If the zygote has not implanted by day ten, implantation becomes increasingly unlikely in subsequent days.A chemical pregnancy is a pregnancy that was detected by testing but ends in miscarriage before or around the time of the next expected period.Chromosomal abnormalities are found in more than half of embryos miscarried in the first 13 weeks. Half of embryonic miscarriages (25% of all miscarriages) have an aneuploidy (abnormal number of chromosomes). Common chromosome abnormalities found in miscarriages include an autosomal trisomy (22–32%), monosomy X (5–20%), triploidy (6–8%), tetraploidy (2–4%), or other structural chromosomal abnormalities (2%). Genetic problems are more likely to occur with older parents; this may account for the higher rates observed in older women.Luteal phase progesterone deficiency may or may not be a contributing factor to miscarriage. Second and third trimesters
Second trimester losses may be due to maternal factors such as uterine malformation, growths in the uterus (fibroids), or cervical problems. These conditions also may contribute to premature birth. Unlike first-trimester miscarriages, second-trimester miscarriages are less likely to be caused by a genetic abnormality; chromosomal aberrations are found in a third of cases. Infection during the third trimester can cause a miscarriage. Age
The age of the pregnant woman is a significant risk factor. Miscarriage rates increase steadily with age, with more substantial increases after age 35. In those under the age of 35 the risk is about 10% while it is about 45% in those over the age of 40. Risk begins to increase around the age of 30.
Most early miscarriages will complete on their own; in other cases, medication treatment or aspiration of the products of conception can be used to remove remaining tissue. While bed rest has been advocated to prevent miscarriage, this has not been found to be of benefit. Those who are experiencing or who have experienced a miscarriage benefit from the use of careful medical language. Significant distress can often be managed by the ability of the clinician to clearly explain terms without suggesting that the woman or couple are somehow to blame.Evidence to support Rho(D) immune globulin after a spontaneous miscarriage is unclear. In the UK, Rho(D) immune globulin is recommended in Rh-negative women after 12 weeks gestational age and before 12 weeks gestational age in those who need surgery or medication to complete the miscarriage. Methods
No treatment is necessary for a diagnosis of complete miscarriage (so long as ectopic pregnancy is ruled out). In cases of an incomplete miscarriage, empty sac, or missed abortion there are three treatment options: watchful waiting, medical management, and surgical treatment. With no treatment (watchful waiting), most miscarriages (65–80%) will pass naturally within two to six weeks. This treatment avoids the possible side effects and complications of medications and surgery, but increases the risk of mild bleeding, need for unplanned surgical treatment, and incomplete miscarriage. Medical treatment usually consists of using misoprostol (a prostaglandin) alone or in combination with mifepristone pre-treatment. These medications help the uterus to contract and expel the remaining tissue out of the body.