The Shettles Method: Evidence & Limitations
The Shettles Method is a natural conception theory that suggests the timing of intercourse around ovulation may influence whether a baby is conceived male or female.
What is the Shettles Method?
The theory proposes that Y-chromosome-bearing sperm are faster but less resilient, while X-chromosome-bearing sperm are slower but may survive for longer.
Based on this theory, intercourse very close to ovulation has traditionally been suggested for conceiving a boy, while intercourse several days before ovulation has been suggested for conceiving a girl.
What does the scientific evidence say?
Although the Shettles Method has been popular for decades, current scientific evidence does not demonstrate that timing intercourse around ovulation can reliably influence a baby's sex.
A major prospective study published in The New England Journal of Medicine examined intercourse timing in relation to ovulation and subsequent pregnancies. Male and female births showed similar patterns of intercourse around ovulation.
The researchers concluded that, for practical purposes, intercourse timing in relation to ovulation did not influence the sex of the baby.
Timing still matters for conception
Ovulation tracking can still be useful when trying to conceive. Understanding your fertile window can help identify the part of your cycle when pregnancy is more likely.
Cycle tracking can therefore help you understand your body and recognise fertility patterns, but it should not be considered a reliable method for choosing a baby's sex.
The Genesyx approach
Genesyx presents information about the Shettles Method for educational and cycle-awareness purposes. We believe it is important to distinguish between historical fertility theories and scientifically established evidence.
Current research does not support guaranteeing or reliably predicting a baby's sex based on intercourse timing, cycle tracking or the Shettles Method.