Perinatal mental health: how nordic data sources have contributed to existing evidence and future avenues to explore

Figures & data

Table 1. Selected studies on perinatal mental health derived from three Nordic data sources (Denmark, Norway, and Sweden).

Author	Year	Recruitment period	Region	Cohort size	Source of information	Population characteristics	Exposures examined	Outcomes examined	Adjusted for	Main results
Danish data sources
Bauer	2019	1981-2005	Denmark	8850	iPSYCH2012 cohort linked to the Danish Psychiatric Central Research Register	Sample selected from the Danish Civil Registration System of all singleton births who were alive and resided in Denmark at one year of age and whose mother was known	Personal and parental psychiatric history, genetic risk score based on genome-wide data from Psychiatric Genomics Consortium sample	Postpartum psychiatric disorders	age, age squared, parental psychiatric history, country of origin, parity	Parental psychiatric history associated with postpartum psychiatric disorders among women with previous psychiatric history (OR, 1.14; 95% CI 1.02–1.28) Genetic risk score for major depression associated with an increased risk of postpartum psychiatric disorders in both women with (OR, 1.44; 95% CI: 1.19–1.74) and without (OR, 1.88; 95% CI: 1.26–2.81) personal psychiatric history Schizophrenia genetic risk score only minimally associated with postpartum disorders
Munk-Olsen	2006	1973-2005	Denmark	630,373 women; 547,431 men	Register-based cohort formed by linking information from Danish health and civil service registers	Danish-born persons followed up from their 15th birthday or January 1, 1973, whichever came later, until date of onset of the disorder in question, date of death, date of emigration from Denmark, or July 1, 2005	First-time parents	First-time psychiatric hospital admission or outpatient contact 0 to 12 months after becoming a parent	age, calendar time	Primiparous women had increased risk of incident hospital admission with any mental disorder through the first 3 months after childbirth The highest risk 10 to 19 days postpartum (RR 7.31; 95% CI: 5.44-9.81) Risk increased for psychiatric outpatient contacts through the first 3 months after childbirth, also with the highest risk occurring 10 to 19 days postpartum (RR, 2.67; 95% CI, 1.99-3.59). Fatherhood not associated with increased risk of hospital admission or outpatient contact
Munk-Olsen	2015	1994-2005	Denmark	21,276	Danish IVF Register, Danish Psychiatric Central Register, Danish National Hospital Register, Integrated Database for Longitudinal Labor Market Research	All women having IVF and their partners with recorded information in the IVF register covering fertility treatments in Denmark at all public and private treatment sites	Childbirth	First-time psychiatric episodes (first psychiatric inpatient or outpatient treatment)	adoption, age, calendar year, income, education, comorbidity Index, psychiatric disorder in spouse, death of spouse, abortion history, number of IVF treatments	IRR for any type of psychiatric disorder 0-90 days postpartum 11.3 per 1000 person-years (95% CI: 8.2-15.0), and 3.8 (3.4-4.3) among women not giving birth IVF-treated mothers increased risk of a psychiatric episode postpartum (IRR: 2.9, 95% CI: 2.0-4.2) Risk of psychiatric episodes from 90 days postpartum and onwards decreased (IRR: 0.9, 95% CI: 0.7-1.0).
Finnish data sources
Lehtola	2020	2011-2015	Finland	80	FinnBrain Birth Cohort Study	Families who participated in the newborn scan whose parents filled in prenatal and 3- and 6-month postnatal questionnaires. Scanned infants all born at gestational week 36 or later, weighed more than 2500 g, had Apgar scores > 6 at 5 min after birth, did not have any diagnosed CNS anomaly or abnormal findings in the MRI scan.	Newborn white matter fractional anisotropy (FA), a measure of white matter maturity	Maternal postpartum depressive symptoms and infant negative reactivity at 6 months	infant sex, parity,maternal alcohol/tobacco use, maternal prenatal depressive symptoms and post-conceptional age	-Maternal depressive symptoms positively related to infant negative reactivity among infants with high or average FA in the whole brain and in corpus callosum and cingulum, but not among those with low FA. -The link between maternal depressive symptoms and infant negative reactivity was moderated by newborn FA
von Bondorff	2015	1971-2011	Finland	10,682	Helsinki Birth Cohort Study & Finnish Centre for Pensions	The Helsinki Birth Cohort Study comprises 13 345 individuals born in Helsinki, Finland at Helsinki University Central Hospital or Helsinki City Maternity Hospital between 1934 and 1944 and who had data on birth anthropometry extracted from birth records	Body size at birth	Disability pension (DP)	birth order, socioeconomic status in childhood, highest educational attainment and highest occupational class in adulthood.	-Among men, higher birth weight associated with a lower hazard of transitioning into DP, adjusted hazard ratio (HR) 0.94 (95% confidence interval [CI] 0.88–0.99 for 1 SD increase in birth weight). -Among women no associations between body size at birth and all-cause DP
Lahti	2014	1969-2010	Finland	13,243	Helsinki Birth Cohort Study	According to hospital birth records, 341 offspring were born to grand multiparous mothers. From Finnish national hospital discharge and causes of death registers, identified 1682 participants with mental disorders.	Maternal grand multiparity	Severe Mental Disorders in Adult Offspring	mothers’ and father’s occupational statuses in childhood, the birth weight of the offspring, and maternal BMI at childbirth.	-Maternal grand multiparity predicted significantly increased risks of mood disorders (Hazard Ratio = 1.64, p = 0.03), non-psychotic mood disorders (Hazard Ratio = 2.02, p = 0.002), and suicide attempts (Hazard Ratio = 3.94, p = 0.01) in adult offspring
Icelandinc data sources
Hauksdóttir	2013	2007-2009	Iceland	3,755	Icelandic national cohort	Public Health Institute in Iceland conducted a mailed health survey, Health and Well-being in Iceland 2007. Based on a stratified random sample (n = 9,807) of the Icelandic national population.	Major national economic collapse	self-reported levels of psychological stress	Age, sex, education, marital status, and size of residency area.	-Age-adjusted mean stress levels increased between 2007 and 2009 (p = 0.004), though the increase was observed only for women (p = 0.003), not for men (p = 0.34) -The odds ratios for experiencing high stress levels were increased only among women (odds ratio (OR) = 1.37), especially among women who were unemployed (OR = 3.38)
Gisladottir	2014	1993-2011	Iceland	N = 915 cases; n = 1641 controls	Rape Trauma Service	Register-based cohort study, linking data from the RTS at the Accident and Emergency Department of Landspitali University Hospital with data from the national Icelandic birth register (IBR).	Characteristics and risk factors during pregnancy, including maternal smoking, body mass index, weight gain during pregnancy, illicit drug use	Sexual violence	Age, parity, year of delivery and gestational length at first weight measurement for BMI and weight gain.	-Compared with unexposed women, sexually assaulted women were younger and more often primiparous in subsequent pregnancy, more likely not to be employed (7.8% vs. 4.3%; aRR 2.42, 95% CI 1.49-3.94), not cohabiting (45.6% vs. 14.2%; aRR 2.15, 95% CI 1.75-2.65), smokers (45.4% vs. 13.5%; aRR 2.68, 95% CI 2.25-3.20), and more likely to have used illicit drugs during pregnancy (3.4% vs. 0.4%; aRR 6.27, 95% CI 2.13-18.43).
Norwegian data sources
Adams	2012	2008-2010	Akershus University Hospital, Norway	2206	ABC study	Women with a singleton pregnancy and intended vaginal delivery recruited at the routine fetal ultrasound examination at 18 weeks of gestation	Fear of childbirth assessed by the Wijma Delivery Expectancy Questionnaire Version A, and defined as a sum score ≥85	Labor duration in hours	labor induction, labor augmentation, emergency caesarean delivery, instrumental vaginal delivery, birthweight and maternal age	Fear of childbirth present in 7.5% of women Labor duration significantly longer in women with fear of childbirth (adjusted unstandardized coefficient 0.78; 95% CI: 0.20–1.35, corresponding to a 47-minute difference)
Garthus-Niegel	2017	2008-2010	Akershus University Hospital, Norway	1472	ABC study	Women recruited during their routine fetal ultrasound examination, performed at 17 weeks’ gestation, and asked to complete questionnaires at 17 weeks’ gestation, 32 weeks’ gestation, 8 weeks and 2 years postpartum	Postpartum PTSD symptoms	Child development, assessed by means of the Ages & Stages Questionnaire (ASQ-3) and the ASQ-Social-Emotional (ASQ:SE): gross motor, fine motor, communication and socio-emotional development	Sex, maternal depression and anxiety or infant temperament	Postpartum PTSD symptoms had a prospective relationship with poor child social-emotional development 2 years later Child sex and infant temperament moderated the association between maternal PTSD symptoms and child social–emotional development
Kjeldgaard	2017	1998-2008	Norway	731	Norwegian MoBa study	All pregnant women scheduled to give birth at 50 of Norway’s 52 hospitals with maternity units received a postal invitation to participate together with appointments for routine ultrasound examination at around week 17 of pregnancy	History of depression	Hyperemesis gravidarum	Symptoms of current depression, maternal age, parity, body mass index, smoking, sex of the child, education and pelvic girdle pain	A lifetime history of depression associated with higher odds for hyperemesis gravidarum (OR = 1.49, 95% CI (1.23; 1.79)). - Two thirds of women with hyperemesis gravidarum had neither a history of depression nor symptoms of current depression − 1.2% of women with a history of depression developed hyperemesis gravidarum
Swedish data sources
Asif	2020	2012-2019	Uppsala, Sweden	2990	BASIC study	Swedish-speaking women in Uppsala ≥ 18 years, vaginally delivered with singleton pregnancies	Obstetric perineal lacerations	PPD (assessed with the Depression Self-Reporting Scale, completed at 6 weeks postpartum)	BMI, education, parity, vacuum extraction	Significant association of severe lacerations with PPD in women with low resilience (OR: 5.5, 95% CI: 1.2-26.0)
Esscher	2016	1980-2007	Sweden	103	Swedish Cause of Death Register, Medical Birth Register, National Patient Register	Women died by suicide during pregnancy, or within 1 year after delivery, through linkage of the Swedish Cause of Death Register with the Medical Birth Register	NA	Maternal suicide during pregnancy	None	Maternal suicide ratio: 3.7 per 100 000 live births Suicide ratio higher in women born in low-income countries (OR: 3.1, 95% CI: 1.3-7.7)
Henriksson	2019	NR	Uppsala, Sweden	45	BASIC study	Plasma samples selected from a subgroup of women participating in the BASIC project: Swedish-speaking women in Uppsala who were ≥ 18 years	- Untargeted gas chromatography–mass spectrometry plasma metabolomics - Seasonal differences in the metabolic profiles	Antenatal depressive symptoms based on EPDS score cut off of ≥ 12 points	None	Independently of season, no differences were observed Seasonal differences in the metabolic profiles of control samples, suggesting favorable cardiometabolic profile in the summer vs. winter (lower glucose and sugar acid and lactate to pyruvate ratio, and higher abundance of arginine and phosphate) Similar differences between cases and controls among summer pregnancies: association between a stressed metabolism and depressive symptoms

ABC: Akershus Birth Cohort study; BASIC: Biology, Affect, Stress, Imaging, Cognition study; BMI: body mass index; CI: confidence intervals; EPDS: Edinburgh Postnatal Depression Scale; iPSYCH2012: Integrative Psychiatric Research; IRR: incidence rate ratio; IVF: in vitro fertilization; MobA: Mother and Child Cohort Study; NA: not applicable; NR: not reported; OR: odds ratio; PPD: peripartum depression; PTSD: post-traumatic stress disorder; RR: relative risk.