Insulin-like growth factor-1 gene splice variants as markers of muscle damage in levator ani muscle after the first vaginal delivery.
OBJECTIVE
Studies in animals and human muscle have demonstrated differential splicing of the insulin-like growth factor-1 gene in response to mechanical strain and damage. We conducted a study on the expression of insulin-like growth factor-1 splice variants in the levator ani muscle after the first vaginal delivery.


METHODS
Ten women were recruited after the first vaginal delivery. Biopsy specimens were taken vaginally of the pubovisceral component of the levator ani muscle. Five nonpregnant women were recruited as control subjects. Samples were processed with real-time quantitative polymerase chain reaction, with specific primers for the insulin-like growth factor-1 splice variants.


RESULTS
Insulin-like growth factor splice variants mechano growth factor and insulin-like growth factor-1Ea were significantly up-regulated (100- and 1000-fold) in the delivery population, compared with control subjects (P=.012 and .04, respectively). Statistical analysis indicated a correlation between the expression of the insulin-like growth factor-1 splice variants and the length of the second stage.


CONCLUSIONS
These results show that damaged levator ani muscle results from stretch and overload after the first vaginal delivery.
Cortes
Eduardo
E
Pelvic Floor Unit, Royal Free Hospital and Department of Obstetrics and Gynaecology, Royal Free and University College Medical School, London, UK. e.cortes@medsch.ucl.ac.uk
te Fong
Lan F Wong
LF
Hameed
Mahjabeen
M
Harridge
Stephen
S
Maclean
Allan
A
Yang
Shi Yu
SY
Reid
Wendy M
WM
Goldspink
Geoffrey
G
D000328:Adult; D001004:Anus Diseases / Q000378:metabolism* / Q000473:pathology; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D003199:Computer Systems; D004274:DNA, Recombinant; D036861:Delivery, Obstetric; D005260:Female; D014644:Genetic Variation; D006801:Humans; D007158:Immunologic Techniques; D007334:Insulin-Like Growth Factor I / Q000235:genetics* / Q000378:metabolism*; D009135:Muscular Diseases / Q000378:metabolism* / Q000473:pathology; D010298:Parity; D049590:Postpartum Period / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013194:Staining and Labeling; D014621:Vagina
D015415:Biomarkers; D004274:DNA, Recombinant; D007334:Insulin-Like Growth Factor I