Single Center Outcome of Multiple Births in the Premature and Very Low Birth Weight Cohort in Singapore

OBJECTIVE

The aim of this study is to compare neonatal mortality and morbidity in multiple and singleton preterm/very low birthweight (PT/VLBW) multiethnic Asian infants.

STUDY DESIGN

Cohort study of 676 singleton and 299 multiple PT/VLBW infants born between 2008 and 2012 at KK Women's and Children's Hospital, the largest tertiary perinatal center in Singapore with further stratification by gestational ages 23 to 25 (Group 1), 26 to 28 (Group 2), and ≥29 (Group 3) weeks. Outcome measures included predischarge mortality and major neonatal morbidity.

RESULTS

Overall survival to discharge was comparable for singletons 611/676 (90%) and multiples 273/299 (91%). Use of assisted reproductive technologies (47 vs. 4%), antenatal steroids (80 vs. 68%), and delivery by cesarean section (84 vs. 62%) were significantly higher (p < 0.001) in multiples while pregnancy induced hypertension (8.7 vs. 31.6%, p < 0.001) and maternal chorioamnionitis (31 vs. 41%, p < 0.01) were seen less commonly compared with singleton pregnancies. Survival was comparable between singletons and multiples except for a lower survival in multiples in Group 2 (81.7 vs. 92.4%, p = 0.007). Major neonatal morbidities were comparable for multiples and singletons in the overall cohort. Presence of hemodynamically significant patent ductus arteriosus (HsPDA) requiring treatment (88.9 vs. 72.5%), air leaks (33 vs. 14.6%, p = 0.02), NEC (30 vs. 14.6%, p = 0.04), and composite morbidity (86 vs. 66%, p = 0.031) were significantly higher in multiples in Group 1. A significantly higher incidence of HsPDA (68.1 vs. 52.4%, p = 0.008) was also observed in multiples in Group 2. Multiple pregnancy was not an independent predictor of an adverse outcome on regression analysis (OR: 0.685, 95% confidence interval: 0.629-2.02) even in GA ≤25 weeks.

CONCLUSION

Neonatal mortality and morbidity were comparable in our cohort of PT/VLBW singletons and multiple births, but preterm multiple births ≤25 weeks had a higher incidence of neonatal morbidity.

KEY POINTS

· Use of assisted reproductive technologies was significantly higher in multiples as compared to singletons.. · Major neonatal morbidities and mortality were similar between singletons and multiples in our cohort.. · In gestations less than 25 weeks multiples had higher neonatal morbidities than their singleton counterparts..

Saline Enemas versus Glycerin Suppositories to Promote Enteral Feeding in Premature Infants: A Pilot Randomized Controlled Trial

BACKGROUND

Meconium retention is associated with feeding intolerance. Trials using glycerol and Gastrografin to expedite the evacuation of meconium have failed to generate clinically valid results for efficacy and safety.

OBJECTIVE

We assessed the feasibility of aggressive meconium evacuation with saline rectal washout (RW) in very-low-birth-weight infants to reduce the time it took them to reach full enteral feeds.

METHODS

We conducted an open-label, pilot, randomized controlled trial (RCT) (birth weight stratified, i.e., to 750-999 g and 1,000-1,500 g) of early aggressive meconium evacuation with twice-daily normal saline RW compared to conventional management with glycerin suppositories (GS), until full enteral feeds (110 mL/kg/day) were reached. Primary outcome was time to reach full enteral feeds. Safety, process, and secondary efficacy outcomes were also evaluated.

RESULTS

Sixty-one infants were randomized, 28 to RW and 33 to GS. The process and feasibility outcomes were met. RW was found to be safe; none of the RW-randomized infants developed necrotizing enterocolitis (≥ stage II) or complications secondary to RW. Evidence of efficacy was supported: in the 750-999 g stratum (n = 15), the median time to full enteral feeds was shorter with RW (11.0 days, 95% CI: 10.4-11.6) than with GS (15.6 days, 95% CI: 13.0-18.2) by a reduction of 4.6 days (p = 0.027). In the 1,000-1,500 g stratum (n = 46), there was no evidence of benefit: RW 10.2 days (95% CI 8.3-12.1) and GS 10.1 days (95% CI 9.3-10.9, p = 0.304).

CONCLUSION

Our protocol was feasible and an adequately powered RCT is required to confirm the findings of this trial.

Achalasia and Down syndrome: a unique association not to be missed

Achalasia is a rare primary oesophageal motility disorder that presents as a functional obstruction at the oesophago-gastric junction. The prevalence of achalasia in Down syndrome is much higher, which implies a unique association between these two uncommon conditions. Although the exact aetiology of achalasia is unknown, studies have proposed that its pathogenesis is related to autoimmune, infectious or genetic factors, leading to the intrinsic loss of inhibitory myenteric neurons in both the oesophagus and lower oesophageal sphincter. We herein report the case of a 16-month-old girl with Down syndrome and achalasia who was initially treated for gastro-oesophageal reflux disease. The diagnosis of achalasia was made only when her condition deteriorated, with subsequent failure to thrive, and upon further investigations, including barium swallow study and upper endoscopy. We also review the various mechanisms postulated in the development of achalasia in Down syndrome, as well as the various treatment modalities available for this rare disorder.

Neonatal Outcome of the Late Preterm Infant (34 to 36 Weeks): The Singapore Story

INTRODUCTION

Late preterm (LP) neonates (34 to 36 weeks gestation) are often managed like term neonates though current literature has identified them to have greater complications. The primary objective of our study was to evaluate and compare morbidity and resource utilisation in LPs especially in view of paucity of Asian studies in this regard.

MATERIALS AND METHODS

A retrospective audit was carried out on 12,459 neonates born in KK Women's and Children's Hospital (KKWCH). The chief outcome measures were hypoglycaemia, hypothermia, respiratory morbidity, feeding problems and neonatal jaundice. Resource utilisation included neonatal intensive care unit (NICU) admission, mechanical ventilation, parenteral nutrition and length of hospitalisation.

RESULTS

Of 12,459 deliveries, 1221 (10%) were LP deliveries with a significantly increasing trend of 8.6% to 10% from 2002 to 2008 (P = 0.001). Neonatal morbidity in the form of hypoglycaemia (34 weeks vs 35 to 36 weeks vs term: 26% vs 16% vs 1%); hypothermia (5% vs 1.7% vs 0.2%); feeding difficulties (30% vs 9% vs 1.4%); respiratory distress syndrome (RDS) (4% vs 1% vs 0.1%); transient tachypnea of the newborn (TTNB) (23% vs 8% vs 3%) and neonatal jaundice (NNJ) needing phototherapy (63% vs 24% vs 8%), were significantly different between the 3 groups, with highest incidence in 34-week-old infants. Resource utilisation including intermittent positive pressure ventilation (IPPV) (15% vs 3.5% vs 1%), total parenteral nutrition/intravenous (TPN/IV) (53% vs 17% vs 3%) and length of stay (14 ± 22 days vs 4 ± 4.7 days vs 2.6 ± 3.9 days) was also significantly higher (P <0.001) in LPs.

CONCLUSION

LP neonates had significantly higher morbidity and resource utilisation compared to term infants. Among the LP group, 34-week-old infants had greater complications compared to infants born at 35 to 36 weeks.

Neonatal outcome of extremely preterm Asian infants ⩽28 weeks over a decade in the new millennium

OBJECTIVE

To evaluate predischarge neonatal mortality and morbidity and associated risk factors in extremely preterm Asian infants ⩽28 weeks, over a decade, so as to facilitate formulation of perinatal guidelines and counseling.

STUDY DESIGN

Cohort study of 887 liveborn extremely preterm neonates between 2000 and 2009 at KKH, the centralized perinatal center in Singapore. Outcome measures were predischarge mortality, presence of one or more major neonatal morbidities and the composite outcome of mortality or neonatal morbidity.

RESULT

Overall survival to discharge was 709/887 (80%) and was significantly higher with increasing gestational age (GA) (19% at 23 weeks to 93% at 28 weeks, P<0.001). Survival remained unchanged between 78 and 86% during the decade with no significant secular trend. Overall incidence of major morbidities were bronchopulmonary dysplasia (29%), late onset sepsis (23%), severe retinopathy of prematurity (21%), Grade 3 to 4 intraventricular hemorrhage (12%) and necrotizing enterocolitis ⩾Bells' stage II/focal intestinal perforation (9%). Composite morbidity was seen in 465/835 (56%) neonatal intensive-care unit admissions, decreased with increasing GA (P<0.001; odds ratio 0.65 (95% confidence interval 0.56 to 0.75) and was independently predicted by birth weight, Clinical Risk Index for Babies-revised version II score, male gender, presence of patent ductus arteriosus and airleaks.

CONCLUSION

Although there was no significant trend in neonatal survival or composite morbidity over the decade, improved survival and morbidity were seen with increasing GA.

Systemic Candidiasis in Extremely Low Birthweight (ELBW) Neonates Despite the Routine Use of Topical Miconazole Prophylaxis: Trends, Risk Factors and Outcomes over an 11-Year Period

INTRODUCTION

This study aims to determine the incidence, trends of systemic candidiasis and meningitis in extremely low birthweight (ELBW) neonates (<1000 gms) despite the routine use of topical miconazole prophylaxis and to compare the risk factors, adverse outcomes and comorbidities with controls.

MATERIALS AND METHODS

Retrospective cohort study of ELBW neonates with systemic candidiasis and meningitis over an 11-year period (1997 to 2007). Matched case control analyses were performed to determine the risk factors and comorbidities which were severe intraventricular haemorrhage (IVH), severe retinopathy of prematurity (ROP), patent ductus arteriosus (PDA) requiring treatment, necrotising enterocolitis (NEC), chronic lung disease (CLD) and cholestatic jaundice. Mortality and end organ involvement secondary to systemic candidiasis were identified as adverse outcomes.

RESULTS

Of the 757 ELBW neonates, 51 (6.7%) had evidence of systemic candidiasis with a significant 3-fold increase in trend noted in 2007 as compared against 1997 (12.1% vs 3.8%) (RR 1.2, 95% CI, 1.06 to 1.36, P <0.001). This corresponds to a significant increasing trend of preceding or co-existent bacterial blood stream infections (BSI) in neonates with systemic candidiasis (0% in 1997 vs 7.1% in 2007, RR 1.40, 95% CI, 1.04 to 1.25, P = 0.005). On logistic regression analysis, decreasing gestational age was an independent risk factor for systemic candidiasis (OR 2.0, 95% CI, 1.52 to 2.63, P <0.001). Candida meningitis was detected in 4/38 (10.5%) and end organ involvement in 17 (33%). The organisms isolated were Candida parapsilosis 31 (61%), Candida albicans 17 (33%) and Candida glabrata 3 (5.8%). Significantly higher mortality was seen in cases when compared to controls 10/51 (19.6%) vs 76/706 (10.7%) (OR 2.02, 95% CI, 1.02 to 4.40, P <0.001).

CONCLUSION

Increasing trend in the incidence of systemic candidiasis despite routine use of topical miconazole prophylaxis is of concern and future studies comparing the use of systemic fl uconazole versus oral nystatin may need to be considered.

Borderline Viability—Neonatal Outcomes of Infants in Singapore over a Period of 18 Years (1990 – 2007)

Introduction: This study assesses the trends and predictors of mortality and morbidity in infants of gestational age (GA) <27 weeks from 1990 to 2007. Materials and Methods: This is a retrospective cross-sectional cohort study of infant deliveries between 1990 and 2007 in the largest perinatal centre in Singapore. This is a study of infants born at <27 weeks in 2 Epochs (Epoch 1 (E1):1990 to 1998, Epoch 2 (E2):1999 to 2007) using logistic regression models to identify factors associated with mortality and composite morbidity. The main outcomes that were measured were the trends and predictors of mortality and morbidity. Results: Four hundred and eight out of 615 (66.3%) live born infants at 22 to 26 weeks survived to discharge. Survival improved with increasing GA from 22% (13/59) at 23 weeks to 87% (192/221) at 26 weeks (P <0.01). Survival rates were not different between E1 and E2, (61.5% vs 68.8%). In logistic regression analysis, higher survival was independently associated with increasing GA and birthweight, while airleaks, severe intraventricular haemorrhage (IVH) and necrotizing enterocolitis (NEC) contributed to increased mortality. Rates of major neonatal morbidities were bronchopulmonary dysplasia(BPD) (45%), sepsis (35%), severe retinopathy of prematurity (ROP) (31%), severe IVH/ periventricular leucomalacie (PVL) (19%) and NEC (10%). Although composite morbidity comprising any of the above was not significantly different between the 2 Epochs (75% vs 73%) a decreasing trend was seen with increasing GA (P <0.001). Composite morbidity/mortality was significantly lower at 26 weeks (58%) compared to earlier gestations (P<0.001, OR 0.37, 95% CI, 0.28 to 0.48) and independently associated with decreasing GA and birth weight, male sex, hypotension, presence of patent ductus arteriosus (PDA) and airleaks. Conclusion: Increasing survival and decreasing composite morbidity was seen with each increasing week in gestation with marked improvement seen at 26 weeks. Current data enables perinatal care decisions and parental counselling. Key words: Composite Morbidity, Neonatal Mortality

Borderline viability--neonatal outcomes of infants in Singapore over a period of 18 years (1990 - 2007)

INTRODUCTION

This study assesses the trends and predictors of mortality and morbidity in infants of gestational age (GA) <27 weeks from 1990 to 2007.

MATERIALS AND METHODS

This is a retrospective cross-sectional cohort study of infant deliveries between 1990 and 2007 in the largest perinatal centre in Singapore. This is a study of infants born at <27 weeks in 2 Epochs (Epoch 1 (E1):1990 to 1998, Epoch 2 (E2):1999 to 2007) using logistic regression models to identify factors associated with mortality and composite morbidity. The main outcomes that were measured were the trends and predictors of mortality and morbidity.

RESULTS

Four hundred and eight out of 615 (66.3%) live born infants at 22 to 26 weeks survived to discharge. Survival improved with increasing GA from 22% (13/59) at 23 weeks to 87% (192/221) at 26 weeks (P <0.01). Survival rates were not different between E1 and E2, (61.5% vs 68.8%). In logistic regression analysis, higher survival was independently associated with increasing GA and birthweight, while airleaks, severe intraventricular haemorrhage (IVH) and necrotizing enterocolitis (NEC) contributed to increased mortality. Rates of major neonatal morbidities were bronchopulmonary dysplasia (BPD) (45%), sepsis (35%), severe retinopathy of prematurity (ROP) (31%), severe IVH/ periventricular leucomalacie (PVL) (19%) and NEC (10%). Although composite morbidity comprising any of the above was not significantly different between the 2 Epochs (75% vs 73%) a decreasing trend was seen with increasing GA (P <0.001). Composite morbidity/ mortality was significantly lower at 26 weeks (58%) compared to earlier gestations (P <0.001, OR 0.37, 95% CI, 0.28 to 0.48) and independently associated with decreasing GA and birth weight, male sex, hypotension, presence of patent ductus arteriosus (PDA) and airleaks.

CONCLUSION

Increasing survival and decreasing composite morbidity was seen with each increasing week in gestation with marked improvement seen at 26 weeks. Current data enables perinatal care decisions and parental counselling.

High Prevalence of Hearing Loss in Down Syndrome at First Year of Life

Introduction: Infants with Down syndrome (DS) are at higher risk of hearing loss (HL). Normal hearing at one year of age plays an important part in language development. An audit was conducted to determine the impact of the newborn hearing screening program on the incidence, type and timing of diagnosis of HL during first year of life. Materials and Methods: Infants with DS were scheduled for Universal Newborn Hearing Screening (UNHS) within 4 weeks of life. If they passed, they had a high-risk screen at 3 to 6 months. They were referred to the otolaryngology department if they did not pass the UNHS or the high-risk screen. Information was obtained from the computerised data tracking system and case notes. Infants born from April 2002 to January 2005 and referred to the DS clinic of our hospital were analysed. Results: Thirty-seven (82.2%) of 45 infants underwent UNHS, of which 12 (32.4%) infants did not pass. Of remaining 33 infants, 27 had high-risk screen done of which 14 (51.8%) did not pass. Twenty-eight infants were referred to the ear, nose, throat (ENT) clinic: 12 from UNHS, 14 from high-risk screens and 2 from the DS clinic. Eleven (39.2%) defaulted follow-up. Fourteen (82.3%) of 17 infants who attended the ENT Clinic had HL. Twelve (85.7%) were conductive, and 2 (14.2%) mixed. Nine (64.2%) had mild-moderate HL and 3 (21%) had severe HL. The mean age of diagnosis was 6.6±3.3 months. All were treated medically, plus surgically if indicated. By 12 months of age, the hearing had normalised in 4 (28.6%) infants and remained the same in 3 (21.4%). Five (35.7%) defaulted follow-up. Thirty-five out of 45 (77.8%) underwent complete hearing screen in the first year of life (UNHS & High-risk screen). Six out of 45 (13.3%) had incomplete screening. Fourteen out of 41 (34.1%) had HL of varying degrees. Four out of 45 (8.8%) did not have any audiological assessment in first year of life. Conclusion: The incidence of HL in the first year of life was high (34.1%). Eighty-five percent were conductive with 64.2% in mild-moderate range. One third of infants hearing normalized after treatment, one third remained unaltered and one third of infants did not attend follow-up. An aggressive approach involving early screening after birth and continued surveillance and early referral to appropriate agencies are essential for establishing timely diagnosis and treatment. Measures to reduce the high default rate during long-term follow-up are needed. Parent education and integrated multidisciplinary follow-up clinic may be useful. Key words: Deafness, Trisomy, UNHS

High prevalence of hearing loss in Down syndrome at first year of life

INTRODUCTION

Infants with Down syndrome (DS) are at higher risk of hearing loss (HL). Normal hearing at one year of age plays an important part in language development. An audit was conducted to determine the impact of the newborn hearing screening program on the incidence, type and timing of diagnosis of HL during first year of life.

MATERIALS AND METHODS

Infants with DS were scheduled for Universal Newborn Hearing Screening (UNHS) within 4 weeks of life. If they passed, they had a high-risk screen at 3 to 6 months. They were referred to the otolaryngology department if they did not pass the UNHS or the high-risk screen. Information was obtained from the computerised data tracking system and case notes. Infants born from April 2002 to January 2005 and referred to the DS clinic of our hospital were analysed.

RESULTS

Thirty-seven (82.2%) of 45 infants underwent UNHS, of which 12 (32.4%) infants did not pass. Of remaining 33 infants, 27 had high-risk screen done of which 14 (51.8%) did not pass. Twenty-eight infants were referred to the ear, nose, throat (ENT) clinic: 12 from UNHS, 14 from high-risk screens and 2 from the DS clinic. Eleven (39.2%) defaulted follow-up. Fourteen (82.3%) of 17 infants who attended the ENT Clinic had HL. Twelve (85.7%) were conductive, and 2 (14.2%) mixed. Nine (64.2%) had mild-moderate HL and 3 (21%) had severe HL. The mean age of diagnosis was 6.6 ± 3.3 months. All were treated medically, plus surgically if indicated. By 12 months of age, the hearing had normalised in 4 (28.6%) infants and remained the same in 3 (21.4%). Five (35.7%) defaulted follow-up. Thirty-five out of 45 (77.8%) underwent complete hearing screen in the first year of life (UNHS & High-risk screen). Six out of 45 (13.3%) had incomplete screening. Fourteen out of 41 (34.1%) had HL of varying degrees. Four out of 45 (8.8%) did not have any audiological assessment in first year of life.

CONCLUSION

The incidence of HL in the first year of life was high (34.1%). Eighty-five percent were conductive with 64.2% in mild-moderate range. One third of infants hearing normalized after treatment, one third remained unaltered and one third of infants did not attend follow-up. An aggressive approach involving early screening after birth and continued surveillance and early referral to appropriate agencies are essential for establishing timely diagnosis and treatment. Measures to reduce the high default rate during long-term follow-up are needed. Parent education and integrated multidisciplinary follow-up clinic may be useful.

Morbidity of Parainfluenza 3 Outbreak in Preterm Infants in a Neonatal Unit

Introduction: Parainfluenza type 3 virus (PIV-3) is an important nosocomial pathogen which causes pneumonia and bronchiolitis in infants. We report an outbreak of PIV-3 respiratory infection which occurred in the neonatal unit of KK Hospital in June 2005. This is the second PIV-3 outbreak in our unit after the first in December 1994. Materials and Methods: The clinical characteristics and outcome of 7 infants tested positive for PIV-3 on nasopharyngeal aspirate in June 2005 were reviewed retrospectively. Results: Seven cases were infected with PIV-3 during this outbreak. The median birthweight of affected infants was 970 g (range, 740 to 2585 g), gestational age was 27 weeks and 4 days (range, 24 to 35 weeks), and postnatal age was 84 days (range, 28 to 250 days). Apnoeas and bradycardias were significant symptoms in 3 infants, 5 infants had progressive respiratory distress while the remaining 2 infants had flu-like illness. Five infants required ventilatory support and there were no deaths. The index case was an infant with chronic lung disease who was on oxygen supplementation and subsequently required ventilatory support with nasal CPAP. Despite implementation of control measures to prevent the spread of infection through early identification with strict cohorting of infected cases, contact tracing/screening, and reinforcement of hand hygiene precautions, the outbreak lasted for 24 days. Conclusion: PIV-3 respiratory infection in preterm infants can present with non-specific symptoms, leading to significant morbidity especially in those with underlying pulmonary pathology. Early recognition of symptoms and diagnosis by physicians, and prompt institution of control measures are necessary to prevent the spread of infection. Key words: Assisted ventilation, Chronic Lung Disease, Nosocomial respiratory infection, Viral

Morbidity of parainfluenza 3 outbreak in preterm infants in a neonatal unit

INTRODUCTION

Parainfluenza type 3 virus (PIV-3) is an important nosocomial pathogen which causes pneumonia and bronchiolitis in infants. We report an outbreak of PIV-3 respiratory infection which occurred in the neonatal unit of KK Hospital in June 2005. This is the second PIV-3 outbreak in our unit after the fi rst in December 1994.

MATERIALS AND METHODS

The clinical characteristics and outcome of 7 infants tested positive for PIV-3 on nasopharyngeal aspirate in June 2005 were reviewed retrospectively.

RESULTS

Seven cases were infected with PIV-3 during this outbreak. The median birthweight of affected infants was 970 g (range, 740 to 2585 g), gestational age was 27 weeks and 4 days (range, 24 to 35 weeks), and postnatal age was 84 days (range, 28 to 250 days). Apnoeas and bradycardias were significant symptoms in 3 infants, 5 infants had progressive respiratory distress while the remaining 2 infants had flu-like illness. Five infants required ventilatory support and there were no deaths. The index case was an infant with chronic lung disease who was on oxygen supplementation and subsequently required ventilatory support with nasal CPAP. Despite implementation of control measures to prevent the spread of infection through early identification with strict cohorting of infected cases, contact tracing/screening, and reinforcement of hand hygiene precautions, the outbreak lasted for 24 days.

CONCLUSION

PIV-3 respiratory infection in preterm infants can present with non-specific symptoms, leading to significant morbidity especially in those with underlying pulmonary pathology. Early recognition of symptoms and diagnosis by physicians, and prompt institution of control measures are necessary to prevent the spread of infection.

Transcatheter Removal of Peripherally Inserted Central Catheter Adherent to the Ventricular Septum

We describe an unusual case of a young child with peripherally inserted central catheter (PICC) adherent to the ventricular septal wall 5 days following insertion. The impacted PICC was successfully retrieved using a transcatheter procedure. The technique describes the freeing of an intracardiac central line with closed ends.

Two-year neurodevelopmental outcome in children conceived by intracytoplasmic sperm injection: prospective cohort study

OBJECTIVE

Primary outcome was to compare neurodevelopmental outcome at two years in intracytoplasmic sperm injection (ICSI) conceived children versus matched controls. Secondary outcome was to determine incidence of major congenital malformations and study perinatal outcome.

DESIGN

Prospective cohort study.

SETTING

Tertiary care perinatal centre over a period of 13 months.

POPULATION

Seventy-six ICSI conceived children and 261 matched controls selected by matching for maternal age, sex, date of delivery, race, plurality and parity.

METHODS

Mental Development Index (MDI) and Psychometric Development Index (PDI) of the Bayley's Scale of Development (BSID-II) and Vineland Adaptive Behaviour Scale (VABS) were used to assess the neurodevelopmental and functional outcome. The congenital malformations were classified according to ICD-9 code.

MAIN OUTCOME MEASURES

Primary outcome measure--neurodevelopmental and functional outcomes. Secondary outcome measure--congenital malformations and perinatal outcomes.

RESULTS

Neurodevelopmental and functional outcome were comparable in both groups. The mean MDI score was 92 [16] versus 90 [14] in the study and control groups respectively. Fourteen (18.4%) in the ICSI group had MDI <85 compared with 87 (33%) controls (P= 0.002). On linear regression the MDI was independently affected by plurality (P= 0.001), maternal education and socio-economic status (P= 0.01). The study group had a lower gestation (36 [3] vs 37.1 [2] weeks; P= 0.005) and a higher incidence of prematurity <34 weeks [19 (25%)] vs [31 (12%)] P= 0.012]. Six (7.9%) of the ICSI babies and seven (2.7%) of the controls had a major congenital malformation (P= 0.05).

CONCLUSIONS

Children born by ICSI pregnancies did not have an adverse neurodevelopmental outcome. The incidence of major congenital malformations in ICSI needs further evaluation.

Neonatal hepatic abscess in preterm infants:a rare entity?

INTRODUCTION AND OBJECTIVE

Neonatal pyogenic hepatic abscess in preterm infants is a rare entity. We present 6 cases of neonatal liver abscesses diagnosed in our hospital as well as an approach that will facilitate the early diagnosis and management of neonatal pyogenic liver abscess based on our case series and review of the literature.

MATERIALS AND METHODS

Retrospective review of case records of all 6 patients diagnosed with neonatal liver abscess from January 2000 to December 2002 in KK Women's and Children's Hospital, Singapore.

RESULTS

All neonates were premature with gestational ages between 24 and 34 weeks. Persistence of positive blood culture despite appropriate antibiotic treatment in 67% of the cases prompted use of hepatobiliary ultrasounds to detect liver abscess. Surgical drainage of liver abscess was performed in 33% of the cases, with the remainder treated conservatively with appropriate intravenous antibiotics. Half of the infants recovered with resolution of their liver abscess on serial hepatobiliary ultrasound. The other half died of fulminant sepsis.

CONCLUSIONS

Neonatal pyogenic liver abscess, though rare, is associated with good outcome if diagnosed promptly and appropriate treatment instituted. In a preterm infant with sepsis, a high index of suspicion is required if there is persistence of positive blood culture despite appropriate antibiotic treatment, and hepatobiliary ultrasound should be done to detect and monitor neonatal liver abscess.

Immunogenicity and reactogenicity of two regimens of diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated polio and Haemophilus influenzae type b vaccines administered to infants primed at birth with hepatitis B vaccine

An open, randomized study evaluated the immune response and safety of two different regimens of diphtheria-tetanus-acellular pertussis-hepatitis B-inactivated poliovirus-Haemophilus influenzae type b (DTPa-HBV-IPV-Hib) immunization in infants primed at birth with hepatitis B vaccine. One-half of the 150 healthy, full-term infants received a DTPa HBV-IPV-Hib vaccine at 1 1/2, 3 and 5 months of age; the other received a DTPa-IPV-Hib vaccine at 1 1/2, 3 and 5 months of age with separate HBV vaccine at 1 and 5 months of age. Immune response was similar following the two regimens with 100% of the vaccinees seroprotected for HBV, diphtheria, tetanus, Hib and poliovirus types 2 and 3 diseases after the full vaccination course. One vaccinee in the DTPa HBV-HPV- Hib group failed to respond to the poliovirus type 1 antigen. Response to the three pertussis antigens ranged from 92-97% in the DTPa-IPV-Hib plus separate HBV group and 100% in the DTPa HBV-IPV-Hib group. The most frequently reported post-vaccination symptoms were irritability in the DTPa-IPV-Hib plus separate HBV group (49% of vaccinees) and fever, defined as axillary temperature > or =37.5 degrees C, in the DTPa HBV- IPV-Hib group (50% of vaccinees).

In vitro-selected RNA cleaving DNA enzymes from a combinatorial library are potent inhibitors of HIV-1 gene expression

Selective inactivation of a target gene by antisense mechanisms is an important biological tool to delineate specific functions of the gene product. Approaches mediated by ribozymes and RNA-cleaving DNA enzymes (DNA enzymes) are more attractive because of their ability to catalytically cleave the target RNA. DNA enzymes have recently gained a lot of importance because they are short DNA molecules with simple structures that are expected to be stable to the nucleases present inside a mammalian cell. We have designed a strategy to identify accessible cleavage sites in HIV-1 gag RNA from a pool of random DNA enzymes, and for isolation of DNA enzymes. A pool of random sequences (all 29 nucleotides long) that contained the earlier-identified 10-23 catalytic motif were tested for their ability to cleave the target RNA. When the pool of random DNA enzymes was targeted to cleave between any A and U nucleotides, DNA enzyme 1836 was identified. Although several DNA enzymes were identified using a pool of DNA enzymes that was completely randomized with respect to its substrate-binding properties, DNA enzyme-1810 was selected for further characterization. Both DNA enzymes showed target-specific cleavage activities in the presence of Mg(2+) only. When introduced into a mammalian cell, they showed interference with HIV-1-specific gene expression. This strategy could be applied for the selection of desired target sites in any target RNA.

Targeted cleavage of HIV-1 coreceptor-CXCR-4 by RNA-cleaving DNA-enzyme: inhibition of coreceptor function

HIV needs the chemokine receptors (HIV-1 coreceptors) to initiate infection and gain entry into a susceptible cell. CCR5 receptor is used by macrophage tropic viruses to establish infection, and CXCR-4 is used by T lymphocyte tropic virus which are usually found at the terminal stages of the disease. These chemokine receptors are, therefore, attractive targets to interfere with the entry as well as spread of HIV-1 in the host. As our antiviral approach, we have earlier assembled a DNA-enzyme-916 against CCR5 (Goila and Banerjea, 1998). We have now designed against the CXCR-4 gene a mono-DNA-enzyme, which showed sequence specific cleavage activity. When CXCR-4-DNA-enzyme was placed in tandem with CCR5-DNA-enzyme, specific cleavage of their respective target sites were observed using a 60 bases long synthetic target RNA which possessed the target sites for both the DNA-enzymes. The cleavage by the CXCR-4 DNA-enzyme was found to be significantly more efficient than by the CCR5-DNA-enzyme. Analyses of the cleaved fragments by mono- and di-DNA-enzyme indicated strongly that hybridization of the CCR5-DNA-enzyme with its cognate target RNA, actually facilitated the cleavage by the CXCR-4 DNA-enzyme. Furthermore, the di-DNA-enzyme was able to cleave the substrate RNA to completion. These DNA-enzymes, when introduced into a mammalian cell line expressing the appropriate chemokine receptor, interfered specifically with the HIV-1 coreceptor functions. Using this strategy, it may be possible to interfere with the infection and spread of R5 as well as X4 viruses.