Table 1 Findings of reviews and meta-analyses on factors affecting the health and behavioral risk-taking by pregnant women.

Authors	Maternal risk factor	Influencing factors	Information about the study	Main findings and comments
OR: odds ratio. PTSD: post-traumatic stress disorder. r = correlation coefficient. sign.: significant. a: Systematic review. b: Meta-analysis.
Nicotine and alcohol consumption
35 a	Nicotine consumption	Social factors, nicotine consumption behavior, social relationships, pregnancy-specific factors	n = 19 studiesfrom 1997 to 2008	Significant correlation between prenatal nicotine consumption and the following factors:income (4 of 5 studies); partner who smokes (6 of 6 studies); high number of children (11 of 12 studies); high nicotine consumption (7 of 8 studies); prenatal care appointments attended less often and only during the later stages of pregnancy (4 of 5 studies).
36 a	Alcohol consumption	Psychosocial and behavioral factors	n = 14 studies (n = 11 cross-sectional studies; n = 3 longitudinal studies)from 2002 to 2009	Significant and consistent correlations between prenatal alcohol consumption and pre-pregnancy alcohol consumption (7 of 7 studies) and experience of abuse/violence (3 of 3 studies). Significant correlation with higher age (7 of 12 studies), nicotine consumption (5 of 10 studies) and larger number of children (4 of 10 studies).Inconsistent findings with regard to socio-economic status, level of education, unemployment, marital status and alcohol dependency.
37 a	Nicotine and alcohol consumption	Social support	n = 13 studies2003–2013	Significant correlations between prenatal nicotine consumption and social support (7 of 10 studies); no consistent correlation with prenatal alcohol consumption (1 of 3 studies).
Diet and weight gain/obesity
37 a	Nutrition	Social support	n = 3 studies2003–2013	Significant correlations between social support and satisfaction with social support and nutrition for women on low incomes and with an immigrant background (2 of 3 studies).No meaningful results possible because of the limited number of studies.
38 a	Quality of food	Mental health of the mother in the perinatal period	n = 9 studies (n = 4 cohort studies; n = 5 cross-sectional studies)2005–2013	Significant correlations between unhealthy diet and poor quality food and prenatal depressive symptoms (3 of 3 studies) and stress symptoms (3 of 3 studies).Only limited significance because of the low number of studies. No statements can be made on the impact of factors.Other factors such as social support, mental illness prior to pregnancy and socio-economic factors could be important.
39 a	Excessive weight gain	Anxiety, depression, stress, social support, dissatisfied with body image, self-esteem and self-efficacy	n = 12 studies (n = 2 cross-sectional studies; n = 8 longitudinal studies; n = 2 randomized control group studies)2000–2014	Significant correlations between excessive weight gain and depression (2 of 2 studies); dissatisfaction with own body image (4 of 6 studies) and social support (1 study).No statements possible on the impact of factors.
40 a	Excessive weight gain	Psychological characteristics (affective state, cognition, motive for weight gain and diet)	n = 35 studies (n = 8 cross-sectional studies; n = 25 cohort studies; n = 2 case control studies)	Significant correlations between excessive weight gain and weight-related and diet-related cognition:dissatisfaction with own body image (2 of 4 studies); negative attitude to weight gain (4 of 6 studies); inaccurate perceptions of own weight both in women with normal weight and in overweight women (1 of 2 studies); higher levels of cognitive dietary restraint (2 of 3 studies).Additional predictors which will need further study include perceived barriers to healthy eating (1 study); concern about weight gain (1 study); limited knowledge about weight gain (1 study).Negative affective states (anxiety, depression and stress) were not found to be related to weight gain.
41 a, b	Obesity and overweight	Mental health problems during pregnancy and post partum	n = 62 studies	Obese/overweight pregnant women had an increased risk of prenatal depression (obese pregnant women OR = 1.43; overweight pregnant women OR = 1.19); of postpartum depression (obese pregnant women: OR = 1.30; overweight pregnant women: OR = 1.09), and an increased risk of anxiety symptoms during pregnancy (OR = 1.41).
42 a	Excessive weight gain	Maternal symptoms of anxiety	n = 13 studies (n = 10 longitudinal studies; n = 3 interventional studies)from 2000 to 2015	Significant correlation between obesity and anxiety experienced by the expectant mother (5 of 7 studies).Results should be viewed as a comorbidity as anxiety symptoms were not recorded prior to the pregnancy.
Mental health problems
43 a, b	Perinatal depression	Unwanted pregnancy	n = 10 studies (n = 5 cross-sectional studies; n = 4 longitudinal studies; n = 1 randomized control group study)from 1991 to 2014	Prevalence of maternal perinatal depression associated with unwanted pregnancy: 21 %Note: Only 3 studies collected data at the time of the pregnancy itself. Different instruments were used to record or measure depression.
44 a	Perinatal depression	Experience of abuse	n = 43 studies (n = 29 cross-sectional studies; n = 14 longitudinal studies)to 2011	Every form of abuse (direct, indirect, physical, sexual or emotional abuse) was found to be positively correlated with prenatal and postnatal depression (only 5 studies found no significant association).
45 a	Prenatal anxiety and depression	Psychosocial, gynecological and behavioral factors	n = 97 studiesfrom 2003 to 2015	Significant association between prenatal depression/anxiety and the following factors:lack of support by intimate partner or lack of social support (sign. predictor in 29 studies vs. not a sign. predictor in 0 studies); experience of previous abuse or violence by partner (sign. predictor in 28 studies vs. not a sign. predictor in 0 studies); adverse life events and high levels of perceived stress (sign. predictor in 21 studies vs. not a sign. predictor in 0 studies); previous mental illness (sign. predictor in 23 studies vs. not a sign. predictor in 0 studies); unplanned or unwanted pregnancy (sign. predictor in 22 studies vs. not a sign. predictor in 2 studies); current/previous pregnancy complications/pregnancy loss (sign. predictor in 17 studies vs. not a sign. predictor in 4 studies); nicotine consumption during pregnancy (sign. predictor in 11 studies vs. not a sign. predictor in 1 study).More research is needed with regard to the following risk factors: alcohol abuse; substance abuse; familial history of mental illness; partner unemployed; quality of upbringing; mode of delivery.
46 a	Perinatal psychological disorders	Psychosocial and gynecological factors	n = 47 studies (n = 13 studies where data was collected during pregnancy; n = 34 studies where data was collected after the birth)to 2010	Significant associations between perinatal mental disorders (mainly anxiety/depression) and the following factors:socio-economic disadvantage (OR = 2.1–13.2); unintended pregnancy (OR = 1.6–8.8); young maternal age (OR = 2.1–5.4); unmarried (OR = 3.4–5.8); lack of intimate partner empathy or support (OR = 2.0–9.4); hostile in-laws (OR = 2.1–4.4); experienced intimate partner violence (OR = 2.11–6.75); lack of practical and emotional support (OR = 2.8–6.1); child is female (OR = 1.8–2.6); previous maternal history of mental illness (OR = 5.1–5.6).
47 a, b	Perinatal psychological disorders	Domestic violence	n = 67 studies (n = 51 cross-sectional studies; n = 16 longitudinal studies)up to 2011	Women with prenatal or postpartum depression had a three to five times higher risk of experiencing violence:experience of violence for women with prenatal depression (experienced violence over the patientʼs lifetime: OR = 3.0, during the previous year: OR = 2.8, or during the pregnancy: OR = 5.0); Violence experienced by women with postpartum depression: (experienced violence during the previous year: OR = 2.9; or during the pregnancy: OR = 3.1).Women with prenatal symptoms of anxiety had an up to 2.9-times higher risk of experiencing violence.Women with prenatal or postnatal PTSD had a 4.6- to 6.4-times higher risk of experiencing violence.
48 a	Prenatal depression	Psychosocial, gynecological and behavioral factors	n = 57 studiesfrom 1980 to 2008	Significant correlations between prenatal depressive symptoms and the following factors:stressful life events; lack of social support, and domestic violence.
49	Perinatal anxiety disorders	Psychosocial, gynecological and behavioral factors	n = 98 (n = 47 studies on predictors)from 2006 to 2014	Young age (5 studies); single/no partner (6 studies); low socio-economic status (5 studies), low level of education (9 studies); lack of social support (7 studies); conflicts in relationship with partner (5 studies), previous mental illness (3 studies); obstetrical complications: previous miscarriage/spontaneous abortion (5 studies); unplanned pregnancy; poor health/pregnancy complications (3 studies).
50 a, b	Perinatal depression and anxiety	Risk factors and protective factors affected by partner	n = 120 studies (62 % cross-sectional studies; 37 % longitudinal studies)from 1980 to 2013	Partner factors associated with a risk of prenatal depression or anxiety:conflicts (depression r = 0.30; anxiety r = 0.35); partner consumes alcohol and drugs (for depression r = 0.16); emotional withdrawal of partner (for depression r = 0.32).Partner factors which reduce the risk of prenatal depression or anxiety:emotional closeness (for depression r = − 0.25; for anxiety r = − 0.22); emotional support (for depression r = − 0.26; for anxiety r = − 0.20), and global support (for depression r = − 0.28; for anxiety r = − 0.32).Additional factors specifically associated with prenatal depression:positive communication (r = − 0.31); instrumental support (r = − 0.16), and relationship satisfaction (r = − 0.29).