Recent evidence suggests that a long inter-pregnancy interval (IPI: time interval between live birth and estimated time of conception of subsequent pregnancy) poses a risk for adverse short-term perinatal outcome. We aimed to study the effect of short (<6 months) and long (>60 months) IPI on long-term cardiovascular morbidity of the offspring. A population-based cohort study was performed in which all singleton live births in parturients with at least one previous birth were included. Hospitalizations of the offspring up to the age of 18 years involving cardiovascular diseases and according to IPI length were evaluated. Intermediate interval, between 6 and 60 months, was considered the reference. Kaplan–Meier survival curves were used to compare the cumulative morbidity incidence between the groups. Cox proportional hazards model was used to control for confounders. During the study period, 161,793 deliveries met the inclusion criteria. Of them, 14.1% (n = 22,851) occurred in parturient following a short IPI, 78.6% (n = 127,146) following an intermediate IPI, and 7.3% (n = 11,796) following a long IPI. Total hospitalizations of the offspring, involving cardiovascular morbidity, were comparable between the groups. The Kaplan–Meier survival curves demonstrated similar cumulative incidences of cardiovascular morbidity in all groups. In a Cox proportional hazards model, short and long IPI did not appear as independent risk factors for later pediatric cardiovascular morbidity of the offspring (adjusted HR 0.97, 95% CI 0.80–1.18; adjusted HR 1.01, 95% CI 0.83–1.37, for short and long IPI, respectively). In our population, extreme IPIs do not appear to impact long-term cardiovascular hospitalizations of offspring.

Major obstetrics and gynecology societies offer inconsistent recommendation regarding optimal delivery timing in uncomplicated dizygotic twins. We sought to investigate the impact of delivery timing within term gestation, in dizygotic twins, on the short- and long-term offspring morbidity. A prospectively analyzed cohort of dizygotic twin deliveries was conducted. All women delivered at a regional tertiary medical center, at term (≥37 0/7), between the years 1991 and 2014, were included. The primary exposure was delivery at 37 0/7–37 + 6/7 weeks, while delivery at ≥38 0/7 weeks’ gestation was considered the reference. Neonatal short- and long-term outcomes according to hospitalizations of offspring up to 18 years of age due to cardiac, respiratory, hematological, neurological, and infectious morbidity were compared. Kaplan–Meier survival curves were used to compare cumulative incidences per each major-system hospitalization. Cox regression models were used to estimate the adjusted hazard ratios, while adjusting for variables with clinical importance. During the study period, 612 dizygotic twin deliveries met the inclusion criteria. Of them, 200 (31.3%) occurred at 37–37 6/7 weeks, and 412 (68.7%) occurred at ≥38 0/7 weeks’ gestation. In the long-term analysis, rates of hospitalizations involving several major morbidity categories exhibited comparable rates in both groups. The Cox regression models did not demonstrate an independent association between gestational age within term and later major pediatric morbidity in offspring (total long-term morbidity: adjusted hazard ratio 1.33, 95% confidence interval 0.77–2.29). Dizygotic twin deliveries occurring at different gestational ages within term do not appear to significantly impact on major short- and long-term outcomes.

Other than obesity, no definitive insights have been gained regarding the apparent association between mode of delivery and long-term endocrine and metabolic outcomes in the offspring. We aimed to determine whether elective cesarean delivery (CD) impacts on long-term endocrine and metabolic morbidity of the offspring. A population-based cohort analysis was performed including all singleton-term deliveries occurring between 1991 and 2014 at a single tertiary medical center. A comparison was performed between children delivered via a non-emergent CD and those delivered vaginally (VD). Hospitalizations of the offspring up to the age of 18 years involving endocrine morbidity were evaluated. A Kaplan–Meier survival curve was used to compare cumulative morbidity incidence. Cox and a Weibull regression models were used to control for confounders. During the study period 131,880 term deliveries met the inclusion criteria; 8.9% were elective non-urgent CDs (n=11,768) and 91.1% (n=120,112) were VDs. The survival curve demonstrated a significantly higher cumulative incidence of endo-metabolic morbidity in offspring born via CD (P=0.010). In the regression models, adjusted for maternal obesity, CD was not noted as an independent risk factor for long-term pediatric endocrine and metabolic morbidity of the offspring while maternal obesity emerged as a strong predictor. We therefore conclude that CD per-se does not appear to increase the risk for long-term pediatric endo-metabolic morbidity of the offspring.

Otitis media (OM) carries a tremendous global health burden and potentially severe long-term consequences. The objective of this study was to determine the impact of birth at different gestational ages on the incidence of childhood OM.

A population-based cohort analysis was conducted. All singleton deliveries occurring between 1991 and 2014 at a regional tertiary medical center were included. Gestational age on delivery was divided into six subgroups: early (<34 weeks gestation; 0 out of 7) and late (34 weeks gestation; 0 out of 7 to 36 weeks gestation; 6 out of 7) preterm, and early (37 weeks gestation; 0 out of 7 to 38 weeks gestation; 6 out of 7), full (39 weeks gestation; 0 out of 7 to 40 weeks gestation; 6 out of 7), late (41 weeks gestation; 0 out of 7 to 41 weeks gestation; 6 out of 7) and post (⩾42 weeks 0 out of 7) term deliveries. Rates of OM-related hospitalizations up to 18 years of age were assessed. Weibull parametric hazards model was used to study the association between gestational age at birth and the risk for OM-related hospitalizations while controlling for potential confounders.

During the study period, 238,622 deliveries met the inclusion criteria. OM-related hospitalizations of the offspring (n=4724) were significantly more common in the preterm (early 3.6%, late 2.4%) and early-term born children (2.2%) and decreased gradually across the full (1.9%), late (1.7%) and post (1.6%) term groups (χ2-test for trends P<0.001). In the Weibull regression model, early preterm, as well as early-term deliveries exhibited an independent association with pediatric OM (adjusted hazard ratios: 1.67 and 1.09, respectively, P<0.02).

Deliveries occurring at preterm and early term are associated with higher rates of pediatric OM-related hospitalizations, which decrease gradually as gestational age advances.