Iatrogenic vs. Spontaneous Preterm Birth: A Retrospective Study of Neonatal Outcome Among Very Preterm Infants

Risk of severe influenza infection in women with a history of pregnancy complications: A longitudinal cohort study

BACKGROUND

Risk factors for influenza complications in women are poorly understood. We examined the association between pregnancy outcomes and risk of influenza hospitalization up to three decades later.

METHODS

We analyzed a cohort of 1,421,531 pregnant women who delivered in Quebec, Canada between 1989 and 2021. Patients were followed over time beginning at the first delivery. The main exposure measures included obstetric complications such as preeclampsia, gestational diabetes, and preterm birth. The main outcome was influenza hospitalization up to 32 years later. We used adjusted Cox regression models to estimate hazard ratios (HR) and 95% confidence intervals (CI) for the association between obstetric complications and risk of influenza hospitalization following pregnancy.

RESULTS

A total of 4,016 women were hospitalized for influenza during 32 years of follow-up. Influenza hospitalization was more frequent among women with pregnancy complications than women without complications (18.0 vs 14.1 per 100,000 person-years). Compared with no pregnancy complication, women with gestational diabetes (HR 1.48, 95% CI 1.30-1.69), preeclampsia (HR 1.45, 95% CI 1.28-1.65), placental abruption (HR 1.36, 95% CI 1.12-1.66), preterm birth (HR 1.40, 95% CI 1.27-1.55), cesarean section (HR 1.22, 95% CI 1.13-1.31), and severe maternal morbidity (HR 1.43, 95% CI 1.22-1.68) had a greater risk of influenza hospitalization later in life. These pregnancy outcomes were associated with severe influenza infections requiring critical care.

CONCLUSIONS

Women with pregnancy complications have an elevated risk of severe influenza complications later in life and have potential to benefit from seasonal vaccination to prevent influenza hospitalization.

Development and validation of a prenatal predictive nomogram for the risk of NICU admission in infants born to Chinese mothers over 35 years of age: a retrospective cohort study

BACKGROUND

The rising number of women giving birth at advanced maternal age has posed significant challenges in obstetric care in recent years, resulting in increased incidence of neonatal transfer to the Neonatal Intensive Care Unit (NICU). Therefore, identifying fetuses requiring NICU transfer before delivery is essential for guiding targeted preventive measures.

OBJECTIVE

This study aims to construct and validate a nomogram for predicting the prenatal risk of NICU admission in neonates born to mothers over 35 years of age.

STUDY DESIGN

Clinical data of 4218 mothers aged ≥ 35 years who gave birth at the Department of Obstetrics of the Second Hospital of Shandong University between January 1, 2017 and December 31, 2021 were reviewed. Independent predictors were identified by multivariable logistic regression, and a predictive nomogram was subsequently constructed for the risk of neonatal NICU admission.

RESULTS

Multivariate logistic regression demonstrated that the method of prenatal screening, number of implanted embryos, preterm premature rupture of the membranes, preeclampsia, HELLP syndrome, fetal distress, premature birth, and cause of preterm birth are independent predictors of neonatal NICU admission. Analysis of the nomogram decision curve based on these 8 independent predictors showed that the prediction model has good net benefit and clinical utility.

CONCLUSION

The nomogram demonstrates favorable performance in predicting the risk of neonatal NICU transfer after delivery by mothers older than 35 years. The model serves as an accurate and effective tool for clinicians to predict NICU admission in a timely manner.

Exploring Risk Factors and Perinatal Outcomes of Preterm Birth in a Tertiary Care Hospital: A Comprehensive Analysis

Background Preterm birth before 37 weeks of gestation is a global public health challenge, particularly in India, where the prevalence varies regionally. Understanding risk factors, such as maternal age and complications like hypertensive disorders, is vital. India's diverse healthcare landscape and regional disparities further complicate this issue. Preterm infants face increased mortality and morbidity risks like respiratory distress and intraventricular hemorrhage. This study in a tertiary care hospital aimed to analyze risk factors, assess perinatal outcomes, and contribute to the understanding of preterm birth in this complex context, providing valuable insights for maternal and child health strategies. Methods This retrospective cohort study was conducted at the Venkateshwara Institute of Medical Science, Rajabpur, over one year, extracting data from electronic health records. The study aimed to analyze risk factors associated with preterm delivery and assess perinatal outcomes. The study included diverse pregnancies, both singleton and multiple gestations, and employed sample size calculations to ensure statistical validity. Trained medical personnel collected extensive data on maternal characteristics, obstetric history, antenatal care, perinatal outcomes, and mode of delivery. Statistical analysis, utilizing SPSS (IBM, Chicago, USA), involved descriptive statistics, comparative analysis, chi-square tests, t-tests, Mann-Whitney U tests, and multivariate logistic regression models. Findings with a p-value <0.05 were considered significant. Results The study included 2042 deliveries, with a preterm birth prevalence of 14.2%. Multiparous women had higher preterm birth rates than primigravida (72.92% vs. 27.08%). Maternal age, history of preterm delivery, hypertensive disorders, inadequate antenatal care compliance, previous cesarean section, multiple gestations, antepartum hemorrhage (APH), polyhydramnios, oligohydramnios, and premature rupture of membranes (PROM) were significantly associated with preterm birth. Apgar scores at one minute and five minutes, neonatal complications, and mortality rates were notably worse among preterm births. Vaginal delivery rates were significantly lower in the preterm group (36.3%) compared to full-term deliveries (48.8%), with a higher rate of emergency cesarean sections (19.7% vs. 10.8%). Conclusion This study provides valuable insights into the risk factors and perinatal outcomes of preterm delivery at a tertiary care hospital, with precise values illustrating the extent of associations. The findings such as history of preterm delivery, hypertensive disorders, and inadequate antenatal care compliance as the most commonly associated conditions with preterm birth and management of such associated conditions may help reduce the rate of premature birth.

Neurodevelopmental outcomes in preterm or low birth weight infants with germinal matrix-intraventricular hemorrhage: a meta-analysis

BACKGROUND

This meta-analysis aimed to identify the near- and long-term neurodevelopmental prognoses of preterm or low birth weight (LBW) infants with different severities of intraventricular hemorrhage (IVH).

METHODS

Four databases were searched for observational studies that were qualified using the Newcastle-Ottawa Scale.

RESULTS

37 studies involving 32,370 children were included. Compared to children without IVH, children with mild IVH had higher incidences of neurodevelopmental impairment (NDI), cerebral palsy (CP), motor/cognitive delay, hearing impairment and visual impairment, as well as lower scores of the mental development index (MDI) and psychomotor development (PDI). Moreover, compared to mild IVH, severe IVH increased susceptibilities of children to NDI, motor delay, CP, hearing impairment and visual impairment, with worse performances in MDI, PDI, motor score and IQ. Mild IVH was not associated with seizures or epilepsy.

CONCLUSIONS

Adverse neurodevelopmental outcomes positively associated with the occurrence and severity of IVH in preterm or LBW infants, providing evidence for counseling and further decisions regarding early therapeutic interventions.

IMPACT

Adverse neurodevelopmental outcomes later in life were closely associated with the occurrence and severity of IVH in preterm or LBW infants. Our results highlight the importance to make prediction of the neurodevelopmental outcomes of children born preterm or LBW with a history of IVH, which will guide affected parents when their children need clinical interventions to reach the full potential. We emphasize the importance of identifying specific developmental delays that may exist in children with IVH, providing detailed information for the development of comprehensive intervention measures.

Integrative analysis of noncoding mutations identifies the druggable genome in preterm birth

Preterm birth affects ~10% of pregnancies in the US. Despite familial associations, identifying at-risk genetic loci has been challenging. We built deep learning and graphical models to score mutational effects at base resolution via integrating the pregnant myometrial epigenome and large-scale patient genomes with spontaneous preterm birth (sPTB) from European and African American cohorts. We uncovered previously unidentified sPTB genes that are involved in myometrial muscle relaxation and inflammatory responses and that are regulated by the progesterone receptor near labor onset. We studied genomic variants in these genes in our recruited pregnant women administered progestin prophylaxis. We observed that mutation burden in these genes was predictive of responses to progestin treatment for preterm birth. To advance therapeutic development, we screened ~4000 compounds, identified candidate molecules that affect our identified genes, and experimentally validated their therapeutic effects on regulating labor. Together, our integrative approach revealed the druggable genome in preterm birth and provided a generalizable framework for studying complex diseases.

Adjuvant Treatment with Oral Dydrogesterone in the Prevention of Preterm Labor: A Randomized, Double-Blinded, Placebo-Controlled Trial

We conducted a double-blind, randomized, placebo-controlled clinical trial to evaluate the efficacy of oral dydrogesterone (DG) on maternal and neonatal consequences in the treatment of preterm labor. We included 100 nulliparous mothers (24-34 weeks) with normal pregnancy who had preterm labor pain. Participants who received magnesium sulfate were randomly assigned to the investigation group (DG 30 mg/day) or placebo group. Maternal and neonatal outcomes were compared between the two groups. Recurrent uterine contraction (UC) rates (92% vs. 88%, P = 0.862) and the incidence of preterm delivery (66% vs. 58%, P = 0.834) were not different in the DG and placebo groups. No significant differences were observed in terms of gestational age at delivery (33.5 ± 3.5 vs. 34.2 ± 3.2, P = 0.281), latency period (5.53 ± 2.29 days vs. 5.59 ± 2.57 days, P = 0.622), cervical dilation (1.82 ± 0.26 cm vs. 1.84 ± 0.29 cm, P = 0.281), and effacement (53 ± 4.47% vs. 57.21 ± 6.27%, P = 0.622) between the placebo and DG groups. The percentage of neonates with a 1-min Apgar score < 7 was higher in the placebo group compared with that of the DG group (12% vs. 0%, P = 0.0001). However, both groups were similar in the frequency of a 5-min Apgar score < 7. No differences in the term of adverse effects of medications were recorded. Our results showed that DG adjuvant to magnesium sulfate could not be effective in improving the incidence of preterm labor, rate of recurrent UC, latency period, pregnancy outcomes, and maternal and neonatal outcomes when compared with the placebo group.

Prevalence of preterm birth in Scandinavian countries: a systematic review and meta-analysis

OBJECTIVES

As welfare societies, Scandinavian countries share characteristics of equality related to healthcare access, gender, and social services. However, cultural and lifestyle variations create country-specific health differences. This meta-analysis assessed the prevalence of preterm birth (PTB) and its categories in Scandinavian countries.

METHODS

A systematic search in key databases of literature published between 1990 and 2021 identified studies of the prevalence of PTB and its categories. Following the use of the Freeman-Tukey double arcsine transformation, a meta-analysis of weighted data was performed using the random-effects model and meta-prop method.

RESULTS

We identified 109 observational studies that involved 86,420,188 live births. The overall pooled prevalence (PP) of PTB was 5.3% (PP = 5.3%, 95% confidence interval [CI] 5.1%, 5.5%). The highest prevalence was in Norway (PP = 6.2%, 95% CI 5.3%, 7.0%), followed by Sweden (PP = 5.3%, 95% CI 5.1%, 5.4%), Denmark (PP = 5.2%, 95% CI 4.9%, 5.3%), and Iceland (PP = 5.0%, 95% CI 4.4%, 5.7%). Finland had the lowest PTB rate (PP = 4.9%, 95% CI 4.7%, 5.1%).

CONCLUSIONS

The overall PP of PTB was 5.3%, with small variations among countries (4.9%-6.2%). The highest and lowest PPs of PTB were in Norway and Finland, respectively.

Deep representation learning identifies associations between physical activity and sleep patterns during pregnancy and prematurity

Preterm birth (PTB) is the leading cause of infant mortality globally. Research has focused on developing predictive models for PTB without prioritizing cost-effective interventions. Physical activity and sleep present unique opportunities for interventions in low- and middle-income populations (LMICs). However, objective measurement of physical activity and sleep remains challenging and self-reported metrics suffer from low-resolution and accuracy. In this study, we use physical activity data collected using a wearable device comprising over 181,944 h of data across N = 1083 patients. Using a new state-of-the art deep learning time-series classification architecture, we develop a 'clock' of healthy dynamics during pregnancy by using gestational age (GA) as a surrogate for progression of pregnancy. We also develop novel interpretability algorithms that integrate unsupervised clustering, model error analysis, feature attribution, and automated actigraphy analysis, allowing for model interpretation with respect to sleep, activity, and clinical variables. Our model performs significantly better than 7 other machine learning and AI methods for modeling the progression of pregnancy. We found that deviations from a normal 'clock' of physical activity and sleep changes during pregnancy are strongly associated with pregnancy outcomes. When our model underestimates GA, there are 0.52 fewer preterm births than expected (P = 1.01e - 67, permutation test) and when our model overestimates GA, there are 1.44 times (P = 2.82e - 39, permutation test) more preterm births than expected. Model error is negatively correlated with interdaily stability (P = 0.043, Spearman's), indicating that our model assigns a more advanced GA when an individual's daily rhythms are less precise. Supporting this, our model attributes higher importance to sleep periods in predicting higher-than-actual GA, relative to lower-than-actual GA (P = 1.01e - 21, Mann-Whitney U). Combining prediction and interpretability allows us to signal when activity behaviors alter the likelihood of preterm birth and advocates for the development of clinical decision support through passive monitoring and exercise habit and sleep recommendations, which can be easily implemented in LMICs.

Comparison of Neonatal Morbidity and Mortality Following Spontaneous and Medically Indicated Preterm Births: A Retrospective Population-Based Study Using Data from the Slovenian National Perinatal Information System 2013-2018

BACKGROUND This retrospective population-based study analyzed data from the Slovenian National Perinatal Information System (NPIS) between 2013 and 2018 to compare neonatal morbidity and mortality following spontaneous and medically indicated preterm births. MATERIAL AND METHODS Retrospective population-based cohort. Entries to the NPIS database were searched by gestational age (GA) <37 weeks in Slovenia between 2013 and 2018. Of 9200 (6252 following spontaneous birth, 2948 following medically indicated) neonates included, 1358 were born at extremely to very preterm GA (998 following spontaneous birth, 360 following medically indicated). Logistic regression analysis was used to examine the association between neonatal mortality and composite severe neonatal morbidity and preterm birth type (spontaneous vs medically indicated) controlling for potential confounding variables. Analysis was first performed for all preterm births (GA 22 0/7 to 36 6/7) and later only for extremely to very preterm births (GA 22 0/7 to 31 6/7). RESULTS Neonatal mortality was significantly lower following spontaneous preterm birth at extremely to very preterm GA (odds ratio [OR] 0.34; 95% confidence interval [CI] [0.14, 0.81]), while there was no association in all preterm births group (OR 0.56; 95% CI [0.26, 1.20]). No significant correlation between preterm birth type and neonatal morbidity was found (OR 0.76; 95% CI [0.54, 1.09] for all preterm births and OR 0.71; 95% CI [0.47, 1.07] for extremely to very preterm births). CONCLUSIONS In this population study from Slovenia between 2013 and 2018, medically indicated preterm births at <32 weeks of GA were associated with significantly increased neonatal mortality but not neonatal morbidity.

Mechanisms of group B Streptococcus-mediated preterm birth: lessons learnt from animal models

Group B Streptococcus (GBS) is an opportunistic pathogenic bacterium which upon colonization in the female reproductive tract can cause preterm births, fetal injury, and demise. Several determinants for GBS pathogenesis have been explored so far through the studies using animal models ranging from mice to non-human primates. The results from these experimental data have identified outer membrane vesicles, β-hemolysin, hyaluronidase, and Cas9 of GBS as major virulence factors leading to preterm births. Most of these factors drive inflammation through activation of NLRP3 and elevated production of IL1-β. However, the absence of one of the factors from the pathogen reduces but does not completely abolish the pathogenesis of GBS suggesting the involvement of more than one factor in causing preterm birth. This makes further exploration of other virulence factors of GBS pathogenesis important in gaining an insight into the mechanistic basis of GBS-mediated preterm births.

Lay summary

Group B Streptococcus (GBS) is a pathogenic bacteria whose infection in the reproductive tract during pregnancy can cause premature delivery. This bacterial infection is one of the major causes of death of mother and baby during pregnancy, and the bacteria is prevalent in all parts of the world. This makes the research on GBS so important and many of the mechanisms behind GBS infection during pregnancy still remain unexplored. In this review, we have outlined how various animal models contributed in finding the mechanism of GBS pathogenesis. The review also focuses on compiling various virulence factors which makes GBS pathogenic in the vulnerable. Understanding the mechanisms of infection by GBS will be crucial in developing drugs and vaccines to protect against the harmful effects of the bacteria.

Demographic Profile, Etiology, and Perinatal Outcome Associated With Preterm Birth in a Tertiary Hospital of Eastern India: A Retrospective Study

Background Preterm birth (PB), defined as birth occurring at less than 37 weeks of gestation, is a leading cause of perinatal mortality and morbidity in the world. Objectives This study aimed to evaluate the socio-demographic characteristics and etiological factors associated with preterm birth and consequent adverse perinatal outcomes retrospectively at a tertiary care hospital.  Methods A single-centre retrospective observational study was conducted in the department of Obstetrics & Gynaecology, Fakir Mohan Medical College & Hospital, Balasore, Odisha, India, from April 2019 to March 2020. Data were retrieved from the antenatal ward admission register, case files, theatre records, and neonatal care unit records and reviewed. Descriptive statistics were used to describe data. Chi-square test and student's t-test were used to find significance of difference between variables. Results The incidence of preterm birth in the study population was 5.52%. The mean gestational age of preterm deliveries was 34.39 ± 1.92 weeks. The bulk of the women hailed from a rural background and belonged to the lower socioeconomic strata. About 47.29% of the women were nulliparous and spontaneous preterm birth was noted in 70.40%. Premature rupture of membranes (PROM), anaemia, intrauterine growth restriction (IUGR), preeclampsia, and eclampsia were the most common adverse pregnancy conditions prevalent in these women. Preterm deliveries comprised 31.21% of all neonatal intensive care unit (NICU) admissions. Respiratory distress syndrome, birth asphyxia, neonatal sepsis, and jaundice were the most common complications. Neonatal death occurred in 51 (9.21%) preterm infants with birth asphyxia being the commonest cause of such deaths. Maternal factors and adverse neonatal outcome variables were compared between the spontaneous and iatrogenic/medically indicated preterm birth groups. Preeclampsia, IUGR, and cesarean section were more significantly associated with the iatrogenic group. Conclusion Our study provides a general overview of the associated etiological factors and perinatal health concerns associated with preterm birth in a rural/semi-urban setting in Eastern India. The findings might provide essential data for taking steps toward the prevention and management of preterm birth from a developing country's perspective.

The Impact of Different Degrees of Intraventricular Hemorrhage on Mortality and Neurological Outcomes in Very Preterm Infants: A Prospective Cohort Study

Objective

Intraventricular hemorrhage (IVH) is a common complication in preterm infants and is related to neurodevelopmental outcomes. Infants with severe IVH are at higher risk of adverse neurological outcomes and death, but the effect of low-grade IVH remains controversial. The purpose of this study was to evaluate the impact of different degrees of IVH on mortality and neurodevelopmental outcomes in very preterm infants.

Methods

Preterm infants with a gestational age of &lt;30 weeks admitted to neonatal intensive care units were included. Cerebral ultrasound was examined repeatedly until discharge or death. All infants were followed up to 18–24 months of corrected age. The impact of different grades of IVH on death and neurodevelopmental disability was assessed by multiple logistic regression.

Results

A total of 1,079 preterm infants were included, and 380 (35.2%) infants had grade I-II IVH, 74 (6.9%) infants had grade III-IV IVH, and 625 (57.9%) infants did not have IVH. The mortality in the non-IVH, I-II IVH, and III-IV IVH groups was 20.1, 19.7, and 55.2%, respectively (p &lt; 0.05), and the incidence of neurodevelopmental disabilities was 13.9, 16.1, and 43.3%, respectively (p &lt; 0.05), at 18–24 months of corrected age. After adjusting for confounding factors, preterm infants with III-IV IVH had higher rates of cerebral palsy [26.7 vs. 2.4%, OR = 6.10, 95% CI (1.840–20.231), p = 0.003], disability [43.3 vs. 13.9%, OR = 2.49, 95% CI (1.059–5.873), p = 0.037], death [55.2 vs. 20.1%, OR = 3.84, 95% CI (2.090–7.067), p &lt; 0.001], and disability + death [73.7 vs. 28.7%, OR = 4.77, 95% CI (2.518–9.021), p &lt; 0.001] compared to those without IVH. However, the mortality and the incidence of neurodevelopmental disability in infants with I-II IVH were similar to those without IVH (p &gt; 0.05).

Conclusions

Severe IVH but not mild IVH increased the risk of mortality and neurodevelopmental disability in very preterm infants.

Magnitude of spontaneous preterm birth and its associated factors among preterm birth in NICU wards in Asella Teaching and Referral Hospital, Asella, Oromia, Ethiopia

Objective

To assess the prevalence of spontaneous preterm births and to identify the associated risk factors.

Methods

This single-centre cross-sectional study enrolled women that experienced a preterm birth as registered on the neonatal log-book between 30 December 2019 and 30 December 2020. A pre-tested structured checklist was used to collect data (sociodemographic characteristics; obstetric-related factors; medical history; and pregnancy-related factors). Bivariate logistic regression analyses were applied to identify factors associated with spontaneous preterm birth. A multivariate model identified significant independent risk factors.

Results

A total of 310 patients participated in the study. The prevalence of spontaneous preterm birth in this population was 67.1% (208 of 310; 95% confidence interval [CI] 61.5, 71.9). Patients without a partner (adjusted odds ratio [AOR] = 1.470, 95% CI 1.23, 4.42), patients residing in a rural area (AOR = 2.51, 95% CI 1.123, 5.513) and those with a history of PIH during their current pregnancy (AOR = 0.104, 95% CI 0.053, 0.014) were significantly more likely to have a spontaneous preterm birth.

Conclusion

The prevalence of spontaneous preterm birth in in this study was high. Healthcare providers and all stakeholders should focus on screening pregnant women at the risk of spontaneous preterm birth.