• Pregnancy and the risk of autoimmune disease.

      Khashan, Ali S; Kenny, Louise C; Laursen, Thomas M; Mahmood, Uzma; Mortensen, Preben B; Henriksen, Tine B; O'Donoghue, Keelin; Anu Research Centre, Department of Obstetrics and Gynaecology, Cork University, Maternity Hospital, University College Cork, Wilton, Cork, Republic of Ireland. (2012-01-31)
      Autoimmune diseases (AID) predominantly affect women of reproductive age. While basic molecular studies have implicated persisting fetal cells in the mother in some AID, supportive epidemiological evidence is limited. We investigated the effect of vaginal delivery, caesarean section (CS) and induced abortion on the risk of subsequent maternal AID. Using the Danish Civil Registration System (CRS) we identified women who were born between 1960 and 1992. We performed data linkage between the CRS other Danish national registers to identify women who had a pregnancy and those who developed AID. Women were categorised into 4 groups; nulligravida (control group), women who had 1st child by vaginal delivery, whose 1st delivery was by CS and who had abortions. Log-linear Poisson regression with person-years was used for data analysis adjusting for several potential confounders. There were 1,035,639 women aged >14 years and 25,570 developed AID: 43.4% nulligravida, 44.3% had their first pregnancy delivered vaginally, 7.6% CS and 4.1% abortions. The risk of AID was significantly higher in the 1st year after vaginal delivery (RR = 1.1[1.0, 1.2]) and CS (RR = 1.3[1.1, 1.5]) but significantly lower in the 1st year following abortion (RR = 0.7[0.6, 0.9]). These results suggest an association between pregnancy and the risk of subsequent maternal AID. Increased risks of AID after CS may be explained by amplified fetal cell traffic at delivery, while decreased risks after abortion may be due to the transfer of more primitive fetal stem cells. The increased risk of AID in the first year after delivery may also be related to greater testing during pregnancy.
    • Risk of affective disorders following prenatal exposure to severe life events: a Danish population-based cohort study.

      Khashan, Ali S; McNamee, Roseanne; Henriksen, Tine B; Pedersen, Marianne G; Kenny, Louise C; Abel, Kathryn M; Mortensen, Preben B; Anu Research Centre, Department of Obstetrics and Gynecology, University College , Cork, Cork University Maternity Hospital, Cork, Ireland. a.khashan@ucc.ie (2012-01-31)
      OBJECTIVE: To examine the effect of prenatal exposure to severe life events on risk of affective disorders in the offspring. METHODS: In a cohort of 1.1 million Danish births from May 1978 until December 1997, mothers were considered exposed if one (or more) of their close relatives died or was diagnosed with serious illness up to 6 months before conception or during pregnancy. Offspring were followed up from their 10th birthday until their death, migration, onset of affective disorder or 31 December 2007; hospital admissions were identified by linkage to the Central Psychiatric Register. Log-linear Poisson regression was used for data analysis. RESULTS: The risk of affective disorders was increased in male offspring whose mothers were exposed to severe life events during the second trimester (adjusted RR 1.55 [95% CI 1.05-2.28]). There was an increased risk of male offspring affective disorders in relation to maternal exposure to death of a relative in the second trimester (adjusted RR 1.74 [95% CI 1.06-2.84]) or serious illness in a relative before pregnancy (adjusted RR 1.44 [95% CI 1.02-2.05]). There was no evidence for an association between prenatal exposure to severe life events and risk of female offspring affective disorders. CONCLUSIONS: Our population-based study suggests that prenatal maternal exposure to severe life events may increase the risk of affective disorders in male offspring. These findings are consistent with studies of populations exposed to famine and earthquake disasters which indicate that prenatal environment may influence the neurodevelopment of the unborn child.
    • Undiagnosed coeliac disease in a father does not influence birthweight and preterm birth.

      Khashan, Ali S; Kenny, Louise C; McNamee, Roseanne; Mortensen, Preben B; Pedersen, Marianne G; McCarthy, Fergus P; Henriksen, Tine B; Anu Research Centre, Department of Obstetrics and Gynaecology, University College, Cork, Cork University Maternity Hospital, Ireland. a.khashan@ucc.ie (2012-01-31)
      There is conflicting evidence regarding the effect of coeliac disease (CD) in the father on birthweight and preterm birth. We investigated the association between paternal CD and birthweight and preterm birth. Medical records of all singleton live-born children in Denmark between 1 January 1979 and 31 December 2004 were linked to information about parents' diseases. Fathers who were diagnosed with CD were then identified. Fathers with CD were considered treated if they were diagnosed before pregnancy and untreated if they were diagnosed after the date of conception. The outcome measures were: birthweight, small-for-gestational age (birthweight<10th centile for gestational age) and preterm birth (<37 weeks). We compared the offspring of men without CD (n = 1 472 352) and offspring of those with CD [untreated (n = 138) and treated (n = 473)]. There was no significant association between untreated CD in the father and birthweight (adjusted mean difference = -3 g; [95% CI -46, 40]) or preterm birth (adjusted odds ratio (OR) = 0.86, [95% CI 0.53, 1.37]) (compared with no CD). There was some evidence for an association between treated paternal CD and birthweight (adjusted mean difference = -81 g; [95% CI -161, -3]), but not preterm birth (adjusted OR = 1.76, [95% CI 0.95, 3.26]). Untreated paternal CD was not associated with an increased risk of reduced birthweight, or of preterm birth. There was some evidence that diagnosis and presumed treatment of paternal CD with a gluten-free diet is associated with reduced birthweight.