 37 weeks) birth in pregnancies after assisted conception. Relative risks were 3.00 (2.07 to 4.36) for very low birth weight (< 1500 g), 1.70 (1.50 to 1.92) for low birth weight (< 2500 g), 1.40 (1.15 to 1.71) for small for gestational age, 1.54 (1.44 to 1.66) for caesarean section, 1.27 (1.16 to 1.40) for admission to a neonatal intensive care unit, and 1.68 (1.11 to 2.55) for perinatal mortality. Results of the non-matched studies were similar. In matched studies of twin gestations, relative risks were 0.95 (0.78 to 1.15) for very preterm birth, 1.07 (1.02 to 1.13) for preterm birth, 0.89 (0.74 to 1.07) for very low birth weight, 1.03 (0.99 to 1.08) for low birth weight, 1.27 (0.97 to 1.65) for small for gestational age, 1.21 (1.11 to 1.32) for caesarean section, 1.05 (1.01 to 1.09) for admission to a neonatal intensive care unit, and 0.58 (0.44 to 0.77) for perinatal mortality. The non-matched studies mostly showed similar trends.Conclusions Singleton pregnancies from assisted reproduction have a significantly worse perinatal outcome than non-assisted singleton pregnancies, but this is less so for twin pregnancies. In twin pregnancies, perinatal mortality is about 40% lower after assisted compared with natural conception.     

The outcome of twin pregnancies complicated by single fetal death after 20 weeks of gestation.

A retrospective study involving 972 twin births was conducted to evaluate the maternal and fetal outcomes of twin pregnancies complicated by single fetal death. The incidence of single fetal death in twin pregnancies after 20 weeks was 3.3%. Preterm birth rates for 37 and 32 gestational weeks were 81.3% and 41.6% respectively. The median interval between the diagnosis of fetal death and the delivery was 11 days (range 1-27 days). Eighteen (56%) infants were delivered by cesarean and 14 (43%) vaginally. Twin-twin transfusion syndrome (TTTS) was the cause of single fetal death in 8 of 32 twin pregnancies (25%). Ten of the surviving co-twins were lost in the neonatal period (31.3%) and half of those neonatal deaths were due to TTTS. TTTS is the major contributor for perinatal mortality in same-sex twins complicated by single fetal death. The death of one twin in utero should not be the only indication for preterm delivery, and in case of severe prematurity with a stable intrauterine environment; expectant management may be advisable until fetal lung maturation ensues.     

Canine perinatal mortality: a cohort study of 224 breeds

Canine perinatal mortality is known to be relatively high. However, the literature on perinatal mortality in dogs is still sparse and often refers to a single or only a few breeds. The aim of this large-scale observational study was to describe the perinatal mortality in purebred dogs of various breeds at both puppy and litter level. In addition, the influence of breed, breed size, litter size, age of the bitch, litter number and season for whelping on the risk of perinatal mortality at litter level was studied and the mean litter size at eight days and eight wks after birth was calculated. A retrospective cohort study was performed by studying 10,810 litters of 224 breeds registered in the Norwegian Kennel Club in 2006 and 2007. Perinatal mortality was defined as the sum of stillborn puppies and puppies that died during the first wk after birth (early neonatal mortality) and was present in 24.6% of the litters. Eight percent of the puppies died before eight days after birth, with 4.3% as stillbirth and 3.7% as early neonatal mortality. For most breeds the perinatal mortality was low, but for some breeds a higher perinatal mortality was found. The mean litter size at eight days and eight wks after birth was 4.97 (±0.02) and 4.92 (±0.02) puppies, respectively. Of all puppies born, only 1% died during the period from eight days to eight wks after birth. Random effects logistic regression analysis indicated that increasing litter size and age of the bitch were associated with an increased risk of stillbirth, early neonatal mortality and total perinatal mortality at the litter level (P < 0.001). The random breed effect was significant for all outcomes. Litter number also had a significant effect on stillbirth, early neonatal mortality and total perinatal mortality at the litter level, with the highest risk of perinatal mortality found in the first litter (P < 0.001). Further, the risk of early neonatal mortality was doubled in litters with stillborn puppies. No significant effect of whelping season on perinatal mortality at litter level was found. An interaction existed between the age of the bitch and litter number and the risk of stillbirth was three times as high (odds ratio = 3.00) in litters from bitches having their first litter after the age of six y. Breed was a more important determinant of perinatal mortality in litters than breed size. However, more than 90% of the variation in perinatal mortality was found at the individual litter level and efforts to minimize puppy mortality should be targeted at the management of the individual litter rather than at the breed level.     

疤痕子宫妊娠妇女经产道分娩的可行性、安全性和相关危险因素分析

目的:探讨疤痕子宫妊娠妇女经产道分娩的可行性、安全性和相关危险因素。方法:选择疤痕子宫妊娠妇女120例,根据分娩方式的不同分为剖宫产组(80例)与自然分娩组(40例),观察再次剖宫产的原因与两组的预后情况。结果:再次剖宫产的指征主要为疤痕子宫(患者拒绝试产)、产程异常、胎儿窘迫、前置胎盘等。自然分娩组的产时出血量明显少于剖宫产组(P0.05),产后出血与产后感染发生率也均明显低于剖宫产组(P0.05)。两组的5分钟Apgar评分对比差异无统计学意义,但自然分娩组新生儿黄疸与新生儿湿肺发生情况明显低于剖宫产组(P0.05)。自然分娩组的分娩满意度为97.50%,剖宫产组为83.75%,自然分娩组明显高于剖宫产组(P0.05)。结论:疤痕子宫妊娠妇女经产道分娩可行性好,能减少对于产妇与新生儿的影响,安全性佳,但也要根据产妇的实际情况进行具体选择。     

Contribution of twin pregnancy to perinatal mortality and fetal growth retardation; reversal of growth retardation after birth.

A survey of factors associated with perinatal mortality in 511 twins and fetal growth retardation and its reversal in 262 twins is presented. The incidence of stillbirth was almost 50% higher in twins than in singletons and the neonatal mortality was six times as high. Eighty percent of the neonatal deaths occurred in infants born prior to or at 30 weeks of gestation; 93% of the deaths were in infants weighing less than 1500 g and 75% occurred within 48 hours of birth. Fetal malnutrition was the main cause of stillbirth, and respiratory distress syndrome and asphyxia neonatorum were the main causes of neonatal death. One quarter of the twins had fetal growth retardation, a prevalence 10 times that in singletons. In almost all, the growth retardation was reversed by high-energy feedings. Although twins represented only 1% of all pregnancies and 2% of live births, they composed 12% of infants with early neonatal death and 17% of growth-retarded infants. A program is suggested for reduction of twin mortality and morbidity.     

Prognosis for infants with idiopathic respiratory distress syndrome.

Infants with the idiopathic respiratory distress syndrome admitted to the intensive care unit during January 1972 to September 1974 were reviewed. The overall mortality rate for infants whose birth weight was 1000 g or more was under 10%, and for those who established spontaneous respiration after birth it was less than 5%. The hyperoxia test was not a useful guide to prognosis. It was possible on the basis of the infants'' ability to establish spontaneous ventilation after birth to divide them into two groups. In those who established adequate ventilation the mortality rate was 4-5%; in those who did not it was 57%. This test should be generally applied, since not only does it give an immediate guide to the severity of the disease, which is better than that provided by birth weight, gestational age, or the hyperoxia test, but it may be applied to infants born in and outside a hospital providing neonatal intensive care. Improvement in the outlook for infants with a bad prognosis will be achieved only by improvements in perinatal care designed to minimize severe intrapartum asphyxia in infants of low birth weight.     

Successful management of quadruplet pregnancy in a perinatal unit.

A case of quadruplet pregnancy is outlined and the management is described to demonstrate the application of monitoring and therapeutic procedures currently available for a multifetal pregnancy. Recording of the nonstressed fetal heart rate, ultrasound monitoring and glucocorticoid stimulation of pulmonary biochemical maturity were done. A successful outcome was achieved with a combined obstetric-neonatal approach and the experience of a perinatal unit.     

Attitudes to viability of preterm infants and their effect on figures for perinatal mortality.

OBJECTIVE--To examine how local attitudes to management of extreme preterm labour can influence data on perinatal mortality. DESIGN--One year prospective study in a geographically defined population. SETTING--The 17 perinatal units of Trent region. PATIENTS--All preterm infants of less than or equal to 32 weeks'' gestation in the Trent region. INTERVENTIONS--Infants who had been considered viable at birth were referred for intensive care; those who had been considered non-viable received terminal care. MAIN OUTCOME MEASURES--Whether each infant was born alive, dead, or alive but considered non-viable. RESULTS--Large differences were observed among units in the rates of delivery of infants of less than or equal to 27 weeks'' gestation (rates varied from 7.2 to 0 per 1000 births). These differences were not present in the data relating to infants of between 28 and 32 weeks'' gestation. The variation seemed to result from different approaches to the management of extreme preterm labour--that is, whether management took place in a labour ward or a gynaecology ward. CONCLUSIONS--Place of delivery of premature babies (less than or equal to 27 weeks'' gestation) may influence classification and hence figures for perinatal mortality. In addition, the fact that the onus of judgment regarding viability and classification is often placed on relatively junior staff might also affect the figures for perinatal mortality. The introduction of a standard recording system for all infants greater than 500 g would be advantageous.