Mortality and morbidity of extremely low birth weight infants in Hong Kong, 2010-2017: a single-centre review.

BACKGROUND: Extremely low birth weight (ELBW) infants exhibit high rates of mortality and morbidity. We retrospectively assessed factors associated with mortality and morbidity among ELBW infants. METHODS: Perinatal demographic data were reviewed for all ELBW infants born between 2010 and 2017 at a tertiary neonatal unit. RESULTS: For non-survivors (21% of ELBW infants) and survivors, the median gestational ages were 24.1 and 26.2 weeks, respectively, and median birth weights were 650 g and 780 g, respectively (all P<0.001). Regression analyses showed that non-survival was positively associated with lower gestational age (adjusted odds ratio [aOR]=6.71 for every 1-week decrease; 95% confidence interval [CI]=1.73-26.00; P=0.006) and grade 3 or 4 intraventricular haemorrhage (aOR=29.23; 95% CI=1.39-613.84; P=0.030); non-survival was negatively associated with the presence of bronchopulmonary dysplasia (aOR=0.01; 95% CI= <0.001-0.23; P=0.005); length of neonatal intensive care unit stay for survivors was positively associated with the presence of necrotising enterocolitis (B-coefficient=89.60; 95% CI=43.86-135.34; P<0.001); and length of hospital stay for survivors was positively associated with the presence of necrotising enterocolitis (B-coefficient=2.08; 95% CI=0.43-3.73; P=0.015) and a low Apgar score at 1 minute (B-coefficient=-0.63; 95% CI=-1.04 to -0.22; P=0.003). CONCLUSION: Extremely low birth weight infants exhibited significant mortality and morbidity; there was no survival prior to 23.6 weeks' gestation or below 550 g birth weight. The presence of grade 3 or 4 intraventricular haemorrhage was independently associated with non-survival. Survivors were significantly more likely to exhibit bronchopulmonary dysplasia; survivors with necrotising enterocolitis were more likely to require longer stays in the neonatal intensive care unit and in hospital.

Triplet pregnancy with fetal reduction: experience in Hong Kong.

INTRODUCTION: Triplet and higher-order multiple pregnancies are well known to be associated with increased adverse outcomes. This study reviewed the perinatal outcomes in women with a triplet pregnancy who underwent fetal reduction versus expectant management at a university hospital in Hong Kong. METHODS: This was a retrospective review of triplet pregnancies at Prince of Wales Hospital in Hong Kong from 1 January 2008 to 30 September 2014. Women carrying a triplet pregnancy were classified as having had expectant management, fetal reduction to twins, or fetal reduction to a singleton. Maternal and pregnancy characteristics were compared. Outcome measures included fetal loss, gestational age at delivery, birth weight, neonatal survival rate, neonatal death, neonatal complications, and need for and length of neonatal intensive care unit stay. RESULTS: A total of 52 triplet pregnancies were identified. One pregnancy that was lost to follow-up and one that was terminated were excluded. The majority of pregnancies (84%) were the result of assisted reproductive technology. Fetal reduction was performed in 26 (52%) pregnancies, of which 22 were reduced to twins and four to a singleton. The mean gestations at delivery were 32.6, 35.2, and 39.6 weeks in the expectant management, fetal reduction to twins, and fetal reduction to a singleton groups, respectively. Significantly more pregnancies with expectant management resulted in a preterm birth. All pregnancies with fetal reduction to a singleton resulted in a term birth. A higher mean birth weight, lower neonatal death rate, and reduced need for admission to and length of stay in the neonatal intensive care unit were observed in the fetal reduction groups. CONCLUSIONS: Approximately 50% of women with a triplet pregnancy in Hong Kong elected to undergo fetal reduction. This was associated with a significant reduction in extreme preterm delivery and associated morbidity and mortality.

Identification of fragile X pre-mutation carriers in the Chinese obstetric population using a robust FMR1 polymerase chain reaction assay: implications for screening and prenatal diagnosis.

INTRODUCTION: There is significant morbidity associated with fragile X syndrome. Unfortunately, most maternal carriers are clinically silent during their reproductive years. Because of this, many experts have put forward the notion of preconception or prenatal fragile X carrier screening for females. This study aimed to determine the prevalence of fragile X syndrome pre-mutation and asymptomatic full-mutation carriers in a Chinese pregnant population, and the distribution of cytosine-guanine-guanine (CGG) repeat numbers using a robust fragile X mental retardation 1 (FMR1) polymerase chain reaction assay. METHODS: This was a cross-sectional survey in prospectively recruited pregnant women from a university hospital in Hong Kong. Chinese pregnant women without a family history of fragile X syndrome were recruited between April 2013 and May 2015. A specific FMR1 polymerase chain reaction assay was performed on peripheral blood to determine the CGG repeat number of the FMR1 gene. Prenatal counselling was offered to full-mutation and pre-mutation carriers. RESULTS: In 2650 Chinese pregnant women, two individuals with pre-mutation alleles (0.08%, one in 1325) and one asymptomatic woman with full-mutation (0.04%, one in 2650) alleles were identified. The overall prevalence of pre-mutation and full-mutation alleles was 0.11% (1 in 883). Furthermore, 30 (1.1%) individuals with intermediate alleles were detected. In the 2617 women with normal CGG repeats, the most common CGG repeat allele was 30. CONCLUSIONS: The overall prevalence of pre-mutation and asymptomatic full-mutation carriers in the Chinese pregnant population was one in 883, detected by a new FMR1 polymerase chain reaction assay.