Appropriate maternal weight gain in singleton and twin pregnancies: what is the evidence?

Abstract

A review of the literature on maternal weight gain in singleton and twin pregnancies has identified two main messages. Firstly, that very little robust evidence exists on which to base advice to mothers about appropriate weight gain during pregnancy. Evidence that does exist has tended to be observational, or based on under-powered intervention studies and unable to provide definitive conclusions. Secondly, that although specific weight gains have been recommended by the Institute of Medicine (IOM) in the USA, many women who gained weight outside these guidelines apparently achieved successful pregnancy and birth outcomes, in part because there were numerous confounders. Crucially, resources need to be invested to address women's concerns with weight management, so that they can receive the necessary support from midwives and others who care for them. Currently, women tend to receive little advice on weight gain during pregnancy and it is vital they are made aware of the increased risks associated with obesity, and that opportunities to minimise complications should be available and accessible prior to and during pregnancy. Overall, these findings highlight the difficulties in drawing up recommendations for individual women, whether expecting twins or singletons, on the basis of studies of populations, and the distinct difference between the USA and the UK in how weight gain is rationalised.

Gestational weight gain charts for twin pregnancies in Southeast China

“…These were later updated in 2009, on the basis of the recorded interquartile range of weight gain from a study of females delivering twins after more than 36 weeks of gestation [1]. However, these guidelines for twin pregnancies have been questioned and have been referred to as "provisional standards" [11,12]. Moreover, studies analyzing these guidelines have presented conflicting results demonstrating that women who gain weight beyond the IOM guidelines achieve healthy pregnancy outcomes [12,13].…”

“…However, these guidelines for twin pregnancies have been questioned and have been referred to as "provisional standards" [11,12]. Moreover, studies analyzing these guidelines have presented conflicting results demonstrating that women who gain weight beyond the IOM guidelines achieve healthy pregnancy outcomes [12,13]. Studies have also indicated that excessive weight gain in may improve neonatal birth weight without worsening maternal outcomes [11,13,14].…”

Gestational weight gain according to number of fetuses in Japanese women

“…Results of this study may be helpful for Japanese women with multifetal pregnancies. However, it should be noted that "appropriate gestational weight gain" is not indicated in this study because of the nature of this study, as Leese et al [9] pointed out.…”

Weight Management in Pregnancy

“…Colleagues in the United Kingdom take a far different approach to weight management in pregnancy, although both the United Kingdom and the United States use BMI as the standard measure for obesity 6,7 Citing the lack of evidence on which to base advice, the Royal College of Obstetricians and Gynaecologists (RCOG) instead opts to identify the sources of increased weight in pregnancy (Table 3). Colleagues in the United Kingdom take a far different approach to weight management in pregnancy, although both the United Kingdom and the United States use BMI as the standard measure for obesity 6,7 Citing the lack of evidence on which to base advice, the Royal College of Obstetricians and Gynaecologists (RCOG) instead opts to identify the sources of increased weight in pregnancy (Table 3).…”

“…The methodological quality of all of the studies was rated poor to fair. 6 The IOM provides only provisional recommendations for twin gestations (Table 5). In the Campbell analysis noted above, 5 quantitative studies were pooled and also found no effect on GWG.…”