IStock Photo 9571556 © susaro

“You get what you get and you don’t get upset.” This paean to fairness echoes daily in preschool classrooms. Until recently, expectant parents hoping their incubating baby was a particular gender had no choice but to follow the same advice. In fact, those hoping for a boy have a slight edge; the odds that a newborn is male are 1 in 1.95, or about 51%. With modern ultrasound technology, parents-to-be don’t have to wait much longer than 18 weeks into the pregnancy to find out what color to paint the nursery, but some determined couples attempt to swing the odds on pink versus blue even before conceiving.

Dr. Landrum Shettles, a Columbia Presbyterian infertility specialist, first published his theory of “sex selection” in 1970. The Shettles method consists of timing intercourse to allow sperm carrying the desired sex chromosome to have the greatest chance of fertilization. In theory, the faster, less hardy, Y-chromosome-carrying “male sperm” need to arrive close to the mother’s ovulation date to succeed, while slower but enduring female sperm should make the trip earlier. Shettles claims a success rate of “75% or better for those seeking girls and 80 percent for those seeking boys,” but dissention remains—other researchers have been unable to substantiate a link between intercourse timing and resultant gender.

Research notwithstanding, a cottage industry has sprung up to help those who are willing to take more involved steps to influence the odds that their intended Little Mikey does not turn out to be a Michelle. Several clinics offer pre-implantation genetic diagnosis, in which lab-fertilized embryos are screened for the desired gender (along with genetic diseases) prior to implantation. For those on a budget, home kits like the GenSelect are available online, complete with ovulation predictors, gender-coded vitamins, and “vaginal environment adjustment aids.” Families that fail to achieve their claimed 96% success rate can apply for a money back guarantee on the $199 per month price, which at least will go a long way toward a fresh coat of paint for the nursery.