Table 1 Characteristics of the included studies
Source | Study | Participants | Quality | Delivery modes | Outcome assessment | Full-cohort analyses | Sibling-comparison analyses | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Design | Location | Period | Â | Â | Â | Â | No. of participants | Adjustment for confounders | No. of participants | Adjustment for confounders | |
Ahlqvist et al. (2019) [32] | PCS | Sweden | 1982–1987 | Singleton pregnancy; no restrictions on gestational age at delivery. | 7 | Vaginal delivery; elective caesarean delivery; emergency caesarean delivery | Obesity | 97,291 | Prepregnancy BMI, maternal diabetes at delivery, maternal hypertension at delivery, maternal smoking, parity, parental education, maternal age, birth weight standardized according to gestational age, preeclampsia, gestational age | 3346 | Prepregnancy BMI, maternal diabetes at delivery, maternal hypertension at delivery, maternal smoking, parity, maternal age, birth weight standardized according to gestational age, preeclampsia, gestational age |
Almqvist et al. (2012) [33] | PCS | Sweden | 1993–1999 | Singleton pregnancy; no restrictions on gestational age at delivery. | 9 | Unassisted vaginal delivery; assisted vaginal delivery; elective caesarean delivery; emergency caesarean delivery | Childhood asthma and allergic diseases | 139,610 | Gender, birth weight, gestational age, birth order, Apgar score, hypoxia/asphyxia, maternal age, smoking during pregnancy, mother living with father of the child, mother’s birth country, mother’s BMI | 40,986 | Gender, birth weight, gestational age, birth order, Apgar score, maternal age, smoking during pregnancy, mother living with father of the child, mother’s BMI |
Axelsson et al. (2019) [34] | PCS | Denmark | 1997–2010 | Singleton pregnancy; no restrictions on gestational age at delivery. | 9 | Vaginal delivery; elective caesarean delivery; emergency caesarean delivery | Time to first autism diagnosis | 671,606 | Maternal age, parental age difference, parental education, maternal marital status, maternal smoking, gender, 5-min Apgar score, use of CPAP or a ventilator, asphyxia, parental epilepsy, preeclampsia or hypertension, gestational diabetes, parity, maternal antibiotic use during the pregnancy, maternal infections during the pregnancy, parental psychiatric history | 7632 | Maternal age, parental education, maternal marital status, maternal smoking, gender, 5-min Apgar score, use of CPAP or ventilator, asphyxia, preeclampsia or hypertension, gestational diabetes, parity, maternal antibiotics use during the pregnancy, maternal infections during the pregnancy |
Axelsson et al. (2019) [8] | PCS | Denmark | 1997–2010 | Singleton pregnancy; no restrictions on gestational age at delivery. | 9 | Vaginal delivery; elective caesarean delivery; emergency caesarean delivery | ADHD | 671,592 | Maternal age, parental age difference, parental education, maternal marital status, maternal smoking, gender, 5-min Apgar score, instrument use at delivery, use of CPAP or ventilator, asphyxia, parental epilepsy, preeclampsia or hypertension, gestational diabetes, parity, induction of labor, induction of contractions, maternal antibiotics use during the pregnancy, maternal infections during the pregnancy, parental ADHD history | 15,466 | Maternal age, parental education, maternal marital status, maternal smoking, gender, 5-min Apgar score, instrument use at delivery, use of CPAP or ventilator, asphyxia, parental epilepsy, preeclampsia or hypertension, gestational diabetes, parity, induction of labor, induction of contractions, maternal antibiotics use during the pregnancy, maternal infections during the pregnancy |
Axelsson et al. (2020) [35] | PCS | Denmark | 1982–2001 | Singleton pregnancy; no restrictions on gestational age at delivery. | 9 | Vaginal delivery; elective caesarean delivery; emergency caesarean delivery | Affective disorder | 1,009,444 | Gender, maternal age, paternal age difference, paternal education, maternal education, maternal marital status, parity, maternal psychiatric history, paternal psychiatric history | - | Gender, maternal age, paternal education, maternal education, maternal marital status, parity |
Bråbäck et al. (2013) [15] | PCS | Sweden | 1999–2006 | Singleton pregnancy; only included term deliveries. | 9 | Unassisted vaginal delivery; assisted vaginal delivery; elective caesarean delivery; emergency caesarean delivery | Childhood asthma medication | 199,837 | Year of birth, gender, maternal and paternal asthma medication, socioeconomic indicators, maternal age, maternal smoking, urban/rural living, county, maternal history of diabetes and hypertension, premature rupture of the membranes, preeclampsia, gestational diabetes, gestational hypertension, maternal BMI, small for gestational age, large for gestational age, maternal fever during labor, chorioamnionitis, meconium aspiration, neonatal respiratory distress, transient tachypnoea | 19,965 | Gender, maternal age and parity, small for gestational age, large for gestational age, preeclampsia, maternal BMI, maternal diabetes, gestational diabetes, neonatal respiratory distress |
Brander et al. (2016) [37] | PCS | Sweden | 1973–1996 | Singleton pregnancy; no restrictions on gestational age at delivery. | 8 | Unassisted vaginal delivery; assisted vaginal delivery; caesarean delivery | First instance of OCD diagnosis | 2,386,686 | Gender, year of birth, age of mother and father, parity | 1,487,770 | Gender, year of birth, age of mother and father, parity |
Brander et al. (2018) [36] | PCS | Sweden | 1973–2003 | Singleton pregnancy; no restrictions on gestational age at delivery. | 8 | Unassisted vaginal delivery; assisted vaginal delivery; caesarean delivery | Tourette’s and chronic tic disorders | 3,026,861 | Gender, year of birth, age of mother and father, parity | 1,895,884 | Gender, year of birth, age of mother and father, parity |
Curran et al. (2015) [14] | PCS | Sweden | 1982–2010 | Singleton pregnancy; no restrictions on gestational age at delivery. | 8 | Unassisted vaginal delivery; assisted vaginal delivery; elective caesarean delivery; emergency caesarean delivery | First diagnosis of autism spectrum disorder | 2,697, 314 | Year of birth, gender, maternal age, gestational age, 5-min Apgar score, maternal and paternal country of birth, small for gestational age, large for gestational age, first born, family income, maternal and paternal depression, bipolar disorder, nonaffective disorder | 26,822 | Year of birth, gender, maternal age, gestational age, 5-min Apgar score, paternal country of birth, small for gestational age, large for gestational age, first born, family income, maternal and paternal depression, bipolar disorder, nonaffective disorder |
Curran et al. (2016) [12] | PCS | Sweden | 1990–2008 | Singleton pregnancy; no restrictions on gestational age at delivery. | 9 | Unassisted vaginal delivery; assisted vaginal delivery; elective caesarean delivery; emergency caesarean delivery | ADHD | 1,722,548 | Year of birth, gender, maternal age, maternal smoking during pregnancy, gestational age, 5-min Apgar score, maternal and paternal country of birth, small for gestational age, large for gestational age, firstborn, family income, maternal and paternal depression, bipolar disorder, non-affective disorder | 17,382 | Year of birth, gender, maternal age, maternal smoking during pregnancy, gestational age, 5-min Apgar score, paternal country of birth, small for gestational age, large for gestational age, firstborn, family income, maternal and paternal depression, bipolar disorder, non-affective disorder |
Ekstrom et al. (2020) [31] | PCS | Sweden | 1973–1987 | Singleton pregnancy; no restrictions on gestational age at delivery. | 8 | Vaginal delivery; caesarean delivery | Low cardiorespiratory fitness | 339,451 | Birthweights standardized according to gestational age, gestational age, maternal age, parity, diabetes, hypertension, preeclampsia, SLE, parental education, household disposable income, parental country of birth, highest parental occupational class | 20,590 | Birthweights standardized according to gestational age, gestational age, maternal age, parity, diabetes, hypertension, preeclampsia, SLE, household disposable income, highest parental occupational class |
Hawkins et al. (2019) [38] | PCS | United States | 1980–2008 | Singleton pregnancy and multiple pregnancy; no restrictions on gestational age at delivery. | 9 | Vaginal delivery; caesarean delivery | Childhood obesity | 98,952 | Gender, maternal race, maternal education, maternal age, marital status, number of children in household, year of birth | 38,508 | Gender, maternal education, maternal age, marital status, sibling order, year of birth |
Khashan et al. (2014) [39] | PCS | Sweden | 1982–2009 | Singleton pregnancy; no restrictions on gestational age at delivery. | 8 | Unassisted vaginal delivery; assisted vaginal delivery; elective caesarean delivery; emergency caesarean delivery | Type 1 diabetes before the age of 15 years; type 1 diabetes; any diabetes diagnosis | 2,638,083 | Offspring age, year of birth, maternal diabetes, gestational age | 12,174 | Year of birth, maternal diabetes, gestational age |
Li et al. (2022) [42] | PCS | Sweden | 1973–2008 | Singleton pregnancy; no restrictions on gestational age at delivery. | 8 | Unassisted vaginal delivery; assisted vaginal delivery; caesarean delivery | Stress-related disorders: PTSD, ASR, adjustment disorder, and other stress reactions | 3,212,294 | Paternal and maternal age, year of birth, gender, attained age, maternal country of birth, maternal education, history of parental psychiatric disorders | 2,404,096 | Paternal and maternal age, year of birth, gender, attained age |
MartÃn-Calvo et al. (2020) [40] | PCS | Spain | 1999–2016 | Singleton pregnancy and multiple pregnancy; no restrictions on gestational age at delivery. | 5 | Vaginal delivery; caesarean delivery | Overweight or obesity | 2791 | Offspring’s age, gender, maternal age, maternal pregestational BMI, updated smoking habit, complications during pregnancy, gestational age, birth weight | 341 | Offspring’s age, gender, maternal age, maternal pregestational BMI, updated smoking habit, gestational age, birth weight |
Nielsen et al. (2013) [13] | PCS | Denmark | 1973–2005 | Singleton pregnancy; no restrictions on gestational age at delivery. | 8 | Vaginal delivery; caesarean delivery | Offspring’s risk of multiple sclerosis | 1,703,559 | Birth order, gestational age, birth weight, maternal age, calendar period | 1,980,226 | Mother’s identity, maternal age, gender, birth weight, gestational age, birth order, birth cohort in 1-year intervals |
Yuan et al. (2016) [16] | PCS | United States | 1996–2012 | Singleton pregnancy; no restrictions on gestational age at delivery. | 7 | Vaginal delivery; caesarean delivery | Obesity in offspring in childhood, adolescence, and early adulthood | 22,068 | Maternal age, race, region, year of birth, prepregnancy BMI, maternal height, gestational diabetes, preeclampsia, pregnancy-induced hypertension, gestational age at delivery, birth weight, prepregnancy smoking, previous caesarean delivery, gender, birth order | 12,903 | Maternal age, race, region, year of birth, prepregnancy BMI, maternal height, gestational diabetes, preeclampsia, pregnancy-induced hypertension, gestational age at delivery, birth weight, prepregnancy smoking, previous caesarean delivery, gender, birth order |
Zhang et al. (2021) [41] | PCS | Sweden | 1990–2003 | Singleton pregnancy; only included term deliveries. | 9 | Vaginal delivery; elective caesarean delivery; emergency caesarean delivery | Neurodevelopmental disorders: ADHD, ASD, intellectual disability, and tic, communication, and learning disorders | 1,179,341 | Gender, year of birth, gestational age, paternal and maternal age, parity, mother education, maternal smoking during pregnancy, maternal and paternal history of psychiatric disorders, maternal hypertension, maternal diabetes, maternal infections during pregnancy, fetal malpresentation, large for gestational age, polyhydramnios, oligohydramnios, preeclampsia, pelvic disproportion, extra adjustment for placenta disorders, dystocia, failed induction, fetal distress, intrapartum caesarean delivery | 808,020 | Gender, year of birth, gestational age, paternal and maternal age, parity, mother education, maternal and paternal history of psychiatric disorders, maternal diabetes, maternal infections during pregnancy, large for gestational age, intrapartum caesarean delivery, further adjusted for dystocia, failed induction, fetal distress |