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Doppler flow study is a type of ultrasound that measures the amount of blood flowing in and out of the placenta.
The following tests have been promoted as supposedly diagnosing placental insufficiency, but all have been unsuccessful at predicting stillbirth due to placental insufficiency:
- Placental grading
- Amniotic fluid index
- Fetal biophysical profile test scoring
- Doppler velocimetry
- Routine ultrasound scanning
- Detection and management of maternal diabetes mellitus
- Antenatal fetal heart rate monitoring using cardiotocography
- Vibroacoustic stimulation, fetal movement counting
- Home vs. hospital-based bed rest and monitoring in high-risk pregnancy
- In-hospital fetal surveillance unit
- Use of the partograph during labor
- Cardiotocography during labor with or without pulse oximetry
This is equivalent of zero intervention. It has been associated with almost 100% mortality rate of one or all fetuses. Exceptions to this include patients that are still in Stage 1 TTTS and are past 22 weeks gestation.
A biophysical profile checks for the baby's heart rate, muscle tone, movement, breathing, and the amount of amniotic fluid surrounding the baby.
A staging system proposed by fetal surgeon Dr. Ruben Quintero is commonly used to classify the severity of TTTS.
Stage I: A small amount of amniotic fluid (oligohydramnios) is found around the donor twin and a large amount of amniotic fluid (polyhydramnios) is found around the recipient twin.
Stage II: In addition to the description above, the ultrasound is not able to identify the bladder in the donor twin.
Stage III: In addition to the characteristics of Stages I and II, there is abnormal blood flow in the umbilical cords of the twins.
Stage IV: In addition to all of the above findings, the recipient twin has swelling under the skin and appears to be experiencing heart failure (fetal hydrops).
Stage V: In addition to all of the above findings, one of the twins has died. This can happen to either twin. The risk to either the donor or the recipient is roughly equal & is quite high in Stage II or higher TTTS.
The Quintero staging does not provide information about prognosis, and other staging systems have been proposed.
If a small amount of bleeding is seen in early pregnancy a physician may request:
- A quantitative human chorionic gonadotropin (hCG) blood test to confirm the pregnancy or assist in diagnosing a potential miscarriage
- Transvaginal pelvic ultrasonography to confirm that the pregnancy is not outside of the uterus
- Blood type and Rh test to rule out hemolytic disease of the newborn
For bleeding seen in later pregnancy tests may include:
- Complete blood count (CBC) and blood type and screen
- Ultrasound to determine placental location
- Kleihauer-Betke (KB) test especially if there was maternal trauma
Depending on gestational age the differential diagnoses for abdominal pregnancy include miscarriage, intrauterine fetal death, placental abruption, an acute abdomen with an intrauterine pregnancy and a fibroid uterus with an intrauterine pregnancy .
Previa can be confirmed with an ultrasound. Transvaginal ultrasound has superior accuracy as compared to transabdominal one, thus allowing measurement of distance between placenta and cervical os. This has rendered traditional classification of placenta previa obsolete.
False positives may be due to following reasons:
- Overfilled bladder compressing lower uterine segment
- Myometrial contraction simulating placental tissue in abnormally low location
- Early pregnancy low position, which in third trimester may be entirely normal due to differential growth of the uterus.
In such cases, repeat scanning is done after an interval of 15–30 minutes.
In parts of the world where ultrasound is unavailable, it is not uncommon to confirm the diagnosis with an examination in the surgical theatre. The proper timing of an examination in theatre is important. If the woman is not bleeding severely she can be managed non-operatively until the 36th week. By this time the baby's chance of survival is as good as at full term.
History may reveal antepartum hemorrhage. Abdominal examination usually finds the uterus non-tender, soft and relaxed. Leopold's Maneuvers may find the fetus in an oblique or breech position or lying transverse as a result of the abnormal position of the placenta. Malpresentation is found in about 35% cases. Vaginal examination is avoided in known cases of placenta previa.
It is recommended that women with vasa previa should deliver through elective cesarean prior to rupture of the membranes. Given the timing of membrane rupture is difficult to predict, elective cesarean delivery at 35–36 weeks is recommended. This gestational age gives a reasonable balance between the risk of death and that of prematurity. Several authorities have recommended hospital admission about 32 weeks. This is to give the patient proximity to the operating room for emergency delivery should the membranes rupture. Because these patients are at risk for preterm delivery, it is recommended that steroids should be given to promote fetal lung maturation. When bleeding occurs, the patient goes into labor, or if the membranes rupture, immediate treatment with an emergency caesarean delivery is usually indicated.
The exact incidence of maternal mortality related to placenta accreta and its complications is unknown, but has been reported to be as high as 6-7% in case series and surveys.
Pregnant patients may have bleeding from the reproductive tract due to trauma, including sexual trauma, neoplasm, most commonly cervical cancer, and hematologic disorders. Molar pregnancy (also called hydatiform mole) is a type of pregnancy where the sperm and the egg have joined within the uterus, but the result is a cyst resembling a grape-like cluster rather than an embryo. Bleeding can be an early sign of this tumor developing.
In general, the indications for anticoagulation during pregnancy are the same as the general population. This includes (but is not limited to) a recent history of deep venous thrombosis (DVT) or pulmonary embolism, a metallic prosthetic heart valve, and atrial fibrillation in the setting of structural heart disease.
In addition to these indications, anticoagulation may be of benefit in individuals with lupus erythematosus, individuals who have a history of DVT or PE associated with a previous pregnancy, and even with individuals with a history of coagulation factor deficiencies and DVT not associated with a previous pregnancy.
In pregnant women with a history of recurrent miscarriage, anticoagulation seems to increase the live birth rate among those with antiphospholipid syndrome and perhaps those with congenital thrombophilia but not in those with unexplained recurrent miscarriage.
To diagnose the rare primary abdominal pregnancy, Studdiford's criteria need to be fulfilled: tubes and ovaries should be normal, there is no abnormal connection (fistula) between the uterus and the abdominal cavity, and the pregnancy is related solely to the peritoneal surface without signs that there was a tubal pregnancy first. Studdiford's criteria were refined in 1968 by Friedrich and Rankin to include microscopic findings.
Some disorders and conditions can mean that pregnancy is considered high-risk (about 6-8% of pregnancies in the USA) and in extreme cases may be contraindicated. High-risk pregnancies are the main focus of doctors specialising in maternal-fetal medicine.
Serious pre-existing disorders which can reduce a woman's physical ability to survive pregnancy include a range of congenital defects (that is, conditions with which the woman herself was born, for example, those of the heart or , some of which are listed above) and diseases acquired at any time during the woman's life.
The use of the so-called Solomon technique or dichorionization in fetoscopic laser therapy for TTTS is proven to be beneficial in preventing post-laser TAPS. With this technique, not only all anastomoses are coagulated but also a line is drawn between those in order to coagulate anastomoses that might not (yet) be visible during fetoscopy. It should be stressed that the success of such a technique is highly dependent on the specific situation. For example, when one of the fetusses obstructs the view on the vascular equator (the part of the placenta where the anastomoses need to be coagulated), complete dichorionization by the Solomon technique might not be possible.
Pre-eclampsia can mimic and be confused with many other diseases, including chronic hypertension, chronic renal disease, primary seizure disorders, gallbladder and pancreatic disease, immune or thrombotic thrombocytopenic purpura, antiphospholipid syndrome and hemolytic-uremic syndrome. It must be considered a possibility in any pregnant woman beyond 20 weeks of gestation. It is particularly difficult to diagnose when preexisting disease such as hypertension is present. Women with acute fatty liver of pregnancy may also present with elevated blood pressure and protein in the urine, but differ by the extent of liver damage. Other disorders that can cause high blood pressure include thyrotoxicosis, pheochromocytoma, and drug misuse.
Although the risk of placental abruption cannot be eliminated, it can be reduced. Avoiding tobacco, alcohol and cocaine during pregnancy decreases the risk. Staying away from activities which have a high risk of physical trauma is also important. Women who have high blood pressure or who have had a previous placental abruption and want to conceive must be closely supervised by a doctor.
The risk of placental abruption can be reduced by maintaining a good diet including taking folic acid, regular sleep patterns and correction of pregnancy-induced hypertension.
It is crucial for women to be made aware of the signs of placental abruption, such as vaginal bleeding, and that if they experience such symptoms they must get into contact with their health care provider/the hospital "without any delay".
Hydrops fetalis can be diagnosed and monitored by ultrasound scans. Prenatal ultrasound scanning enables early recognition of hydrops fetalis and has been enhanced with the introduction of MCA Doppler.
Principles of management are to treat the shock and replace the uterus. The patient should be moved rapidly to the OR to facilitate anesthesia monitoring during this procedure. Usually this complication is only recognized after delivery of the placenta, wherein pitocin has already been started, which just exacerbates the problem. The uterus clamps down around the inversion making it very difficult to perform a replacement. This is a true obstetrical emergency, so extra doctors, nurses, anesthesiologists should be summoned to the room to assist. The pitocin should be turned off immediately. Giving tocolytics such as terbutaline or magnesium sulfate have a lower success rate. Halothane and Nitroglycerine (100mcg to 200 mcg intravenously) have a higher success rate.
Once you have achieved uterine relaxation, place your fist into the vagina. Find the biggest part of the inversion and push with your fist cephalward to replace the uterus. This takes firm steady force, so keep your fist in the vagina if you need to rest your hand. Then continue more force toward the fundus to replace the uterus. You can use your left hand on the outside of the abdomen to help you feel where the fundus should be replaced. This helps guide the angle of your fist in replacing the uterus. Once it is replaced, give the patient Misoprostol 1000 mcgs rectally to help with increasing uterine tone. Other medications such as Methergine and Hemabate can be used. If you have heavy bleeding, consider inserting a Bakri balloon into the uterine cavity to tamponade the bleeding.
These patients have usually sustained heavy blood loss, and should be monitored in the ICU postoperatively. If you have given nitroglycerine, they must have cardiac monitoring postoperatively.
Other personnel should be monitoring vital signs, ordering blood products, assisting the anesthesiologist, drawing labs, and stabilizing the patient. Remember that nitroglycerine can cause hypotension, which can be reversed with ephedrine.
If external replacement fails, a laparotomy may be required, in which the uterus is gently pulled the right way round using forceps.
Placental abruption is suspected when a pregnant mother has sudden localized abdominal pain with or without bleeding. The fundus may be monitored because a rising fundus can indicate bleeding. An ultrasound may be used to rule out placenta praevia but is not diagnostic for abruption. The diagnosis is one of exclusion, meaning other possible sources of vaginal bleeding or abdominal pain have to be ruled out in order to diagnose placental abruption. Of note, use of magnetic resonance imaging has been found to be highly sensitive in depicting placental abruption, and may be considered if no ultrasound evidence of placental abruption is present, especially if the diagnosis of placental abruption would change management.
Platelets may be enlarged. The membrane surface connected canalicular system is disrupted with prominent tubules and small membranous vesicles. Alpha granules may be missing from the platelets. Despite these abnormalities there is no increased tendency to bleed in this syndrome.
Microscopic analysis of the hair shows twisted hairs of unequal size and different shapes (pili torti, aniso- and poikilotrichosis), longitudinal breaks and breaks located at nodes (trichorrhexis nodosa). Scanning electron microscopy might reveal hair budding (trichorrhexis blastysis). Biochemical analysis may reveal sulfur-deficient brittle hair (trichothiodystrophy; note that disulfide bonds determine hair waviness).
There have been many assessments of tests aimed at predicting pre-eclampsia, though no single biomarker is likely to be sufficiently predictive of the disorder. Predictive tests that have been assessed include those related to placental perfusion, vascular resistance, kidney dysfunction, endothelial dysfunction, and oxidative stress. Examples of notable tests include:
- Doppler ultrasonography of the uterine arteries to investigate for signs of inadequate placental perfusion. This test has a high negative predictive value among those individuals with a history of prior pre-eclampsia.
- Elevations in serum uric acid (hyperuricemia) is used by some to "define" pre-eclampsia, though it has been found to be a poor predictor of the disorder. Elevated levels in the blood (hyperuricemia) are likely due to reduced uric acid clearance secondary to impaired kidney function.
- Angiogenic proteins such as vascular endothelial growth factor (VEGF) and placental growth factor (PIGF) and anti-angiogenic proteins such as soluble fms-like tyrosine kinase-1 (sFlt-1) have shown promise for potential clinical use in diagnosing pre-eclampsia, though evidence is sufficient to recommend a clinical use for these markers.
- Recent studies have shown that looking for podocytes (specialized cells of the kidney) in the urine has the potential to aid in the prediction of preeclampsia. Studies have demonstrated that finding podocytes in the urine may serve as an early marker of and diagnostic test for preeclampsia.
Factors increasing the risk (to either the woman, the fetus/es, or both) of pregnancy complications beyond the normal level of risk may be present in a woman's medical profile either before she becomes pregnant or during the pregnancy. These pre-existing factors may relate to physical and/or mental health, and/or to social issues, or a combination.
Some common risk factors include:
- Age of either parent
- Adolescent parents
- Older parents
- Exposure to environmental toxins in pregnancy
- Exposure to recreational drugs in pregnancy:
- Ethanol during pregnancy can cause fetal alcohol syndrome and fetal alcohol spectrum disorder.
- Tobacco smoking and pregnancy, when combined, causes twice the risk of premature rupture of membranes, placental abruption and placenta previa. Also, it causes 30% higher odds of the baby being born prematurely.
- Prenatal cocaine exposure is associated with, for example, premature birth, birth defects and attention deficit disorder.
- Prenatal methamphetamine exposure can cause premature birth and congenital abnormalities. Other investigations have revealed short-term neonatal outcomes to include small deficits in infant neurobehavioral function and growth restriction when compared to control infants. Also, prenatal methamphetamine use is believed to have long-term effects in terms of brain development, which may last for many years.
- Cannabis in pregnancy is possibly associated with adverse effects on the child later in life.
- Exposure to Pharmaceutical drugs in pregnancy. Anti-depressants, for example, may increase risks of such outcomes as preterm delivery.
- Ionizing radiation
- Risks arising from previous pregnancies:
- Complications experienced during a previous pregnancy are more likely to recur.
- Many previous pregnancies. Women who have had five previous pregnancies face increased risks of very rapid labor and excessive bleeding after delivery.
- Multiple previous fetuses. Women who have had more than one fetus in a previous pregnancy face increased risk of mislocated placenta.
- Multiple pregnancy, that is, having more than one fetus in a single pregnancy.
- Social and socioeconomic factors. Generally speaking, unmarried women and those in lower socioeconomic groups experience an increased level of risk in pregnancy, due at least in part to lack of access to appropriate prenatal care.
- Unintended pregnancy. Unintended pregnancies preclude preconception care and delays prenatal care. They preclude other preventive care, may disrupt life plans and on average have worse health and psychological outcomes for the mother and, if birth occurs, the child.
- Height. Pregnancy in women whose height is less than 1.5 meters (5 feet) correlates with higher incidences of preterm birth and underweight babies. Also, these women are more likely to have a small pelvis, which can result in such complications during childbirth as shoulder dystocia.
- Weight
- Low weight: Women whose pre-pregnancy weight is less than 45.5 kilograms (100 pounds) are more likely to have underweight babies.
- Obese women are more likely to have very large babies, potentially increasing difficulties in childbirth. Obesity also increases the chances of developing gestational diabetes, high blood pressure, preeclampsia, experiencing postterm pregnancy and/or requiring a cesarean delivery.
- Intercurrent disease in pregnancy, that is, a disease and condition not necessarily directly caused by the pregnancy, such as diabetes mellitus in pregnancy, SLE in pregnancy or thyroid disease in pregnancy.