孕妇阴道流血的病因及诊治Word文档格式.docx

1、Deputy EditorVanessa A Barss, MDDisclosuresAll topics are updated as new evidence becomes available and our peer review process is complete.Literature review current through: Mar 2014. | This topic last updated: 一月 6, 2014. INTRODUCTIONVaginal bleeding is a common event at all stages of pregnancy. T

2、he source is virtually always maternal, rather than fetal. Bleeding may result from disruption of blood vessels in the decidua （ie, pregnancy endometrium） or from discrete cervical or vaginal lesions. The clinician typically makes a provisional clinical diagnosis based upon the patients gestational

3、age and the character of her bleeding （light or heavy, associated with pain or painless, intermittent or constant）. Laboratory and imaging tests are then used to confirm or revise the initial diagnosis.An overview of the etiology and evaluation of vaginal bleeding in pregnant women will be reviewed

4、here. Specific causes of bleeding and their management are discussed in detail separately. （See individual topic reviews on each subject）.FIRST TRIMESTER BLEEDINGOverviewVaginal bleeding is common in the first trimester, occurring in 20 to 40 percent of pregnant women. It may be any combination of l

5、ight or heavy, intermittent or constant, painless or painful. The four major sources of bleeding in early pregnancy are:Ectopic pregnancyMiscarriage （threatened, inevitable, incomplete, complete）Implantation of the pregnancyCervical, vaginal, or uterine pathology （eg, polyps, inflammation/infection,

6、 trophoblastic disease）Bleeding related to miscarriage is the most common cause of first trimester bleeding （prevalence of miscarriage 15 to 20 percent of pregnancies）. Although bleeding may be heavy, only about 1 percent of expectantly managed women require blood transfusion 1. Ectopic pregnancy is

7、 much less common （prevalence of ectopic pregnancy: 2 percent of pregnancies）, but the most serious etiology of first trimester bleeding as rupture of the extrauterine pregnancy is a life-threatening complication; therefore, this diagnosis must be excluded in every pregnant woman with bleeding.Evalu

8、ationThe exact etiology of uterine bleeding in the first trimester often cannot be determined; the goal of the evaluation is to make a definitive diagnosis when possible and exclude the presence of serious pathology in the remaining cases （algorithm 1）. Ectopic pregnancy is particularly important to

9、 exclude since it can be life-threatening. Thus, the first step in evaluation is to determine whether the patient has had an ultrasound examination, as well as the results of the test. Prior documentation that the pregnancy is in the normal intrauterine location immediately narrows the differential

10、diagnosis, although the possibility that the prior ultrasound may have missed a heterotopic pregnancy （ie, one intrauterine and one extrauterine pregnancy） or a cornual （interstitial） ectopic pregnancy should always be considered. If in doubt, consider having an experienced sonographer repeat the ul

11、trasound examination. It is also important to determine whether the patient is hemodynamically unstable so that supportive measures and treatment can be rapidly initiated.HistoryThe extent of bleeding should be determined: is the woman passing blood clots or is the blood soaking through her clothes?

12、 Does she feel lightheaded? Does she have significant pelvic pain or cramping? Has she passed any tissue? If she answers yes to these questions, then ectopic pregnancy and miscarriage are much more likely diagnoses than implantation bleeding or cervicovaginal disease （eg, polyps, cervicitis, cancer）

13、. On the other hand, it is important to remember that the presence of only light, intermittent, painless bleeding does not exclude the possibility of a life-threatening underlying disorder, such as ectopic pregnancy.What is the patients medical history? A past history of ectopic pregnancy or risk fa

14、ctors for ectopic pregnancy （eg, history of pelvic inflammatory disease, presence of an intrauterine contraceptive device, adnexal surgery） increases the probability of this disorder. （See Incidence, risk factors, and pathology of ectopic pregnancy.）A history of two or more consecutive miscarriages

15、or a condition associated with miscarriage （eg, parental chromosomal translocation, maternal antiphospholipid syndrome, uterine anomaly） suggests bleeding may be related to impending pregnancy loss. （See Spontaneous abortion: Risk factors, etiology, clinical manifestations, and diagnostic evaluation

16、Use of assisted reproductive techniques to achieve conception increases the risk of heterotopic pregnancy. （See Abdominal pregnancy, cesarean scar pregnancy, and heterotopic pregnancyPhysical examinationOrthostatic changes in blood pressure or pulse are indicative of severe blood loss requiring supp

17、ortive care and rapid treatment. However, occasionally, young pregnant women can have massive bleeding without demonstrating tachycardia or hypotension. Care should be taken to avoid unnecessary delay in the management of such patients.Any tissue the patient has passed should be examined. Patients m

18、ay mistake blood clot for the products of conception. If the tissue represents a partial or complete miscarriage, the fetal membranes, fronds indicative of placental villi, or an intact fetus should be visible upon careful examination. Visualization of villi can be facilitated by floating the produc

19、ts of conception in water （picture 1A-B）.The patients abdomen should be examined before performing an internal examination. It is best to begin by examining the quadrant where the patient is experiencing the least pain. Gentle percussion is preferred to deep palpation since it causes less pain and g

20、uarding. Midline pain is more consistent with miscarriage, while lateral pain is more consistent with ectopic pregnancy. Nongynecologic causes of pain are also to be considered. （See Approach to abdominal pain and the acute abdomen in pregnant and postpartum womenThe clinician should determine wheth

21、er uterine size is appropriate for the estimated gestational age. The size - gestational age correlation is learned by experience and is often described in terms of fruit （eg, 6- to 8-week size = small pear, 8- to 10-week size = orange, 10- to 12-week size = grapefruit）. The uterus remains a pelvic

22、organ until approximately 12 weeks of gestation, when it becomes sufficiently large to palpate transabdominally just above the symphysis pubis. The normal uterus is nontender, smooth, and firm.If the pregnancy is at or beyond 10 to 12 weeks of gestation, a handheld Doppler device can be used to chec

23、k the fetal heart beat. The fetal heart rate usually can be easily distinguished from the maternal heart rate since the fetal heart rate is typically in the range of 110 to 160 beats per minute; however, the difference in maternal and fetal heart rates can be minimal if the mother has tachycardia 2.

24、 Doppler confirmation of fetal cardiac activity is reassuring, as it indicates bleeding is not related to fetal demise and unlikely to be related to an ectopic pregnancy. On the other hand, loss of a previously detected fetal heart beat should raise suspicion that fetal demise has occurred. However,

25、 inability to detect fetal heart motion by Doppler, particularly in the first trimester, may merely reflect the difficulty in blindly finding the location of the tiny fetal heart.After the abdominal examination, the patient is placed in the lithotomy position. The external genitalia are examined to

26、assess the volume and source of bleeding and then a speculum is inserted into the vagina. If blood clots, products of conception, or both are present, they can be removed with gauze sponges on a sponge forceps. This tissue is examined as described above and, by convention, sent for pathologic examin

27、ation to confirm the presence of products of conception and to exclude gestational trophoblastic disease. The utility of routine histopathological examination is questionable, as it rarely suggests the underlying cause of the pregnancy failure or establishes a diagnosis of gestational trophoblastic

28、disease 3. However, pathologists can sometimes diagnose entities that are the probable cause of the loss or associated with recurrence. These include massive chronic intervillositis, massive intervillous fibrin deposition, maternal vasculitis, findings suggestive of some chromosomal anomalies （eg, t

29、riploidy, some trisomies）, and septic abortion.Speculum examination may reveal a source of bleeding unrelated to pregnancy; in such cases, further evaluation depends upon the nature of the abnormality:Vaginal laceration （see Evaluation and management of lower genital tract trauma in women）Vaginal ne

30、oplasm （see Vaginal cancerVaginal warts （see Condylomata acuminata （anogenital warts）Vaginal discharge （see Approach to women with symptoms of vaginitisCervical polyps, fibroids, ectropion （see Congenital cervical anomalies and benign cervical lesionsMucopurulent cervical discharge or friability at

31、the endocervical os （see Acute cervicitisCervical neoplasm （see Invasive cervical cancer: Epidemiology, risk factors, clinical manifestations, and diagnosisVisualization of the cervical os helps to distinguish between a threatened and an impending/inevitable miscarriage. Direct visualization of the

32、gestational sac in a dilated cervix is generally sufficient to diagnose an impending/inevitable miscarriage clinically. The cervix will usually also be open with an incomplete or a recent complete miscarriage. An open internal cervical os will admit a small instrument, such as a cotton-tipped swab. Ultrasound can provide additional information in these cases, such as w