It sounds like a strange question, until you remember that, of course, many mothers do pick their child’s birthday. It happens with elective delivery, when you schedule an induced vaginal birth or a cesarean section. We’re talking within a week or two of your due date, to be sure. You can’t choose the January 15th if you’re due in November, but you’ll often have a say over Monday versus Tuesday of next week.
That part is not surprising, but here comes the next part. At some level, the mother may exert some influence on the timing of her baby’s birth. It’s not reliable and not conscious, but your mind affects your physiology every day by intervening with stress hormone levels and other measurable factors. This brings us to a study that was conducted earlier this decade, back in 2011. It was just one study involving a small number of mothers, so we do need to take the results with a grain of salt. That said, it was a study at the Yale University School of Public Health —a fairly respectable institution— and what it found was a slight increase in spontaneous (meaning not induced, not C-section) births on Valentine’s Day (3.6 percent above normal) and a decrease births on Halloween (5.3 percent below normal).
The Yale researchers concluded that mothers might be able to influence birth timing, motivated by negative symbolism (Halloween) and positive symbolism (Valentine’s Day). It’s a curiosity, but for more perspective we should consider that birth rates have been noted to increase on particularly stressful days, for instance the day that US president John F. Kennedy was assassinated. The idea is that women who were close enough to term were shocked into labor, and that others delivered prematurely. Similarly, the attacks of September 11, 2001 have been linked to a spike in premature births.
It’s all fairly plausible, but if it’s true then we might expect the spontaneous birthrate to increase on a negative symbolism day such as Halloween, not decrease. This brings up another matter that requires us to put on our skeptic hats when it comes to the influence of Halloween and Valentine’s Day. Yes, Halloween is full of negative symbolism but, for most people in Western culture, especially those with young children, it is about candy and games. Meanwhile, there are other days characterized by negativity that are felt more widely, September 11th being one example. You also may have your own day of the year that is disturbing for one reason or another, but that may not come to mind, consciously or unconsciously, as you prepare to deliver a child.
So, yes, a mother’s feelings may possibly exert some influence on birth, lightly delaying or encouraging the onset of labor, but this must be weighed against a multitude of other factors. And so, let’s not get too excited when we see studies like the one from Yale.