placenta previa int III
because the uterine blood supply is less in the _____ segment, the placenta tends to grow larger than it would normally, leaving a larger denuded surface area when it is removed.
After birth, most women inspect their child carefully. A woman may worry that because of the problem with placental implantation, there might be something wrong with her child. During the postpartum period, she needs adequate time with her child to be certain he or she is all right. Any woman who has had a placenta previa is more prone than normal to postpartum hemorrhage because the placental site is in the lower uterine segment, which does not contract as efficiently as the upper segment. Also, because the uterine blood supply is less in the lower segment, the placenta tends to grow larger than it would normally, leaving a larger denuded surface area when it is removed. As a second complication, a woman is more likely to develop endometritis because the placental site is close to the cervix, the portal of entry for pathogens.
Have ____ equipment available in case the fetal heart sounds indicate fetal distress, such as bradycardia or tachycardia, late deceleration, or variable decelerations.
An abdominal examination may reveal that the fetal head is not engaged because of the interfering placenta. However,this finding gives little indication of how much of the placenta is obscuring the os and preventing the head from engaging. Anticipate the order for a transvaginal ultrasound to detect this. If no previa is detected, the physician may attempt a careful speculum examination of the vagina and cervix to rule out another cause for bleeding, such as ruptured varices or cervical trauma. Vaginal examinations (actual investigation of dilatation) to determine whether placenta previa exists are done in an operating room or a fully equipped birthing room so that if hemorrhage does occur with the manipulation, an immediate cesarean birth can be carried out to remove the child and the bleeding placenta and contract the uterus. Have oxygen equipment available in case the fetal heart sounds indicate fetal distress, such as bradycardia or tachycardia, late deceleration, or variable decelerations.
The bleeding that occurs is usually ____, ______, _____ ____, and sudden enough to frighten a woman. It is not associated with increased activity or participation in sports.
Assessment Because routine ultrasounds are performed so frequently dur-ing pregnancy, most instances of placenta previa are diagnosed today before any symptoms occur. Although many low-lying placentas detected on early ultrasounds migrate upward to an on cervical position, the condition is explained to a woman and she is cautioned to avoid coitus, to get adequate rest, and to call her health care provider at any sign of vaginal bleeding. Bleeding with placenta previa begins when the lower uterine segment starts to differentiate from the upper segment late in pregnancy (approximately week 30) and the cervix begins to dilate. The bleeding results from the placenta's inability to stretch to accommodate the differing shape of the lower uterine segment or the cervix. The bleeding that occurs is usually abrupt, painless, bright red, and sudden enough to frighten a woman. It is not associated with increased activity or participation in sports. It may stop as abruptly as it began, so that by the time a woman is seen at the health care site she is no longer bleeding, or it may slow after the initial hemorrhage but continue as continuous spotting.
As soon as the fetus reaches ___ weeks of age (2500 g), an amniocentesis analysis for lung maturity shows a positive result (a favorable lecithin-sphingomyelin ratio), bleeding occurs again, labor begins, or the fetus shows symptoms of distress, the fetus needs to be born
Birth As soon as the fetus reaches 37 weeks of age (2500 g), an amniocentesis analysis for lung maturity shows a positive result (a favorable lecithin-sphingomyelin ratio), bleeding occurs again, labor begins, or the fetus shows symptoms of distress, the fetus needs to be born (Scearce & Uzelac, 2007). On the day of birth, a woman needs a great deal of support. It is one thing to talk about being ready for surgery; it is another to be truly ready. She may be as frightened as she was the evening her bleeding first began. If the pregnancy is past 36weeks at the time of the initial bleeding, a birth decision will generally be made immediately. If the placenta previa isfound to be total, birth through the placenta is impossible and the baby must be born by cesarean birth. If the placenta previais partial, the amount of the blood loss, the condition of the fetus, and a woman's parity will influence the birth decision.With a cesarean birth for placenta previa, although the skin incision is still a transverse (bikini) one, the uterine cut must be made high, possibly vertically above the low implantation site of the placenta. If an ultrasound clearly reveals the placental location, a transverse uterine incision may be possible.
what steroid that hastens fetal lung maturity, maybe prescribed for the mother to encourage the maturity of fetal lungs if the fetus is less than 34 weeks' gestation
Continuing Care Measures. The point at which a diagnosisof placenta previa is made and the age of the gestation dictate the final management. If labor has begun, bleeding is continuing, or the fetus is being compromised (measured by the response of the fetal heart rate to contractions), birth must be accomplished regardless of gestational age. If the bleeding has stopped, the fetal heart sounds are of good quality, maternal vital signs are good, and the fetus is not yet 36 weeks of age, a woman is usually managed by expectant watching. As many as half of all women with bleeding from placenta previa are managed this way.Typically, a woman remains in the hospital on bed rest forclose observation for 48 hours. If the bleeding stops, she can be sent home with a referral for bed rest and home care. Careful assessment of fetal heart sounds is made and laboratory tests,such as hemoglobin or hematocrit, are frequently obtained. Betamethasone, a steroid that hastens fetal lung maturity, maybe prescribed for the mother to encourage the maturity of fetal lungs if the fetus is less than 34 weeks' gestation (Box 21.5).
list some immediate care measures (interventions)
Immediate Care Measures. To ensure an adequate blood supply to a woman and fetus, place the woman immediately on bed rest in a side-lying position. Be sure to assess:•Duration of the pregnancy•Time the bleeding began•Woman's estimation of the amount of blood—ask her to estimate in terms of cups or tablespoons (a cup is 240 mL;a tablespoon is 15 mL)•Whether there was accompanying pain•Color of the blood (red blood indicates bleeding is fresh or is continuing) •What she has done for the bleeding (if she inserted a tam-pon to halt the bleeding, there may be hidden bleeding)•Whether there were prior episodes of bleeding during the pregnancy•Whether she had prior cervical surgery for premature cervical dilatation
what is a good method for weighing perineal pads
Inspect the perineum for bleeding. Estimate the present rate of blood loss. Weighing perineal pads before and after use and calculating the difference by subtraction is a good method to determine vaginal blood loss. An Apt orKleihauer-Betke test (test strip procedures) can be used to de-tect whether the blood is of fetal or maternal origin. Never attempt a pelvic or rectal examination with painless bleeding late in pregnancy because any agitation of the cervix whenthere is a placenta previa may initiate massive hemorrhage, possibly fatal to both mother and child. Obtain baseline vital signs to determine whether symptoms of shock are present. Continue to assess blood pressure every 5 to 15 minutes or continuously with an electronic cuff. Other necessary actions are intravenous fluid therapy using a large-gauge catheter and monitoring urine output frequently, as often as every hour,as an indicator of blood volume adequacy. Attach external monitoring equipment to record fetal heart sounds and uterine contractions. An internal monitor for either fetal or uterine assessment that requires invasion of the cervix, is contraindicated. Hemoglobin, hematocrit, prothrombin time, partial thromboplastin time, fibrinogen, platelet count, type and cross-match, and antibody screen will be assessed to establish baselines, detect a possible clotting disorder, and ready blood for replacement if necessary. Vaginal birth is always safest for an infant. Therefore, it is essential to determine the placenta's location as accurately as possible in the hope that its position will make vaginal birth feasible. If the previa is under 30% by ultrasound, it may be possible for the fetus to be born past it. If over 30%, and the fetus is mature, the safest birth method for both mother and baby is often a cesarean birth (Arquette & Holcroft, 2007).
What four stages does placenta previa occur
It occurs in four degrees: implantation in the lower rather than in the upper portion of the uterus (low-lying placenta); marginal implantation (the placenta edge approaches that of the cervical os); implantation that occludes a portion of the cervical os (partial placenta previa); and implantation that totally obstructs the cervical os (total placenta previa). The degree to which the placenta covers the internal cervical os is generally estimated in percentages: 100%, 75%, 30%, and so forth. Increased parity, advanced maternal age, past cesarean births, past uterine curettage, multiple gestation, and perhaps a male fetus are all associated with placenta previa. The incidence is approximately 5 per 1000 pregnancies. It is thought to occur whenever the placenta is forced to spread to find an adequate exchange surface. An increase in congenital fetal anomalies may occur if the low implantation does not allow optimal fetal nutrition or oxygenation (Arquette & Holcroft, 2007).
what is placenta previa
Placenta previa (Fig. 21.6) is a condition of pregnancy in which the placenta is implanted abnormally in the uterus. It is the most common cause of painless bleeding in the third trimester of pregnancy (Scearce & Uzelac, 2007).
Because the placenta is loosened, the fetal ____ supply may be compromised, placing the fetus at risk also.
Therapeutic Management The bleeding of placenta previa, like that of ectopic preg-nancy, is an emergency situation. The site of bleeding, the open vessels of the uterine decidua (maternal blood), places the mother at risk for hemorrhage. Because the placenta is loosened, the fetal oxygen supply may be compromised, plac-ing the fetus at risk also. With the placental loosening, preterm labor (labor that occurs before the end of week 37 of gestation) may begin, posing the additional threat of preterm birth to the fetus.
