How many trimesters in pregnancy what are the causes of prolonged labour. Trimester means a 3 month period.

Q.8. How many trimesters in pregnancy what are the causes of prolonged labour.
Trimester means a 3 month period.
First trimester--> The first three months (12 weeks) of pregnancy second trimester--> The middle 3 months (13 to 24 weeks) of pregnancy.
Third trimester--> The third and final 3 months (25 weeds to delivery) of pregnancy.
Causes of prolonged laboun-->
1. Cephalopelvic disproportion CPD it is the most important cause of prolonged labour the causes of cephalopelvic disproportion one:
i. Fetal-->
Malpositions
Malformation (eg. hydrocephaly)
Maerosomia of a large baby
ii. Maternal-->
Contracted pelvis
iii. A combination of maternal and fetal factors.
2. Abnormalities which can cause prolonged labour in the absence of CPD are:-
i. Fetal malprestation: Brow, shoulder, face of breech.
ii. Maternal abnormalities-->
Pelvic tumors
Stenos is or scarring of the cervix
Septae of stenosis of the vagina.
Primary uterine dysfunction (i.e. uterine dysfunction of inertia which is not secondary to disproportion.