Maternal Going to Sleep Position and Late Stillbirth: Time to Act but With Care

Abstract

https://doi.org/10.1016/j.eclinm.2019.04.002 2589-5370/© 2019 Published by Elsevier Ltd. T Stillbirth remains a common tragedy, occurring several million often wonder if their behavior contributed to or caused the stillbirth. Third, manywomenwho experience venous compression upon lying times throughout the world each year [1]. Although stillbirth rates have been meaningfully reduced in many countries, there continue to be large numbers of potentially preventable stillbirths. It is particularly difficult to prevent late term stillbirths (≥37 weeks gestation) since many are unexplained. In this issue of EClinicalMedicine, Cronin and colleagues show that about 6% of late term stillbirths may be due to going to sleep in the supine position [2]. They used an individual participant data meta-analysis of five case control studies including 851 cases and 2257 controls. The risk of stillbirth was increased in women going to sleep in the supine position compared to the left side (adjusted odds ratio 2.63 (95% CI 1.72, 4.04)). The risk was not increased with going to sleep on the right side and the relationship remained across conditions such as small for gestational age fetus, maternal obesity and smoking [2]. These data are exciting because they suggest that maternal going to sleep position is a modifiable risk factor for stillbirth. Some risk factors such as maternal age or race/ethnicity are not modifiable. Others are potentially modifiable but with great difficulty. Examples include obesity and smoking. In addition, the link between supine sleep and stillbirth is biologically plausible. In the supine position, the uterus may compress venous blood flow, leading to decreased uterine perfusion, and eventually, stillbirth [3,4]. If all women avoided supine going to sleep, the authors conclude that late stillbirth would be reduced by 6% [2]. Although it is attractive to move forward with strong public health campaigns based on these data, it is also important to be careful. First, there are several observations that warrant caution. One is the fact that supine position upon waking up has not been related to stillbirth [5]. It is true that going to sleep position reflects a longer sleep period relative to position on waking up [6]. Nonetheless, this observation is inconsistent with the working hypothesis and raises