Epidemiology of Periviable Births: The Impact and Neonatal Outcomes of Twin Pregnancy

Neonatal outcomes of early preterm births according to the delivery indications

OBJECTIVE

To compare the neonatal outcomes of early preterm births according to delivery indications and determine the obstetric risk factors associated with adverse outcomes.

METHODS

We retrospectively studied pregnancies delivered between 22 + 0 and 26 + 6 weeks at the tertiary center between April 2013 and April 2022. Stillbirths, elective termination of pregnancy, and multifetal pregnancies were excluded. Patients were classified into two groups according to delivery indications: spontaneous preterm birth (sPTB) due to premature rupture of membranes (PROM), preterm labor, or acute cervical insufficiency; and indicated preterm birth (iPTB). Obstetric and neonatal outcomes were compared between the groups.

RESULTS

Of the 121 neonates, 73 % (88/121) underwent sPTB. The overall survival rates were 73 % and 49 % in the sPTB and iPTB groups, respectively (p = 0.017). Multivariate logistic regression analysis was performed with adjustment for gestational age at delivery, fetal growth restriction, cesarean section, histological chorioamnionitis, and funisitis. Moreover, in the 1-year follow-up, the proportion of body mass below the third percentile was significantly higher in the iPTB-group than in the sPTB-group (53 % vs. 20 %, p = 0.019). Furthermore, diagnoses of developmental delay and cerebral palsy were slightly higher in the iPTB-group (33 % and 20 %, respectively) than in the sPTB-group (27 % and 9 %, respectively); however, this difference was not statistically significant.

CONCLUSIONS

In early preterm births, iPTB was associated with a higher neonatal mortality than sPTB.

Trends in Active Treatment of Live-born Neonates Between 22 Weeks 0 Days and 25 Weeks 6 Days by Gestational Age and Maternal Race and Ethnicity in the US, 2014 to 2020

IMPORTANCE

Birth in the periviable period between 22 weeks 0 days and 25 weeks 6 days' gestation is a major source of neonatal morbidity and mortality, and the decision to initiate active life-saving treatment is challenging.

OBJECTIVE

To assess whether the frequency of active treatment among live-born neonates in the periviable period has changed over time and whether active treatment differed by gestational age at birth and race and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

Serial cross-sectional descriptive study using National Center for Health Statistics natality data from 2014 to 2020 for 61 908 singleton live births without clinical anomalies between 22 weeks 0 days and 25 weeks 6 days in the US.

EXPOSURES

Year of delivery, gestational age at birth, and race and ethnicity of the pregnant individual, stratified as non-Hispanic Asian/Pacific Islander, non-Hispanic Black, Hispanic/Latina, and non-Hispanic White.

MAIN OUTCOMES AND MEASURES

Active treatment, determined by whether there was an attempt to treat the neonate and defined as a composite of surfactant therapy, immediate assisted ventilation at birth, assisted ventilation more than 6 hours in duration, and/or antibiotic therapy. Frequencies, mean annual percent change (APC), and adjusted risk ratios (aRRs) were estimated.

RESULTS

Of 26 986 716 live births, 61 908 (0.2%) were periviable live births included in this study: 5% were Asian/Pacific Islander, 37% Black, 24% Hispanic, and 34% White; and 14% were born at 22 weeks, 21% at 23 weeks, 30% at 24 weeks, and 34% at 25 weeks. Fifty-two percent of neonates received active treatment. From 2014 to 2020, the overall frequency (mean APC per year) of active treatment increased significantly (3.9% [95% CI, 3.0% to 4.9%]), as well as among all racial and ethnic subgroups (Asian/Pacific Islander: 3.4% [95% CI, 0.8% to 6.0%]); Black: 4.7% [95% CI, 3.4% to 5.9%]; Hispanic: 4.7% [95% CI, 3.4% to 5.9%]; and White: 3.1% [95% CI, 1.1% to 4.4%]) and among each gestational age range (22 weeks: 14.4% [95% CI, 11.1% to 17.7%] and 25 weeks: 2.9% [95% CI, 1.5% to 4.2%]). Compared with neonates born to White individuals (57.0%), neonates born to Asian/Pacific Islander (46.2%; risk difference [RD], -10.81 [95% CI, -12.75 to -8.88]; aRR, 0.82 [95% CI, [0.79-0.86]), Black (51.6%; RD, -5.42 [95% CI, -6.36 to -4.50]; aRR, 0.90 [95% CI, 0.89 to 0.92]), and Hispanic (48.0%; RD, -9.03 [95% CI, -10.07 to -7.99]; aRR, 0.83 [95% CI, 0.81 to 0.85]) individuals were significantly less likely to receive active treatment.

CONCLUSIONS AND RELEVANCE

From 2014 to 2020 in the US, the frequency of active treatment among neonates born alive between 22 weeks 0 days and 25 weeks 6 days significantly increased, and there were differences in rates of active treatment by race and ethnicity.

Clinical treatment outcomes and their changes in extremely preterm twins: a multicenter retrospective study in Guangdong Province, China

OBJECTIVES

To investigate the clinical treatment outcomes and the changes of the outcomes over time in extremely preterm twins in Guangdong Province, China.

METHODS

A retrospective analysis was performed for 269 pairs of extremely preterm twins with a gestational age of <28 weeks who were admitted to the department of neonatology in 26 grade A tertiary hospitals in Guangdong Province from January 2008 to December 2017. According to the admission time, they were divided into two groups: 2008-2012 and 2013-2017. Besides, each pair of twins was divided into the heavier infant and the lighter infant subgroups according to birth weight. The perinatal data of mothers and hospitalization data of neonates were collected. The survival rate of twins and the incidence rate of complications were compared between the 2008-2012 and 2013-2017 groups.

RESULTS

Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of severe asphyxia and smaller head circumference at birth (P<0.05). The mortality rates of both of the twins, the heavier infant of the twins, and the lighter infant of the twins were lower in the 2013-2017 group compared with the 2008-2012 group (P<0.05). Compared with the 2008-2012 group, the 2013-2017 group (both the heavier infant and lighter infant subgroups) had lower incidence rates of pulmonary hemorrhage, patent ductus arteriosus (PDA), periventricular-intraventricular hemorrhage (P-IVH), and neonatal respiratory distress syndrome (NRDS) and a higher incidence rate of bronchopulmonary dysplasia (P<0.05).

CONCLUSIONS

There is a significant increase in the survival rate over time in extremely preterm twins with a gestational age of <28 weeks in the 26 grade A tertiary hospitals in Guangdong Province. The incidences of severe asphyxia, pulmonary hemorrhage, PDA, P-IVH, and NRDS decrease in both the heavier and lighter infants of the twins, but the incidence of bronchopulmonary dysplasia increases. With the improvement of diagnosis and treatment, the multidisciplinary collaboration between different fields of fetal medicine including prenatal diagnosis, obstetrics, and neonatology is needed in the future to jointly develop management strategies for twin pregnancy.

Effect of delayed interval delivery of remaining fetus(es) in multiple pregnancies on survival: a systematic review and meta-analysis

BACKGROUND

The management of the pregnancy after delivery of the first fetus during a second-trimester miscarriage or very early preterm birth has not been well defined.

OBJECTIVE

The objective of the study was to evaluate whether delayed interval delivery of the remaining fetus(es) in twins/triplets is associated with improved survival, when compared with immediate delivery, after miscarriage or very preterm birth of the first fetus in multiple pregnancy.

DATA SOURCES

PubMed, MEDLINE, and Cochrane Library were systematically searched through January 2019. STUDY ELIGIBILITY CRITERIA (STUDY DESIGN, POPULATIONS, AND INTERVENTIONS): The following eligibility criteria applied: full-text original article; included at least 5 cases of delayed interval delivery for remaining fetus(es); and reported the survival rate of the first-born and the remaining fetus(es).

STUDY APPRAISAL AND SYNTHESIS METHODS

K.W.C. and W.W. searched, screened, and reviewed the articles. The quality of the studies was assessed according to the Strengthening the Reporting of Observational studies in Epidemiology checklist. If possible, data were stratified for assigned chorionicity. Effect sizes were pooled through a meta-analysis.

RESULTS

A total of 2295 published article and abstracts were identified. Only 16 studies met inclusion criteria. Meta-analysis of 492 pregnancies (432 twins [88%], 56 triplets [11%], 3 quadruplets and 1 quintuplets) showed that delayed interval delivery significantly improved the perinatal survival of remaining fetus(es) compared with the first born (odds ratio, 5.22, 95% confidence interval, 2.95-9.25, I² = 53%), before 20+0 weeks (odds ratio, 6.32, 95% confidence interval, 1.99-20.13, I² = 0%), between 20+0 and 23+6 weeks (odds ratio, 3.31, 95% confidence interval, 1.95-5.63, I² = 0%), and after 24+0 weeks (odds ratio, 1.92, 95% confidence interval, 1.21-3.05, I² = 0%), in dichorionic twin pregnancy (odds ratio, 14.89, 95% confidence interval, 6.19-35.84, I² = 0%), and unselected triplet pregnancy (odds ratio, 2.33, 95% confidence interval, 1.02-5.32, I² = 0%. ). Among the survivors, there were no significant differences in the short-term and long-term neonatal morbidities between the first-born and the remaining fetus(es). Serious maternal morbidity was reported in 39% of pregnancy after delayed interval delivery (71 of 183). In addition, 2 cases were managed by postpartum hysterectomy and 1 reported postoperative uterovaginal fistula. There were no recorded cases of maternal mortality.

CONCLUSION

Delayed interval delivery when a fetus has delivered in a multiple pregnancy is an effective management option to increase the survival rate of the remaining fetus(es). About 39% of women may experience morbidity following this management option.

What is the safest mode of delivery for extremely preterm cephalic/non-cephalic twin pairs? A systematic review and meta-analyses

Background

Given the controversy around mode of delivery, our objective was to assess the evidence regarding the safest mode of delivery for actively resuscitated extremely preterm cephalic/non-cephalic twin pairs before 28 weeks of gestation.

Methods

We searched Cochrane CENTRAL, MEDLINE, EMBASE and http://clinicaltrials.gov from January 1994 to January 2017. Two reviewers independently screened titles, abstracts and full text articles, extracted data and assessed risk of bias. We included randomized controlled trials and observational studies. Our primary outcome was a composite of neonatal death (<28 days of life) and severe brain injury in survivors (intraventricular hemorrhage grade ≥ 3 or periventricular leukomalacia). We performed random-effects meta-analyses, generating odds ratios with 95% confidence intervals for the first and second twin separately, and for both twins together. We assessed the risk of bias using a modified Newcastle Ottawa Scale (NOS) for observational studies and used Grading of Recommendations Assessment, Development and Evaluation approach (GRADE).

Results

Our search generated 2695 articles, and after duplicate removal, we screened 2051 titles and abstracts, selecting 113 articles for full-text review. We contacted 36 authors, and ultimately, three observational studies met our inclusion criteria. In cephalic/non-cephalic twin pairs delivered by caesarean section compared to vaginal birth at 24⁺⁰–27⁺⁶ weeks the odds ratio for our composite outcome of neonatal death and severe brain injury for the cephalic first twin was 0.35 (95% CI 0.00–92.61, two studies, I² = 76%), 1.69 for the non-cephalic second twin (95% CI 0.04–72.81, two studies, I² = 55%) and 0.83 for both twins (95% CI 0.05–13.43, two studies, I² = 56%). According to the modified Newcastle Ottawa Scale we assessed individual study quality as being at high risk of bias and according to GRADE the overall evidence for our primary outcomes was very low.

Conclusion

Our systematic review on the safest mode of delivery for extremely preterm cephalic/non-cephalic twin pairs found very limited existing evidence, without significant differences in neonatal death and severe brain injury by mode of delivery.

Electronic supplementary material

The online version of this article (10.1186/s12884-017-1554-7) contains supplementary material, which is available to authorized users.