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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.
Obstetric ultrasonography can detect fetal abnormalities, detect multiple pregnancies, and improve gestational dating at 24 weeks. The resultant estimated gestational age and due date of the fetus are slightly more accurate than methods based on last menstrual period. Ultrasound is used to measure the nuchal fold in order to screen for Downs syndrome.
Pregnancy detection can be accomplished using one or more various pregnancy tests, which detect hormones generated by the newly formed placenta, serving as biomarkers of pregnancy. Blood and urine tests can detect pregnancy 12 days after implantation. Blood pregnancy tests are more sensitive than urine tests (giving fewer false negatives). Home pregnancy tests are urine tests, and normally detect a pregnancy 12 to 15 days after fertilization. A quantitative blood test can determine approximately the date the embryo was conceived because HCG doubles every 36 to 48 hours. A single test of progesterone levels can also help determine how likely a fetus will survive in those with a threatened miscarriage (bleeding in early pregnancy).
The management of PROM remains controversial, and depends largely on the gestational age of the fetus and other complicating factors. The risks of quick delivery (induction of labor) vs. watchful waiting in each case is carefully considered before deciding on a course of action.
As of 2012, the Royal College of Obstetricians and Gynaecologists advised, based on expert opinion and not clinical evidence, that attempted delivery during maternal instability, increases the rates of both fetal death and maternal death, unless the source of instability is an intrauterine infection.
In all women with PROM, the age of the fetus, its position in the uterus, and its wellbeing should be evaluated. This can be done with ultrasound, electronic fetal heart rate monitoring, and uterine activity monitoring. This will also show whether or not uterine contractions are happening which may be a sign that labor is starting. Signs and symptoms of infection should be closely monitored, and, if not already done, a group B streptococcus (GBS) culture should be collected.
At any age, if the fetal well-being appears to be compromised, or if intrauterine infection is suspected, the baby should be delivered quickly by artificially stimulating labor (induction of labor).
A biophysical profile checks for the baby's heart rate, muscle tone, movement, breathing, and the amount of amniotic fluid surrounding the baby.
To know for sure if a woman has experienced premature rupture of membranes (PROM), a health care clinician must prove that (1) the fluid leaking from the vagina is amniotic fluid, and (2) that labor has not yet started. To do this, a health care clinician will take a medical history, do a gynecological exam using a sterile speculum, and ultrasound.
- History: a person with PROM typically recalls a sudden gush of fluid loss from the vagina, or steady loss of small amounts of fluid.
- Sterile speculum exam: a health care clinician will insert a sterile speculum into the vagina in order to see inside and perform the following evaluations. Digital cervical exams, in which gloved fingers are inserted into the vagina to measure the cervix, are avoided until the women is in active labor to reduce the risk of infection.
- Pooling test: Pooling is when a collection of amniotic fluid can be seen in the back of the vagina (vaginal fornix). Sometimes leakage of fluid from the cervical opening can be seen when the person coughs or does a valsalva maneuver.
- Nitrazine test: A sterile cotton swab is used to collect fluid from the vagina and place it on nitrazine (phenaphthazine) paper. Amniotic fluid is mildly basic (pH 7.1 - 7.3) compared to normal vaginal secretions which are acidic (pH 4.5 - 6). Basic fluid, like amniotic fluid, will turn the nitrazine paper from orange to dark blue.
- Ferning test: A sterile cotton swab is used to collect fluid from the vagina and place it on a microscope slide. After drying, amniotic fluid will form a crystallization pattern called arborization which resembles leaves of a fern plant when viewed under a microscope.
- Fibronectin and alpha fetoprotein
Obstetric ultrasound has become useful in the assessment of the cervix in women at risk for premature delivery. A short cervix preterm is undesirable: A cervical length of less than 25 mm at or before 24 weeks of gestational age is the most common definition of cervical incompetence.
Fetal fibronectin (fFN) has become an important biomarker—the presence of this glycoprotein in the cervical or vaginal secretions indicates that the border between the chorion and deciduas has been disrupted. A positive test indicates an increased risk of preterm birth, and a negative test has a high predictive value. It has been shown that only 1% of women in questionable cases of preterm labor delivered within the next week when the test was negative.
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.
Instead of referring to "fetal distress" current recommendations hold to look for more specific signs and symptoms, assess them, and take the appropriate steps to remedy the situationthrough the implementation of intrauterine resuscitation. Traditionally the diagnosis of "fetal distress" led the obstetrician to recommend rapid delivery by instrumental delivery or by caesarean section if vaginal delivery is not advised.
Miscarriage is the loss of a pregnancy prior to 20 weeks. In the UK miscarriage is defined as the loss of a pregnancy during the first 23 weeks.
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.
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
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.
Upon diagnosis, many providers will prescribe Ursodeoxycholic Acid. While there is no cure for ICP, and no way to guarantee a successful outcome, studies have shown a slightly better fetal and maternal outcome from administration of Ursodeoxycholic Acid, whereas Cholestyramine appears to only relieve itching.
If additional blood tests to check clotting function identify a problem, giving Vitamin K may help avoid the risk of hemorrhage at delivery.
Delivery by 35–37 completed weeks may be important to fetal outcome as a recent study demonstrated that in severe ICP (defined as bile acids greater than 40 umol/L) the risk of stillbirth was 1.5% compared to 0.5% of uncomplicated pregnancies. This risk rose further if bile acids doubled,
Chorioamnionitis can be diagnosed from a histologic examination of the fetal membranes.
Infiltration of the chorionic plate by neutrophils is diagnostic of (mild) chorioamnionitis. More severe chorioamnionitis involves subamniotic tissue and may have fetal membrane necrosis and/or abscess formation.
Severe chorioamnionitis may be accompanied by vasculitis of the umbilical blood vessels (due to the fetus' inflammatory cells) and, if very severe, funisitis (inflammation of the umbilical cord's connective tissue).
While most pregnant women experience some itch from time to time, itching on the palms and soles without a visible rash, or persisting severe or extensive itch symptoms should be reported to the midwife or obstetrican.
To obtain a diagnosis of ICP, there are two LFT (liver function tests) and Serum bile acid test. The liver function tests (LFTs) is a simple blood test, the results of which should be available by the next day. If the ALT level is elevated, this, plus pruritus of palms and soles, could be considered as potentially diagnostic of ICP but only with elevated bile acid levels (however LFTs are not always elevated in ICP patients). The serum bile acid blood test for ICP is a quantitative measurement of bile salts. The results of this test often take longer to return, but the test is more specific for ICP.
Other problems with the liver that occur in pregnancy should be considered by the treating clinician. These include preeclampsia, the HELLP syndrome, and acute fatty liver of pregnancy. Furthermore, other causes of hepatitis, like hepatitis viruses, cancer and certain medications, should also be considered.
Generally it is preferable to describe specific signs in lieu of declaring "fetal distress" that include:
- Decreased movement felt by the mother
- Meconium in the amniotic fluid ("meconium stained fluid")
- Non-reassuring patterns seen on cardiotocography:
- increased or decreased fetal heart rate (tachycardia and bradycardia), especially during and after a contraction
- decreased variability in the fetal heart rate
- late decelerations
- Biochemical signs, assessed by collecting a small sample of baby's blood from a scalp prick through the open cervix in labor
- fetal metabolic acidosis
- elevated fetal blood lactate levels (from fetal scalp blood testing) indicating the baby has a lactic acidosis
Some of these signs are more reliable predictors of fetal compromise than others. For example, cardiotocography can give high false positive rates, even when interpreted by highly experienced medical personnel. Metabolic acidosis is a more reliable predictor, but is not always available.
Chorioamnionitis is a risk factor for periventricular leukomalacia and cerebral palsy.
Precipitate delivery may cause intracranial hemorrhage resulting from a sudden change in pressure on the fetal head during rapid expulsion.
It may cause aspiration of amniotic fluid, if unattended at or immediately following delivery.
There may be infection as a result of unsterile delivery.
While a transverse lie prior to labor can be manually versed to a longitudinal lie, once the uterus starts contracting the uterus normally will not allow any version procedure. A shoulder presentation is an indication for a caesarean section. Generally, as it is diagnosed early, the baby is not damaged by the time of delivery. With the rupture of the membranes, there is an increased risk of a cord prolapse as the shoulder may not completely block the birth canal. Thus the caesarean section is ideally performed before the membranes break.
Emergency exploratory laparotomy with cesarean delivery accompanied by fluid and blood transfusion are indicated for the management of uterine rupture. Depending on the nature of the rupture and the condition of the patient, the uterus may be either repaired or removed (cesarean hysterectomy). Delay in management places both mother and child at significant risk.
There are several misfortunes associated with precipitate delivery for both the mother and the infant. They are classified as maternal and neonatal.
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.