Nutrition in Pregnancy
Published: 06 September 2023
Published: 06 September 2023
Pregnancy nutrition is a topic that can easily be overlooked, yet it plays a crucial role in maternal health as well as fetal and infant wellbeing (Walsh & McAuliffe 2015).
Midwives are ideally placed to provide education on nutrition during pregnancy, but to date, there is very little published research evaluating midwives’ knowledge, attitudes and confidence on the subject. What little research there is tends to be exploratory and descriptive and suggests that midwives lack basic knowledge of nutritional requirements.
One study that stands out in particular, however, suggests that whilst midwives’ attitudes towards educating pregnant patients about nutrition are positive, their knowledge and confidence do not align with these attitudes.
As Arrish, Yeatman and Williamson (2016) suggest, this is most likely due to a lack of education during training, along with very few continuing professional development resources that focus on pregnancy nutrition.
One of the many myths surrounding pregnancy is that the patient should be ‘eating for two’. While extra food intake might be required in the second and third trimesters to ensure the baby receives adequate nutrients, ‘eating for two’ is not necessary (DoHaAC 2021a).
It is only in the last 12 weeks that patients need an extra 200 calories (840 kilojoules) per day for appropriate weight gain, depending on their activity level (WSLHD 2019; Tommy’s 2021).
Read: Obesity in Pregnancy
Steady weight gain is important during pregnancy, however, excessive gestational weight gain can increase the risk of gestational diabetes and hypertension (Better Health Channel 2022).
The following table outlines recommended weight gain during pregnancy, depending on the patient’s pre-pregnancy BMI.
Pre-pregnancy BMI | Recommended weight gain (over the whole pregnancy) |
---|---|
Below 18.5 | 12.5 kg to 18 kg |
18.5 to 24.9 (18.5 to 22.9 if Asian) |
11.5 kg to 16 kg |
25 to 29.9 (23 to 27.5 if Asian) |
7 kg to 11.5 kg |
Over 30 (over 27.5 if Asian) |
5 kg to 9 kg (less than 7kg if Asian) |
(Adapted from DoHaAC 2021b)
As Hull et al. (2020) report, interventions to prevent excessive gestational weight gain seem to have limited success. However, their study exploring the effectiveness of having a single goal of eating a high fibre diet resulted in less weight gain, and less retained weight at one year postpartum. It’s an area that seems deserving of much greater attention and research in the future.
Many organisations such as the Royal College of Midwives and Slimming World are also now calling for clearer guidance on healthy weight management for expectant mothers, along with more support, training and equipment for midwives to avoid the consequences of both excessive and low gestational weight gain (RCM 2018).
For example, Australian data shows that one in five people (21%) start pregnancy with a body mass index (BMI) in the ‘obese’ range (DoHaAC 2021b), which is linked to increased risk of miscarriage, premature birth, gestational diabetes, stillbirth and other serious health issues (RCM 2018).
Conversely, low gestational weight gain can increase the risk of having a low birth weight baby (RANZCOG 2017).
The Australian Dietary Guidelines recommend the following daily servings during pregnancy:
Food group | Daily servings | Examples of one serving |
---|---|---|
Vegetables and legumes/beans | 5 |
|
Fruits | 2 |
|
Grains (mostly wholegrain and high-fibre) | 8½ |
|
Lean meats, poultry, fish, eggs, tofu, nut, seeds and legumes/beans | 3½ |
|
Dairy products or alternatives | 2½ |
|
(Adapted from Better Health Channel 2022)
(DoHaAC 2021a)
Some foods should be avoided altogether or strictly limited during pregnancy because of their potential to cause harm to either parent or baby, such as:
(Queensland Government 2023)
In general, the following foods should be limited or avoided altogether during pregnancy:
(Queensland Government 2023; NHS 2023)
Another feature of pregnancy nutrition that tends to be under-reported is pregnancy pica. Pica describes a compulsive craving for non-nutritive substances such as earth, clay, chalk, soap and ice during pregnancy (Iftikhar 2020).
Pica is estimated to affect between 27 and 68% of pregnant patients, depending on geography (Mahtani 2021).
It’s thought that pica might be an indication the body is deficient in certain nutrients. It may also be associated with anaemia during pregnancy (Iftikhar 2020).
Perhaps it’s because of a lack of in-depth training in pregnancy nutrition, or a lack of time during antenatal visits, or even the perception that there is already an abundance of nutritional advice on the internet and in magazines, but whatever the reason, healthy lifestyle and nutritional advice do not always seem to get the attention they deserve.
Perhaps, as the Royal College of Midwives (2018) suggests, this is a significant missed opportunity to share healthy lifestyle messages and nutritional guidance during pregnancy.