Science News
from research organizations

Pinpointing When A Fetus Develops Male Genitalia, And Birth Defects Related To Male Sex Organs

Date:
March 18, 2008
Source:
Journal of Clinical Investigation
Summary:
New data has indicated that in rats, "male" hormones drive the decision to become a male during a window of time before male genitalia develop, and that blocking "male" hormones during this time caused male genitalia birth defects. These defects were associated with a decreased ano-genital distance, leading to the suggestion that measuring human neonatal AGD could provide a noninvasive method to predict those at risk of developing male genitalia birth defects.
Share:
       
FULL STORY

New data has indicated that in rats, "male" hormones drive the decision to become a male during a window of time before male genitalia develop, and that blocking "male" hormones during this time caused male genitalia birth defects.

These defects were associated with a decreased ano-genital distance, leading to the suggestion that measuring human neonatal AGD could provide a noninvasive method to predict those at risk of developing male genitalia birth defects.

Cryptorchidism, the absence in the scrotum of one or both testes (usually because of the failure of the testis to descend), and hypospadias, the abnormal positioning of the opening of the urethra, are common birth defects of the male genitalia and are risk factors for the adult-onset disorders of low sperm count and testicular cancer.

Although it is known that "male" hormones, in particular testosterone, drive the pathway that leads to a fetus becoming a male (including the development of the male genitalia), the cause of defects in this process is unclear.

However, Michelle Welsh and colleagues at The Queen's Medical Research Institute, United Kingdom, have now determined that in rats, the "male" hormones drive the decision to become a male during a window of time before the male genitalia develop.

During this period of time, blocking the action of "male" hormones led to cryptorchidism and hypospadias, and these defects were associated with a decrease in the distance between the anus and the genitalia (AGD).

Based on the timing in rats, the authors believe that the equivalent window in humans is likely to be 8--14 weeks of gestation.

Furthermore, they suggest that measuring AGD in neonatal humans could provide a noninvasive method to predict neonatal and adult reproductive disorders (cryptorchidism and hypospadias, and low sperm count and testicular cancer, respectively).

Journal reference: Identification in rats of a programming window for reproductive tract masculinization, disruption of which leads to hypospadias and cryptorchidism. Journal of Clinical Investigation. March 12, 2008


Story Source:

The above post is reprinted from materials provided by Journal of Clinical Investigation. Note: Materials may be edited for content and length.


Cite This Page:

Journal of Clinical Investigation. "Pinpointing When A Fetus Develops Male Genitalia, And Birth Defects Related To Male Sex Organs." ScienceDaily. ScienceDaily, 18 March 2008. <www.sciencedaily.com/releases/2008/03/080313185758.htm>.
Journal of Clinical Investigation. (2008, March 18). Pinpointing When A Fetus Develops Male Genitalia, And Birth Defects Related To Male Sex Organs. ScienceDaily. Retrieved July 3, 2015 from www.sciencedaily.com/releases/2008/03/080313185758.htm
Journal of Clinical Investigation. "Pinpointing When A Fetus Develops Male Genitalia, And Birth Defects Related To Male Sex Organs." ScienceDaily. www.sciencedaily.com/releases/2008/03/080313185758.htm (accessed July 3, 2015).

Share This Page: