Avoiding late preterm deliveries to reduce neonatal complications: an 11-year cohort study

The impact of premature rupture of membrane on neonatal outcomes in infants born at 34 weeks gestation or later

BACKGROUND

Premature rupture of membranes (PROMs) is a known risk for adverse neonatal outcomes, often leading to neonatal hospitalization due to suspected perinatal infection or other issues. This study assesses PROM's clinical impact on neonatal outcomes in infants born at 34 weeks of gestation or later.

METHODS

We studied hospitalized neonates born between December 2018 and November 2019, with gestational ages of 34 weeks or more and PROM diagnosis. We extracted patient data from clinical records, including demographics, maternal history, medical profiles, and neonatal outcomes. Neonates were categorized based on symptoms, PROM duration, neonatal intensive care unit (NICU) stay, and respiratory support. Data underwent thematic analysis.

RESULTS

Of 275 neonates, the average PROM duration was 7.9 ± 8.1 hours, with 247 cases (89.8%) showing symptoms. Among them, 34 (12.4%) had PROM lasting over 18 hours, 48 (17.5%) were born prematurely, and 79 (28.7%) required intensive care. Symptomatic neonates had significantly higher rates of needing intensive care, respiratory support, prolonged antibiotics, and extended hospitalization ( p < 0.05). NICU stays (≥3 days) were significantly associated with prematurity (odds ratio [OR] = 5.49; 95% CI, 2.39-12.60) and an initial pH level <7.25 (OR = 3.35; 95% CI, 1.46-7.68). Extended respiratory support (≥3 days) was significantly correlated with tocolysis ≥7 days (OR = 13.20; 95% CI, 3.94-44.20), Apgar score <7 at 1 minute after birth (OR = 4.28; 95% CI, 1.67-10.97), and inadequate intrapartum antibiotic prophylaxis (IAP) (OR = 2.34; 95% CI, 1.04-5.23).

CONCLUSION

Neonates born at or after 34 weeks of gestation with PROM should undergo vigilant monitoring if early symptoms (<24 hours) manifest. Risk factors for requiring NICU care or extended respiratory support (≥3 days) include prematurity, low initial pH (<7.25), prolonged tocolysis requirement (≥7 days), an Apgar score below 7 at 1 minute, and inadequate IAP.

Clinical Comparison of Preterm Birth and Spontaneous Preterm Birth in Severe Preeclampsia

Severe preeclampsia is accompanied by many complications, which is extremely harmful to pregnant women and fetuses. However, in the classification of preterm birth, it is generally divided into spontaneous preterm birth and therapeutic preterm birth, and insufficient attention has been paid to preterm birth in severe preeclampsia. This article aims to explore the clinical difference between preterm birth in severe preeclampsia and spontaneous preterm birth. In the experiment, this paper selected pregnant women who delivered and were treated in a hospital from April 2010 to April 2020 as cases. In terms of grouping, not only are they divided into severe eclampsia group (observation group 1), spontaneous preterm birth group (observation group 2), and general delivery group (control group) according to the cause of premature birth, but also according to the gestational age of severe eclampsia onset, preterm weeks, and other groups. Not only the clinical difference between severe preeclampsia preterm birth and spontaneous preterm birth was compared horizontally, but also the factors affecting the complications of preterm pregnant women, perinatal asphyxia rate, and mortality were longitudinally analyzed. The experimental results in this paper showed that there were significant differences in maternal complications and neonatal mortality between the severe preeclampsia preterm group and the spontaneous preterm group ( $P$  < 0.05). In addition, the severe preeclampsia preterm birth group was more harmful than the spontaneous preterm birth group. The complication rate of the severe preeclampsia preterm birth group was 10% higher than that of the spontaneous preterm birth group, and the neonatal mortality rate was 2% higher.

Factors Associated with Increased Risk of Early Severe Neonatal Morbidity in Late Preterm and Early Term Infants

Although the risk of neonatal mortality is generally low for late preterm and early term infants, they are still significantly predisposed to severe neonatal morbidity (SNM) despite being born at relatively advanced gestations. In this study, we investigated maternal and intrapartum risk factors for early SNM in late preterm and early term infants. This was a retrospective cohort study of non-anomalous, singleton infants (34⁺⁰-38⁺⁶ gestational weeks) born at the Mater Mother's Hospital in Brisbane, Australia from January 2015 to May 2020. Early SNM was defined as a composite of any of the following severe neonatal outcome indicators: admission to neonatal intensive care unit (NICU) in conjunction with an Apgar score <4 at 5 min, severe respiratory distress, severe neonatal acidosis (cord pH < 7.0 or base excess <-12 mmol/L). Multivariable binomial logistic regression analyses using generalized estimating equations (GEE) were used to identify risk factors. Of the total infants born at 34⁺⁰-38⁺⁶ gestational weeks, 5.7% had at least one component of the composite outcome. For late preterm infants, pre-existing diabetes mellitus, instrumental birth and emergency caesarean birth for non-reassuring fetal status were associated with increased odds for early SNM, whilst for early term infants, pre-existing and gestational diabetes mellitus, antepartum hemorrhage, instrumental, emergency caesarean and elective caesarean birth were significant risk factors. In conclusion, we identified several risk factors contributing to early SNM in late preterm and early term cohort. Our results suggest that predicted probability of early SNM decreased as gestation increased.

Is the Cerebro-Placental Ratio Sufficient to Predict Adverse Neonatal Outcome in Small for Gestational Age Fetuses > 34 Weeks of Gestation?

Fetuses with an estimated weight (EFW) below the 10th percentile are at risk for adverse perinatal outcome and clinical management remains a challenge. We examined EFW and cerebro-placental ratio (CPR) with regard to their predictive capability in the management and outcome of such cases. Fetuses were first diagnosed as small after 34 weeks of gestation with an actual EFW below the 10th percentile at our tertiary academic center. We determined the optimum cutoff value for CPR and EFW in predicting adverse neonatal outcome. Mean gestational age at diagnosis was 36 weeks. One hundred and two cases were included in our study. We determined a CPR of 1.4 and an EFW of 2152 g to be the best cutoff value for predicting adverse fetal outcome, with an area under the curve (AUC) of 0.65 (95% CI 0.54–0.76); p = 0.009, and 0.76 (95% CI 0.66–0.86); p < 0.0001, respectively. However, when comparing EFW with CPR, EFW seems to be slightly better in predicting adverse fetal outcome in our group. While the use of CPR alone for the management of small fetuses is not sufficient, it is an important additional tool that may be of value in the clinical setting.

Childhood neurodevelopment after spontaneous versus indicated preterm birth

BACKGROUND

Preterm birth is the leading cause of neonatal morbidity and mortality. Individuals who survive preterm birth are at a higher risk for many long-term adverse effects, including neurodevelopmental deficits. There are many well-established risk factors for worse neurologic outcomes spanning the prenatal and postnatal periods; however, investigators have yet to assess whether the cause of preterm birth has an impact on neurodevelopment.

OBJECTIVE

Our objective was to assess whether neurologic outcomes differ by children born via indicated versus spontaneous preterm birth.

STUDY DESIGN

We performed secondary analysis of a multicenter trial assessing magnesium for neuroprotection in women at risk for preterm delivery from 24 to 31 weeks. We included women with live, nonanomalous, singleton gestations who delivered preterm; we excluded women whose children were missing 2-year follow-up information for reasons other than perinatal demise. The primary exposure was type of preterm birth: (1) spontaneous if the child's mother presented with preterm labor or ruptured membranes, or (2) indicated if the child was delivered preterm iatrogenically. The primary outcome was death (including stillbirths, neonatal intensive care unit deaths, and deaths after discharge) or an abnormal Bayley II score by 2 years of age, defined as a Mental Developmental Index score or Psychomotor Developmental Index score 2 standard deviations below the mean. Secondary outcomes included death or Mental Developmental Index and Psychomotor Developmental Index scores 1 standard deviation or less, and neonatal morbidities associated with prematurity. Bivariate analyses of baseline characteristics by exposure were conducted. A logistic regression model was fitted to adjust for confounders.

RESULTS

Of 1678 subjects, 1631 (97.2%) underwent spontaneous preterm birth and 47 (2.8%) underwent indicated preterm birth. Baseline maternal demographics and gestational age at delivery were similar between groups (29.6 weeks ± 7.8 versus 28.8 weeks ± 2.5, P = .07). A Psychomotor Developmental Index score 2 standard deviations or less below the mean or death occurred in 340 (20.9%) spontaneous preterm birth subjects and 17 (36.2%) indicated preterm birth subjects (P = .01). When adjusting for confounders, there remained an increased probability of a Psychomotor Developmental Index scores 2 standard deviations or less or death in indicated preterm birth subjects (P = .02). Although not statistically significant, indicated preterm birth was also associated with higher odds of Mental Developmental Index scores 2 standard deviations or less or death, Psychomotor Developmental scores 1 standard deviation or less or death, and Mental Developmental Index scores 1 standard deviation or less or death (1.76, 1.59, and 1.45, respectively). Limiting the analysis to small for gestational age infants, there was no difference in neurologic outcomes. The same was true for when we excluded small for gestational age infants from our analysis. However, after adjusting for small for gestational age, the odds of a Psychomotor Developmental Index score 2 standard deviations or less or death remained significant higher in the indicated preterm birth group (adjusted odds ratio, 1.98; 95% confidence interval, 1.01-3.88).

CONCLUSION

In this cohort of pregnant women who delivered preterm, indicated deliveries were associated with worse psychomotor development than were spontaneous deliveries. Other outcomes appeared to be poor, but our numbers were limited. This finding should be confirmed in a larger cohort of women undergoing medically indicated preterm deliveries.

MATERNAL AND FETAL RISK FACTORS ASSOCIATED WITH LATE PRETERM INFANTS

Objective:

To determine maternal and fetal risk factors associated with the birth of late preterm infants in comparison to those born at term.

Methods:

A case-control study was carried out in a tertiary center for high-risk pregnancies. For the cases, the study enrolled post-partum mothers and their respective newborns with gestational ages equal or greater than 34 weeks and less than 37 weeks. As controls, the post-partum mothers and their newborns with gestational ages of 37 weeks or greater were selected. The sample was calculated with a ratio of two controls for each case, resulting in 423 patients. Association studies were performed using the chi-square test or Fisher’s exact test and logistic regression analysis.

Results:

The variables associated with late prematurity were inadequate prenatal (Odds Ratio [OR] 1.23; confidence interval of 95% [95%CI] 1.12-1.34; p≤0.001), premature rupture of membranes (OR 4.98; 95%CI 2.66-9.31; p≤0.001), length of hospital stay ≥24 hours until birth (OR 0.18; 95%CI 0.06-0.52; p≤0.001), cesarean section (OR 2.74; 95%CI 1.69-4.44; p≤0.001) and small for gestational age newborn (OR 3.02; 95%CI 1.80-5.05; p≤0.001).

Conclusions:

Inadequate prenatal care and membranes’ premature rupture were found as factors associated with the late preterm birth. It is important to identify the factors that allow intervention with adequate prenatal care in order to reduce poor outcomes due to late prematurity.

Impact of the new guidelines on the management of premature rupture of membranes for the prevention of late preterm birth: an 11-year retrospective study

Objectives To evaluate the number of late preterm (LPT) births (between 34 0/7 and 36 6/7 weeks) that could have been prevented if expectant management of preterm premature rupture of membranes (PPROM) had been applied according to new recommendations. Methods A retrospective cohort study included all births at one Swiss center between January 1, 2002 and December 31, 2012. Births were categorized using an adapted evidence-based classification. Two scenarios were considered: best scenario (maximum averted cases) and a conservative scenario (minimum averted cases). Results Among 2017 LPT births (5.0% of all deliveries; n=40,609), 1122 (60.6%) women had PPROM. Spontaneous labor occurred in 473 (42.2%) cases and 649 (57.8%) had induction of labor or an elective cesarean section. In the latter group, 44 (6.8%) had evidence-based indications for LPT delivery and 605 (83.2%) had non-evidence-based indications. Depending on the scenario, the rate of avoided LPT cases would have varied between 4.2% (95% confidence interval [CI]: 3.4-5.2) if the conservative scenario was applied, and 30% (95% CI: 28.0-32.0) for the best scenario. Conclusion Adoption of new guidelines for the management of PPROM will prevent a considerable number of LPT births and help decrease the adverse effects and potential disability associated with late preterm infants.

Medically indicated late preterm delivery and its impact on perinatal morbidity and mortality: a retrospective population-based cohort study

Objective: In the last few decades, attention has been focused on morbidity and mortality associated with late preterm delivery (34-36 + 6/7 weeks), accounting for 60-70% of all preterm births. This study is aimed to determine (1) the prevalence of late preterm deliveries (spontaneous and medically indicated) in our population; and (2) the rate of neonatal morbidity and mortality as well as maternal complications associated with the different phenotypes of late preterm deliveries. Study design: This retrospective population-based cohort study, included 96,176 women who had 257,182 deliveries, occurred between 1988 and 2011, allocated into three groups: term (n = 242,286), spontaneous (n = 10,063), and medically indicated (n = 4833) late preterm deliveries. Results: (1) Medically indicated late preterm deliveries were associated with increased maternal morbidity, as well as neonatal morbidity and mortality, in comparison with other study groups (p < .01 for all comparisons); (2) medically indicated late preterm delivery was an independent risk factor for composite neonatal morbidity (low Apgar score at 5', seizures, asphyxia, acidosis) after adjustment for confounding factors (maternal age and ethnicity and neonatal gender) and stratification according to gestational age at delivery; and (3) the proportion of medically indicated late preterm deliveries affected the neonatal mortality rate. Below 35% of all late preterm deliveries, indicated late preterm birth were associated with a reduction in neonatal mortality; however, above this threshold medically indicated late preterm deliveries were associated with an increased risk for neonatal death. Conclusions: (1) Medically indicated late preterm deliveries were independently associated with adverse composite neonatal outcome; and (2) to benefit in term of neonatal outcome from the tool of medically indicated late preterm birth, their proportion should be kept below 35% of all late preterm deliveries, while exceeding this threshold increases the risk of neonatal mortality.