Outcome of extremely-low-birthweight infants

The overall 1-year survival rate of 261 infants born at 500 g-999g over a 7-year period was 46%. The survival rate of the 220 inborn infants, corrected for birth defects, would have increased from 47% to 57% if delivery room deaths were excluded and to 62% if postneonatal deaths had also been ignored. Survival improved progressively with increasing 100g weight groups. The disability rate in the 108 survivors who were at least 2 years old corrected for prematurity was 28% with little variation between the 100g weight groups. There were no significant trends in annual perinatal mortality, 1-year survival and disability rate in survivors over the study period for the inborn population. The male infants had significantly lower normal-survival rate than the female infants. Small-for-gestational-age infants, comprising 11% of the inborn group, had significantly better survival but a higher disability rate. Multiple births had significantly lower survival and normal-survival rates than had singleton births. Infants whose mothers were transferred for delivery at the perinatal centre before onset of labour had a significantly better survival rate than those whose mothers had 'booked' and those who were transferred in labour.     

Are active labour and mode of delivery still a challenge for extremely low birth weight infants? Experience at a tertiary care hospital

Objective

This study was to evaluate the impact of mode of delivery and timing of caesarean section in extremely preterm births, below 28 weeks of gestation, on long-term survival and psychomotor outcomes.

Study design

This was a single-centre retrospective cohort study of 84 cases of extremely low birth weight infants with complete maternal, obstetrical and neonatological information. Mortality and survival with neurological disabilities at 18 months of life were considered outcome measures.

Results

Forty percent of deliveries were at or less than 25 weeks of gestation and birth weight was ≤500 g in 14% of all infants. The overall survival rate was 54.8% with a prevalence of neuromotor impairment with disability among the survivors of 26.1%. After adjustment using multiple logistic regression, only extreme prematurity (≤25 weeks) and birth weight below 500 g had significant effects on survival (p < 0.05), regardless of mode and timing of delivery.

Conclusions

Mode of delivery and labour seem not to play a significant role in adverse neonatal outcomes, either mortality or neuro-developmental impairment, in extremely low birth weight infants.     

Outcome of Singleton Infants Delivered Vaginally or by Caesarean Section at 23 to 28 Weeks'' Gestation

The survival and impairment rates of 276 inborn singleton infants of 23-28 weeks' gestation were reported according to route of delivery and mode of presentation. The Caesarean section rate was 29% overall, ranging from 13% at 25 weeks to 46% at 28 weeks. In the vertex group, no significant difference in survival or impairment rate was found between Caesarean and vaginal births. In the non-vertex group, Caesarean births had a similar survival rate but a significantly lower impairment rate compared to vaginal births. For Caesarean births, no significant difference in survival or impairment rate was found between vertex and non-vertex groups. In contrast, for vaginal births, the mode of presentation was important: the non-vertex group had a significantly lower survival rate and higher impairment rate compared to the vertex group. We found no evidence to support the use of Caesarean section in extremely preterm infants with vertex presentation, except for recognized maternal or fetal indications. The findings in the non-vertex group indicated that there is a definite need for a randomized clinical trial to investigate the possible benefits of Caesarean section in extremely preterm infants with non-vertex presentation.     

Outcome of Extremely Low Birth-weight Infants in Relation to the Hospital of Birth

There were 351 liveborn infants of birth-weight 500-999 g born in the State of Victoria in the years 1979 and 1980; 89/351 (25.4%) survived to the age of 2 years: 42 (47.2%) survivors were of gestational ages of 24 to 26 weeks and 47 (52.8%) were born at 27 to 32 weeks' gestation. Survival of these extremely low birth-weight infants was significantly better (71/245, 29%) for births in tertiary centres compared with those born elsewhere (18/106, 17%). Of the 351 livebirths, 69.8% occurred in 1 of the 3 tertiary centres. All 89 survivors were traced; 84 (94.4%) were assessed at the age of at least 2 years by a multidisciplinary team. Three children had been fully assessed at 1 year of age and paediatric reports were available for 2 children. The quality of survival of children born in tertiary centres was significantly better than those transferred to a tertiary centre after birth; the prevalence of serious functional handicap was 72.2% (13/18) for outborn children compared with 22.5% (16/71) for those born in tertiary centres. The prevalence of serious functional handicap in the inborn survivors was lowest (9/55, 16.4%) in singleton births who had been of appropriate birth-weight for gestation. A review of the 18 surviving outborn infants' records indicated that 6 (33.3%) could have been transferred to a tertiary centre in utero and for the 12 infants where birth in a tertiary centre was not feasible, improvements in the early neonatal care were possible in another 7 infants.     

Wessex Perinatal Mortality Survey 1982

Summary. A survey of 335 perinatal deaths in the Wessex region revealed a perinatal mortality rate of 10·1 per 1000 total births. Lethal malformations accounted for 82 (24%) deaths. Of the 253 normally formed infants, 124 (49%) died during pregnancy and 33 (13%) in labour. More than 60% of the stillbirths weighed >1500 g. Of the 96 postpartum deaths, half occurred within 24 h of delivery, mostly following complications of labour and circumstances suggesting hypoxia. The Aberdeen classification showed half of the mothers had pregnancy complications: other predisposing factors were identified in 10% of perinatal deaths. There were 185 neonatal deaths of which 150 occurred within 7 days and 35 within the next 3 weeks. Sixteen (46%) of the late neonatal deaths were due to a congenital abnormality; pregnancy or labour complications were present in six (32%) of the remaining 19 normally formed infants. Review of existing methods of antenatal supervision in particular, followed by the use of better monitoring systems for earlier detection of fetal distress and prompt action when indicated, together with improvement in neonatal care in the first 24 h after birth should further reduce the perinatal mortality.     

Wessex perinatal mortality survey 1982

A survey of 335 perinatal deaths in the Wessex region revealed a perinatal mortality rate of 10.1 per 1000 total births. Lethal malformations accounted for 82 (24%) deaths. Of the 253 normally formed infants, 124 (49%) died during pregnancy and 33 (13%) in labour. More than 60% of the stillbirths weighed greater than 1500 g. Of the 96 postpartum deaths, half occurred within 24 h of delivery, mostly following complications of labour and circumstances suggesting hypoxia. The Aberdeen classification showed half of the mothers had pregnancy complications: other predisposing factors were identified in 10% of perinatal deaths. There were 185 neonatal deaths of which 150 occurred within 7 days and 35 within the next 3 weeks. Sixteen (46%) of the late neonatal deaths were due to a congenital abnormality; pregnancy or labour complications were present in six (32%) of the remaining 19 normally formed infants. Review of existing methods of antenatal supervision in particular, followed by the use of better monitoring systems for earlier detection of fetal distress and prompt action when indicated, together with improvement in neonatal care in the first 24 h after birth should further reduce the perinatal mortality.     

The National Birth Center Study. Part III--Intrapartum and immediate postpartum and neonatal complications and transfers, postpartum and neonatal care, outcomes, and client satisfaction.

This is the final article of the three-part report of the National Birth Center Study. Eight percent of the mothers or infants had serious complications; 16% were transferred, 12% before and 4% after the deliveries. Fifteen percent of transfers were emergencies. Nulliparous women were much more likely than parous women to experience dystocia, be transferred, or have cesarean sections. Seventy-five percent of the nulliparous women gave birth in the centers, compared with 95% of the parous women. Eighty-four percent of the women had at least one postpartum home or office visit. There were 11,814 mothers, no maternal deaths, and 15 intrapartum/neonatal deaths (1.3/1,000 births, 0.7 excluding congenital anomalies). Postterm deliveries with macrosomic infants, placental abruption, sustained fetal distress, and thick meconium were associated with high mortality. Mortality was very low for those not transferred and much lower for transfers during labor as compared with those after the delivery. Women with no medical/obstetric risk factors had the lowest rates of transfers and serious complications. Except for postterm pregnancies, the intrapartum/neonatal mortality rate for birth center clients was not higher than rates from studies of low-risk hospital births, and the cesarean section rate was lower. There is no evidence that hospitals are a safer place for low-risk births.     

Trends in neonatal mortality in Benin City, Nigeria

A total of 18,334 live births and 376 neonatal deaths at the University of Benin Teaching Hospital were analyzed. The neonatal mortality rate has declined significantly from 49.5/1000 in 1974 to 16.4/1000 live births in 1981. The decrease mainly resulted from the reduction of mortality of full size infants (greater than 2500 g) and deaths resulting from perinatal asphyxia. Further reduction may be anticipated if careful attention is paid to the management of breech delivery and if a more intensive care for low birth weight infants is provided.     

THE NATIONAL BIRTH CENTER STUDY

This is the final article of the three-part report of the National Birth Center Study. Eight percent of the mothers or infants had serious complications; 16% were transferred, 12% before and 4% after the deliveries. Fifteen percent of transfers were emergencies. Nulliparous women were much more likely than parous women to experience dystocia, be transferred, or have cesarean sections. Seventy-five percent of the nulliparous women gave birth in the centers, compared with 95% of the parous women. Eighty-four percent of the women had at least one postpartum home or office visit. There were 11,814 mothers, no maternal deaths, and 15 intrapartum/neonatal deaths (1.3/1,000 births, 0.7 excluding congenital [Text missing in PDF]omalies). Postterm deliveries with macrosomic infants, placental abruption, sustained fetal distress, and thick meconium were associated with high mortality. Mortality was very low for those not transferred and much lower for transfers during labor as compared with those after the delivery. Women with no medical/obstetric risk factors had the lowest rates of transfers and serious complications. Except for postterm pregnancies, the intrapartum/neonatal mortality rate for birth center clients was not higher than rates from studies of low-risk hospital births, and the cesarean section rate was lower. There is no evidence that hospitals are a safer place for low-risk births.     

Changing Outcome for Infants of Birth-weight 500-999g Born Outside Level 3 Centres in Victoria

Summary: The aim of this study of extremely low birth-weight (ELBW, birth-weight 500–999 g) infants born in Victoria was to determine the changes between 3 distinct eras; 1979-80, 1985-87, and 1991-92, in the proportions who were born outside level 3 perinatal centres (outbom), the proportions of outborn infants who were transferred after birth to a level 3 neonatal unit, the survival rate for outborn infants, and sensorineural impairment and disability rates in outborn survivors. The proportion of ELBW livebirths who were outborn fell significantly over successive eras, from 30.2% (106 of 351) in 1979-80, to 23.0% (129 of 560) in 1985-87, and to 15.6% (67 of 429) in 1991-92. Between 1979-80 and 1985-87, die proportions who were outborn fell predominantly in those of birth-weight from 800–999 g, whereas between 1985-87 and 1991-92 the proportions who were outborn fell predominandy in those of birth-weight 500–799 g. The proportions of outborn infants who were transferred after birth to a level 3 neonatal unit were similar in die 3 eras, at 49.1%, 38.0% and 41.2%, respectively. The survival rates for outborn infants were lower in each era dian for infants born in a level 3 perinatal centre. Only 1 outborn infant not transferred after birth to a level-3 unit survived in any era. The survival rates for infants transferred after birth were similar in the first 2 eras, but rose significantly in 1991-92 (34.6%, 36.7% and 60.7%, respectively). The rates of sensorineural impairments and disabilities in survivors fell significantly between die first 2 eras, and remained low in the last era. It is pleasing that the proportion of tiny babies who were outborn fell significantly over time, reflecting increased referral of high-risk mothers to level 3 perinatal centres before birth. For ELBW outborn infants, survival prospects free of substantial disability are reasonable, but not as good as for those born in level 3 perinatal centres.     

Obstetric variables predicting survival of the immature newborn (less than or equal to 1000 gm): a five-year experience at a single perinatal center

The immature neonate constitutes less than 3% of total births and yet accounts for almost 50% of all perinatal deaths. In a 5-year period, 476 consecutive live and inborn neonates weighing less than or equal to 1000 gm were studied. The purpose of this study was to describe our experience with these pregnancies and determine the obstetric predictors of survival. Statistical methods of univariate and multivariate analysis were used. Survival was defined as the discharge home of an alive infant. The overall survival rate without exclusions was 40.3%. The following variables were most significant and accurately predicted survivors in 76.2% and nonsurvivors in 69.2% of cases: a combination of birth weight, 5-minute Apgar score, gestational age, cervical dilatation on admission, sex, a more recent study time interval, and race. Of the factors studied, the following were directly related to advancing gestational age and birth weight: higher Apgar scores at 1 and 5 minutes, increased operative delivery rate, and increased frequency of tocolysis and glucocorticoid usage; of these factors, only the 5-minute Apgar score remained statistically significant, when controlling for gestational age and birth weight by multivariate analysis.     

Survival prospects of extremely preterm infants: a 10-year experience in a single perinatal center.

During a 10-year period, 1977 to 1986, 233 (53%) of 442 inborn live births between 23 and 28 weeks' gestation survived; their 1-year survival rate was 7% at 23 weeks, 30% at 24 weeks, 31% at 25 weeks, 55% at 26 weeks, 67% at 27 weeks, and 71% at 28 weeks. No significant change in survival rate was observed over the years. Twelve percent of pregnancies and 20% of infants were multiple gestations. Singleton births had significantly higher survival rates compared with multiple births (58% versus 41%). The obstetric intervention rate, as measured by the frequency of cesarean section, increased significantly over the years: from 15% in 1977-1978 to 33% in 1985-1986. The neonatal intervention rate, as measured by the frequency of live births offered neonatal intensive care, remained unchanged. Ten percent were not treated: 4% had major malformations and 6% were considered "nonviable." Active perinatal management, which assumed fetal-neonatal viability, accounted for better survival rates compared with centers with a more passive management policy. Information on survival based on gestational cohorts plays an important role in helping obstetricians, neonatologists, and parents make appropriate management decisions.     

Effects of antenatal corticosteroid administration on mortality and long-term morbidity in early preterm, growth-restricted infants

OBJECTIVE: To evaluate the effect of antenatal corticosteroids on mortality, morbidity, and disability or handicap rate in early preterm, growth-restricted infants. METHODS: This case-control study in two tertiary care centers included all live-born singleton infants with growth-restriction due to placental insufficiency, who were delivered by cesarean because of cardiotocographic signs of fetal distress before the beginning of labor at a gestational age of 26-32 weeks during the years 1984-1991. Infants who had been treated antenatally with corticosteroids more than 24 hours and less than 7 days before birth were matched by birth weight, sex, and year of birth with infants whose mothers had been admitted more than 24 hours before delivery but were not treated antenatally with steroids. The main outcome measure was survival without disability or handicap at 2 years corrected age. A sample of 60 case-control pairs would give 81% power to demonstrate 50% increase of this outcome [odds ratio (OR) 3.0] by corticosteroid treatment. Behavior and physical growth were evaluated at school age by questionnaire. RESULTS: The study group and control group consisted of 62 infants each. Survival without disability or handicap at 2 years' corrected age was more frequent in the corticosteroid group [OR 3.2, confidence interval (CI) 1.1, 11.2]. In the long-term follow-up at school age there was a statistically significant negative effect on physical growth (OR 5.1, CI 1.4, 23.8), but no differences in behavior were detected.CONCLUSION: Benefits from antenatal corticosteroids for early preterm, growth-restricted infants appear to outweigh possible adverse effects.     

Neonatal outcome of infants delivered at 26-28 weeks of gestation

The delivery results of 42 infants born to 40 mothers at the gestational age of 26-28 weeks during a period of 5 years were analyzed. The study was evaluated in two periods of time: in the first period out of 15 infants born only 5 (33.3%) survived, while in the second period 21 (77.7%) out of 27 infants survived (p less than 0.01). 38 infants were transferred to a neonatal intensive care unit for premature infants. Only 41% of the infants transferred in the first period survived, as compared to 80.7% of those transferred during the second period (p less than 0.01). There was no significant difference in the mean birth weight at each gestational age between the survivors and those who subsequently died in both periods of the study. In the study groups, cesarean section rate rose from 13.3% in the first period to 44% in the second. Mode of delivery, regardless of the presenting part, did not seem to influence neonatal survival. Obstetrical management, including the performance of operative delivery for fetal indications and active neonatal resuscitation, seems to be reasonable for infants at the gestational age of 26 weeks or more.     

Diabetes in pregnancy: a population-based study of incidence, referral for care, and perinatal mortality

During 1979 and 1980 in Washington State, 260 infants (live births plus fetal deaths greater than or equal to 20 weeks' gestation) were born to women with preexisting diabetes mellitus, the equivalent to a population-based incidence of 2.1 per 1000 total births. One quarter of these women had non-insulin-dependent diabetes prior to pregnancy. The perinatal mortality rate for all infants of diabetic mothers in this series was 108 per 1000, which was eight times the state perinatal mortality rate. Only 45% of births occurred in the five tertiary centers in the state, whereas 39% occurred in hospitals that had fewer than six deliveries per year complicated by overt diabetes. The mortality rate was slightly, but not significantly, lower among infants born in referral hospitals than among those born in primary-level hospitals. Congenital malformations accounted for 43% of the 28 perinatal deaths, and fetal losses between 20 and 27 weeks' gestation accounted for another 21%. During the 2-year study period there were only three cases in which antepartum care in nonspecialty centers may have contributed to a perinatal loss.     

Survival and Neonatal and Neurodevelopmental Outcome of 24–29 Week Gestation Infants According to Primary Cause of Preterm Delivery

Summary: A total of 189 infants of 24–29 weeks' gestation were born in a regional perinatal centre during a 2-year period. They were divided into groups according to the primary cause of preterm delivery: antepartum haemorrhage (n=37, 20%), preeclampsia (n=27, 14%), preterm premature rupture of membranes (n=64, 34%), preterm labour (n=27, 14%), chorioamnionitis (n=16, 8%), other complications (n=18, 10%). The perinatal mortality rate (PMR) was 286/1,000 of whom 44% were stillbirths. The 'other complication' group had the highest PMR due to a large number of intrauterine deaths, with no differences in neonatal mortality between the groups. Preeclampsia was associated with an increased risk of necrotizing enterocolitis and chorioamnionitis was associated with an increased risk of periventricular haemorrhage. Follow-up to at least 2 years was performed in 122 (97%) of survivors. Cerebral palsy occurred in 7%, while 18% had neurodevelopmental disability. No relationship was found between primary cause of preterm delivery and outcome. This information should be of value in counselling parents when preterm delivery is imminent.     

Thoracoamniotic shunting for fetal pleural effusions with hydrops

OBJECTIVE: The purpose of this study was to evaluate perinatal outcome after thoracoamniotic shunting for fetal pleural effusions with hydrops. STUDY DESIGN: This was a retrospective study. RESULTS: Shunting was performed immediately after diagnosis and was successful in all 54 of the cases that were attempted. There were 7 pregnancy terminations, 9 in utero deaths, and 38 live births, of which 7 children died in the neonatal period and 31 children survived. Among the liveborn infants, 27 infants were delivered preterm (71%), of whom 7 infants (15%) had preterm premature rupture of membranes and 4 infants (8.5%) had chorioamnionitis. Perinatal death (23/54 infants; 43%) was related to underlying anomalies (7 cases), pulmonary hypoplasia (5 cases), chorioamnionitis (2 cases), or treatment failure for unknown reasons (9 cases). All 31 survivors had chylothorax; for 28 of the survivors, the chylothorax was primary, and for 3 survivors, the chylothorax was the result of right congenital diaphragmatic hernia, pulmonary sequestration, or Noonan syndrome. CONCLUSION: After the shunting, pleural effusion with hydrops has a 57% survival rate; premature delivery is the leading source of morbidity.     

Outcome of neonates with birth weights of less than 801 grams

The follow-up results of intensive care for 68 infants with birth weights less than 801 g treated at Stanford University Hospital were reviewed. The overall survival rate for these infants was 35%, but was 50% for those infants who had been successfully resuscitated in the delivery room and were admitted to the Intensive Care Nursery. Infants under 601 g in weight or less than 25 weeks gestation were more likely to die in the delivery room, but survival among those admitted to the Intensive Care Nursery did not depend on birth weight or gestational age. One-minute and 5-minute Apgar scores less than 5 and interstitial emphysema were associated with increased risk of neonatal death. Only two of 22 survivors (9%) were severely handicapped and another eight (36%) had remediable disabilities at 2 years of age. No infant developed hydrocephalus and only one infant had spasticity. We suggest that the low incidence of major handicaps among survivors encourages the vigorous resuscitation of infants weighing less than 801 g at birth, yet strategies must be developed that will minimize both prolonged dying and the cost of intensive care for nonviable infants.     

Outcome of premature infants delivered after prolonged premature rupture of membranes before 25 weeks of gestation

OBJECTIVE: To identify factors influencing the outcome of premature infants delivered after prolonged premature rupture of membranes before 25 weeks' gestation. DESIGN AND POPULATION: All premature infants with gestational age <34 weeks, either inborn or outborn, with history of rupture of membranes before 25 weeks' gestation, admitted to our NICU between January 1992 and July 1997, were eligible for this retrospective study. Collected information included birth weight, gestational age at rupture of membranes and at delivery, duration between rupture of membranes and delivery (latency period), severity of oligohydramnios, pre- and post-natal managements, and follow-up of survivors. RESULTS: A total of 28 neonates fulfilled the inclusion criteria. Despite new strategies of ventilation and optimal management, the overall mortality rate was 43% (12/28). Nonsurvivors were significantly less mature at rupture of membranes, and had severe oligohydramnios (anamnios). We also noted less antenatal corticosteroids and antibiotic therapy in this group. Nine of eleven infants (82%) following rupture of membranes before 22 weeks' gestation died shortly after birth. The two remaining infants developed severe bronchopulmonary dysplasia. Nine deaths occurred in thirteen cases (69%) of anamnios. The major death causes were refractory respiratory failure and neurologic complications. Half of all survivors (8/16) developed bronchopulmonary dysplasia. CONCLUSION: The outcome of premature infants following prolonged premature rupture of membranes before 25 weeks' gestation is influenced by gestational age at rupture, severity of oligohydramnios, and antenatal antibiotics and corticosteroids. Neonates with rupture of membranes before 22 weeks have a very low chance of survival at the present time.     

Fetal macrosomia in African women: a study of 249 cases

Objectives  To determine the incidence and risk factors of macrosomia in a Nigerian centre, and to assess the relation of maternal body mass index (BMI) at birth and of the total weight gain during pregnancy to macrosomia and adverse pregnancy outcome. Design  A retrospective review of fetal macrosomia over a 5-year period. Setting  Abia State University Teaching Hospital, Aba in Southeast Nigeria. Subjects  A total of 9,970 parturients managed from 1 January 1999 to 31 December 2003. Out of 249 documented cases of infants with birth weights ≥4,500 g, 240 (96.4%) maternal and neonatal records of macrosomia were available for review. Maternal and neonatal characteristics of the 240 cases were compared with 8,800 other parturients with singleton fetuses in vertex presentation. Results  Macrosomic babies represented 2.5% of the infants delivered (249 of 9,970). Most of the mothers (92.5%) were multiparous. Maternal median weight gain was 11 kg (7–15), while the mean weight gain was 12.5 kg. Maternal median BMI was 28.1 kg/m² at delivery, while the mean BMI was 30.3 kg/m² (range 23–40) at delivery. Macrosomia was suspected in 80% on the basis of clinical examination, sonography, and the presence of the following risk factors in association: previous delivery of an infant weighing >4,000 g (62.5%), maternal weight at booking of more than 80 kg (90%), maternal BMI before delivery of ≥28 kg/m² (50%), gestational diabetes mellitus (2.5%), and weight increase of more than 13 kg during pregnancy (5%). The mean birth weight of the babies was 4,750 g (4,500–5,000). The overall CS rate was 15%. The difference in the CS rate between these mothers and the control was not significant (P = 0.41). Only 9 (3.8%) mothers were successfully delivered with the aid of ventouse due to delayed second stage of labor. There was a significant difference in the complication rates between the mothers of large infants and the control (P < 0.001). Four maternal deaths were associated with macrosomia for a maternal mortality rate of 1667/100,000. Four infants had shoulder dystocia and associated injuries. The perinatal mortality rate was 112.5/1,000 births. Conclusions  The higher the total body weight at birth, the higher the rate of macrosomia. Macrosomia had implications for high morbidity and mortality in the mothers and their infants. Delivery methods need to be evaluated. Caesarean section should be more readily used.