Key message
Negative associations were found between poor maternal habits and oocyte quality and the outcomes of ICSI. Women desiring pregnancy should be aware of
Human fertility rates have declined over time for several reasons and, in recent years, there has been a huge increase in the literature on the periconception environment, which is determined by pre-existing maternal medical conditions and changing lifestyles, including smoking, diet and body mass index (BMI) (Steegers-Theunissen and Steegers, 2015). According to recent studies, lifestyle and nutritional factors have been acknowledged as critical determinants of regular reproductive function (reviewed in Oostingh et al., 2019).
The effects of lifestyle and nutritional factors on different aspects of reproductive function can be investigated in assisted reproductive technology (ART) because every step, from fertilization to the delivery of a healthy baby, can be evaluated. Previous studies have demonstrated negative associations between poor maternal lifestyle and nutritional habits and different reproductive outcomes. An increased risk of unfavourable oocyte and embryo development, as well as trends towards decreased implantation and chances of pregnancy for women consuming daily servings of sugar or artificial sweetener were observed (Setti et al., 2018). The consumption of artificially sweetened soft drinks has also been associated with increased risk of preterm delivery in two other studies (Englund-Ogge et al., 2012; Halldorsson et al., 2010). Negative relationships have also been demonstrated between alcoholic drink consumption and smoking habits and embryo quality and blastocyst development (Braga et al., 2015).
A recent systematic review, which described the risk factors associated with poor ovarian response (POR) to stimulation in ART, showed that smoking habit is associated with POR (Amaral et al., 2019). However, little is known regarding the remaining lifestyle and nutritional habits.
In this study it is postulated that not only the number of oocytes, but also their quality with regard to morphology, would justify the reduced reproductive outcomes observed in women with poor lifestyle factors and nutritional habits. As oocyte quality is an essential factor impacting the development of embryos and their implantation potential, women with increased rates of dimorphisms in their oocyte cohorts would ultimately present with reduced pregnancy outcomes.
Lifestyle factors are behaviours that are within a person's control and can be changed to improve well-being (Homan et al., 2007). Knowing their influence on reproductive outcomes may yield valuable information for counselling couples undergoing treatment with ART. Therefore, the aim of this study was to investigate the influence of maternal lifestyle factors and nutritional habits on reproductive outcomes, from oocyte morphology to live birth, of infertile patients undergoing intracytoplasmic sperm injection (ICSI) cycles. It is thought that no similar analysis has yet been documented.
This historical cohort study, performed in a private university-affiliated IVF centre, included 752 couples undergoing ICSI between January 2015 and December 2019. Before starting ovarian stimulation, female participants were asked to complete a detailed non-validated questionnaire regarding cigarette smoking habits, consumption of items such as refined sugar, soft drinks, alcoholic beverages, milk and dairy, and white and red meat, as well as exercise frequency over the past 6 months. Oocyte
Patient demographics, response to ovarian stimulation, distribution of oocyte dimorphisms and ICSI outcomes are presented in Table 1. The causes of infertility were: male factor (n = 278, 36.97%), idiopathic (n = 127, 16.89%), ovarian disorders (n = 65, 8.64%), endometriosis grades I or II (n = 50, 6.65%), tubal-uterine factors (n = 97, 12.90%), and a combination of these (n = 135, 17.95%).
In the present study it was observed that smoking habits, and the consumptions of alcohol, refined sugar and artificial sweetener were negatively associated with oocyte number and quality, as well as with implantation (dose-dependent relationship), clinical pregnancy (dose-dependent for alcoholic beverages) and live birth rates (dose-dependent for cigarette smoking and alcoholic beverages). On the other hand, adhering to good habits such as exercising and eating healthy food items such as milk
Amanda Setti obtained her BSc degree at Universidade de Santo Amaro (2005), specialist degree in human assisted reproduction at Instituto Sapientiae (2007), and MSc degree at Faculdade de Ciências Médicas da Santa Casa de São Paulo (2015). She has been a scientific researcher at Fertility Medical Group since 2009. Key message Negative associations were found between poor maternal habits and oocyte quality and the outcomes of ICSI. Women desiring pregnancy should be aware of
Amanda Setti obtained her BSc degree at Universidade de Santo Amaro (2005), specialist degree in human assisted reproduction at Instituto Sapientiae (2007), and MSc degree at Faculdade de Ciências Médicas da Santa Casa de São Paulo (2015). She has been a scientific researcher at Fertility Medical Group since 2009. Key message Negative associations were found between poor maternal habits and oocyte quality and the outcomes of ICSI. Women desiring pregnancy should be aware of periconception preventative approaches by consulting with specialized healthcare and nutritional professionals to adjust diet and lifestyle before ICSI treatment.