Association between chorionicity and preterm birth in twin pregnancies: a systematic review involving 29 864 twin pregnancies

Abstract

Background The perinatal mortality and morbidity among twins vary by chorionicity. Although it is considered that monochorionicity is associated with an increased risk of preterm birth in twin pregnancies, no systematic review exists evaluating this association. Objectives This systematic review was undertaken to assess the association between preterm birth and chorionicity in twin pregnancies. Search strategy We searched the electronic databases from January 1990 to July 2019 without language restrictions. Selection criteria All studies on twin pregnancies where chorionicity and preterm birth were evaluated were included. Data collection and analysis Findings are reported as odds ratios with 95% confidence intervals. The estimates are pooled using random-effects meta-analysis. Main results From 13 156 citations, we included 39 studies (29 864 pregnancies). Monochorionicity was significantly associated with increased risk of preterm birth at ≤28, ≤32, ≤34 Conclusions Monochorionicity is significantly associated with preterm birth at all gestations.

Perinatal Outcomes and Risk Factors for Preterm Birth in Twin Pregnancies in a Chinese Population: A Multi-center Retrospective Study

“…In our study, monochorionicity was significantly associated with preterm birth in twin pregnancy, which approximately doubled the risk for preterm birth in all gestations. The result was in accordance with a systematic review including 29,864 twin pregnancies published in 2020 (14). In this review, monochorionicity significantly increased the risk of preterm (39)(40)(41)(42).…”

“…Recommendations for early delivery for monochorionic twins may contribute to the increased preterm birth rate due to iatrogenic prematurity. However, a study also revealed that monochorionicity itself has a high association with spontaneous preterm birth (14). In our study, subgroup analysis was conducted to evaluate the effect of chorionicity on spontaneous and iatrogenic preterm birth before 32 and 34 weeks of gestation.…”

“…Methods for predicting preterm birth and risk factors for preterm birth in twin pregnancy have long been studied. A history of preterm birth (12), maternal clinical characteristics, such as age and height (13,14), gestational weight gain (GWG) (15,16), maternal complications, such as preeclampsia (17), biophysical and biochemical tests, (18) are all proposed to aid in identifying and optimizing management of preterm birth in twin gestation.…”

Development and external validation of a nomogram for predicting preterm birth at < 32 weeks in twin pregnancy

“…The great variety in PTB rates signifies that there are epigenetic transgenerational stress factors and determinants from the social environment and the health care system 18 – 20 . In addition, perinatal morbidity and mortality among twins vary by chorionicity, and monochorionicity is significantly associated with an increased risk of PTB 21 .…”

Predictive Value of Mid-Trimester Cervical Measurement Data Combined With Maternal Characteristics for Twin Preterm Birth at &lt; 32 Weeks: A Retrospective Analysis and External Validation Study

“…[18][19][20] Previous studies have demonstrated the association between SPTB in twin pregnancies and speci c clinical indicators, such as ethnic origin, age, nulliparity, chorionicity, body mass index (BMI), tobacco usage, history of previous preterm delivery, cervical length and funnelling. [21][22][23][24][25][26][27][28][29][30][31][32] Different combinations of clinical variables might indicate different likelihoods of SPTB. The purpose of this study is to synthesize an array of maternal demographic factors and clinical variables and develop a practical algorithm to calculate the risk of SPTB for twin pregnancies, similar to the rst trimester genetic disease screening tools or the Framingham heart disease score.…”