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Published on: November 20, 2015
Effects of Ponderal Index on Neonatal Mortality and Morbidities in Extremely Premature Infants
Jae Kyoon Hwang1, Ha-Na Kang2, Ja-Hye Ahn3
1Department of Pediatrics, Hanyang University Guri Hospital, Guri, Korea.
Insights
Extremely premature infants with a mildly-low ponderal index (MPI) indicating mild intrauterine stress showed better neonatal outcomes. This suggests mild intrauterine stress may accelerate fetal maturation, improving survival rates for very premature infants.
Area of Science:
- Neonatology
- Perinatology
- Pediatric Research
Background:
- Intrauterine stress and growth restriction are critical factors affecting extremely premature infants.
- The ponderal index (PI) is a measure of fetal growth and nutritional status.
- Understanding the impact of varying PI levels on neonatal outcomes is crucial for clinical practice.
Purpose of the Study:
- To evaluate the effect of intrauterine stress, assessed by ponderal index (PI) percentiles, on extremely premature infants.
- To test the hypothesis that infants with a mildly-low ponderal index (MPI) experience better neonatal outcomes.
Main Methods:
- A cohort of 2,721 infants born between 23 and 28 weeks of gestation was analyzed.
- Infants were categorized into four groups based on PI percentile: severely-low PI (SPI), mildly-low PI (MPI), adequate PI (API), and high PI (HPI).
- Neonatal outcomes, including mortality and specific morbidities, were compared across the PI groups.
Main Results:
- Mortality rates were significantly lower in the MPI and adequate PI (API) groups compared to the severely-low PI (SPI) and high PI (HPI) groups.
- The MPI group exhibited a lower incidence of severe intraventricular hemorrhage (IVH) compared to other groups.
- Neonatal morbidities were generally better in the MPI and API groups than in the SPI and HPI groups.
Conclusions:
- Mild intrauterine stress, as indicated by MPI, is associated with reduced mortality and lower rates of severe neonatal morbidities, including severe IVH.
- The findings suggest that mild intrauterine stress may promote fetal maturation, leading to improved outcomes in extremely premature infants.
- These results highlight the importance of considering PI percentiles in the management and prognostication of extremely premature neonates.
Background:
To evaluate how intrauterine stress affects extremely premature infants in terms of intrauterine growth restriction. We hypothesized that extremely premature infants with mildly-low ponderal index (MPI) would have better neonatal outcomes.
Methods:
We selected 2,721 subjects of 23 to 28 weeks of gestation between 2013 and 2015 from Korean Neonatal Network database. They were divided into 4 groups based on ponderal index (PI) percentile; PI ≤ 3rd as severely-low PI (SPI, n = 82), 3rd < PI ≤ 10th as MPI (n = 190), 10th < PI ≤ 90th as adequate PI (API, n = 2,179), and PI > 90th as high PI (HPI, n = 270).
Results:
The mortality in MPI and API groups was comparable (16.3% vs. 16.9%). It was significantly lower than that in the SPI and HPI groups (30.5% and 24.9%, respectively; P = 0.001). The MPI and API groups had better neonatal morbidities compared with the SPI and/or HPI groups, while the MPI group (8.2%) showed a lower incidence of severe intraventricular hemorrhage (IVH) than the other groups (SPI, 21.3%; API, 15.0%; HPI, 19.7%, respectively; P = 0.004). The MPI group had a trend of a bottom in neonatal mortality and morbidities in extremely premature infants.
Conclusion:
The MPI and API groups had lower mortality, massive pulmonary hemorrhage, severe bronchopulmonary dysplasia or death, pulmonary hypertension and neonatal seizure rates than the SPI and/or HPI groups, while the MPI group showed a lower incidence of severe IVH than the other groups. We speculate that the lower incidence of neonatal morbidities and mortality in the MPI group indicating mild intrauterine stress might accelerate fetal maturation resulting in better outcomes in extremely premature infants.
