Married US moms aim to have first baby in the spring

The study provides new evidence that the probability of a first baby being born in the spring is significantly linked to the mother's age, education, marital status and whether or not they're a smoker.

The study also found that were it possible to pay to guarantee a spring birth, on average a married woman aged between 20-45 would be willing to part with $877 USD to achieve it.

"Our work has discovered that there really is a desire to give birth in the spring in the US," said Professor Sonia Oreffice, who is a Professor of Economics. "This is often to do with the health of mom and baby because spring and summer are the furthest away from the peak of influenza cases and other germs.

"Knowing parents are making these choices for their first child, coupled with the fact that overall the most prevalent birth season is summer, helps policy-makers to better design policies targeting job flexibility, parenthood and child health and development."

The research was also carried out by Damian Clarke, Associate Professor, Universidad de Santiago de Chile & IZA and Professor Climent Quintana-Domeque of the University of Exeter, using data from US birth certificates, US Census data and a series of surveys with mothers. It specifically looked at the choices made around when to have a first baby, because there is often a far wider range of factors which influence parents' decision making when considering subsequent children.

"We also found that women in certain occupations -- teachers, library workers and those in the training sector were more likely to aim for a spring baby," added Professor Oreffice. "We believe this is because women are trying to link their summer vacation to their short US maternity leave in order to spend more time with their baby."

Unmarried mothers who had not listed the father's name on their child's birth certificate did not show any of the above patterns; reflecting that these pregnancies are the most likely to be unplanned. The same was true for those moms who had used Assisted Reproductive Technology (ART) such as IVF, to conceive. The researchers also noted a drop in the number of December conceptions for ART births in both younger and older mothers, suggesting a link with the fertility clinics' Christmas closures.