827
Neonates Analyzed
Final cohort
10
LV Parameters
Outcome variables
2014–2018
Study Period
4 years
48–72h
Echo Timing
Post-delivery
Figure 1: Overview of Selection Process
Selection process of neonates according to BW/PW ratio groups
908
Neonates
↓
81
Neonates excluded
Exclusion reasons:
- 22 Associated anomalies
- 19 Perinatal depression/low 5 min APGAR
- 11 Genetic diagnosis
- 10 Cardiac disease
- 9 Severe respiratory distress
- 5 Severe sepsis/shock
- 5 Others
↓
827
Neonates
↓
BW/PW Ratio
Less than 10th percentile
16
Neonates
Between 10th and 90th percentile
323
Neonates
More than 90th percentile
488
Neonates
Abbreviation: BW/PW = Birth Weight to Placental Weight
Study Design
Single-center prospective cohort study
Setting & Population
- NewYork-Presbyterian Brooklyn Methodist Hospital
- Nursery ward and NICU (2014–2018)
- Neonates ≥35 weeks gestational age
- Routine screening echocardiography
- Echo within 48–72 hours post-delivery
Statistical Methods
- MIPCA for missing data imputation
- Chi-squared test (categorical variables)
- One-way ANOVA (continuous variables)
- Genetic algorithm for model selection (AIC)
- Backward stepwise regression (F-test, α=0.05)
Table 1: Baseline Characteristics (Categorical Variables)
Differences between BW/PW ratio groups
| Variable | Small BW/PW (n=16) | Normal BW/PW (n=323) | Large BW/PW (n=488) | Total (n=827) |
|---|---|---|---|---|
| Sex | ||||
| Male | 10 (62.5%) | 172 (53.3%) | 249 (51.0%) | 431 (52.1%) |
| Female | 6 (37.5%) | 151 (46.7%) | 239 (49.0%) | 396 (47.9%) |
| Birth Weight Category | ||||
| SGA | 5 (31.3%) | 37 (11.5%) | 48 (9.8%) | 90 (10.9%) |
| AGA | 10 (62.5%) | 249 (77.1%) | 382 (78.3%) | 641 (77.5%) |
| LGA | 1 (6.3%) | 37 (11.5%) | 58 (11.9%) | 96 (11.6%) |
| APGAR at 1 min | ||||
| Normal | 16 (100%) | 312 (96.6%) | 477 (97.7%) | 805 (97.3%) |
| Moderately depressed | 0 (0%) | 10 (3.1%) | 11 (2.3%) | 21 (2.5%) |
| Severely depressed | 0 (0%) | 1 (0.3%) | 0 (0%) | 1 (0.1%) |
| NICU Admission | ||||
| No | 15 (93.8%) | 287 (88.9%) | 455 (93.2%) | 757 (91.5%) |
| Yes | 1 (6.3%) | 36 (11.1%) | 33 (6.8%) | 70 (8.5%) |
| Mode of Delivery | ||||
| Vaginal delivery | 12 (75.0%) | 218 (67.5%) | 337 (69.1%) | 567 (68.6%) |
| Cesarean section | 4 (25.0%) | 105 (32.5%) | 151 (30.9%) | 260 (31.4%) |
| Parity | ||||
| Nulliparous | 5 (31.3%) | 142 (44.0%) | 187 (38.3%) | 334 (40.4%) |
| Multiparous | 11 (68.8%) | 181 (56.0%) | 301 (61.7%) | 493 (59.6%) |
| Preeclampsia | ||||
| No | 15 (93.8%) | 305 (94.4%) | 466 (95.5%) | 786 (95.0%) |
| Yes | 1 (6.3%) | 18 (5.6%) | 22 (4.5%) | 41 (5.0%) |
| GDM | ||||
| No | 14 (87.5%) | 267 (82.7%) | 412 (84.4%) | 693 (83.8%) |
| Yes | 2 (12.5%) | 56 (17.3%) | 76 (15.6%) | 134 (16.2%) |
| GDM Management | ||||
| Diet or untreated | 1 (50.0%) | 19 (33.9%) | 31 (40.8%) | 51 (38.1%) |
| Medical | 1 (50.0%) | 23 (41.1%) | 22 (28.9%) | 46 (34.3%) |
| Insulin | 0 (0%) | 14 (25.0%) | 23 (30.3%) | 37 (27.6%) |
| Ethnicity | ||||
| White | 4 (25.0%) | 89 (27.6%) | 123 (25.2%) | 216 (26.1%) |
| African American | 6 (37.5%) | 78 (24.1%) | 128 (26.2%) | 212 (25.6%) |
| Asian | 2 (12.5%) | 66 (20.4%) | 106 (21.7%) | 174 (21.0%) |
| Hispanic | 3 (18.8%) | 67 (20.7%) | 98 (20.1%) | 168 (20.3%) |
| Others | 1 (6.3%) | 23 (7.1%) | 33 (6.8%) | 57 (6.9%) |
Note: No statistically significant differences were found in categorical variables across BW/PW ratio groups.
Table 2: Baseline Characteristics (Continuous Variables)
Mean ± Standard Deviation by BW/PW ratio groups
| Variable | Small BW/PW (n=16) | Normal BW/PW (n=323) | Large BW/PW (n=488) | Total (n=827) |
|---|---|---|---|---|
| Birth weight (g) | 2,836.88 ± 476.15 | 3,266.19 ± 519.56 | 3,274.91 ± 500.48 | 3,258.59 ± 508.51 |
| Birth height (cm) | 47.66 ± 2.65 | 49.64 ± 2.66 | 49.72 ± 2.64 | 49.60 ± 2.68 |
| Birth HC (cm) | 33.13 ± 1.35 | 34.05 ± 1.56 | 34.08 ± 1.55 | 34.03 ± 1.56 |
| Birth CC (cm) | 31.97 ± 2.19 | 32.73 ± 2.03 | 32.60 ± 1.91 | 32.64 ± 1.97 |
| Ponderal index (g/cm³) | 2.61 ± 0.27 | 2.66 ± 0.29 | 2.66 ± 0.29 | 2.66 ± 0.29 |
| Gestational age (weeks) | 39.04 ± 1.34 | 39.12 ± 1.29 | 38.77 ± 1.28 | 38.92 ± 1.30 |
| Maternal age (years) | 31.88 ± 4.59 | 31.90 ± 5.61 | 31.34 ± 5.46 | 31.56 ± 5.50 |
| Maternal BMI (kg/m²) | 30.88 ± 5.32 | 30.55 ± 5.93 | 31.24 ± 6.32 | 30.93 ± 6.14 |
| Maternal SBP (mm Hg) | 121.06 ± 13.43 | 120.57 ± 14.53 | 119.44 ± 13.38 | 119.91 ± 13.86 |
| Maternal DBP (mm Hg) | 74.94 ± 10.00 | 74.61 ± 10.26 | 73.93 ± 9.80 | 74.21 ± 10.00 |
| Maternal MBP (mm Hg) | 90.31 ± 10.27 | 89.93 ± 11.19 | 89.10 ± 10.51 | 89.44 ± 10.78 |
| Placental weight (g) | 612.50 ± 116.79 | 510.98 ± 108.80 | 473.27 ± 91.51 | 490.29 ± 103.32 |
| Placental diameter 1 (cm) | 19.31 ± 2.47 | 18.55 ± 2.45 | 18.26 ± 2.42 | 18.39 ± 2.44 |
| Placental diameter 2 (cm) | 16.84 ± 2.38 | 16.18 ± 2.33 | 15.83 ± 2.24 | 15.98 ± 2.29 |
| Placental thickness (cm) | 2.36 ± 0.53 | 2.34 ± 0.62 | 2.35 ± 0.56 | 2.35 ± 0.58 |
Key Finding: Significant differences (highlighted) were found in birth weight, height, head circumference, chest circumference, gestational age, and placental weight. Small BW/PW neonates had lower anthropometric measures but higher placental weight.
Neonatal Measurements by Group
Placental Weight by Group
Table 3: Differences in LV Parameters Between BW/PW Ratio Groups
Mean ± Standard Deviation
| LV Parameter | Small BW/PW (n=16) | Normal BW/PW (n=323) | Large BW/PW (n=488) | Total (n=827) | p-value |
|---|---|---|---|---|---|
| IVSd (mm) | 3.24 ± 0.55 | 3.47 ± 0.57 | 3.51 ± 0.55 | 3.48 ± 0.56 | 0.161 |
| IVSs (mm) | 4.48 ± 0.69 | 4.95 ± 0.78 | 5.01 ± 0.75 | 4.97 ± 0.77 | 0.031 |
| LVIDd (mm) | 16.71 ± 2.00 | 17.56 ± 1.78 | 17.70 ± 1.84 | 17.61 ± 1.82 | 0.098 |
| LVIDs (mm) | 10.93 ± 1.35 | 11.39 ± 1.40 | 11.40 ± 1.41 | 11.38 ± 1.40 | 0.428 |
| LVPWd (mm) | 2.68 ± 0.42 | 2.88 ± 0.46 | 2.93 ± 0.46 | 2.90 ± 0.46 | 0.086 |
| LVPWs (mm) | 4.25 ± 0.58 | 4.57 ± 0.63 | 4.65 ± 0.62 | 4.60 ± 0.63 | 0.034 |
| FS (%) | 35.31 ± 4.37 | 35.33 ± 4.63 | 35.69 ± 4.36 | 35.52 ± 4.47 | 0.486 |
| LVmass (g) | 5.24 ± 1.49 | 6.13 ± 1.68 | 6.29 ± 1.64 | 6.19 ± 1.67 | 0.034 |
| LVmass/vol (g/m³) | 15.95 ± 5.46 | 16.69 ± 5.57 | 16.81 ± 5.06 | 16.73 ± 5.30 | 0.716 |
| Presence of ASH (n, %) | 1 (6.3%) | 25 (7.7%) | 33 (6.8%) | 59 (7.1%) | 0.664ᵃ |
ᵃ Chi-squared p-value. Note: No significant differences in most LV parameters among groups by direct comparison (ANOVA). Regression analysis (Table 4) reveals significant associations when controlling for other factors.
LV Parameters Comparison by BW/PW Group
🔑 Primary Finding: BW/PW Ratio → Shortening Fraction
The BW/PW ratio was significantly associated with an increase in shortening fraction (FS): estimate = 0.29 (95% CI: 0.03–0.55, p = 0.027). This suggests placental efficiency independently influences cardiac function.
Table 4: Regression Models for LV Parameters
Significant predictors via genetic algorithm and backward stepwise selection
| LV Parameter | Predictor | Estimate | SE | 95% CI | p-value | R²/R² adj |
|---|
Model Performance: R² Values
Placental Factor Associations Summary
Significant associations from regression (p < 0.05)
| Placental Factor | LV Parameter | Estimate | 95% CI | p-value | Direction |
|---|---|---|---|---|---|
| BW/PW Ratio | FS | 0.29 | 0.03–0.55 | 0.027 | ↑ Positive |
| Placental Thickness | IVSd | 0.13 | 0.05–0.21 | 0.002 | ↑ Positive |
| IVSs | 0.16 | 0.06–0.26 | 0.001 | ↑ Positive | |
| LVPWd | 0.08 | 0.02–0.14 | 0.003 | ↑ Positive | |
| LVPWs | 0.16 | 0.08–0.24 | <0.001 | ↑ Positive | |
| LVmass | 0.22 | 0.04–0.40 | 0.017 | ↑ Positive | |
| LVmass/vol | 0.71 | 0.16–1.26 | 0.011 | ↑ Positive | |
| Placental Diameter 2 | IVSd | 0.09 | 0.05–0.13 | <0.001 | ↑ Positive |
| IVSs | 0.11 | 0.07–0.15 | <0.001 | ↑ Positive | |
| LVIDd | 0.18 | 0.10–0.26 | <0.001 | ↑ Positive | |
| LVIDs | 0.08 | 0.01–0.15 | 0.016 | ↑ Positive | |
| LVPWd | 0.07 | 0.05–0.09 | <0.001 | ↑ Positive | |
| LVPWs | 0.09 | 0.05–0.13 | <0.001 | ↑ Positive | |
| LVmass | 0.24 | 0.18–0.30 | <0.001 | ↑ Positive | |
| LVmass/vol | 0.66 | 0.42–0.90 | <0.001 | ↑ Positive | |
| Placental Diameter 1 | LVIDd | -0.07 | -0.13 to -0.01 | 0.039 | ↓ Negative |
| LVmass | -0.11 | -0.21 to -0.01 | 0.024 | ↓ Negative | |
| LVmass/vol | -0.55 | -0.94 to -0.16 | 0.005 | ↓ Negative | |
| Placental Weight | IVSs | -0.001 | -0.002 to -0.0002 | 0.019 | ↓ Negative |
Conclusions
Primary Conclusion
This single-center prospective cohort study demonstrates that the BW/PW ratio can independently affect LV dimensions and morphology. Several placental factors showed significant correlations with increased LV dimensions, emphasizing the potential influence of placental health and efficiency on fetal cardiac growth.
Main Findings
- BW/PW ratio → FS: Significant positive association (estimate=0.29, p=0.027)
- Placental thickness: Positively correlated with IVSd, IVSs, LVPWd, LVPWs, LVmass, LVmass/vol
- Placental diameter 2: Positively correlated with multiple LV parameters (all p<0.001)
- Gestational age: Strong correlations with multiple LV dimensions
- GDM: Significantly increased IVSs (p=0.010); insulin use correlated with IVSd (p<0.001)
- Model fit: LVmass model achieved highest R² (0.406)
Study Strengths
- Prospective cohort design
- Routine screening adds clinical relevance
- Comprehensive factor consideration
- Rigorous statistical approach
- STROBE guidelines compliance
- Large sample size (n=827)
Study Limitations
- Single-center design
- Selection bias from screening echo
- MIPCA imputation limitations
- Cannot establish causality
- No long-term follow-up
- Missing confounders
Citation
Gad A, Malouche D, Chhabra M, Hoang D, Suk D, Ron N, Dygulska B, Gudavalli MB, Nadroo AM, Narula P and Elmakaty I (2024) Impact of birth weight to placental weight ratio and other perinatal risk factors on left ventricular dimensions in newborns: a prospective cohort analysis. J. Perinat. Med. 52(4): 433–444. doi: 10.1515/jpm-2023-0384