A woman, aged 40, primigravida, with infertility in the medical history, on the 42-43 week of pregnancy. Labour activity is weak. Longitudinal presentation of the fetus, I position, anterior position. The head of the fetus is engaged to pelvic inlet. Fetus heart rate is 140 bmp, rhythmic, muffled. Cervix dilation is 4 cm. On amnioscopy: greenish colour of amniotic fluid and fetal membranes. Cranial bones are dense, cranial sutures and small fontanel are diminished. What should be tactics of delivery?