Demographic characteristics of the ELBWI in the PIVH and non-PIVH groups
A total of 205 ELBWIs, including 97 males and 108 females, were included in this study, with a male to female ratio of 0.90:1. Among them, 190 patients (92.7%) were born at our hospital, and 15 patients (7.3%) were born at other hospitals. The mean gestational age of the ELBWIs was 27.3 (26.5, 28.6) weeks, and the mean birth weight was 870 (750, 950) grams. There were 82 cases (40%) of PIVH, of which 51 cases (62.2%) occurred within 3 days after birth and 31 cases (37.8%) occurred within 4 to 7 days after birth. Among the 205 ELBWIs, 26 (12.6%) had severe PIVH, and 56 (27.3%) had mild PIVH. The incidence rates of PIVH in the 23+ 1-26-, 26+ 1-28-, and 28+ 1-32-week groups were 72.5% (29/40), 33.3% (31/93), and 30.6% (22/72), respectively, and the difference was statistically significant (χ2 = 22.002, p = 0.000). The incidence rates of severe PIVH in the 23+ 1-26-, 26+ 1-28-, and 28+ 1-32-week groups were 40.0% (16/40), 10.7% (10/93), and 1.4% (1/72), respectively, and the difference was statistically significant (χ2 = 34.392, p = 0.000).
Compared to the non-PIVH group, the PIVH group had a significantly younger gestational age and lower birth weight (p = 0.000 and p = 0.021, respectively). In the PIVH group, 59.8% of infants were delivered by cesarean section, while in the non-PIVH group, this percentage was 28.5% (p = 0.000). Additionally, 56.1% (46/82) of infants in the PIVH group required resuscitation at birth (p = 0.003), and 47.6% (39/82) needed endotracheal intubation in the delivery room (p = 0.001). The median 1-minute Apgar score was 7 (5,8) in the PIVH group and 8 (6,8) in the non-PIVH group (p = 0.003). No significant differences in sex, place of delivery, IVF status, presence of twins, premature rupture of membranes, presence of amniotic fluid, fetal distress, 5-minute Apgar score, chest compressions in the delivery room, threatened preterm labor, antenatal use of glucocorticoids, antenatal use of MgSO4, intrauterine infection, gestational diabetes mellitus or gestational hypertension were found between the PIVH group and the non-PIVH group (all p > 0.05, Table 1).
Table 1
Demographic characteristics of extremely low birth weight infants in PIVH and non-PIVH groups
Values | PIVH(n = 82) | Non-PIVH(n = 123) | χ2/Z | p |
Sex Male Female | 41(50.0) 41(50.0) | 56(45.5) 67(54.5) | 0.395 | 0.530 |
Gestational age | 27(25.6,28.2) | 27.5(27,29) | −4.100 | 0.000 |
Birth weight | 835(700,940) | 890(780,950) | −2.312 | 0.021 |
Mode of delivery Vaginal delivery Cesarean section | 33(40.2) 49(59.8) | 88(71.5) 35(28.5) | 19.931 | 0.000 |
Delivery site In-born Out-born | 74(90.2) 8 (9.8) | 116(94.3) 7(5.7) | 1.199 | 0.274 |
Multiple pregnancy Yes No | 25(30.5) 57(69.5) | 39(31.7) 84(68.3) | 0.034 | 0.854 |
IVF Yes No | 19(23.2) 63(76.8) | 21(17.1) 102(82.9) | 1.165 | 0.280 |
Premature rupture of membranes Yes No | 16(19.5) 66(80.5) | 38(30.9) 85(69.1) | 3.285 | 0.070 |
Stained amniotic fluid Yes No | 10(12.2) 72(87.8) | 17(13.8) 106(86.2) | 0.114 | 0.736 |
Fetal distress Yes No | 14(17.1) 68(82.9) | 19(15.4) 104(84.6) | 0.096 | 0.756 |
Resuscitation at birth Yes No | 46(56.1) 36(43.9) | 43(35.0) 80(65.0) | 8.949 | 0.003 |
Apgar score 1- minute 5- minute | 7(5,8) 8(8,9) | 8(6,8) 9(8,9) | −2.954 −1.437 | 0.003 0.151 |
Chest compressions in delivery room Yes No | 5(6.1) 77(93.9) | 7(5.7) 116(94.3) | 0.000 | 1.000 |
Intubated in delivery room Yes No | 39(47.6) 43(52.4) | 32(26.0) 91(74.0) | 10.088 | 0.001 |
Threatened preterm labor Yes No | 56(68.3) 26(31.7) | 78(63.4) 45(36.6) | 0.517 | 0.472 |
Antenatal use of glucocorticoids Yes No | 47(57.3) 35(42.7) | 84(68.3) 39(31.7) | 2.569 | 0.109 |
Antenatal use of MgSO4 Yes No | 38(46.3) 44(53.7) | 67(54.5) 56(45.5) | 1.302 | 0.254 |
Intrauterine infection Yes No | 8(9.8) 74(90.2) | 10(8.1) 113(91.9) | 0.162 | 0.687 |
Gestational diabetes mellitus Yes No | 13(15.9) 69(84.1) | 20(16.3) 103(83.7) | 0.006 | 0.938 |
Gestational hypertension Yes No | 16(19.5) 66(80.5) | 38(30.9) 85(69.1) | 3.285 | 0.070 |
Treatments and Complications of the ELBWI in the PIVH and Non-PIVH Groups
Compared to the non-PIVH group, the PIVH group had a greater percentage of infants who could not be weaned off the ventilator within 1 week of birth (73.0% vs. 30.1%, p = 0.000). Moreover, a larger proportion of infants in the PIVH group needed high-frequency ventilators for more than 24 hours (34.1% vs. 8.1%, p = 0.000), as well as nitric oxide (13.4% vs. 0.8%, p = 0.001) and vasoactive drugs (50.0% vs. 18.7%, p = 0.000). The incidence of sepsis and the requirement for blood transfusions to address anemia were also greater in the PIVH group (28.0% vs. 8.9%, p = 0.000, and 48.8% vs. 26.0%, p = 0.001, respectively). Nevertheless, there were no significant differences in the occurrence of PS use, PDA, anemia, coagulation disorders, or thrombocytopenia between the two groups. (all p < 0.05, Table 2).
Table 2
Treatments and Complications of ELBWI in PIVH and Non-PIVH groups
Values | PIVH(n = 82) | Non-PIVH(n = 123) | χ2 | p |
Failure to withdraw IMV Yes No | 60(73.2) 22(26.8) | 37(30.1) 86(69.9) | 36.645 | 0.000 |
Use of HFOV for at least 24 hours Yes No | 28(34.1) 54(65.9) | 10(8.1) 113(91.9) | 22.053 | 0.000 |
Use of NO Yes No | 11(13.4) 71(86.6) | 1 (0.8) 122(99.2) | 11.983 | 0.001 |
Use of PS Yes No | 71(86.6) 11(13.4) | 96(78.0) 27(22.0) | 2.374 | 0.123 |
Use of Vasoactive drugs Yes No | 41(50.0) 41(50.0) | 23(18.7) 100(81.3) | 22.448 | 0.000 |
Sepsis Yes No | 23(28.0) 59(72.0) | 11(8.9) 112(91.1) | 12.981 | 0.000 |
PDA Yes No | 53(64.6) 29(35.4) | 67(54.5) 56(45.5) | 2.094 | 0.148 |
Ibuprofen treatment for PDA Yes No | 2 (2.4) 80(97.6) | 7 (5.7) 116(94.3) | 0.586 | 0.444 |
Anemia Yes No | 64(78.0) 18(22.0) | 81(65.9) 42(34.1) | 3.534 | 0.060 |
Blood transfusion for anemia Yes No | 40(48.8) 42(51.2) | 32(26.0) 91(74.0) | 11.189 | 0.001 |
Coagulation dysfunction Yes No Unknown | 10(12.2) 13(15.9) 59(72.0) | 8 (6.5) 28(22.8) 87(70.7) | 3.000 | 0.223 |
Thrombopenia Yes No | 50(61.0) 32(39.0) | 72(58.5) 51(41.5) | 0.121 | 0.727 |
IMV: invasive mechanical ventilation, HFOV: high frequency oscillatory ventilation, NO: nitric oxide, PS: pulmonary surfactant, PDA: patent ductus arteriosus |
Risk factors and prediction for PIVH in the ELBWI
The studies included significant risk factors in the univariate analysis, such as gestational age, birth weight, mode of delivery, resuscitation at birth, 1-minute Apgar score, intubation in the delivery room, failure to withdraw IMV within 1 week of birth, use of HFO for at least 24 hours, use of NO, use of vasoactive drugs, sepsis, and blood transfusion for anemia. According to the multivariable logistic regression analysis, failure to withdraw IMV within 1 week of birth (OR = 3.668, 95% CI = 1.557–8.641; P = 0.003) and the use of vasoactive drugs (OR = 2.193, 95% CI = 1.033–4.658; P = 0.041) were identified as independent risk factors for PIVH, as detailed in Table 3. Analysis of the ROC curve demonstrated that the model achieved an AUC of 0.792 (95% CI 0.726–0.857), with a maximum Youden index of 0.496. The sensitivity and specificity were calculated to be 68.3% and 81.3%, respectively, as illustrated in Fig. 2. The omnibus test revealed that the current model significantly outperformed the null model (χ2 = 58.304, p < 0.001). Additionally, the Hosmer & Lemeshow test (χ2 = 7.041, p = 0.532) indicated that the model fit the data accurately.
Table 3
Analysis of risk factors for PIVH in ELBWI
Variables | β | SE | Wald χ2 | OR (95% CI) | P value |
Gestational age | -0.116 | 0.139 | 0.702 | 0.890(0.678–1.169) | 0.402 |
Birth weight | 0.000 | 0.001 | 0.018 | 1.000(0.997–1.003) | 0.892 |
Mode of delivery | -0.022 | 0.419 | 0.003 | 0.978(0.430–2.224) | 0.958 |
Resuscitation at birth | 0.761 | 0.536 | 2.017 | 2.140(0.749–6.114) | 0.156 |
1-minute Apgar score | 0.164 | 0.144 | 1.292 | 1.178(0.888–1.564) | 0.256 |
Intubated in delivery room | 0.213 | 0.445 | 0.228 | 1.237(0.517–2.962) | 0.633 |
Failure to withdraw IMV | 1.300 | 0.437 | 8.838 | 3.668(1.557–8.641) | 0.003 |
Use of HFOV for at least 24 hours | 0.612 | 0.500 | 1.495 | 1.844(0.692–4.916) | 0.221 |
Use of NO | 1.596 | 1.160 | 1.890 | 4.931(0.507–47.940) | 0.169 |
Use of Vasoactive drugs | 0.785 | 0.384 | 4.179 | 2.193(1.033–4.658) | 0.041 |
Sepsis | 0.486 | 0.521 | 0.870 | 1.626(0.585–4.517) | 0.351 |
Blood transfusion for anemia | -0.375 | 0.419 | 0.802 | 0.687(0.303–1.561) | 0.370 |