Association between interpregnancy interval and adverse perinatal outcomes among subsequent twin pregnancies: a nationwide population-based study.

The existing evidence on the association between interpregnancy interval (IPI) and pregnancy outcomes primarily focuses on singleton pregnancies, with limited research on twin pregnancies. This study aimed to investigate the association between IPI and adverse perinatal outcomes in twin pregnancies. This population-based, retrospective cohort study analyzed data from the National Center for Health Statistics in the United States between 2016 and 2020. We included multiparous women aged 18 to 45 years with live-born twins without congenital anomalies, born between 26 and 42 weeks of gestation. Poisson regression models, adjusted for potential confounders, were used to evaluate the associations between IPI and adverse outcomes, including preterm birth (PTB) <36 weeks, small for gestational age (SGA), neonatal intensive care unit (NICU) admission, neonatal composite morbidity, and infant death. Missing data on covariates were managed using multiple imputations. Dose-response analyses were performed using the restricted cubic splines (RCS) approach. Subgroup analyses were stratified by maternal age, parity, and combination of neonatal sex. Sensitivity analyses were conducted using complete data and excluding pregnancies with intervening events during the IPI. A total of 143,014 twin pregnancies were included in the analysis. Compared to the referent group (IPI of 18-23 months), an IPI of less than 6 months was associated with an increased risk of PTB<36 weeks (RR, 1.21; 95% confidence interval [95% CI]: 1.17-1.25), SGA (RR, 1.11; 95% CI: 1.03-1.18), neonatal composite morbidity (RR, 1.19; 95% CI: 1.12-1.27), NICU admission (RR, 1.18; 95% CI: 1.14-1.22), and infant death (RR, 1.29; 95% CI: 1.05-1.60). An IPI of 5 years or more was associated with an increased risk of PTB<36 weeks (RR, 1.18; 95% CI: 1.15-1.21), SGA (RR, 1.24; 95% CI: 1.18-1.30), neonatal composite morbidity (RR, 1.10; 95% CI: 1.05-1.15), and NICU admission (RR, 1.14; 95% CI: 1.11-1.17). The dose-response analyses showed that these outcomes had U-shaped or J-shaped associations with IPI. The associations between IPI and the outcomes slightly differed by advanced maternal age, parity, and combination of neonatal sex. The sensitivity analyses yielded similar results to the main findings. Extreme IPI, less than 6 months or more than 5 years, was associated with adverse outcomes in twin pregnancies. IPI could be used as a predictor for risk stratification in high-risk twin pregnancies.

Ye S ，Huang X ，Fan D ，Chen G ，Li P ，Rao J ，Zhou Z ，Guo X ，Liu Z ，Lin D ... -  《-》

Effect of Interpregnancy Interval on Adverse Perinatal Outcomes in Southern China: A Retrospective Cohort Study, 2000-2015.

In January 2016, a universal two-child policy was introduced in China. The association of interpregnancy interval (IPI) with perinatal outcomes has not previously been assessed among Chinese population. We investigated the effect of IPI after live birth on the risks of preterm delivery, and small, and large for gestational age births in China. We conducted a cohort study among 227 352 Chinese women with their first and second delivery during 2000 to 2015. IPI was calculated as months from first live delivery to conception of the second pregnancy. Poisson regression models with robust variance were fit to evaluate associations of IPI with risk of adverse perinatal outcomes, adjusted for potential confounders. Compared to IPI of 24- <30 months, IPI <18 months was associated with higher risks of preterm birth (PTB) and small for gestational age (SGA). For IPI <6 months, the adjusted relative risks (RR) for PTB and SGA were 2.04 (95% confidence interval [CI] 1.83, 2.27) and 1.43 (95% CI 1.31, 1.57), respectively. Women with IPI ≥60 months had higher risks of PTB and large for gestational age (LGA). For IPI ≥120 months, the adjusted RRs for PTB and LGA were 1.67 (95% CI 1.43, 1.94) and 1.10 (95% CI 0.97, 1.26). Women with IPI <18 months after live birth had higher risk of PTB and SGA, and IPI ≥60 months was associated with higher risk of PTB and LGA. These findings may provide information to Chinese couples about the appropriate interpregnancy interval for a second pregnancy.

Zhang L ，Shen S ，He J ，Chan F ，Lu J ，Li W ，Wang P ，Lam KBH ，Mol BWJ ，Yeung SLA ，Xia H ，Schooling CM ，Qiu X ... -  《-》

Adverse Perinatal and Neonatal Outcomes among Adolescent Pregnancies in the United States.

Despite a downward trend in recent years, adolescent pregnancies in the United States remain higher than any other western country. Adolescent pregnancies have been inconsistently associated with adverse perinatal outcomes. The objective of this study is to investigate the association between adolescent pregnancies and adverse perinatal and neonatal outcomes in the United States. This is a retrospective cohort study of singleton births in the United States from 2014 to 2020 using national vital statistics data. Perinatal outcomes included gestational diabetes, gestational hypertension, preterm delivery <37 weeks (preterm birth [PTB]), cesarean delivery (CD), chorioamnionitis, small for gestational age (SGA), large for gestational age (LGA), and neonatal composite outcome. Chi-square tests were used to compare outcomes among adolescent (13-19 years) versus adult (20-29 years) pregnancies. Multivariable logistic regression models were used to examine association of adolescent pregnancies with perinatal outcomes. For each outcome, we utilized three models: unadjusted logistic regression, adjusted for demographics, and adjusted for demographics and medical comorbidities. Similar analyses were used to compare younger (13-17 years) and older (18-19 years) adolescent pregnancies to adults. In a cohort of 14,014,078 pregnancies, we found that adolescents were at an increased risk of PTB (adjusted odds ratio [aOR]: 1.12, 99% confidence interval (CI): 1.12-1.13) and SGA (aOR: 1.02, 99% CI: 1.01-1.03) compared with adult pregnancies. We also found that multiparous adolescents with a prior history of CD were at an increased risk of CD, compared with adults. For all other outcomes, adult pregnancies were at higher risk for adverse outcomes in the adjusted models. When comparing birth outcomes among adolescents, we found that older adolescents are at an increased risk of PTB, whereas younger adolescents are at an increased risk of both PTB and SGA. After adjusting for confounders, our study demonstrates adolescents have an increased risk of PTB and SGA, compared with adults. · Adolescents as a whole subgroup have an increased risk of PTB and SGA compared with adults.. · Younger adolescents have a risk of PTB and SGA, whereas older adolescents have a risk of PTB only.. · Adverse birth outcomes in adults are gestational diabetes, chorioamnionitis, LGA, and worse neonatal composite score..

Katlaps I ，Ghafari-Saravi A ，Mandelbaum A ，Packer CH ，Doshi U ，Garg B ，Caughey AB ，Valent AM ... -  《-》

Twin pregnancy following a short interpregnancy interval: Maternal and neonatal outcomes.

To evaluate maternal and neonatal outcomes of women with twin pregnancies following a short interpregnancy interval (IPI < 6 months). A retrospective computerized database study in a single tertiary medical center between 2005 and 2021. Women who had an index singleton delivery and a subsequent twin gestation in their next pregnancy at the Shaare Zedek Medical Center (SZMC) were included. Maternal and neonatal outcomes of twin pregnancies following a short IPI (<6 months) were compared to those with an optimal IPI (18-48 months). Univariate analysis was followed by multiple logistic regression models; adjusted odds ratios (aORs) and 95 % confidence intervals (CIs) were calculated. During the study period, 2,079 women had an index singleton delivery followed by a twin gestation in their next pregnancy recorded at our medical center; 116 (5.9 %) had a history of short IPI, and 1,057 (50.8 %) had a history of optimal IPI. Women with a history of short IPI had higher rates of preterm labor < 37 weeks and < 34 weeks, NICU admissions and prolonged hospital stay of the first and second fetuses, mechanical ventilation of the first fetus, 1 and 5 Minute Apgar score lower than 7 of the second fetus and lower rates of elective cesarean delivery. An adjusted multivariate analysis showed that a history of short IPI was not an independent risk factor for preterm birth either < 34 weeks or < 37 weeks or for composite adverse neonatal outcome of the first and second twin. Twin pregnancy following a short IPI was not associated with neither preterm labor nor composite adverse neonatal outcome.

Weiss A ，Lang Ben Nun E ，Sela HY ，Rotem R ，Grisaru-Granovsky S ，Rottenstreich M ... -  《-》

Maternal and neonatal outcomes of twin pregnancies complicated by gestational diabetes mellitus.

Gestational diabetes mellitus (GDM) is associated with a higher risk of adverse maternal outcomes, but its effects on maternal and perinatal outcomes of twin pregnancies remain conflicting. This retrospective cohort study included all primipara who delivered twin pregnancies at a single tertiary perinatal center between January 1, 2016 and December 31, 2022. Excluded were those who had a single pregnancy, twin pregnancies with pre-existing diabetes, missing information on GDM screening, a delivery before gestational 28 weeks, complications related to monochorionic placentation, multifetal reduction, fetal anomalies, and monochorionic monoamniotic twins. Maternal outcomes included preterm birth, pre-eclampsia, hypothyroidism, preterm premature rupture of membranes (PROM), placental abruption, severe postpartum hemorrhage, and oligohydramnios. Neonatal outcomes included small-for-gestational-age (SGA), large-for-gestational-age (LGA), birthweight, Apgar score, neonatal intensive care unit (NICU) admission, extrauterine growth restriction (EUGR), and neonatal hypoglycemia. A total of 3269 twins were delivered, with 897 women (27.4%) diagnosed with GDM during pregnancies; moreover, 72 (8.0%) of these women received insulin treatment. The GDM group showed a significantly higher maternal age at delivery (≥35 years), as well as incidences of overweight and obesity. These factors also elevated the odds of insulin treatment in GDM women with twin pregnancies (OR = 1.881, 95% CI = 1.073-3.295, P = 0.027; OR = 2.450, 95% CI = 1.422-4.223, P < 0.001; OR = 4.056, 95% CI = 1.728-9.522, P < 0.001, respectively). Chronic hypertension prior to pregnancy was identified as a risk factor for GDM during twin pregnancies (OR = 1.896, 95% CI = 1.290-2.785, P < 0.001), although it did not increase the proportion of women requiring insulin treatment (P = 0.808). Aside from a higher incidence of preterm birth before 37 weeks in insulin-treated GDM twins (OR = 2.096, 95% CI = 1.017-4.321, P = 0.045), there were no significant difference in other maternal outcomes (preterm birth before 34 weeks, pre-eclampsia, hypothyroidism, PROM, placental abruption, placenta previa, severe postpartum hemorrhage, and oligohydramnios) between the GDM group and non-GDM group, and between insulin-treated GDM and non-insulin-treated GDM. The rate of newborns with birthweight <1500 g was significantly lower among twins born to GDM women, but the prevalence of EUGR was notably higher. Additionally, the risk of EUGR was elevated in insulin-treated GDM twins (OR = 3.170, 95% CI = 1.639,6.131, P < 0.001). No significant differences were observed between the GDM group and non-GDM group, or between insulin-treated GDM and non-insulin-treated GDM group in terms of mean birthweight, newborn sex ratio, and incidences of other adverse neonatal outcomes, including gestational age at delivery, LGA, birth weight <2500 g, and 1-min and 5-min Apgar scores. Maternal age ≥35 years, overweight or obesity, and chronic hypertension are significant risk factors for GDM during twin pregnancies. Women with GDM during twin pregnancies may achieve similar outcomes compared to those without GDM. However, the women with GDM during twin pregnancies receiving insulin therapy may have a higher risk of preterm birth and EUGR.

Zhang Z ，Mei L ，Li L ，Xiao J ，Wu X ，Yuan Y ... -  《-》