Preterm infant outcomes in relation to the gestational age of onset and duration of prelabour rupture of membranes: a retrospective cohort study

Previable preterm premature rupture of membranes: 117 cases with neonatal outcomes in light of current research

BACKGROUND

ppPROM <  24 + 0 weeks of gestation complicates <  1 % of all pregnancies but is responsible for significant maternal and neonatal morbidity. It is associated with 18-20% of perinatal deaths.

OBJECTIVE

To evaluate neonatal outcome after expectant management in ppPROM in order to obtain evidence-based information for purposes of future counselling.

METHODS

A single-centre, retrospective cohort study of 117 neonates born 1994 to 2012 after ppPROM <  24 weeks of gestation with a latency period >  24 hours and admission to the NICU of the Department of Neonatology, University of Bonn. Data of pregnancy characteristics and neonatal outcome were collected. The results were compared to those found in the literature.

RESULTS

The mean gestational age at ppPROM was 20.45±2,9 weeks (range 11 + 2 -22 + 6) with a mean latency period of 44.7±34.8 days (range 1-135). Mean gestational age at birth was 26.77±3.22 weeks (range 22 + 2-35 + 3). 117 newborns were admitted to the NICU, the overall survival rate at discharge was 72.6% (85/117). Non-survivors had a significantly lower gestational age and higher rates of intra-amniotic infections. The most common neonatal morbidities were RDS (76.1%), BPD (22.2%), pulmonary hypoplasia (PH) (14.5%), neonatal sepsis (37.6%), IVH (34.1% all grades, 17.9% grades III/IV), NEC (8.5%) and musculoskeletal deformities (13.7%). Mild growth restriction as a new complication of ppPROM was observed.

CONCLUSIONS

Neonatal morbidity after expectant management is similar to that described for infants without ppPROM, but carries a higher risk of pulmonary hypoplasia and mild growth restriction.

Assessment of the fetal lungs in utero

Antenatal diagnosis of abnormal pulmonary development has improved significantly over recent years because of progress in imaging techniques. Two-dimensional ultrasound is the mainstay of investigation of pulmonary pathology during pregnancy, providing good prognostication in conditions such as congenital diaphragmatic hernia; however, it is less validated in other high-risk groups such as those with congenital pulmonary airway malformation or preterm premature rupture of membranes. Three-dimensional assessment of lung volume and size is now possible using ultrasound or magnetic resonance imaging; however, the use of these techniques is still limited because of unpredictable fetal motion, and such tools have also been inadequately validated in high-risk populations other than those with congenital diaphragmatic hernia. The advent of advanced, functional magnetic resonance imaging techniques such as diffusion and T2* imaging, and the development of postprocessing pipelines that facilitate motion correction, have enabled not only more accurate evaluation of pulmonary size, but also assessment of tissue microstructure and perfusion. In the future, fetal magnetic resonance imaging may have an increasing role in the prognostication of pulmonary abnormalities and in monitoring current and future antenatal therapies to enhance lung development. This review aims to examine the current imaging methods available for assessment of antenatal lung development and to outline possible future directions.

Latency duration of preterm premature rupture of membranes and neonatal outcome: a retrospective single-center experience

In preterm premature rupture of membranes (PPROM), a decision between early delivery with prematurity complications and pregnancy prolongation bearing the risk of chorioamnionitis has to be made. To define disadvantages of delayed prolongation, latency duration of PPROM in expectantly managed pregnancies was investigated. We included those PPROMs > 48 h leading to preterm birth prior 37 weeks' gestation and retrospectively analyzed 84 preterm infants fulfilling these criteria. The association between latency duration/appearance of PPROM and respiratory outcome (primary outcomes) and neurological outcome (secondary outcomes) was investigated. The study showed that latency duration of PPROM is not associated with clinical or histological chorioamnionitis (p = 0.275; p = 0.332). As the numerous clinical parameters show multicollinearity between each other, we performed a multiple regression analysis to consider this fact. Respiratory distress syndrome is significantly associated with gestational age at PPROM (p < 0.001), and surfactant application is significantly associated with PPROM duration (p = 0.014). The other respiratory parameters including steroids and diuretics therapy, bronchopulmonary dysplasia, and the neurological parameters (intraventricular hemorrhage, Bayley II testing at a corrected age of 24 months) were not significantly associated with PPROM duration or gestational age at PPROM diagnosis.Conclusion: Latency duration of PPROM was not associated with adverse neonatal outcome in expectantly and carefully managed pregnancies, but respiratory distress syndrome was pronounced. The observed effect of pronounced respiratory distress syndrome can be treated with surfactant preparations and was not followed by increased rate of bronchopulmonary dysplasia. What is Known: • In case of preterm premature rupture of membranes, a decision between pregnancy prolongation with the risk of chorioamnionitis and early delivery with prematurity complications has to be made. • Chorioamnionitis is a dangerous situation for the pregnant woman and the fetus. • Impaired neurodevelopmental outcome is strongly correlated with pronounced prematurity due to the increased rate of serious complications. What is New: • Respiratory distress syndrome is significantly associated with gestational age at PPROM, and surfactant application is significantly associated with PPROM duration. • Latency duration of PPROM is not associated with adverse respiratory neonatal outcome (therapy with continuous positive airway pressure, therapy with diuretics and/or steroids, bronchopulmonary dysplasia) in expectantly and carefully managed pregnancies. • Intraventricular hemorrhage and Bayley II testing at a corrected age of 24 months are not associated with latency duration of PPROM when pregnancies are carefully observed.

Risk factors for neonatal bronchopulmonary dysplasia in extremely preterm premature rupture of membranes: a retrospective study

Background

Determination of the optimal timing for termination of pregnancy in cases of preterm premature rupture of membranes (pPROM) during the extremely preterm period is still difficult. Bronchopulmonary dysplasia (BPD) is a major disease widely taken into account when determining the prognosis of respiratory disorders in a neonate. Many aspects of this disease remain unclear. With the aim of further improving the prognosis of neonates born to mothers with pPROM, this study examined cases who were diagnosed with pPROM before 28 weeks of gestation. The study analysed risk factors for neonatal BPD.

Methods

This study included 73 subjects with singleton pregnancy, diagnosed with pPROM during the gestational period from 22 weeks and 0 days to 27 weeks and 6 days. The following factors were retrospectively examined: the gestational week at which pPROM was diagnosed, the gestational week at which delivery occurred, the period for which the volume of amniotic fluid was maintained, and neonatal BPD as a complication. Receiver operating characteristic (ROC) curve analyses were conducted to analyse the relationship of the onset of BPD with the duration of oligohydramnios and the gestational weeks of delivery.

Results

The mean gestational week at which a diagnosis of amniorrhexis was made was 24.5 ± 1.9 weeks (mean ± SD), and that at which delivery occurred was 27.0 ± 3.0 weeks. Fifty-seven cases (78.1%) were diagnosed with oligohydramnios, the mean duration of which was 17.4 ± 20.5 days. The mean birth weight of neonates was 1000 ± 455 g, of which 49 (67.1%) were diagnosed with BPD following birth. No neonates died in this study. The ROC curve indicated that the cut-off values for the duration of oligohydramnios and gestational age at delivery were 4 days and 24.1 weeks, respectively. Multivariate analysis indicated that the duration of oligohydramnios for more than 4 days before delivery and preterm delivery at less than 24.1 weeks were risk factors for the onset of BPD.

Conclusions

Our findings suggest that duration of oligohydramnios for more than 4 days before delivery and preterm delivery less than 24.1 weeks are risk factors for BPD in cases who are diagnosed with pPROM before 28 weeks of gestation.

Care Practices, Morbidity and Mortality of Preterm Neonates in China, 2013-2014: a Retrospective study

This retrospective cohort study aimed to investigate the prevalence, morbidity, mortality and the maternal/neonatal care of preterm neonates and the perinatal risk factors for mortality. We included data on 13,701 preterm neonates born in 15 hospitals for the period 2013–2014 in China. Results showed a prevalence of preterm neonates of 9.9%. Most infants at 24–27 weeks who survived more than 12 hours were mechanically ventilated (56.1%). Few infants born before 28 weeks received CPAP without first receiving mechanical ventilation (8.1%). Few preterm neonates received antenatal steroid(35.8% at 24–27 weeks, 57.9% at 28–31 weeks, 57.0% at 32–33 weeks and 32.7% at 34–36 weeks). Overall mortality was 1.9%. Most of the deaths at 24–27 weeks of gestation occurred within 12 hours after birth, accounting for 68.1%(32/47), and within 12–72 hours after birth at 28–36 weeks of gestation, accounting for 47.4%(99/209). Rates of survival to discharge increased from 68.2% at 24–27 weeks, 93.3% at 28–31 weeks, 99.2% at 32–33 weeks to 99.4% at 34–36 weeks. The smaller of the GA, there was a greater risk of morbidities due to prematurity. Preterm birth weight (OR = 0.407, 95% CI 0.346–0.478), antenatal steroid (OR = 0.680, 95% CI 0.493–0.938), and neonatal asphyxia (OR = 3.215, 95% CI 2.180–4.741) proved to significantly influence the odds of preterm neonatal death. Overall, our results support that most of the preterm neonates at 28–36 weeks of gestation survived without major morbidity. Rate of survival of GAs less than 28 weeks was still low. Maternal and infant care practices need to be improved in the very preterm births.