Placenta previa

Overview:

Placenta previa are the most common disease of antepartum haemorrhage. Under normal circumstances the placenta attached to the body of the posterior wall of the uterus or anterior wall. Placenta previa or placenta plant in the lower uterine segment or coverage in the cervix is located inside the mouth on fetal presentation prior to the performance of placenta previa are at mid-pregnancy to late pregnancy can be serious until the minor vaginal bleeding; are serious complications of treatment in pregnancy incorrectly, you may endanger the safety of mothers and infants. Therefore, it is the cause of maternal mortality and perinatal death of one of the important reasons.

Epidemiology:

The incidence of placenta previa at various historical periods and all over the living customs are different, mainly with women's age, number of pregnancy and childbirth the way, in recent years found that smoking history is also associated. In foreign countries, its incidence at 0.20% ~ 1.0%, internal reports are ~ 0.24% at 1.57%. In the literature, in recent years, the history of previous cesarean section for placenta previa is to study the impact of one of the hot issues and the incidence of placenta previa following relevant factors.

1. The age of age the incidence of placenta previa increased, Ananth et al (1996) 1980 ~ 1993 in Canada, Nova - Sri Lanka all province of 123,941 births vigia analysis, age over 40 years of age pregnancy the incidence of placenta previa 20 years of age than 9 times the high incidence of older high, of course, with the prolific times and other relevant history of abnormal pregnancy.

2. Parity and high parity births and high-yield times the incidence of placenta previa has increased. Abu-Heija, etc. (1999) since April 16, 1994 to May 1997 15 of 95 cases of placenta previa and delivery of 190 cases of the control group over the same period of comparison, placenta previa easily happen in the parity> 4 (P > 0.002), the middle class times> 3 (P <0.01), other similar reports.

3. Spontaneous abortion and spontaneous abortion and induced abortion history of placenta previa are influential. In addition to the two pregnancy outside the plant itself is still possible because of impaired endometrial curettage so. Ananth et al (1997) The causes of placenta previa literature analysis, has four literature 170,640 times through the pregnancy, there is the history of abortion and induced abortion history of placenta previa happen for all of the relative risk of 1.6 (95% CI 1.0 to 2.6) and 1.7 (95% CI 1.0 ~ 2.9), other literature reports of release.

4. The history of previous cesarean section cesarean section rate increased in recent years, and doctors often follow a "one-section, sub-sub-section" of the creed, so many times there is a lot of pregnant women undergoing cesarean section. Ananth et al (1997) at 36 English literature related to cesarean section with placenta previa analysis of the relationship between one mentioned pregnancy 3,600,000 times the previous cesarean section who have happened the next pregnancy the risk of placenta previa increased 2.6 times (95% CI 2.3 to 3.0), article 4 of the detailed information has 170,640 times as the base material of pregnancy showed that: there was one time of cesarean section history, the occurrence of the risk of placenta previa of 4.5 (95% letter limit 3.6 ~ 5.5), have 2 times the history of cesarean section were 7.4 (95% CI 7.1 ~ 7.7), there is 3 times the history of cesarean section were 6.5 (95% CI 3.6 ~ 11.6), 4 times or 4 times more than the history of cesarean section were 44.9 (95% CI 13.5 ~ 149.5). Materials section of this fully illustrates the more the number of placenta previa happen the greater the likelihood Hendricks et al (1999) also reported at 1993 ~ 1997 16,169 times in 164 pregnancy placenta previa in the history of previous cesarean section 1 times 2 or 3 times or more happen in this pregnancy placenta previa will increase 2.2 times (95% CI 1.4 ~ 3.4), 4.1-fold (95% CI 1.9 ~ 8.8) and 22.4-fold (95% CI limited to 6.4 ~ 78.3), Lydon-Rochelle et al (2001) in 1987 to 1996 in 96,975 births found that the incidence of placenta previa to 5.2 ‰ but after the 1st section 2nd significantly the incidence of placenta previa rise (CR for 1.4,95% CI 1.1 ~ 1.6). Similar to other literature results; it where there is history of previous cesarean section should also be noted that this happened to increase the possibility of placenta previa. And the future should have a good indication of cesarean section, especially for the first time, decide who should pay even more attention cesarean section.

5. There is smoking, cocaine and other drugs during the 20 history of the 20th century, the smoking will have noted the incidence of placenta previa increased in recent years, smoking and placenta previa on the relationship between the researchers and the West more National Drug users day by scholars has also paid attention to its relationship with placenta previa. Handler et al (1994) to the University of Illinois Materials hospital from 1988 to 1989 of the 304 cases of placenta previa and have strict matching control group of 2732 cases for analysis, both the smoking rates of 28.6% and 20.3%, and its placenta previa happen ratio of odd-numbered (Odd Ratio, OR) for 1.7,95% CI 1.3 ~ 2.2. Rates of cocaine use was 8.2% and 3.6%, OR for 2.5,95% CI 1.5 ~ 4.0Ananth was also reported, such as at January 1, 1986 to December 31, 1993 the 87,183 th pregnancy smoking during pregnancy smoke compared with non-smokers, the relative risk of 1.36 (95% CI 1.04 ~ 1.79), indicating that it has weak correlation. Chelomow et al (1996) also reported at New England Medical Center Hospital in Cambridge, from June 1992 to March 1994 of 32 cases of placenta previa and its pre-order for 3 cases of contrast, the OR for smokers may 3.0,95% letter is limited to 1.1 ~ 8.6Castles et al (1999) to 5 of pregnancy-related effects of smoking during pregnancy to do meta-analysis of literature, placenta previa pooled ratio of 1.58 over the literature that smoking does increase the risk of placenta previa , but every day the amount of smoking on pregnancy has much to be further studied. Macones, etc. (1997) of 40 cases of confirmed delivery for placenta previa in 80 cases of those without placenta previa pregnancy for the control study of cocaine on the impact of placenta previa, the use of cocaine and the patients who have a history of the urine-positive for based on the results of the use of cocaine from the risk of placenta previa increased, the OR for 4.39,95% CI 1.17 ~ 16.4. Recently, there are those who happen to use marijuana increase the risk of placenta previa report. Therefore, the problem of drug addiction are also risk factors for placenta previa, one must be vigilant

6. Where the placenta, such as twin pregnancy increased, such as twin placenta, etc. The incidence of placenta previa has increased.

7. Demissie, such as fetal gender (1999) reported that placenta previa at the sex, the male-dominated, the authors of New Jersey hospitals from 1989 to 1992 a total of 445,270 times without a single placenta previa births and 7 have been published literature a total of 2685 cases of placenta praevia the male fetus, women do not were compared, the former male, female ratio was 1.05, while the latter ratio is 1.19, that is significant for men than women, the differences were statistically significant (P < 0.001), that is, placenta previa pregnancy of male births than the average singleton pregnancies increase by 14%. The article did not analyze the placental weight, the current performance of the kinds of reasons there is no proper explanation.