Table 1.
Associations between fetal sex and maternal pregnancy outcomes
| First author | Statistical analyses | Subgroups | Tendency towards which sex (M/F/=) | Crude effect estimate (95% CI) | p value | Covariate adjustment | Adjusted effect estimate (95% CI) | p value |
|---|---|---|---|---|---|---|---|---|
| Gestational hypertension | ||||||||
| Andersen et al. 2016 [15] | Logistic regression | F | 0..69 (0..38–1..25) | 0.22 | ||||
| Baibergenova et al. 2006 [16] | Logistic regression | F | 1.06 (0.55–2.50) | 0.87 | ||||
| Campbell et al. 1983 [17] | Logistic regression | M | 1.18 (1.09–1.27) | < 0.0001 | ||||
| Chien et al. 2011 [18] | Logistic regression | M | 0.97 (0.96–0.98) | < 0.0001 | ||||
| Engel et al. 2008 [19] | Chi-square | Total | M | 1.04 (0.94–1.14) | 0.46 | |||
| Mild | M | 1.04 (0.94–1.16) | 0.44 | |||||
| Moderate | F | 0.99 (0.80–1.24) | 0.95 | |||||
| Severe | F | 0.94 (0.62–1.42) | 0.76 | |||||
| Favilli et al. 2013 [20] | Logistic regression | F | 1.69 (0.63–4.57) | 0.43 | Maternal age > 40 years, weight gain, BMI, gestational diabetes | 0.98 (0.43–2.25) | 0.97 | |
| Hou et al. 2014 [21] | Logistic regression | F | 0.97 (0.91–1.02) | 0.25 | ||||
| Juberg et al. 1976 [22] | Chi-square | M | 0.03 | |||||
| Li et al. 2016 [23] | Logistic regression | F | 0.97 (0.78–1.21) | 0.79 | ||||
| Makhseed et al. 1998 [24] | Logistic regression | Total | M | 1.01 (0.86–1.20) | 0.87 | |||
| Primiparous | F | 0.87 (0.65–1.17) | 0.36 | |||||
| Multiparous | M | 1.09 (0.89–1.33) | 0.42 | |||||
| Persson et al. 2014 [25] | Logistic regression | Healthy population | M | 1.03 (1.01–1.06) | 0.003 | |||
| Gestational diabetes | M | 1.08 (0.93–1.26) | 0.31 | |||||
| Diabetes mellitus type I | F | 0.93 (0.79–1.09) | 0.35 | |||||
| Diabetes mellitus type II | F | 0.83 (0.44–1.57) | 0.56 | |||||
| Ricart et al. 2009 [76] | Logistic regression | M | 1.22 (0.91–1.63) | 0.19 | ||||
| Sheiner et al. 2004 [26] | Logistic regression | = | 1.00 (0.95–1.05) | 0.96 | ||||
| Shiozaki et al. 2011 [27] | Logistic regression | F | 0.88 (0.83–0.92) | < 0.0001 | ||||
| Sykes et al. 2014 [77] | Logistic regression | M | 1.33 (0.67–2.63) | 0.42 | ||||
| Tundidor et al. 2012 [28] | Relative risk | F | 0.81 (0.55–1.20) | NR | ||||
| Valvi et al. 2017 [109] | Logistic regression | M | 1.03 (0.58–1.85) | 0.91 | ||||
| Verburg et al. 2016 [29] | Relative risk | Total | M | 1.05 (1.03–1.07) | NR | |||
| 25–29 weeks | F | 0.69 (0.58–0.81) | NR | |||||
| 30–33 weeks | F | 0.87 (0.79–0.97) | NR | |||||
| 34–36 weeks | F | 0.93 (0.87–0.98) | NR | |||||
| 37–39 weeks | M | 1.06 (1.04–1.09) | NR | |||||
| 40–42 weeks | M | 1.07 (1.04–1.11) | NR | |||||
| Zheng et al. 2016 [30] | Logistic regression | F | 0.54 (0.26–1.14) | 0.11 | ||||
| Pre-eclampsia | ||||||||
| Aibar et al. 2012 [31] | Logistic regression | F | 0.99 (0.65–1.49) | 0.94 | ||||
| Aliyu et al. 2012 [32] | Logistic regression | F | 0.90 (0.79–1.03) | 0.12 | ||||
| Andersen et al. 2016 [15] | Logistic regression | Total | F | 0.95 (0.69–1.31) | 0.76 | |||
| Preterm | F | 1.04 (0.42–2.56) | 0.94 | |||||
| Term | M | 1.22 (0.85–1.74) | 0.29 | |||||
| Basso et al. 2001 [33] | Logistic regression | M | 0.94 (0.92–0.97) | < 0.05 | ||||
| Brettel et al. 2008 [34] | Logistic regression | F | 1.17 (1.01–1.35) | 0.03 | ||||
| Campbell et al. 1983 [17] | Logistic regression | F | 1.08 (0.94–1.24) | 0.3 | ||||
| Choong et al. 1995 [35] | Logistic regression | F | 1.45 (1.22–1.71) | < 0.0001 | ||||
| Chu et al. 2014 [36] | Logistic regression | M | 0.60 (0.19–1.83) | 0.39 | ||||
| Hadar et al. 2017 [37] | Logistic regression | F | 0.99 (0.68–1.43) | 0.95 | ||||
| Hou et al. 2014 [21] | Logistic regression | F | 0.95 (0.88–1.02) | 0.13 | ||||
| Juberg et al. 1976 [22] | Chi-square | M | 0.06 | |||||
| Khalil et al. 2013 [38] | Logistic regression | Total | M | 1.04 (0.91–1.19) | 0.57 | |||
| Preterm | F | 1.53 (1.07–2.20) | 0.02 | |||||
| Term | M | 1.08 (0.93–1.25) | 0.31 | |||||
| Postterm | M | 3.46 (1.40–8.53) | 0.007 | |||||
| Lao et al. 2011 [39] | Logistic regression | F | 0.92 (0.81–1.06) | 0.26 | ||||
| Lao et al. 2017 [40] | Logistic regression | M | 1.56 (1.41–1.73) | <0.0001 | ||||
| Li et al. 2016 [23] | Logistic regression | F | 0.66 (0.45–0.98) | 0.04 | ||||
| Lisonkova et al. 2013 [41] | Cox regression | < 34 weeks | M | 1.10 (1.07–1.14) | NR | NR | 1.10 (1.06–1.14) | NR |
| > 34 weeks | M | 1.10 (1.07–1.14) | NR | NR | 1.10 (1.06–1.14) | NR | ||
| Liu et al. 2016 [42] | Logistic regression | Total | 0.96 (0.88–1.04) | 0.31 | ||||
| Preterm | 1.15 (1.00–1.32) | 0.046 | ||||||
| Makhseed et al. 1998 [24] | Logistic regression | Total | F | 0.92 (0.68–1.24) | 0.57 | |||
| Nulliparous | F | 0.74 (0.49–1.10) | 0.13 | |||||
| Multiparous | M | 1.20 (0.76–1.90) | 0.43 | |||||
| Masoumi et al. 2017 [43] | Logistic regression | Total | M | 1.09 (0.90–1.31) | 0.40 | |||
| Severe | M | 1.43 (0.81–2.51) | 0.21 | |||||
| Morsing et al. 2018 [44] | Logistic regression | F | 0.80 (0.59–1.09) | 0.16 | ||||
| Myers et al. 2015 [45] | Logistic regression | = | 0.94 (0.65–1.36) | 0.74 | ||||
| Peled et al. 2013 [46] | Logistic regression | M | 1.79 (0.42–7.56) | 0.43 | ||||
| Persson et al. 2014 [25] | Logistic regression | Healthy population | M | 1.03 (1.01–1.06) | 0.003 | |||
| Gestational diabetes | M | 1.08 (0.93–1.26) | 0.31 | |||||
| Diabetes mellitus type I | F | 0.93 (0.79–1.09) | 0.35 | |||||
| Diabetes mellitus type II | F | 0.83 (0.44–1.57) | 0.56 | |||||
| Quiñones et al. 2005 [47] | Logistic regression | M | 1.15 (0.77–1.70) | 0.5 | ||||
| Reynolds et al. 2012 [48] | Logistic regression | Total | F | 0.85 (0.71–1.02) | 0.08 | |||
| Preterm | F | 1.25 (0.79–1.97) | 0.34 | |||||
| Term | F | 0.86 (0.71–1.04) | 0.13 | |||||
| Roy et al. 2015 [49] | Logistic regression | Total | M | 1.28 (0.72–2.29) | 0.4 | |||
| Preterm | M | 0.77 (0.33–1.81) | 0.55 | |||||
| Term | M | 1.28 (0.66–2.46) | 0.46 | |||||
| Sharifzadeh et al. 2012 [50] | F | 0.88 (0.33–2.35) | 0.8 | |||||
| Sheiner et al. 2004 [26] | Logistic regression | = | 1.00 (0.95–1.05) | 0.96 | ||||
| Shiozaki et al. 2011 [27] | Chi-square | Pre-eclampsia | F | 0.84 (0.79–0.89) | < 0.001 | |||
| Pre-eclampsia with fetal death | M | 1.21 (0.70–1.48) | 0.95 | |||||
| Severe pre-eclampsia | F | 1.21 (1.10–1.33) | 0.001 | |||||
| Severe pre-eclampsia with fetal death | F | 1.14 (0.67–1.93) | 0.63 | |||||
| Sykes et al. 2014 [77] | Logistic regression | M | 1.27 (0.64–2.51) | 0.49 | ||||
| Taylor et al. 2018 [51] | Logistic regression | F | 0.94 (0.67–1.30) | 0.70 | ||||
| Taylor et al. 2018 [51] | Logistic regression | PE overall | F | 0.89 (0.64–1.24) | 0.69 | |||
| Term (> 37 weeks) | F | 0.92 (0.65–1.30) | 0.63 | |||||
| Preterm (<37 weeks) | F | 0.72 (0.37–1.39) | 0.32 | |||||
| Very preterm (<34 weeks) | F | 0.38 (0.13–1.07) | 0.07 | |||||
| Toivanen et al. 1970 [52] | Logistic regression | M | 1.20 (1.06–1.37) | 0.005 | ||||
| Trudel et al. 2015 [53] | Logistic regression | M | 1.01 (0.95–1.07) | 0.82 | ||||
| Vatten et al. 2004 [54] | Logistic regression | Total | M | 1.05 (1.03–1.07) | < 0.0001 | |||
| Preterm (< 37 weeks) | F | 1.17 (1.11–1.22) | < 0.0001 | |||||
| Term (37–42 weeks) | M | 1.06 (1.04–1.08 | < 0.0001 | |||||
| Postterm (> 42 weeks) | M | 1.07 (0.96–1.18) | 0.23 | |||||
| 25–29 weeks | F | 1.55 (1.31–1.83) | < 0.0001 | |||||
| 30–33 weeks | F | 1.33 (1.21–1.46) | < 0.0001 | |||||
| 34–36 wls | F | 1.07 (1.01–1.14) | 0.03 | |||||
| 37–39 weeks | F | 0.98 (0.85–1.01) | 0.18 | |||||
| 40–42 weeks | M | 1.10 (1.07–1.13) | < 0.0001 | |||||
| Verburg et al. 2016 [29] | Relative risk | Total | M | 1.05 (1.03–1.07) | NR | |||
| 25–29 weeks | F | 0.69 (0.58–0.81) | NR | |||||
| 30–33 weeks | F | 0.87 (0.79–0.97) | NR | |||||
| 34–36 weeks | F | 0.93 (0.87–0.98) | NR | |||||
| 37–39 weeks | M | 1.06 (1.04–1.09) | NR | |||||
| 40–42 weeks | M | 1.07 (1.04–1.11) | NR | |||||
| Wandabwa et al. 2010 [79] | Logistic regression | F | 0.65 (0.45–0.95) | 0.03 | ||||
| Weinberg et al. 2017 [55] | Logistic regression | Total | M | 1.01 (0.98–1.04) | 0.71 | |||
| Term (> 37 weeks) | M | 1.05 (1.01–1.08) | 0.01 | |||||
| Preterm (<37 weeks) | F | 0.89 (0.84–0.94) | 0.0001 | |||||
| Zheng et al. 2016 [30] | Logistic regression | Total | F | 0.49 (0.27–0.89) | 0.02 | |||
| Mild | F | 0.65 (0.30–1.43) | 0.29 | |||||
| Severe | F | 2.60 (1.18–5.73) | 0.02 | |||||
| Eclampsia | ||||||||
| Aibar et al. 2012 [31] | Logistic regression | M | 1.54 (0.50–4.72) | 0.45 | ||||
| Aliyu et al. 2012 [32] | Logistic regression | F | 0.92 (0.42–2.01) | 0.83 | ||||
| Campbell et al. 1983 [17] | Logistic regression | F | 0.89 (0.35–2.32) | 0.82 | ||||
| Chien et al. 2011 [18] | Logistic regression | = | 1.00 (0.97–1.04) | 0.89 | ||||
| Hou et al. 2014 [21] | Chi-square | M | 0.13 | |||||
| Llopez-Lera et al. 1990 [82] | Chi-square | M | < 0.05 | |||||
| Persson et al. 2014 [25] | Logistic regression | Healthy population | M | 1.03 (1.01–1.06) | 0.003 | |||
| Gestational diabetes | M | 1.08 (0.93–1.26) | 0.31 | |||||
| Diabetes mellitus type I | F | 0.93 (0.79–1.09) | 0.35 | |||||
| Diabetes mellitus type II | F | 0.83 (0.44–1.57) | 0.56 | |||||
| Wandabwa et al. 2010 [79] | Logistic regression | F | 0.65 (0.45–0.95) | 0.03 | ||||
| Gestational diabetes | ||||||||
| Aibar et al. 2012 [31] | Logistic regression | M | 1.21 (1.06–1.37) | 0.0034 | ||||
| Breschi et al. 1993 [56] | Logistic regression | F | 0.96 (0.36–2.52) | 0.93 | ||||
| Cosson et al. 2016 [57] | Logistic regression | = | 1.00 (0.93–1.08) | 0.96 | ||||
| Ehrlich et al. 2012 [58] | Logistic regression | M | 1.02 (0.99–1.05) | NR | Maternal ethnicity | 1.02 (0.99–1.05) | NR | |
| Maternal ethnicity. education and age | 1.02 (0.99–1.05) | NR | ||||||
| Engel et al. 2008 [19] | Logistic regression | M | 1.07 (0.85–1.36) | 0.54 | ||||
| Favili et al. 2013 [20] | Logistic regression | M | 2.36 (0.58–9.61) | 0.37 | Maternal age > 40 years, BMI, weight gain, gestational hypertension | 0.95 (0.37–2.46) | 0.92 | |
| Heckbert et al. 1988 [59] | Logistic regression | F | 0.97 (0.77–1.21) | 0.79 | ||||
| Hou et al. 2014 [21] | Logistic regression | M | 1.01 (0.96–1.07) | 0.61 | ||||
| Janssen et al. 1996 [60] | Logistic regression | M | 1.02 (0.96–1.08) | 0.5 | ||||
| Kale et al. 2005 [61] | Logistic regression | M | 1.64 (1.12–2.40) | 0.01 | ||||
| Khalil et al. 2013 [38] | Logistic regression | M | 1.41 (1.15–1.72) | < 0.001 | ||||
| Lao et al. 2011 [39] | Logistic regression | M | 1.05 (0.99–1.12 | 0.12 | ||||
| Lao et al. 2017 [40] | Logistic regression | M | 1.06 (1.01–1.11) | 0.08 | ||||
| Lawlor et al. 2009 [84] | Logistic regression | M | 1.61 (0.92–2.81) | 0.09 | ||||
| Liu et al. 2016 [42] | Logistic regression | M | 1.08 (1.00–1.16) | 0.048 | ||||
| Macaulay et al. 2018 [86] | Logistic regression | M | 1.16 (0.73–1.84) | 0.53 | ||||
| Oken et al. 2016 [62] | Logistic regression | M | 1.39 (0.81–2.36) | 0.23 | ||||
| Okereke et al. 2002 [63] | Logistic regression | M | 1.39 (0.81–2.36) | 0.23 | ||||
| Peled et al. 2013 [46] | Logistic regression | M | 3.24 (0.65–16.22) | 0.15 | ||||
| Retnakaran et al. 2015 [64] | Logistic regression | M | 1.03 (1.00–1.05) | 0.047 | ||||
| Retnakaran et al. 2015 [64] | Logistic regression | M | 1.24 (0.92–1.67) | 0.16 | ||||
| Ricart et al. 2009 [76] | Logistic regression | M | 1.05 (0.91–1.22) | 0.17 | ||||
| Sheiner et al. 2004 [26] | Logistic regression | M | 1.07 (1.01–1.12) | 0.01 | ||||
| Spellacy et al. 1985 [65] | Chi-square | M | NS | |||||
| Strutz et al. 2018 [66] | Logistic regression | M | 1.80 (0.40–8.18) | 0.45 | ||||
| Trudel et al. 2015 [53] | Logistic regression | F | 0.96 (0.90–1.04) | 0.32 | ||||
| Verburg et al. 2016 [29] | RR | M | 1.04 (1.01–1.07) | NR | ||||
| Xiao et al. 2014 [67] | Logistic regression | M | 1.29 (0.58–2.89) | 0.53 | ||||
| Placental abruption | ||||||||
| Aliyu et al. 2012 [32] | Logistic regression | F | 0.98 (0.87–1.12) | 0.8 | ||||
| Brettel et al. 2008 [34] | Logistic regression | M | 1.29 (0.97–1.71) | 0.08 | ||||
| Engel et al. 2008 [19] | Logistic regression | F | 0.53 (0.28–0.99) | 0.049 | ||||
| Hou et al. 2014 [21] | Logistic regression | F | 0.98 (0.83–1.15) | 0.76 | ||||
| Jakobovits et al. 1988 [68] | Chi-square | Total | M | NS | ||||
| 17–20 years | M | < 0.001 | ||||||
| 21–25 years | M | < 0.01 | ||||||
| 26–30 years | F | NS | ||||||
| 31–35 years | M | < 0.05 | ||||||
| 36–40 years | M | < 0.05 | ||||||
| 41–42 years | = | NS | ||||||
| Lopez-Llera et al. 1990 [82] | Logistic regression | M | 0.94 (0.54–1.66) | 0.84 | ||||
| Peled et al. 2013 [46] | Logistic regression | M | 2.90 (0.76–11.03) | 0.12 | ||||
| Raissanen et al. 2013 [110] | Logistic regression | Total | M | 1.19 (1.12–1.26) | < 0.0001 | |||
| Nulliparous | M | 1.23 (1.12–1.36) | < 0.0001 | NR | 1.36 (1.23–1.51) | |||
| Multiparous | M | 1.16 (1.08–1.26) | 0.001 | NR | 1.38 (1.27–1.50) | |||
| Schildberger et al. 2016 [69] | Logistic regression | F | 0.84 (0.81–0.87) | < 0.0001 | ||||
| Sheiner et al. 2002 [70] | Logistic regression | F | 0.98 (0.78–1.24) | 0.88 | ||||
| Sheiner et al. 2004 [26] | Logistic regression | M | 1.15 (0.89–1.49) | 0.28 | ||||
| Tikkanen et al. 2013 [90] | Logistic regression | M | 1.18 (1.11–1.25) | < 0.0001 | ||||
| Wandabwa et al. 2005 [91] | Logistic regression | M | 2.20 (1.20–4.90) | < 0.01 | Distance to hospital. age, type of house, hypertension, previous caesarean section, previous stillbirth | 1.90 (1.00–3.80) | NR | |
| Weissmann–Brenner et al. 2015 [71] | Logistic regression | Total | M | 1.20 (0.77–1.87) | 0.42 | |||
| Age < 40 years | M | 1.14 (0.73–1.79) | 0.56 | |||||
| Age > 40 years | M | 5.08 (0.24–106.0) | 0.29 | |||||
| Post-partum hemorrhage | ||||||||
| Favili et al. 2013 [20] | Logistic regression | Total | M | 1.12 (0.34–3.72) | 0.85 | |||
| Age ≥ 40 years | M | 2.10 (0.40–11.01) | 0.38 | |||||
| Age < 40 years | F | 0.35 (0.04–3.37) | 0.36 | |||||
| Weissmann–Brenner et al. 2015 [71] | Logistic regression | Total | M | 1.20 (0.88–1.65) | 0.25 | |||
| Age ≥ 40 years | M | 1.16 (0.84–1.61) | 0.35 | |||||
| Age < 40 years | M | 4.07 (0.45–36.5) | 0.21 | |||||
| Liu et al. 2016 [42] | Logistic regression | F | 0.91 (0.83–0.99) | 0.0046 | ||||
| Miscarriage | ||||||||
| Byrne et al. 1987 [72] | Risk ratio | Total | M | < 0.05 | ||||
| Morphological normal | M | < 0.05 | ||||||
| Morphological abnormal | F | > 0.05 | ||||||
| Cheng et al. 2014 [73] | Risk ratio | F | < 0.001 | |||||
| Del Fabro et al. 2011 [74] | Risk ratio | Total | F | < 0.05 | ||||
| 4–10 weeks | F | < 0.001 | ||||||
| 11–15 weeks | F | 0.07 | ||||||
| 16–20 weeks | F | 0.06 | ||||||