Cesarean section and the outcome of very preterm and very low-birthweight infants

Neonatal Birthweight Spectrum: Maternal Risk Factors and Pregnancy Outcomes in Saudi Arabia

Background and Objectives: Low-birth-weight (LBW) neonates are at increased risk of morbidity and mortality which are inversely proportional to birth weight, while macrosomic babies are at risk of birth injuries and other related complications. Many maternal risk factors were associated with the extremes of birthweight. The objectives of this study are to investigate maternal risk factors for low and high birthweight and to report on the neonatal complications associated with abnormal birth weights. Materials and Methods: We conducted a retrospective analysis of medical records of deliveries ≥ 23 weeks. We classified the included participants according to birth weight into normal birth weight (NBW), LBW, very LBW (VLBW), and macrosomia. The following maternal risk factors were included, mother's age, parity, maternal body mass index (BMI), maternal diabetes, and hypertension. The neonatal outcomes were APGAR scores < 7, admission to neonatal intensive care unit (NICU), respiratory distress (RD), and hyperbilirubinemia. Data were analyzed using SAS Studio, multivariable logistic regression analyses were used to investigate the independent effect of maternal risk factors on birthweight categories and results were reported as an adjusted odds ratio (aOR) and 95% Confidence Interval (CI). Results: A total of 1855 were included in the study. There were 1638 neonates (88.3%) with NBW, 153 (8.2%) with LBW, 27 (1.5%) with VLBW, and 37 (2.0%) with macrosomia. LBW was associated with maternal hypertension (aOR = 3.5, 95% CI = 1.62-7.63), while increasing gestational age was less likely associated with LBW (aOR = 0.51, 95% CI = 0.46-0.57). Macrosomia was associated with maternal diabetes (aOR = 3.75, 95% CI = 1.67-8.41), in addition to maternal obesity (aOR = 3.18, 95% CI = 1.24-8.14). The odds of VLBW were reduced significantly with increasing gestational age (aOR = 0.41, 95% CI = 0.32-0.53). In total, 81.5% of VLBW neonates were admitted to the NICU, compared to 47.7% of LBW and 21.6% of those with macrosomia. RD was diagnosed in 59.3% of VLBW neonates, in 23% of LBW, in 2.7% of macrosomic and in 3% of normal-weight neonates. Hyperbilirubinemia was reported in 37.04%, 34.21%, 22.26%, and 18.92% of VLBW, LBW, NBW, and macrosomic newborns, respectively. Conclusions: Most neonates in this study had normal birthweights. Maternal hypertension and lower gestational age were associated with increased risk of LBW. Additionally, maternal obesity and diabetes increased the risk of macrosomia. Neonatal complications were predominantly concentrated in the LBW and VLBW, with a rising gradient as birthweight decreased. The main complications included respiratory distress and NICU admissions.

Mode of Delivery and Neonatal Outcomes of Preterm Deliveries: A Retrospective Study in Greece

Background and Objectives: Preterm birth is a significant concern in obstetrics and neonatology since preterm neonates are at higher risk of various health complications and may require specialized care. The optimal mode of delivery in preterm birth is a matter of debate. This study aimed to evaluate the mode of delivery in preterm neonates and the associated neonatal outcomes. Material and Methods: This was a retrospective cohort study including all preterm neonates born between January 2010 and December 2020 at the 3rd Department of Obstetrics & Gynecology of Aristotle University of Thessaloniki, Greece. The mode of delivery in relation to gestational age groups and the cause of preterm birth were analyzed. Neonatal outcomes were also evaluated according to gestational age, indication and mode of delivery. Results: A total of 1167 preterm neonates were included in the study; the majority of them were delivered via cesarean section (76.1%). Most of the preterm neonates (n = 715; 61.3%) were delivered at 32+0-36+6 weeks, while cesarean section was the most common mode of delivery after 28+0 weeks. Furthermore, spontaneous onset of labor (OR: 6.038; 95% CI: 3.163-11.527; p < 0.001), multiple gestation (OR: 1.782; 95% CI: 1.165-2.227; p = 0.008) and fetal distress (OR: 5.326; 95% CI: 2.796-10.144; p < 0.001) were the main causes of preterm delivery at 32+0-36+6 weeks. The overall mortality rate was 8.1% among premature neonates. Regarding morbidity, 919 (78.7%) neonates were diagnosed with respiratory disorders, 129 (11.1%) with intraventricular hemorrhage and 30 (2.6%) with necrotizing enterocolitis. Early gestational age at delivery was the main risk factor of neonatal morbidity and mortality. Notably, the mode of delivery did not have any impact on neonatal survival (OR: 1.317; 95% CI: 0.759-2.284; p = 0.328), but preterm neonates born via cesarean section were at higher risk of respiratory disorders, compared to those born via vaginal delivery (OR: 2.208; 95% CI: 1.574-3.097; p < 0.001). Conclusions: Most preterm deliveries occurred in the moderate-to-late preterm period via cesarean section. Early gestational age at delivery was the main prognostic factor of neonatal morbidity and mortality, while the mode of delivery did not have any impact on neonatal survival. Future research on the mode of delivery of the preterm neonates is warranted to establish definitive answers for each particular gestational age.

Preterm Labor: A Comprehensive Review of Guidelines on Diagnosis, Management, Prediction and Prevention

Importance

Preterm labor (PTL) is one of the most common and serious pregnancy complications associated with significant perinatal morbidity and mortality, as well as long-term neurologic impairment in the offspring.

Objective

The aim of this study was to review and compare the most recently published major guidelines on diagnosis, management, prediction, and prevention of this severe complication of pregnancy.

Evidence Acquisition

A descriptive review of guidelines from the National Institute for Health and Care Excellence (NICE), the World Health Organization, the American College of Obstetricians and Gynecologists, the New South Wales Government, and the European Association of Perinatal Medicine (EAPM) on PTL was carried out.

Results

There is a consensus among the reviewed guidelines that the diagnosis of PTL is based on clinical criteria, physical examination, measurement of cervical length (CL) with transvaginal ultrasound (TVUS) and use of biomarkers, although there is disagreement on the first-line diagnostic test. The NICE and the EAPM are in favor of TVUS CL measurement, whereas the New South Wales Government mentions that fetal fibronectin testing is the mainstay for PTL diagnosis. Moreover, there is consistency among the guidelines regarding the importance of treating PTL up to 34 weeks of gestation, to delay delivery for 48 hours, for the administration of antenatal corticosteroids, magnesium sulfate, and in utero transfer to higher care facility, although several discrepancies exist regarding the tocolytic drugs of choice and the administration of corticosteroids and magnesium sulfate after 34 and 30 gestational weeks, respectively. Routine cesarean delivery in case of PTL is unanimously not recommended. Finally, the NICE, the American College of Obstetricians and Gynecologists, and the EAPM highlight the significance of screening for PTL by TVUS CL measurement between 16 and 24 weeks of gestation and suggest the use of either vaginal progesterone or cervical cerclage for the prevention of PTL, based on specific indications. Cervical pessary is not recommended as a preventive measure.

Conclusions

Preterm labor is a significant contributor of perinatal morbidity and mortality with a substantial impact on health care systems. Thus, it seems of paramount importance to develop consistent international practice protocols for timely diagnosis and effective management of this major obstetric complication and subsequently improve pregnancy outcomes.

Cesarean section was not associated with mortality or morbidities advantage in very low birth weight infants: a nationwide cohort study

This study investigated the role of cesarean section (CS) in mortality and morbidity of very-low-birth-weight infants (VLBWIs) weighing less than 1500 g. This nationwide prospective cohort study of the Korean Neonatal Network consisted of 9,286 VLBWIs at 23–34 gestational weeks (GW) of age between 2013 and 2017. The VLBWIs were stratified into 23–24, 25–26, 27–28 and 29–34 GW, and the mortality and morbidity were compared according to the mode of delivery. The total CS rate was 78%, and was directly proportional to gestational age. The CS rate was the lowest at 61% in case of infants born at 23–24 GW and the highest at 84% in VLBWIs delivered at 29–34 GW. Contrary to the significantly lower total mortality (12%) and morbidities including sepsis (21%) associated with CS than vaginal delivery (VD) (16% and 24%, respectively), the mortality in the 25–26 GW (26%) and sepsis in the 27–28 GW (25%) and 29–34 GW (12%) groups were significantly higher in CS than in VD (21%, 20% and 8%, respectively). In multivariate analyses, the adjusted odds ratios (ORs) for mortality (OR 1.06, 95% CI 0.89–1.25) and morbidity including sepsis (OR 1.12, 95% CI 0.98–1.27) were not significantly reduced with CS compared with VD. The adjusted ORs for respiratory distress syndrome (1.89, 95% CI 1.59–2.23) and symptomatic patent ductus arteriosus (1.21, 95% CI 1.08–1.37) were significantly increased with CS than VD. In summary, CS was not associated with any survival or morbidity advantage in VLBWIs. These findings indicate that routine CS in VLBWIs without obstetric indications is contraindicated.

Factors associated with extubation failure in very low birth weight infants: a cohort study in the northeast Brazil

OBJECTIVES

Identifying and understanding the main risk factors associated with extubation failure of very low birthweight (VLBW) infants in different populations can subsequently help in establishing better criteria while taking decision of extubation. The aim of the study was to identify factors associated with extubation failure in VLBW infants.

METHODS

A cohort study of VLBW infants who underwent their first extubation between April 2018 and December 2019 in a Neonatal Intensive Care Unit, Alagoas, Brazil, were included in this study. Extubation failure was defined as reintubation within seven days of extubation. Relative risks of predictive variables different between the extubation success group (ES) and extubation failure group (EF) were estimated with a robust Poisson regression model.

RESULTS

Out of the 112 infants included, 26 (23%) cases exhibited extubation failure. Extremely low birth weight (RR 2.55, 95% CI 1.07, 6.06), mechanical ventilation duration for first extubation greater than seven days (RR 2.66, 95% CI 1.10, 6.45), vaginal delivery (RR 2.07, 95% CI 1.03, 4.18) and maternal chorioamnionitis (RR 4.89, 95% CI 1.26-18.98) remained independently associated with extubation failure. EF had a significant greater need for respiratory support, longer oxygen therapy duration, more bronchopulmonary dysplasia (BPD) and longer length of hospital stay, even when adjusted for confounding variables.

CONCLUSIONS

Extremely low birth weight infants needing mechanical ventilation, wherein the duration for first extubation was longer than seven days, with vaginal delivery and maternal chorioamnionitis failed more frequently at the first attempt of extubation. And this failure increased the risk of BPD and the length of hospital stay.

Improved Survival of Periviable Infants after Alteration of the Threshold of Viability by the Neonatal Resuscitation Program 2015

Periviable infants (PIs) born at 22–25 weeks gestational age (wGA) have a variable survival rate (49.7–86.2%) among hospitals. One factor involved in this difference may be the definition of the threshold of viability. The American Academy of Pediatrics revised the neonatal resuscitation program in late 2015 (NRP 2015) and altered the threshold of viability from 23 to 22 wGA. The impact on the survival of PIs after the guideline alteration has seldom been discussed. Since 2016, the unit of this study has implemented the renewed guideline for PIs. We retrospectively reviewed and analyzed the survival and clinical variables of PIs before and after implementation of the guideline, which included a 10-year cohort in a single center in Taiwan. There were 168 PIs enrolled between 2010 and 2019 (Epoch-I, 2010–2015; Epoch-II, 2016–2019), after excluding those with congenital anomalies and parent-decided comfort care. Compared to those in Epoch-I, the PIs in Epoch-II had significantly higher odds ratios (2.602) (95% confidence interval: 1.170–5.789; p = 0.019) for survival. Younger gestational age, small size for gestational age, cesarean delivery, low blood pH at birth, and surfactant therapeutic treatment were found to be significant risk factors associated with the survival of PIs (p < 0.05 for each). The altered threshold of viability by NRP 2015 may impact the survival of PIs. However, long-term follow-up for surviving PI is required in the future.

Trends in Overall Mortality, and Timing and Cause of Death among Extremely Preterm Infants near the Limit of Viability

Objective

To investigate the trends in mortality, as well as in the timing and cause of death, among extremely preterm infants at the limit of viability, and thus to identify the clinical factors that contribute to decreased mortality.

Methods

We retrospectively reviewed the medical records of 382 infants born at 23–26 weeks’ gestation; 124 of the infants were born between 2001 and 2005 (period I) and 258 were born between 2006 and 2011 (period II). We stratified the infants into two subgroups–“23–24 weeks” and “25–26 weeks”–and retrospectively analyzed the clinical characteristics and mortality in each group, as well as the timing and cause of death. Univariate and multivariate logistic regression analyses were done to identify the clinical factors associated with mortality.

Results

The overall mortality rate in period II was 16.7% (43/258), which was significantly lower than that in period I (30.6%; 38/124). For overall cause of death, there were significantly fewer deaths due to sepsis (2.4% [6/258] vs. 8.1% [10/124], respectively) and air-leak syndrome (0.8% [2/258] vs. 4.8% (6/124), respectively) during period II than during period I. Among the clinical factors of time period, 1-and 5-min Apgar score, antenatal steroid identified significant by univariate analyses. 5-min Apgar score and antenatal steroid use were significantly associated with mortality in multivariate analyses.

Conclusion

Improved mortality rate attributable to fewer deaths due to sepsis and air leak syndrome in the infants with 23–26 weeks’ gestation was associated with higher 5-minute Apgar score and more antenatal steroid use.

Premature rupture of membranes and neonatal respiratory morbidity at 32-41 weeks' gestation: a retrospective single-center cohort study

AIM

To ascertain whether premature rupture of membranes (PROM) independently affects the risk of neonatal respiratory morbidity at 32-41 weeks' gestation because previous reports have given insufficient consideration to the mode of delivery and labor onset.

METHODS

Data on 4,629 consecutive singleton infants were retrospectively collected. Respiratory morbidity was limited to respiratory distress syndrome and transient tachypnea of the newborn, both of which are related to prematurity. Delivery modes were divided into four groups based on the existence of PROM and of labor onset, and the respiratory morbidity was examined according to the number of weeks of gestational age. Multivariate analysis including PROM and delivery mode was conducted to examine the association of respiratory morbidity.

RESULTS

Respiratory morbidity or a positive pressure requirement delivered after PROM and intact amniochorionic membranes accompanied by labor were similar at all weeks. Around 37 weeks, the absence of labor onset was associated with a risk of respiratory morbidity or positive pressure requirement. Significant respiratory risk was not associated with the incidence of PROM (adjusted odds ratio [aOR], 0.98; 95% confidence interval [CI], 0.52-1.83), interval from rupture to delivery (aOR, 1.00; 95% CI, 0.99-1.01), clinical chorioamnionitis, induction management, pregnancy-related complications, or neonatal sex. Delivery by Cesarean section and early gestational age presented a significant risk for respiratory morbidity.

CONCLUSIONS

Neither PROM nor latency after PROM at 32-41 weeks affected neonatal respiratory morbidity. Avoiding Cesarean section instead of simply increasing the time to delivery may help to reduce respiratory morbidity.

No relationship between mode of delivery and neonatal mortality and neurodevelopment in very low birth weight infants aged two years

BACKGROUND

To compare neonatal mortality and neurodevelopmental outcomes at two years of age in very low birth weight infants (≤1500 g) born by cesarean with those by vaginal delivery.

METHODS

In this retrospective, case-control study, we evaluated neonatal mortality, medical conditions and neurodevelopmental outcomes at two years of corrected age in 710 very low birth weight (VLBW) infants born between January 2005 and December 2010. Of the 710 infants, 351 were born by the cesarean and 359/710 by vaginal route.

RESULTS

There were no significant differences in neonatal mortality between the cesarean delivery group and vaginal delivery group [56/351 (15.9%) vs. 71/359 (19.8%), P=0.20]. VLBW infants delivered by the cesarean procedure had a higher incidence of respiratory distress syndrome than those born by the vaginal route [221/351 (63.0%) vs. 178/359 (49.6%), P<0.001]. There were no differences in other neonatal morbidities, including intraventricular hemorrhage [126/351 (35.9%) vs. 134/359 (37.3%), P=0.69], bronchopulmonary dysplasia [39/351 (11%) vs. 31/359 (8.6%), P=0.38] and necrotising enterocolitis [40/351 (11.4%) vs. 32/359 (8.9%), P=0.32] between the two groups. The incidence of poor neurodevelopment after cesarean delivery was similar to that after vaginal delivery [105/351 (29.9) vs. 104/359 (29.0%), P=0.78].

CONCLUSIONS

In neither neurodevelopment nor neonatal mortality did cesarean birth offered significant advantages to VLBW infants. Moreover, the operation might be associated with an increased risk of respiratory distress syndrome for VLBW infants. The mode of delivery of VLBW infants should be largely based on obstetric indications and maternal considerations rather than perceived better outcomes for the neonate.

Evolução da assistência materno-infantil e do peso ao nascer no Estado de Pernambuco em 1997 e 2006

Avaliar a evolução e a influência da assistência materno-infantil na variação do peso ao nascer no estado de Pernambuco. Os dados analisados provêm de duas pesquisas transversais da população de crianças menores de cinco anos, estudadas por inquéritos domiciliares em 1997 (n = 1906) e 2006 (n = 1555). A amostra foi calculada para assegurar a representatividade de dois estratos geoeconômicos: setores urbano e rural. Estudou-se a assistência ao pré-natal e parto e o peso ao nascer. Utilizou-se o teste do qui-quadrado para comparar as variáveis categóricas e calculou-se a diferença da média de peso ao nascer nos anos pesquisados, e os respectivos intervalos de confiança de 95%. Verificou-se importante melhora na assistência ao pré-natal e aumento do parto cesáreo. Houve uma redução significante de 112g na diferença da média de peso ao nascer no meio rural. Em 2006 o acesso a pelo menos 1 consulta de pré-natal ocorreu independente da escolaridade materna, no entanto, o acesso ao pré-natal mais adequado foi maior entre as mães de maior escolaridade, tanto em 1997, como em 2006. Apesar da expansão da assistência no pré-natal e no parto, o acesso iníquo, o excesso de intervenções médicas e o aumento da sobrevida de recém nascidos podem estar contribuindo para as variações da média de peso ao nascer no estado de Pernambuco.

Brain oxygenation monitoring during neonatal resuscitation of very low birth weight infants

OBJECTIVE

To explore if regional cerebral tissue oxygen saturation monitoring by near-infrared spectroscopy (NIRS) is feasible during neonatal resuscitation of very low birth weight (VLBW) infants after birth.

STUDY DESIGN

Cerebral tissue oxygen saturation was measured by NIRS in 51 VLBW infants (mean gestational age: 27.8 weeks) during the first 10 min after delivery.

RESULT

A regional cerebral tissue oxygen saturation signal was available after a median (interquartile range) age of 52 (44 to 68) s. In three infants the signal was obtained after 10 min of age. After delivery cerebral tissue oxygen saturation rose continuously from 37 (31 to 49) % at 1 minute of age and reached a steady state in the range of 61 to 84% ∼7 min after birth. Percentiles of cerebral tissue oxygen saturation of this cohort of preterm infants are given.

CONCLUSION

Cerebral tissue oxygen saturation monitoring is feasible during neonatal resuscitation of VLBW infants within the first minutes of life.

Preterm birth and necrotizing enterocolitis alter gut colonization in pigs

Necrotizing enterocolitis (NEC) in preterm neonates is dependent on bacterial colonization, but it remains unclear whether a particular microbiota or specific pathogens are involved. We hypothesized that gut colonization differs between preterm and term neonates and that overgrowth of Clostridium perfringens predisposes to NEC. By using terminal-RFLP and FISH, we characterized the gut microbiota of preterm, caesarean-delivered, formula-fed pigs (n = 44) with or without NEC and of formula- or colostrum-fed term, and vaginally born pigs (n = 13). A different microbiota with high C. perfringens abundance was observed in preterm pigs with NEC compared with healthy individuals. However, immunization against C. perfringens toxins did not prevent NEC, and C. perfringens inoculation (3.6 × 10 cfu/d) failed to induce NEC (n = 16), whereas prophylactic broad-spectrum antibiotics treatment prevented NEC (n = 24). Colonization in both groups of term pigs differed from preterm pigs and was dominated by Lactobacilli spp. In conclusion, gestational age (GA) and NEC influence neonatal gut colonization, whereas diet has minor effects. C. perfringens is more abundant in pigs with NEC but rather as a consequence than a cause of disease. The general bacterial load and underdeveloped gut immune responses in preterm neonates seem more important for NEC development than specific pathogens.

Method of delivery and intraventricular haemorrhage in extremely preterm infants

OBJECTIVES

It has been reported that caesarean delivery (CD) protects against intraventricular haemorrhage (IVH) in the extremely preterm infant, but it is not known whether this effect involve the more severe grades of IVH. Thus, our aim was to confirm the correlation between the occurrence of IVH and the mode of delivery, and to evaluate this correlation for each grade of IVH.

METHODS

All infants with gestational age (GA) ≤ 28 weeks admitted to the neonatal intensive care unit of a tertiary hospital were studied for each grade IVH and major complications rate.

RESULT

We found that vaginally born infants had a higher rate of each grade of IVH, but the increase was statistically significant only for grade 3 IVH (18% vs. 2%, p < 0.0001) and all grades IVH (45% vs. 20%, p < 0.0001). Multivariate analysis demonstrated that CD (RR: 0.42, 95% CI 0.28-0.63), birth weight ≥ 800 g (RR: 0.48, 95% CI 0.32-0.73), 27-28 weeks of GA (RR: 0.38, 95% CI 0.25-0.60) and antenatal steroids (0.66, 95% CI 0.22-0.46) decrease independently the risk of developing IVH.

CONCLUSIONS

Our study demonstrates that CD decreases the risk of developing IVH in extremely preterm infants including the most severe grades of IVH.