The influence of maternal ethnicity on neonatal respiratory outcome

Abstract

ObjectiveHigher rates of neonatal morbidity and mortality at term combined with earlier spontaneous delivery have led to the hypothesis that babies born to South Asian born (SA-born) women may mature earlier and/or their placental function decreases earlier than babies born to Australian and New Zealand born (Aus/NZ-born) women. Whether babies born to SA-born women do better in the preterm period, however, has yet to be evaluated. In this study we investigated respiratory outcomes, indicative of functional maturity, of preterm babies born to SA-born women compared with those of Aus/NZ-born women to explore this hypothesis further.Study design and settingThis retrospective cohort study was conducted at Monash Health.PatientsData were collected from neonatal and birth records of moderate-late preterm (32–36 weeks) infants born between 2012 and 2015 to SA-born and Aus/NZ-born women.Outcome measuresRates of nursery admissions and neonatal respiratory outcomes were compared.ResultsBabies born to Aus/NZ-born women were more likely to be admitted to a nursery (80%) compared with SA-born babies (72%, p=0.004). Babies born to SA-born mothers experienced significantly less hyaline membrane disease (7.8%), required less resuscitation at birth (28.6%) and were less likely to require ventilation (20%) than babies born to Aus/NZ-born mothers (18%, 42.2%, 34.6%; p<0.001). There was no difference in the duration of ventilation or length of stay in hospital.ConclusionsModerate-late preterm babies born to SA-born women appear to have earlier functional maturity, as indicated by respiratory outcomes, than Aus/NZ-born babies. Our findings support the hypothesis of earlier fetal maturation in SA-born women.

Rates of neonatal morbidity by maternal region of birth and gestational age in New South Wales, Australia 2003‐2016

“…This was a noticeable change from the unadjusted morbidity rates, in which neonates of South Asian‐born women had a higher risk than neonates of AUS/NZ‐born women across the pregnancy and at almost all gestations, with the exception of 32, 35 and 36 weeks. Although these unadjusted results appear inconsistent with Cox et al, 17 who reported lower rates of respiratory morbidity for babies of South Asian‐born mothers than babies of AUS/NZ‐born mothers between 32 and 36 weeks, this may be explained by the different gestational age range of the study population, and the broader nature of our indicator. For example, the major indicator component driving the higher unadjusted rate of morbidity in babies of South Asian‐born women compared with AUS/NZ‐born women was need for intravenous fluids and nutrition (eg glucose infusion) (Table ), which was not included in Cox et al 17 and may be related to the higher burden of gestational diabetes in the South Asian‐born mothers.…”

“…Although these unadjusted results appear inconsistent with Cox et al, 17 who reported lower rates of respiratory morbidity for babies of South Asian‐born mothers than babies of AUS/NZ‐born mothers between 32 and 36 weeks, this may be explained by the different gestational age range of the study population, and the broader nature of our indicator. For example, the major indicator component driving the higher unadjusted rate of morbidity in babies of South Asian‐born women compared with AUS/NZ‐born women was need for intravenous fluids and nutrition (eg glucose infusion) (Table ), which was not included in Cox et al 17 and may be related to the higher burden of gestational diabetes in the South Asian‐born mothers. In our study, adjusted risk of morbidity was lower or equivalent for East and South‐east Asian women compared with AUS/NZ‐born women at all gestations.…”

“…Other Australian studies found an association between maternal region of birth and risk of obstetric intervention during birth 15,16 . Finally, another team in Victoria reported that late preterm births to South Asian‐born women were less likely to be admitted to the nursery and had better respiratory outcomes than those born to Australian/New Zealand‐born women 17 …”

Influence of maternal region of birth on neonatal outcomes of babies born small

“…The characteristics of the SA and ANZ populations were significantly different, with much higher rates of perinatal smoking and substance use reported by ANZ-born women, and higher rates of thyroid disorders for SA-born women. These findings are in line with previous studies 12,17,18 and are all factors known to be associated with SGA and IUGR. 19,20 The finding that SA infants were 60% less likely to have a congenital abnormality, malformation or syndrome may indeed be associated with the high rates of maternal smoking, alcohol and substance use during pregnancies of ANZ-born women.…”

“…Despite the association between SA maternal ROB and both prematurity and shortened gestational length, only 12.9% of SA SGA infants were born preterm (<32 or 32-36 weeks), compared to 25% of ANZ SGA infants in our cohort. This is illustrated in Figure 1, where a larger proportion of SA SGA infants were born closer to term, com- 12 (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19) 14 (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) 3 2-53 (2)(3)(4) Note: Data expressed as number (%) or median (IQR).…”