الفهرس 
Introduction and aim of the workOnly 14 pages are availabe for public view
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Abstract
Second trimester or mid-trimester is a period ranging from 14th to 24th weeks of gestation. It is subdivided into an early period between 14th and 20th weeks and a late period between 20th and 24th weeks.
Termination in the second trimester is more risky than during
the first trimester and therefore; the pharmacologic management seems to be an appealing alternative to surgical evacuation. Misoprostol has been widely used in different dosages and routes for second-trimester pregnancy terminations. Doses ranging from 200 to 800 µg at intervals ranging from 3 to 12 hours have been described . High doses at short intervals have been linked to higher percentage of side effects misoprostol a synthetic prostagladinE1analogue is commonly used for medical abortion because of its uterotonic and cervical softening effect . the latter effect is more likely to be due to the direct effect of misprostol on extracellular matrix metabolis . misoprostol induces severl enzymatic reaction that promote collagen fiber breakdown and rearrangement of collagen fibers in cervical softening and dilatation .
Foley’s catheter insertion generates pressure and tension on the cervix and lower uterine segment by direct effect . It also provides seperation of chorionic membrane from decidu indirectly . cervical ripening is ensured via realese of endogenous prostagladins and other oxytocin mediators as a result of direct and indirect effect of Foley’s catheterization.
Letrozole is a third-generation aromatase inhibitor which is used to treat estrogen-dependent breast cancer. Aromatase, an enzyme of the cytochrome P450 superfamily and the product of CY195 gene, is expressed in the placenta and ovarian granulosa cells. Letrozole plays a role in medical termination through its principal effect on oestrodial synthesis, which is an important factor in the maintenance of early pregnancy. It is postulated that by combining both letrozole together with misoprostol, a synergistic effect will be exerted as the depleted estrogen and progesterone level will be insufficient to support the pregnancy and the uterotonic effect of misoprostol will hasten the abortion process, hence improving the complete abortion.