To study the effect of different types of textiles on conception. A total of 35 female dogs were divided into five equal groups: four test and one control. Each of the four test groups was dressed in one type of textile underpants made of either 100% polyester, 50/50% polyester-cotton mix, 100% cotton, or 100% wool. The pants were worn for 12 months. The dogs were followed during this period and for 6 months after removal of the pants by measuring the serum oestradiol 17beta and progesterone and by mating. Electrostatic potentials were also measured on the textile-covered skin. Eight bitches wearing polyester-containing textile showed diminished serum progesterone in the oestrus of the oestrous cycle, and did not conceive on mating or insemination. Five months after pants had been removed, serum progesterone of the eight dogs had normalised, and they conceived. Electrostatic potentials were detected on the skin of all dogs dressed in polyester-containing textile. The low serum progesterone and non-conception of the eight dogs could point to anovulation and failure of luteinisation. It is suggested that the electrostatic potentials detected on the skin create an 'electrostatic field' that inhibits the ovarian function. However, the effect proved to be reversible.