Abstract: PD13-03
Sources of Funding: None.

Introduction

The influence of parental demographics on fertility and birth outcomes is a topic of great interest to both epidemiologists and the lay public. Given logistics and certainty of exposures, data on all births in the US is often reported at the maternal level. While paternal characteristics are also known to influence birth outcomes, generational trends of paternal characteristics of child births within the United States have been poorly characterized. We sought to summarize the demographics of fathers in the US over the past 4 decades as well as describe the patterns of missing paternal data on birth certificates. _x000D_

Methods

We evaluated 158,621,397 U.S. births spanning from 1973 to 2015 using data from the National Vital Statistics System of the Centers for Disease Control. Paternal, maternal and infant characteristics were analyzed and paternal ages of all births and first births were presented over time along with the mean difference in age between parents. Characteristics of births with known and unknown paternity were also compared.

Results

There has been a significant increase in mean paternal age among whites, blacks and asians over the past 40 years. In 1973, the mean paternal age for all births was 27.6, and 24.6 for first births, rising to 31.4 and 29.1, respectively, in 2015. Paternal age increased for all races combined and each race individually. However, interracial differences in mean age were apparent with asians > whites > blacks. The mean age difference between parents was similar over the past 40 years. In 1973, the mean parental age difference was 2.8 years—2.7 years for whites, 3.2 years for blacks and 4.2 years for asians. In 2015, the mean overall difference was 2.5 years with the difference between asian fathers and their partners decreasing the most to 3.2 years. Of all the recorded births in 1973, 91.3% had knowledge of paternal identity. This fell to 85.5% of fathers identified in 1991 and resides at 88.4% in 2015. Over the past decade, mothers younger than 20 years had the lowest proportion of reported paternal identity at 67.7% with black mothers under 20 at 50.4%. Overall, births without paternal identity were more likely associated with young, black mothers who reported less weight gain during pregnancy, and lower birth weight children.

Conclusions

Overall, paternal age is rising in the US in parallel with maternal age, a trend encompassing all races. The proportion of missing paternal data is also increasing in recent years. Given the association between paternal factors and birth characteristics, further understanding of these trends is necessary.

Funding

None.