Perturbations in finger length and digit ratio (2D:4D) in ICSI children

Abstract

Intracytoplasmic sperm injection (ICSI) is used to overcome severe male-factor infertility where males are azoospermic or have poor quality spermatozoa. Perturbations of finger length (short finger length adjusted for height and high second-to-fourth digit ratio, or 2D:4D) have been described in azoospermic men and men who are rated as having low sexual attractiveness. High 2D:4D has been described in women with high fecundity. Such perturbations may be related to endocrine regulation of some homeobox genes. This study compared finger length and 2D:4D in singleton children conceived with the help of ICSI with those in naturally conceived singleton controls. Participants were recruited from centres in Germany and the UK. There were 211 children conceived by ICSI and 195 controls. Finger length was measured from photocopies of the ventral surface of the hand. In comparison to controls, male and female ICSI children had shorter fingers after correction for height. There was also evidence that female ICSI children may have higher 2D:4D than female controls. Perturbations in finger length in ICSI children may be inherited from their fathers and, in the case of boys, could be associated with lower fertility and reduced sexual attractiveness. For ICSI females, increased 2D:4D may be associated with increased fertility.

Second to fourth digit ratios, male genital development and reproductive health: a clinical study among fertile men and testis cancer patients

“…Wood et al. (2003) have reported that testicular sperm retrieval in azoospermic men was more successful in men with low 2D : 4D than in men with high 2D : 4D (finger length was measured directly in this study) and, recently, Sutcliffe et al. (2010) have reported that children from intracytoplasmic sperm injection had shorter fingers and tended to have higher 2D : 4D (females only) compared with controls.…”

Digit ratio (2D:4D) in Klinefelter's syndrome

“…Sutcliffe et al (2010) compared finger length relative to height in 211 children conceived by ICSI and 195 control children. They reported that the former had shorter fingers after correction for height compared with the control group.…”

“…Age Mean finger length -To consider finger lengths between individuals (rather than relative differences in finger length within individuals) we summed across all four fingers and obtained the mean finger length per individual (Sutcliffe et al, 2010 …”

“…We calculated the mean of finger length summed across all four fingers for each individual (see Sutcliffe et al, 2010) and compared these means across male patients that were older than 17 years. For KS men vs. father pairs (n = 7) we found that the former had shorter fingers than the latter (paired t-test, x À y = 4.57 mm, t = 3.58, p = 0.009, d = 0.41).…”

Outcomes for offspring of men having ICSI for male factor infertility

“…A study was designed to look for transmitted fertility problems in ICSI-conceived children who may show perturbations in finger development, thus reflecting the suggested genetic link between digit length and azoospermia. 54 Digit measures were taken on 211 ICSI and 195 controls, and indeed shorter finger lengths than expected for their height were seen in both females and males conceived by ICSI. The importance of this in terms of fertility potential is not known.…”