17 November: World Prematurity Day and medical research

Preterm birth (birth before 37 weeks' gestation) has been an under-recognised global health issue. Between 10 and 15 million children each year are born preterm. More than 1 million preterm born children die every year, and those who survive are at increased risk of cerebral palsy, blindness, and hearing loss. Even children born at 34–36 weeks' gestation are at an increased risk of disabilities, jaundice, and delayed brain development.

Researchers at the Department of Medical Epidemiology and Biostatistics conduct a wide range of research that involves preterm birth. Here we present four examples of such research published in 2018 to pay attention to the World Prematurity Day.

1) 1) Pregnancy complications following fertility treatment-disentangling the role of multiple gestation.
Oberg A, VanderWeele T, Almqvist C, Hernandez-Diaz S
Int J Epidemiol 2018 08;47(4):1333-1342

In this study, Oberg et al examined 174,000 pregnancies born between 19996 and 2013 where the parents had reported troubles conceiving (clinical infertility). Clinical infertility was associated with a 1.7-fold increased risk of preterm birth. Multiple gestation was responsible for a large proportion of preterm births.

2) 2) Paternal use of antidepressants and offspring outcomes in Sweden: nationwide prospective cohort study.
Viktorin A, Levine S, Altemus M, Reichenberg A, Sandin S
BMJ 2018 06;361():k2233

Viktorin et al examined the association between paternal antidepressant use at conception and offspring health (the future child). Importantly the authors found no association between paternal antidepressant use and preterm birth. Neither did they find any association with malformation, autism spectrum disorder, or intellectual disability in the child.

3) 3) Pregnancy outcome in women undergoing liver biopsy during pregnancy: A nationwide population-based cohort study.
Ludvigsson J, Marschall H, Hagström H, Höijer J, Stephansson O
Hepatology 2018 08;68(2):625-633

Liver disease is common in young women, and during pregnancy; but physicians often abstain from liver biopsy to investigate such women out of fear of pregnancy complications. Through linkage between the Patient Register and the Medical Birth Register, Ludvigsson et al identified 23 pregnancies between 1992 and 2011, exposed to liver biopsy. There were no stillbirths in pregnancies exposed to liver biopsies compared with 0.3% stillbirths in unexposed pregnancies, but 3/23 (13%) pregnancies exposed to liver biopsy were preterm (RR, 2.6; 95% confidence interval, 0.9-7.5). Through a number of sensitivity analyses, the authors show that the reason for preterm birth is likely to be liver disease activity rather than the liver biopsy in itself.

4) 4) Perinatal risk factors in Tourette's and chronic tic disorders: a total population sibling comparison study.
Brander G, Rydell M, Kuja-Halkola R, Fernández de la Cruz L, Lichtenstein P, Serlachius E, et al
Mol. Psychiatry 2018 05;23(5):1189-1197

Brander et al used the Medical Birth Register and the Patient Register to identify siblings with and without Tourette's and chronic tic disorders (TD/CTD). Preterm birth was associated with a 30% increased risk of Tourette's and chronic tic disorders (TD/CTD), but this association failed to reach statistical significance in the full sibling comparison (Hazard ratio=1.20; 95%CI=0.93-1.56).

For further information about preterm birth, contact pediatrician and Professor Jonas F Ludvigsson.

Professor

Jonas Ludvigsson

Telefon:	08-524 823 56
Enhet:	C8.MEB.Ludvigsson
E-post:	Jonas.Ludvigsson@ki.se