4 Epidemiological Studies Say Paternal Age Is A Risk Factor For Autism

Prenatal and Perinatal Risk Factors for Autism
A Review and Integration of Findings

Alexander Kolevzon, MD; Raz Gross, MD, MPH; Abraham Reichenberg, PhD


Arch Pediatr Adolesc Med. 2007;161:326-333.

Objective To review the evidence for the presence of prenatal and perinatal factors that affect the risk of autism and autism spectrum disorders.

Data Sources Relevant articles were identified by searching MEDLINE, screening reference lists of original studies, and searching major journals likely to publish epidemiological studies on the topic.

Study Selection For inclusion in this review, studies required (1) a well-defined sample of cases drawn from population-based registers or cohorts; (2) standardized, prospectively collected obstetric information from birth records or registers; (3) comparison subjects drawn from the general population with information on obstetric complications collected from the same source; and (4) a standardized format for presentation of data, allowing for comparisons among studies.

Main Exposures Parental characteristics and obstetric complications.

Main Outcome Measures Rates of autism and autism spectrum disorders.

Results Seven epidemiological studies were identified that fulfilled inclusion criteria. The parental characteristics associated with an increased risk of autism and autism spectrum disorders included advanced maternal age, advanced paternal age, and maternal place of birth outside Europe or North America. The obstetric conditions that emerged as significant fell into 2 categories: (1) birth weight and duration of gestation and (2) intrapartum hypoxia.

Paternal Age as a Risk Factor for Low Birthweight

Low Birth Weight is often observed in babies who go on to manifest paternal age related autism and schizophrenia.



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AJPH First Look, published online ahead of print Mar 29, 2006
American Journal of Public Health, 10.2105/AJPH.2005.066324
Research and Practice
Paternal Age as a Risk Factor for Low Birthweight
Nancy E. Reichman 1* Julien O. Teitler 2

1 Robert Wood Johnson Medical School
2 Columbia University


Abstract



Objectives. We examined associations between paternal age and low birthweight in the US urban population.

Methods. Using a population-based sample of 4621 births, we used multiple logistic regression analysis to estimate associations between paternal age and low birthweight, controlling for maternal age, other demographic factors, and the child's gender.

Results. When the child’s gender and the mother's race/ethnicity, birthplace, parity, marital status, and health insurance type were controlled, teenaged fathers were 20% less likely and fathers older than 34 years were 90% more likely than fathers aged 20 to 34 years to have low-birthweight babies. The associations were significant when maternal age was also controlled. No racial/ethnic differences in associations between paternal age and low birthweight were found.

Conclusions. We identified paternal age as an independent risk factor for low birthweight in the US urban population, suggesting that more attention needs to be paid to paternal influences on birth outcomes and to the interactive effects of urban environments and individual risk factors on health.

Key Words: Birth Outcomes, Socioeconomic Factors