Impact of multiple births on late and moderate prematurity

Maternal type 1 diabetes, preterm birth, and risk of intellectual disability in the offspring: A nation-wide study in Sweden

OBJECTIVE

There are few data on long-term neurological or cognitive outcomes in the offspring of mothers with type 1 diabetes (T1D). The aims of this study were to examine if maternal T1D increases the risk of intellectual disability (ID) in the offspring, estimate the amount of mediation through preterm birth, and examine if the association was modified by maternal glycated hemoglobin (HbA1c).

DESIGN

Population-based cohort study using population-based data from several national registries in Sweden.

SETTING AND PARTICIPANTS

All offspring born alive in Sweden between the years 1998 and 2015.

MAIN OUTCOME MEASURE

The risk of ID was estimated through hazard ratios with 95% confidence intervals (HR, 95% CI) from Cox proportional hazard models, adjusting for potential confounding. Risks were also assessed in mediation analyses and in subgroups of term/preterm births, in relation to maternal HbA1c and by severity of ID.

RESULTS

In total, 1,406,441 offspring were included. In this cohort, 7,794 (0.57%) offspring were born to mothers with T1D. The risk of ID was increased in offspring of mothers with T1D (HR; 1.77, 1.43-2.20), of which 47% (95% CI: 34-100) was mediated through preterm birth. The HRs were not modified by HbA1c.

CONCLUSION

T1D in pregnancy is associated with moderately increased risks of ID in the offspring. The risk is largely mediated by preterm birth, in particular for moderate/severe cases of ID. There was no support for risk-modification by maternal HbA1c.

Morbidities and rehospitalizations during the first year of life in moderate and late preterm infants: more similarities than differences?

BACKGROUND

The aim was to compare neonatal morbidities in moderate and late preterm infants and to analyze rates and causes for rehospitalizations during the first year of life.

METHODS

Prospective follow-up of a group of moderate and late preterm infants at a tertiary care hospital.

RESULTS

The study population comprised 215 infants (58% males; 60% singletons; 99 moderate and 116 late preterm infants) with a median gestational age of 34 weeks and birth weight of 2100 grams; 20% of them were small for gestational age. Moderate preterm infants more often had a diagnosis of mild respiratory distress syndrome (26% vs. 13%, P<0.01) and feeding problems with longer need for nasogastric tube feeding (median 9.5 vs. 4.2 days, P<0.01) and parenteral nutrition (3.5 vs. 2.7 days, P<0.01), and longer duration of stay at either NICU (10.6 vs. 3.7 days; P<0.01) or hospital (13 vs. 11 days; P<0.01). Fifty-two infants (24.3%) were hospitalized at 67 occasions without differences regarding readmission rates and causes between groups. Median age at readmission was 3 months, median stay 4 days. The most common diagnosis was respiratory illness (43.3%).

CONCLUSIONS

Moderate preterm infants had more neonatal morbidities diagnosed, but the same rehospitalization rates than late preterm infants.

Adverse obstetric outcomes in women with PCOS and multiple gestations

RESEARCH QUESTION

Does multiple gestation alter the risks for adverse obstetric outcomes in women with polycystic ovary syndrome (PCOS)?

DESIGN

Retrospective population-based cohort study using data from the HCUP-NIS from 2004 to 2014. A total of 14,882 women with PCOS, who delivered within that time period, were identified. The study group comprised women with PCOS who had had a multiple gestation (n = 880); the reference group was comprised of the remaining women with PCOS and singleton gestation (n = 14,002).

RESULTS

In women with PCOS, multiple gestation increased the risks of pregnancy complications including pregnancy-induced hypertension (adjusted odds ratio [aOR] 2.030; 95% confidence interval [CI] 1.676-2.460), pre-eclampsia (aOR 2.879; 95% CI 2.277-3.639), pre-eclampsia and eclampsia superimposed on pre-existing hypertension (aOR 1.917; 95% CI 1.266-2.903) and gestational diabetes (aOR 1.358; 95% CI 1.114-1.656). Multiple gestation increases the risk of preterm premature rupture of membranes (aOR 5.807; 95% CI 4.153-8.119), preterm delivery (aOR 8.466; 95% CI 7.071-10.135), Caesarean section (aOR 5.146; 95% CI 4.184-6.329), post-partum haemorrhage (aOR 1.540; 95% CI 1.065-2.228) and the need for transfusion (aOR 3.268; 95% CI 2.010-5.314), as well as wound complications (aOR 3.089; 95% CI 1.647-5.794). Neonates born to mothers with PCOS and having multiple gestations are more likely to be small for gestational age when compared to singleton neonates born to mothers with PCOS (aOR 4.606; 95% CI 3.480-6.095). Among PCOS women with multiple gestations, obesity increased the risks of developing pregnancy-induced hypertension (P < 0.001), pre-eclampsia (P < 0.001) and wound complications (P = 0.045).

CONCLUSION

These results highlight the importance of single embryo transfer and ovulation induction to develop a single follicle in women with PCOS. Obesity further increases obstetrical complications.

Breastfeeding initiation, duration, and experiences of mothers of late preterm twins: a mixed-methods study

Background

Twins and late preterm (LPT) infants are at an increased risk of being breastfed to a lesser extent than term singletons. This study aimed to describe the initiation and duration of any and exclusive breastfeeding at the breast for mothers of LPT twins and term twins during the first 4 months and to explore the breastfeeding experiences of mothers of LPT twins.

Methods

A sequential two-sample quantitative–qualitative explanatory mixed-methods design was used. The quantitative data were derived from a longitudinal cohort study in which 22 mothers of LPT twins and 41 mothers of term twins answered questionnaires at one and four months after birth (2015–2017). The qualitative data were obtained from semi-structured interviews with 14 mothers of LPT twins (2020–2021), based on results from the quantitative study and literature. Analysis included descriptive statistics of quantitative data and deductive content analysis of the qualitative data, followed by condensation and synthesis.

Results

All mothers of LPT twins (100%) and most mothers of term twins (96%) initiated breastfeeding. There was no difference in any breastfeeding during the first week at home (98% versus 95%) and at 1 month (88% versus 85%). However, at 4 months, the difference was significant (44% versus 75%). The qualitative data highlighted that mothers of LPT twins experienced breastfeeding as complex and strenuous. Key factors influencing mothers’ experiences and decisions were their infants’ immature breastfeeding behaviors requiring them to express breast milk alongside breastfeeding, the burden of following task-oriented feeding regimes, and the lack of guidance from healthcare professionals. As a result, mothers started to question the worth of their breastfeeding efforts, leading to changes in breastfeeding management with diverse results. Support from fathers and grandparents positively influenced sustained breastfeeding.

Conclusions

Mothers of LPT twins want to breastfeed, but they face many challenges in breastfeeding during the first month, leading to more LPT twins’ mothers than term twins’ mothers ceasing breastfeeding during the following months. To promote and safeguard breastfeeding in this vulnerable group, care must be differentiated from routine term infant services, and healthcare professionals need to receive proper education and training.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13006-022-00507-3.

The changing impact of assisted reproductive techniques on preterm birth during the period 2007-2020 in Lombardy, Northern Italy

OBJECTIVE

To assess the impact of Assisted Reproductive Techniques (ART) on the risk of preterm birth (PTB).

STUDY DESIGN

This retrospective population-based study used healthcare utilization databases of the Lombardy Region to select all the deliveries occurred between 2007 and 2020. Log-binomial regression models were fitted to estimate prevalence ratio (PR) and the corresponding 95% confidence interval (CI) of PTB among deliveries after ART. Estimates were adjusted for maternal sociodemographic features. Furthermore, the population attributable fraction was computed. All the analyses were performed for calendar period and were repeated excluding multiple births.

RESULTS

In our cohort, an increasing trend in the number of ART emerged, with an overall rate of 25.8 per 1,000 deliveries (N = 28,742). ART was positively related to PTB (aPR = 2.83, 95 % CI: 2.76-2.91) with a downward trend. Over the period study, multiple births after ART decreased (from 20.4 % to 8.4 %) and were constantly burdened by a higher number of PTB. Excluding multiple births, the association was substantially lower (aPR = 1.72, 95 % CI: 1.65-1.79) and did not describe any trend. Moreover, stratifying for type of pregnancy, the association was observed only among singletons. Finally, the proportion of PTB considered attributable to ART increased from about 2-3 % to 6 % till the 2016, then decreased.

CONCLUSION

The investigation suggested that ART was related to PTB; this association may be partly justified by the high rate of multiple births among women who conceived non spontaneously. However, excluding multiple births, ART remained associated with PTB.

Perinatal outcomes in twin late preterm pregnancies: results from an Italian area-based, prospective cohort study

BACKGROUND

Multiple gestations represent a considerable proportion of pregnancies delivering in the late preterm (LP) period. Only 30% of LP twins are due to spontaneous preterm labor and 70% are medically indicated; among this literature described that 16-50% of indicated LP twin deliveries are non-evidence based. As non-evidence-based delivery indications account for iatrogenic morbidity that could be prevented, the objective of our observational study is to investigate first neonatal outcomes of LP twin pregnancies according to gestational age at delivery, chorionicity and delivery indication, then non evidence-based delivery indications.

METHODS

Prospective cohort study among twins infants born between 34 + 0 and 36 + 6 weeks, in Emilia Romagna, Italy, during 2013-2015. The primary outcome was a composite of adverse perinatal outcomes.

RESULTS

Among 346 LP twins, 84 (23.4%) were monochorionic and 262 (75.7%) were dichorionic; spontaneous preterm labor accounted for 85 (24.6%) deliveries, preterm prelabor rupture of membranes for 66 (19.1%), evidence based indicated deliveries were 117 (33.8%), while non-evidence-based indications were 78 (22.5%). When compared to spontaneous preterm labor or preterm prelabor rupture of membranes, pregnancies delivered due to maternal and/or fetal indications were associated with higher maternal age (p <  0.01), higher gestational age at delivery (p <  0.01), Caucasian race (p 0.04), ART use (p <  0.01), gestational diabetes (p <  0.01), vaginal bleeding (p <  0.01), antenatal corticosteroids (p <  0.01), diagnosis of fetal growth restriction (FGR) (p <  0.01), and monochorionic (p <  0.01). Two hundred twenty-six pregnancies (65.3%) had at least one fetus experiencing one composite of adverse perinatal outcome. Multivariate analysis confirmed that delivery indication did not affect the composite of adverse perinatal outcomes; the only characteristic that affect the outcome after controlling for confounding was gestational age at delivery (p <  0.01). Moreover, there was at least one adverse neonatal outcome for 94% of babies born at 34 weeks, for 73% of those born at 35 weeks and for 46% of those born at 36 weeks (p <  0.01).

CONCLUSION

Our study suggests that the decision to deliver or not twins in LP period should consider gestational age at delivery as the main determinant infants' prognosis. Delivery indications should be accurately considered, to avoid iatrogenic early birth responsible of preventable complications.

Perinatal outcome of dichorionic and monochorionic-diamniotic Finnish twins: a historical cohort study

INTRODUCTION

Although the perinatal mortality of monochorionic twins has been reported to be higher, the role of chorionicity is debated and data from Finland are still lacking. To examine the effect of chorionicity on the main outcome measures, perinatal and neonatal mortality and neonatal morbidity of Finnish twins, a comprehensive population-based historical cohort study was performed at Helsinki University Hospitals.

MATERIAL AND METHODS

All 1034 dichorionic and monochorionic-diamniotic twin pregnancies managed at Helsinki University Hospital area during 2006, 2010, 2014 and 2018 were collected from patient databases. Information on chorionicity was retrieved from ultrasound reports and all relevant clinical information from patient records. Differences in perinatal and neonatal mortality and neonatal morbidity were analyzed by performing group comparisons between the twins and chorionicity. The role of chorionicity was also assessed in logistic regression analyses.

RESULTS

There were 1034 dichorionic-diamniotic (DCDA, n = 789, 76.3%, 95% confidence interval [CI] 73.6-78.9) and monochorionic-diamniotic (MCDA, n = 245, 23.7%, 95% CI 21.4-26.0) twin pregnancies during the studied years. Most (n = 580, 56.1%, 95% CI 52.8-59.2) twins were born at term, but 151 (61.6%, 95% CI 55.8-67.3) of MCDA twins were preterm and had lower birthweight and Apgar scores and higher risk of death of one twin. Perinatal and neonatal mortality did not differ between twins A and B, but the immediate outcome of twin B was worse, with lower arterial pH and Apgar scores and increased need of neonatal intensive care unit treatment.

CONCLUSIONS

Chorionicity contributes to the perinatal and neonatal outcome in favor of dichorionic twins. This disadvantage of MCDA twinning is likely explained by earlier gestational age at birth and inequal placental sharing. Irrespective of chorionicity, twin B faces more complications.

Early cleaving embryos result in blastocysts with increased aspartate and glucose consumption, which exhibit different metabolic gene expression that persists in placental and fetal tissues

OBJECTIVES

Using time-lapse microscopy, previous research has shown that IVF mouse embryos that cleave earlier at the first division ('fast') develop into blastocysts with increased glucose consumption and lower likelihood of post-implantation loss as compared to slower cleaving embryos ('slow'). Further, metabolomics analysis employing LC-MS conducted on groups of 'fast' blastocysts revealed that more aspartate was consumed. With the worldwide adoption of single blastocyst transfer as the standard of care, the need for quantifiable biomarkers of viability, such as metabolism of specific nutrients, would greatly assist in embryo selection for transfer.

METHODS

Here we describe the development of a targeted enzymatic assay to quantitate aspartate uptake of single blastocysts.

RESULTS

Results demonstrate that the rates of aspartate and glucose consumption were significantly higher in individual 'fast' blastocysts. Blastocysts, together with placental and fetal liver tissue collected following transfer, were analysed for the expression of genes involved in aspartate and carbohydrate metabolism. In 'fast' blastocysts, expressions of B3gnt5, Slc2a1, Slc2a3, Got1 and Pkm2 were found to be significantly higher. In placental tissue derived from 'fast' blastocysts, expression of Slc2a1, Got1 and Pkm2 were significantly higher, while levels of Got1 and Pkm2 were lower in fetal liver tissue compared to tissue from 'slow' blastocysts.

CONCLUSIONS

Importantly, this study shows that genes regulating aspartate and glucose metabolism were increased in blastocysts that have higher viability, with differences maintained in resultant placentae and fetuses. Consequently, the analysis of aspartate uptake in combination with glucose represents biomarkers of development and may improve embryo selection efficacy and pregnancy rates.

A Comparison of Respiratory Syncytial Viral Prophylaxis in Multiple Births versus Singletons in the Canadian Registry of Palivizumab

OBJECTIVE

The aim of this study is to compare respiratory illness-related hospitalization (RIH) and respiratory syncytial virus (RSV)-related hospitalization (RSVH) in multiple births versus singletons, who received palivizumab during the RSV season and participated in the Canadian registry of palivizumab (CARESS).

STUDY DESIGN

Prospective, observational study of infants aged <2 years recruited across 32 centers over 12 RSV seasons from 2005 to 2017. Demographic data were collected at enrolment and RIH events were recorded monthly.

RESULTS

A total of 25,003 infants were enrolled of whom 6,949 (27.8%) were of multiple birth, and 18,054 (72.2%) were singletons. A significantly larger proportion of the multiple births were premature (80.2%) compared with the singleton group (56.8%). Multiples had a lower gestational age (mean ± standard deviation): 31.2 ± 3.2 versus 33.2 ± 5.5 weeks and birth weight (mean: 1,590 ± 606.8 vs. 2,069.4 ± 1068.5 g; both p < 0.0005). They were younger at enrolment (4.5 ± 5.0 vs. 6.1 ± 6.8 months), and fewer attended daycare (1.9 vs. 4.6%), and experienced exposure to smoking (24.5 vs. 29.9%), but more lived in a crowded household (36.7 vs. 19.4%); all p < 0.0005. Multiples had a longer length of neonatal stay (51.1 ± 65.9 vs. 47.9 ± 67.8 days), and more required respiratory support (65.7 vs. 57.7%), but for shorter duration (22.6 ± 32.9 vs. 24.7 ± 40.6 days); all p < 0.001. RIH and RSVH rates (%) in multiples versus singletons were 4.7; 7.7 and 1.4; and 1.6, respectively. Cox regression showed that multiples had a lower risk of RIH compared with singletons (hazard ratio [HR] = 0.616, 95% confidence interval [CI]: 0.543-0.698, p < 0.0005), but not RSVH (HR: 0.77, 95% CI: 0.57-1.02, p = 0.071).

CONCLUSION

Multiple birth infants, who are known to be at greater risk for severe RSVH compared with singletons, are well protected by palivizumab, provided adherence to the monthly injection scheme is guaranteed.

Admissions and Emergency Visits by Late Preterm Singletons and Twins in the First 5 Years: A Population-Based Cohort Study

OBJECTIVE

To compare admission and emergency visits of late preterm (34^0/7-36^6/7 weeks) versus term infants (37^0/7-41^6/7 weeks) in the first 5 years.

STUDY DESIGN

This population-based cohort study included all singletons and twins born alive at 34^0/7 to 41^6/7 weeks' gestation registered in a health administrative database in Ontario, Canada, between April 1, 2002 and December 31, 2012. Admissions and emergency visits from initial postnatal discharge to 5 years were compared between late preterm and term infants adjusting for maternal and infant characteristics.

RESULTS

A total of 1,316,931 infants (75,364 late preterm infants) were included. Late preterm infants had more frequent admissions than term infants in the first 5 years in both singletons (adjusted incidence rate ratio [95% confidence interval] = 1.46 [1.42-1.49]) and twins (1.21 [1.11-1.31]). The difference in admissions between late preterm and term infants were smaller in twins than singletons and decreased with children's ages. Twins had less frequent admissions than singletons for late preterm infants, but not for term infants. The emergency visits were more frequent in late preterm than term infants in all the periods.

CONCLUSION

Admissions and emergency visits were more frequent in late preterm than term infants through the first 5 years. Admissions were less frequent in late preterm twins than singletons.

A shorter breastfeeding duration in late preterm infants than term infants during the first year

AIM

Little attention has been paid to breastfeeding late preterm (LPT) infants. This study compared breastfeeding, worries, depression and stress in mothers of LPT and term-born infants throughout the first year. We also described factors associated with shorter breastfeeding duration of LPT infants.

METHODS

This longitudinal cohort study of the mothers of singleton infants-129 born LPT and 277 born at term-was conducted at Landspitali-The National University Hospital of Iceland, which has the country's only neonatal intensive care unit. The mothers answered questionnaires when their infants were 1, 4, 8 and 12 months of age.

RESULTS

Mothers breastfed LPT infants for a significantly shorter time than term infants: a median of 7 months (95% confidence interval 5.53-8.48) vs 9 months (95% confidence interval 8.39-9.61) (P < .05). Starting solids at up to 4 months was the strongest risk factor for LPT breastfeeding cessation during the first year, after adjusting for confounders (P < .001). Their mothers reported more worries about their infants' health and behaviour during the first year and were more likely to experience depression at 4 months.

CONCLUSION

Mothers with LPT infants are vulnerable and need greater practical breastfeeding and emotional support in hospital and at home.

Risk factors for spontaneous preterm delivery

BACKGROUND

There is a substantial variation in rates of preterm delivery between different parts of the world. The understanding of these variations, as well as the biological mechanisms behind spontaneous preterm delivery, is limited. Although the benefit of antenatal interventions has been shown to be limited, using well-known risk factors for spontaneous preterm delivery to select the correct pregnant women for targeted interventions is important from both a medical and caregiving perspective.

OBJECTIVE

To provide an introduction to a substantial research area dealing with risk factors of spontaneous preterm delivery.

METHODS

Risk factors in this review were classified as demographical, obstetrical, and gynecological and those related to the current pregnancy according to high-quality evidence of recent literature.

RESULTS AND CONCLUSION

An introduction to a substantial research area in maternal and fetal medicine was provided that might help clinicians to better understand the risk factors related to preterm delivery and select the correct pregnant women for targeted interventions.

Delivery timing after laser surgery for twin-twin transfusion syndrome

OBJECTIVE

To compare outcomes of twin-twin transfusion syndrome (TTTS) patients who underwent early elective delivery vs. expectant management.

STUDY DESIGN

Retrospective study of monochorionic diamniotic twins who underwent laser surgery for TTTS and had dual survivors at 32 weeks. Patients who underwent elective delivery between 32 0/7 to 35 6/7 weeks ("early elective group") were compared with all patients who delivered ≥36 0/7 weeks ("expectant management group"). The primary outcome was a composite of fetal and neonatal morbidity.

RESULTS

The final study population was comprised of 15 early elective and 119 expectant management patients. Those in the early elective group were seven times more likely to experience the primary outcome (OR 7.38 [2.01-27.13], p = 0.0026).

CONCLUSION

Among patients who underwent laser surgery for TTTS who had dual survivors at 32 weeks, elective delivery prior to 36 weeks did not appear to be protective.

Respiratory distress in newborn infants in Western Switzerland

AIM

To assess epidemiological data about respiratory distress (RD) in newborn infants hospitalized in Western Switzerland.

METHODS

During 1 year, two questionnaires were sent out to the seven neonatal and pediatric units of a well-defined geographic region in Switzerland. Data about their obstetrical activity and details about all newborn infants hospitalized with RD were collected, asking for pre-, peri-, and postnatal clinical data in association with RD.

RESULTS

Almost 6% of all newborn infants born in the Canton of Vaud had to be hospitalized for RD. All newborn infants below 32 weeks of gestational age (GA) had developed RD, accounting for 14.6% of all neonates, hospitalized with RD, whereas the moderate to late preterm infants contributed with 36.8% much more to the RD hospitalizations. Associated factors to hospitalizations with RD were prematurity, cesarean delivery, and multiple births.

CONCLUSIONS

Efforts should be made to reduce avoidable RD by reconsidering the management of pregnancies with premature rupture of the membranes around 34 weeks of GA and by delaying elective cesarean sections after 39 completed weeks of gestation.

Growth patterns during early childhood in children born small for gestational age and moderate preterm

Today we lack knowledge if size at birth and gestational age interact regarding postnatal growth pattern in children born at 32 gestational weeks or later. This population-based cohort study comprised 41,669 children born in gestational weeks 32–40 in Uppsala County, Sweden, between 2000 and 2015. We applied a generalized least squares model including anthropometric measurements at 1.5, 3, 4 and 5 years. We calculated estimated mean height, weight and BMI for children born in week 32 + 0, 35 + 0 or 40 + 0 with birthweight 50^th percentile (standardized appropriate for gestational age, sAGA) or 3^rd percentile (standardized small for gestational age, sSGA). Compared with children born sAGA at gestational week 40 + 0, those born sAGA week 32 + 0 or 35 + 0 had comparable estimated mean height, weight and BMI after 3 years of age. Making the same comparison, those born sSGA week 32 + 0 or 35 + 0 were shorter and lighter with lower estimated mean BMI throughout the whole follow-up period. Our findings suggest that being born SGA and moderate preterm is associated with short stature and low BMI during the first five years of life. The association seemed stronger the shorter gestational age at birth.

The effects of birth order on neonatal outcomes in early-preterm, late-preterm and term twin infants

Objectives: Birth order is one of the main factors that influences the neonatal outcome of twins. However, there is little prior data regarding the effect of birth order under different clinical circumstances. This study investigates the effect of birth order on the neonatal outcomes of twins delivered during early-preterm, late-preterm and term gestations according to chorionicity, delivery mode and indication for delivery.Methods: This is a retrospective cohort study of women with twin pregnancies delivered at 24-40 weeks of gestation between 1995 and 2014. We excluded twin pregnancies with the following complications: twin-to-twin transfusion syndrome, monoamnionic twins, delayed interval delivery and fetal death, chromosomal anomalies or major congenital malformation in one or more of the twins. The neonatal outcomes, including death, admission to neonatal intensive care unit (NICU), mechanical ventilator support, and respiratory distress syndrome (RDS) was compared between the first and second twin born at early-preterm (24-33 weeks of gestation), late-preterm (34-36 weeks of gestation) and term (≥37 weeks of gestation) gestations. These outcomes were further analyzed according to chorionicity, mode of delivery and indication for delivery by multivariable analysis (after adjusting for sex, presentation, and birth weight).Results: Among a total of 1,614 women with twin pregnancies who met the selection criteria, 423, 674 and 517 women delivered at early-preterm, late-preterm and term gestation, respectively. Overall, the second-born twins were lighter and had higher rates of NICU admission, mechanical ventilator support, and RDS than did first-born twins. Second twins born at early-preterm gestation had higher rates of RDS and mechanical ventilator support than did first twins. Second twins born at late-preterm gestation had higher rates of NICU admission and mechanical ventilator support than did first twins. Second twins born at term gestation also had a higher NICU admission rate than did first twins. However, in the multivariable analysis of the subgroups, the rates of NICU admission, mechanical ventilator support and RDS were not significantly different between most twin pairs. However, there were several significant differences. There was a higher risk of RDS in the second twins in the early-preterm premature rupture of membranes (PROM) subgroup, and a higher risk of mechanical ventilator support in the late-preterm PROM subgroup. Low birth weight was the only significant factor independently associated with a higher risk of adverse neonatal outcome in the second twins compared with the first twins in all subgroups.Conclusions: Second twins born at early-preterm, late-preterm and term were at higher risk of adverse neonatal outcome than were their respective first twins. However, this finding was mainly represented lower birth weight of the second twin. Still, second twins delivered due to early-preterm and late-preterm PROM had a higher risk of RDS and mechanical ventilator support, respectively, than did the first twin after adjusting for birth weight.

Success after failure: the role of endometrial stem cells in recurrent miscarriage

Endometrial stem-like cells, including mesenchymal stem cells (MSCs) and epithelial progenitor cells, are essential for cyclic regeneration of the endometrium following menstrual shedding. Emerging evidence indicates that endometrial MSCs (eMSCs) constitute a dynamic population of cells that enables the endometrium to adapt in response to a failed pregnancy. Recurrent miscarriage is associated with relative depletion of endometrial eMSCs, which not only curtails the intrinsic ability of the endometrium to adapt to reproductive failure but also compromises endometrial decidualization, an obligatory transformation process for embryo implantation. These novel findings should pave the way for more effective screening of women at risk of pregnancy failure before conception.

Neonatal outcomes of twin pregnancies delivered at late-preterm versus term gestation based on chorionicity and indication for delivery

OBJECTIVE

To investigate the neonatal outcomes of twin pregnancies delivered at late-preterm versus term gestation based on chorionicity and indication for delivery.

STUDY DESIGN

This is a retrospective cohort study of women with twin pregnancies delivered at ≥34 weeks of gestation from 1995 to 2014. Subjects were categorized into two groups according to gestational age at delivery: late-preterm group (34-36 weeks) and term group (≥37 weeks). Neonatal outcome measures including neonatal intensive care unit (NICU) admission, mechanical ventilator support, and respiratory distress syndrome (RDS) were compared between the late-preterm and term group based on chorionicity (monochorionic or dichorionic) and delivery indication (elective or non-elective).

RESULTS

A total of 1198 twin pregnancies were included in the study: 679 in the late-preterm group and 519 in the term group. Late-preterm twin infants had higher rates of NICU admission, mechanical ventilator support, and RDS than did term twin infants, regardless of the chorionicity and indication for delivery. In the multivariable analysis, late-preterm birth, monochorionicity, and non-elective delivery were independently associated with a significantly higher risk of NICU admission and mechanical ventilator support.

CONCLUSION

The late-preterm birth was associated with a higher risk of adverse neonatal outcome regardless of chorionicity and indication for delivery, and showed significantly increased risk by monochorionicity and non-elective delivery.

Perinatal outcome comparing triplets and singleton births at a reference maternity hospital

OBJECTIVE

The objective of the present study was to evaluate adverse perinatal outcome in a group of high order pregnancies pared with singletons by BW and GA at birth.

METHODS

Data was reviewed for all admissions of triplets and quadruplets in a 7 year period. For each study neonate we selected two singleton infants to constitute a control group. Variables analyzed included: respiratory distress syndrome, patent ductus arteriosus, intraventricular hemorrhage, necrotizing enterocolitis (NEC), bronchopulmonary dysplasia, retinopathy of prematurity and periventricular leukomalacia.

RESULTS

We studied a total of 128 multiple and 260 singleton infants. Mean gestational age and birth weight were similar in both groups (31.3 ± 2,5 wks e 31.5 ± 2,8 wks; 1470 ± 461 g vs 1495 ± 540 g). There was no significant difference between the groups in the majority of main morbidities. The incidence of NEC was higher in triplets (6.3 vs 0.8%, p value <0.01). Mortality was higher in singletons (9.6 vs 3.1%, p value <0.037).

CONCLUSIONS

Results show that major neonatal outcomes are very similar between multiples and singletons births when paired by gestational age and birth weight. NEC remained a significant morbidity in infants born from multiple gestations after adjustment for maternal and neonatal risk factors.

Variations in Multiple Birth Rates and Impact on Perinatal Outcomes in Europe

OBJECTIVE

Infants from multiple pregnancies have higher rates of preterm birth, stillbirth and neonatal death and differences in multiple birth rates (MBR) exist between countries. We aimed to describe differences in MBR in Europe and to investigate the impact of these differences on adverse perinatal outcomes at a population level.

METHODS

We used national aggregate birth data on multiple pregnancies, maternal age, gestational age (GA), stillbirth and neonatal death collected in the Euro-Peristat project (29 countries in 2010, N = 5 074 643 births). We also used European Society of Human Reproduction and Embryology (ESHRE) data on assisted conception and single embryo transfer (SET). The impact of MBR on outcomes was studied using meta-analysis techniques with random-effects models to derive pooled risk ratios (pRR) overall and for four groups of country defined by their MBR. We computed population attributable risks (PAR) for these groups.

RESULTS

In 2010, the average MBR was 16.8 per 1000 women giving birth, ranging from 9.1 (Romania) to 26.5 (Cyprus). Compared to singletons, multiples had a nine-fold increased risk (pRR 9.4, 95% Cl 9.1-9.8) of preterm birth (<37 weeks GA), an almost 12-fold increased risk (pRR 11.7, 95% CI 11.0-12.4) of very preterm birth (<32 weeks GA). Pooled RR were 2.4 (95% Cl 1.5-3.6) for fetal mortality at or after 28 weeks GA and 7.0 (95% Cl 6.1-8.0) for neonatal mortality. PAR of neonatal death and very preterm birth were higher in countries with high MBR compared to low MBR (17.1% (95% CI 13.8-20.2) versus 9.8% (95% Cl 9.6-11.0) for neonatal death and 29.6% (96% CI 28.5-30.6) versus 17.5% (95% CI 15.7-18.3) for very preterm births, respectively).

CONCLUSIONS

Wide variations in MBR and their impact on population outcomes imply that efforts by countries to reduce MBR could improve perinatal outcomes, enabling better long-term child health.

Late prematurity in twins: a Polish multicenter study

The study aimed at investigating the impact of late prematurity (LPT) on neonatal outcome in twins and neonatal morbidity and mortality within LPT with regard to the completed weeks of gestation. The study was conducted in six tertiary obstetric departments from different provinces of Poland (Warsaw, Lublin, Poznan, Wroclaw, Bytom). It included 465 twin deliveries in the above centers in 2012. A comparative analysis of maternal factors, the course of pregnancy and delivery and neonatal outcome between LPT (34 + 0-36 + 6 weeks of gestation) and term groups (completed 37 weeks) was performed. The neonatal outcome included short-term morbidities. The analysis of neonatal complication rates according to completed gestational weeks was carried out. Out of 465 twin deliveries 213 (44.8%) were LPT and 156 (33.55%) were term. There were no neonatal deaths among LPT and term twins. One-third of LPT newborns suffered from respiratory disorders or required antibiotics, 40% had jaundice requiring phototherapy, and 30% were admitted to NICU. The analysis of neonatal morbidity with regard to each gestational week at delivery showed that most analyzed complications occurred less frequently with the advancing gestational age, especially respiratory disorders and NICU admissions. The only two factors with significant influence on neonatal morbidity rate were neonatal birth weight (OR = 0.43, 95% CI = 0.2-0.9, p = .02) and gestational age at delivery (OR = 0.62, 95% CI = 0.5-0.8, p < .01). LPT have a higher risk of neonatal morbidity than term twins. Gestational age and neonatal birth weight seem to play a crucial role in neonatal outcome in twins.

Long-term outcomes of moderately preterm, late preterm, and early term infants

At present, moderate preterm (MPT) infants born at 32 to 33 weeks' gestation and late preterm (LPT) infants born at 34 to 36 weeks' gestation make up the largest subgroup of preterm infants and contribute to more than 80% of premature births in the United States. There is increasing evidence that both MPT and LPT infants are at increased risk of neurologic impairments, developmental disabilities, school failure, and behavior and psychiatric problems. Population studies suggest that for each 1 week decrease in gestational age below 39 weeks, there are stepwise increases in adverse outcomes after adjusting for confounders.