Evaluating antenatal risk in twin pregnancies-A feasibility study to identify modifiable factors associated with adverse pregnancy outcomes

Abstract

Introduction: Twin pregnancies have significantly higher rates of perinatal morbidity and mortality compared to singleton pregnancies; current attempts to reduce perinatal mortality have been less successful in twin pregnancies. The paucity of information about modifiable risk factors for adverse neonatal outcomes in twin pregnancies, as well as independent effects of chorionicity may have contributed to this outcome. This study aimed to explore the feasibility of an observational study to identify modifiable factors associated with adverse neonatal outcomes in twin pregnancies.

Material and methods: Patients pregnant with twins at six UK hospitals between December 2019-March 2021 completed researcher-administered questionnaires at approximately 20-, 28- and 36-weeks' gestation, recording a wide range of self-reported social, lifestyle and demographic factors, alongside prospectively recorded clinical data from maternity records. Descriptive statistics were used to describe frequencies of exposures; logistic regression was used to determine whether factors were associated with a composite measure of adverse neonatal outcome.

Results: Data were collected from 65% (181/277) of eligible participants. A total of 98% (175) of participants had positive views about their participation. Some exposures, including cigarette smoking, supine sleep position and reduced fetal movements were less frequent in twin pregnancies compared to singletons, whereas fertility treatment was more common. Furthermore, different patterns of exposure were seen between monochorionic and dichorionic twins. This pilot study found some associations with adverse neonatal outcomes including: low BMI (OR 8.36, 95% CI: 1.02-68.87), maternal age ≥41 years (OR 9.0 95% CI: 1.07-75.84), maternally perceived high-stress levels (OR 1.96, 95% CI: 1.03-3.75) and inadequate antenatal screening (OR 1.44, 95% CI: 1.01-2.06). Sleep duration ≥9 h and right-sided going to sleep position were more frequent among pregnancies with adverse outcomes. Participants who reported receiving no information on fetal movement and reduced maternal perception of movements were more likely to have an adverse outcome, but sample size prohibited analysis based upon chorionicity.

Conclusions: An observational study of modifiable factors in twin pregnancy is feasible. Differences in the frequencies of exposures between twin and singleton pregnancies highlight the need for twin-specific studies to identify modifiable factors and develop preventative strategies for morbidity and mortality in twin pregnancies.

Keywords: feasibility study; modifiable antenatal risk factors; neonatal morbidity and mortality; twin pregnancy.