OG Updates

·         The reduced gastrointestinal motility during pregnancy has been thought to be due to increased circulating levels of progesterone. However, recent evidence suggests that elevated estrogen concentrations mediate the effect by enhancing nitric oxide release from the nonadrenergic noncholinergic nerves that modulate gastrointestinal motility. Gastric emptying has generally been considered to be slowed during pregnancy; however, via indirect methods some researchers have shown no changes in gastric emptying rates in women in the first or second trimesters or at term. Transit time of food through the gastrointestinal tract may be slowed so much that more water than normal is reabsorbed, leading to constipation.

·         Prothrombin (factor II) is only slightly affected by pregnancy, if at all. Some investigators have noted small increases; others have reported normal values. Recent studies have also noted mild increases in factor V, and suggest a thrombinlike influence on the activity of factor V. Factor XI decreases slightly toward the end of pregnancy, and factor XIII (fibrin-stabilizing factor) is appreciably reduced, up to 50% at term.

·         The physiologic hypertrophy of the pituitary gland is associated with an increase in the number of pituitary lactotroph cells at the expense of the somatotropic cell types. Thus, growth hormone secretion is depressed during the second half of pregnancy and the early puerperium. Because levels of circulating insulin-like growth factor (IGF-1) increase throughout pregnancy, a placental growth hormone has been postulated and recently identified. Maternal levels of IGF-1 correlate highly with this distinct placental growth hormone variant but not placental lactogen during pregnancy and in the immediate puerperium.

·         Ultrasound has had a continuous evolution over the last 20 years, with better equipment being produced each year. Real-time sonography allows a 2-D image to demonstrate fetal anatomy, as well as characteristics such as fetal weight, movement, volume of amniotic fluid, and structural anomalies such as myomas or placenta previa which may affect the pregnancy. 3-D sonography allows volume to be ascertained, creating a three-dimensional appearing image on the 2-D screen, which assists in identifying certain anatomical anomalies. Most recently, 4-D machines have been developed, which produce a 3-D image in real time.

·         Recent studies of the uterine artery early diastolic notch have demonstrated its usefulness as another marker for fetal well-being.

·         Maternal diabetes, whether it is gestational, chemical, or insulin-dependent, is the condition classically associated with fetal macrosomia. It was long assumed that fetal macrosomia could be accounted for by the “Pedersen hypothesis”—ie, that the condition was due to inadequate management of diabetes during pregnancy. Initial reports suggested that careful control of blood glucose in insulin-dependent diabetic women would prevent fetal macrosomia, but recent studies have suggested that the problem is not so simple and that the incidence may correlate better with cord blood concentrations of maternally acquired anti-insulin IgG antibodies, and/or increased serum levels of free fatty acids, triglycerides, and the amino acids alanine, serine, and isoleucine.

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·         Preeclampsia is hypertension associated with proteinuria and edema, occurring primarily in nulliparas after the 20th gestational week and most frequently near term. Recent data support the elimination of edema as a diagnostic criterion. Eclampsia is the occurrence of seizures that cannot be attributed to other causes in a preeclamptic patient.

·         While early studies failed to show a significant increase in cerebrospinal fluid (CSF) magnesium concentrations during therapy, more recent studies have shown about a 20% increase in CSF magnesium levels, and these levels parallel those in the serum. Magnesium sulfate decreases the amount of acetylcholine released at the neuromuscular junction, resulting in peripheral neuromuscular blockade at high magnesium concentrations; however, this does not account for its anticonvulsant effect. A recent study demonstrated that magnesium sulfate had a central anticonvulsant effect on electrically-stimulated hippocampal seizures in rats. The researchers speculated that since magnesium ion blocks calcium entry into neurons through the N-methyl-D-aspartate (NMDA) receptor–operated calcium channel, magnesium sulfate might be acting through this mechanism. On the other hand, another study found that magnesium sulfate was ineffective in altering seizure discharge in pentylenetetrazole-induced status epilepticus in rats. These researchers argued that because magnesium blocks calcium entry through the NMDA receptor–operated calcium channel in a voltage-dependent manner, it would be ineffective in neurons that are continuously depolarizing as in status epilepticus. Finally, Doppler studies of brain blood flow in preeclamptic women suggest that magnesium sulfate vasodilates the smaller-diameter intracranial vessels distal to the middle cerebral artery and may exert its main effect in the prophylaxis and treatment of eclampsia by reversing vasospastic cerebral ischemia.

·         D-Dimer or fibrin split products are useful when abruptio placentae is suspected. These are the most sensitive tests to confirm coagulopathy; however, they are qualitative studies and give little information about the severity of abruption. Recent literature has demonstrated a correlation between elevated CA-125 levels and abruption. This assay has little clinical utility, as it usually requires a long turnaround time. A Kleihauer-Betke test may be useful in the Rh-negative patient. The results are useful in calculating the appropriate dose of Rh immune globulin.

·         The use of erythropoietin was found to increase production of hemoglobin F in baboons; however, it stimulated hemoglobin S production in humans. Hemoglobin F synthesis by stimulating Y-chain production appears to be a promising form of therapy for the sickle cell disease and thalassemia syndrome. Y-chains of hemoglobin F inhibit polymerization of hemoglobin S and therefore inhibit sickling. Recombinant erythropoietin and hydroxyurea have been used together recently with elevation of hemoglobin F. More recently intravenous arginine butyrate has been used with the increase in fetal globin synthesis, production of F reticulocytes, and the level of Y-globin.

·         In recent years the diagnosis of persistent hyperemesis gravidarum has been linked to Helicobacter pylori infection.

·         Previously, it was thought that a hormonal imbalance was related to the clinical manifestations of PMS/PMDD, but the most recent consensus is that physiologic ovarian function is the trigger. This is supported by the efficacy of ovarian cyclicity suppression, either medically or surgically, in eliminating premenstrual complaints.

Further research has shown that serotonin (5-HT), a neurotransmitter, is important in the pathogenesis of PMS/PMDD. Both estrogen and progesterone have been shown to influence the activity of serotonin centrally. Many of the symptoms of other mood disorders resembling the features of PMS/PMDD have been associated with serotonergic dysfunction.

·         Recent evidence indicates that spermicides containing nonoxynol-9 (N-9) are not effective in preventing cervical gonorrhea, chlamydia or HIV infection. In addition, frequent use of spermicides containing N-9 has been associated with genital lesions which may be associated with an increased risk of HIV transmission.

·         Three additional hormonal contraceptives methods have recently become available: The transdermal patch (Ortho Evra, Ortho-McNeil Pharmaceuticals, Inc.), the vaginal ring, (NuvaRing, Organon, Inc.) and a single rod implant system (Implanon, Organon, Inc.).

·         Recently, surgically implantable device like Interstim have been found very useful in patients with intractable urgency incontinence and voiding dysfunction.

·         Many surgeons encourage their patients to sip tap water (not ice water) on the first day after uncomplicated gynecologic surgery. On the following day, clear fluids are often given if bowel sounds are normal, and solid food usually is withheld until the patient passes flatus. Some recent studies suggest that early oral intake (clear liquids on postoperative day 1), even among patients with major abdominal surgery, reduces length of hospitalization and is not associated with an increased incidence of ileus.

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·         Recently, new factors have been discovered that are involved with the regulation of bone remodeling: osteoprotegerin, a naturally-occurring protein with potent osteoclastogenesis inhibitory activity; and RANKL (receptor activator of nuclear factor kappa beta ligand), a transmembrane ligand expressed on osteoblasts.

Obstetrics Facts from Previous Papers

·         For the TPAL notation, T refers to the number of term infants delivered regardless of outcome (fetal demise at 37 weeks and term delivery at 38 weeks = 2); P stands for preterm (preterm delivery at 34 weeks = 1); A stands for abortions, either elective or miscarriages (it does not include ectopic pregnancies) (2 abortions + 2 miscarriages = 4); and L refers to number of living offspring (son and daughter = 2).

·         The T-ACE questions: practical prenatal detection of risk-drinking.

·         Ethnicity: Specific ethnic groups are more prone to specific diseases.

a.       Tay-Sachs disease (Ashkenazi Jews, French Canadians)

b.      Canavan disease (Ashkenazi Jews)

c.       Thalassemias (Mediterranean, Southeast Asian, Indian, or African people)

d.      Sickle cell anemia (African, Mediterranean, Caribbean, Latin American, or Indian people)

e.      Cystic fibrosis (Caucasians)

·         Main factor leading to ovulation – High conc of LH leads to ↑activity of collagenase, which digests the collagen fibers surrounding the follicle

·         G6P3215 means – Pt has been pregnant 6 times; 3 term, 2 preterm,1 abortion/ectopic, 5 living

Labour, Delivery & Poostpartum

·         Prolonged latent phase is not associated with increased risk of perinatal morbidity (PNM) or low Apgar scores and should be treated by therapeutic rest. Protraction disorders have a higher rate of PNM and low Apgar scores, but not if spontaneous labor follows the abnormality. Arrest disorders are associated with significantly higher rates of PNM following either spontaneous or instrument-assisted delivery.

·         Postpartum blues occur in 50-80% of women, depression in 8-15%, and psychosis in 1-2/1000.

·         Tricyclic antidepressants and fluoxetine appear safe in pregnancy, but data about newer SSRIs are limited.

·         Emanuel A. Friedman popularized the use of an objective measure of labor progression over 30 years ago. Friedman curves plot cervical dilatation against time passed, with varying expectations for nulliparous and multiparous patients. Used in conjunction with fetal descent, the curves provide clinical feedback about the normalcy of the parturient's progress in labor.

·         Ritgen maneuver:

Moderate upward pressure is applied to the fetal chin by the operator's posterior hand, which is covered with a sterile towel, while the vertex is held against the symphysis. This maneuver allows control of the delivery of the head and favors extension, so that the head is delivered with its smallest diameters passing through the introitus and over the perineum

·         Asynclitism is failure of the vertex to descend with the sagittal suture in the mid plane between the front and back of the pelvis. It is detected clinically on examination when either the anterior or posterior parietal bones precede the sagittal suture.

·         Scanzoni maneuver:

Rotation from OP to OA position with Kielland forceps, then reapplication of Simpson forceps for delivery for the OA position.

·         The pain of stage one of labor is visceral, arising mostly from cervical dilation, and referred to spinal cord levels T10 to L1.

The pain of stage two of labor is caused by stretching of the birth canal and involves the pudendal nerve, S2 through S4

·         Epidural anesthesia may increase the length of the first and second stage of labor, but it does not affect the risk of cesarean section.

·         Paracervical block involves the injection of local anesthetics submucosally into the fornix of the vagina laterally to the cervix (generally at 3 o'clock and 9 o'clock). The somatic sensory fibers of the perineum are not blocked. Paracervical block is effective only for the first stage of labor, and is associated with a high incidence of fetal bradycardia. Its major role is in providing analgesia for dilation and curettage.

·         The Simpson forceps are commonly used in low or outlet forceps deliveries. Kielland forceps are used for midforceps deliveries that involve rotation of the fetal head. Piper forceps are designed to deliver the aftercoming head during a vaginal breech delivery.

·         En Caul Delivery: Delivering the infant without rupturing the membranes. Since the amniotic fluid cushions the infant, it may prevent bruising.

·         BF is not C/I in c/o Mastitis. In fact, it is important to empty the affected breast, so encourage patients to continue breastfeeding or to use a pump.

·         Postpartum thyroiditis may involve transient hyperthyroidism followed first by hypothyroidism and then by a return to euthyroid condition.

·         methods for converting the fetus to vertex:

1.       external version

2.       Breech maneuvers use maternal position and gravity to attempt to facilitate fetal movement into a cephalic presentation. The mother is advised to perform these maneuvers one or more times each day.

3.       Moxibustion is the practice of burning herbs near the foot to stimulate fetal movement and conversion to cephalic presentation. One randomized, controlled study found it more effective than placebo.

·         Face presentations can deliver vaginally if mentum anterior, but brow presentations are unstable and convert either to face or vertex presentation.

·         An inability to void postpartum often leads to the diagnosis of a vulvar hematoma. Such hematomas are often large enough to apply pressure on the urethra. Pain from urethral lacerations is another reason women have difficulty voiding after delivery. Both general anesthesia, which temporarily disturbs neural control of the bladder, and oxytocin, which has an antidiuretic effect, can lead to an overdistended bladder and an inability to void. In this case an indwelling catheter should be inserted and left in for at least 24 h to allow recovery of normal bladder tone and sensation. Preeclampsia often leads to edema, which generally leads to diuresis postpartum.

·         AZT reduces risk by half (from 20% to about 10%). AZT + C-section reduces transmission rate to 5%.

Fetus & Placenta

·         Fetal cardiac output is approximately 200 mL/kg/min, whereas an average adult's cardiac output is 70 mL/kg/min. Fetal oxygen consumption is approximately 8 mL/kg/min, whereas adult oxygen consumption is approximately 3 mL/kg/min. both are 3 times more than adult.

·         Glucose is transported across the placenta via facilitated transport. Iron is transported via endocytosis. Amino acids are transported via active transport. Carbon dioxide passively diffuses across the placenta.

·         Placenta accreta refers to the absence of the decidua and the direct attachment of the placenta to the myometrium. There is no plane of separation between the placental villi and the myometrium. It is an important cause of postpartum hemorrhage because the placenta fails to separate from the myometrium at the time of labor. The hemorrhage can be life-threatening, and a total hysterectomy is the treatment of choice.

·         In the membranaceous placenta, all fetal membranes are covered by villi and the placenta develops as a thin membranous structure. This type of placenta is also known as placenta diffusa.

·         A delay in fetal pulmonary maturation is observed in pregnancies complicated by maternal diabetes or erythroblastosis fetalis. A risk of RDS of 40% exists with an L/S ratio of 1.5 to 2; when the L/S ratio is <1.5, the risk of RDS is 73%. When the L/S ratio is >2, the risk of RDS is slight. However, when the fetus is likely to have a serious metabolic compromise at birth (e.g., diabetes or sepsis), RDS may develop even with a mature L/S ratio (>2.0). This may be explained by lack of PG, a phospholipid that enhances surfactant properties. The identification of PG in amniotic fluid provides considerable reassurance (but not an absolute guarantee) that RDS will not develop. Moreover, contamination of amniotic fluid by blood, meconium, or vaginal secretions will not alter PG measurements.

·         Fetal malformations are more common with velamentous insertion of the umbilical cord. When fetal vessels cross the internal os (vasa previa), rupture of membranes may be accompanied by rupture of a fetal vessel, leading to fetal exsanguination. An increased risk of premature rupture of membranes and of torsion of the umbilical cord has not been described in association with velamentous insertion of the cord.

·         Fraternal or DZ twins arise from the fertilization of two separate ova.

Superfecundation refers to fertilization of different ova in the same menstrual cycle, at two separate episodes of intercourse.

 Superfetation occurs when two ova are fertilized during separate menstrual cycles, i.e., the second ovulation occurred after the first pregnancy was established; this is rare.

·         The incidence of monozygotic twinning is constant at a rate of one set per 250 births around the world. It is unaffected by race, heredity, age, parity, or infertility agents.

·         The Kleihauer-Betke (KB) test will tell you the percentage of fetal cells in the maternal circulation. Generally we assume that the maternal blood volume is 5 L during pregnancy. Multiplying your KB result by 5000 cc will give you the amount of fetal blood in the maternal circulation. For example, a KB of 0.2% should be calculated as .002 × 5000 = 10 cc of fetal blood. If more than 30 cc of fetal blood has passed into the maternal circulation, then more than one vial of anti-D globulin is required.

·         The Liley graph is a plot on semi-logarithmic paper between the change in optical density at 450 nm (delta OD450) of the amniotic fluid bilirubin plotted against gestational age between 27 and 41 weeks. The graph is divided into three zones. Zone 1 indicates an unaffected fetus, Zone 2 is an affected fetus, and Zone 3 indicates a fetus that is at risk for intrauterine death. Prior to 27 weeks, data have been published for the extrapolation of the curve.

·         CVS removes placental tissue and has been associated with increased risk of limb reduction abnormalities.

·         IUGR is a prenatal term, whereas SGA is used for neonates.

·         Note that fetal macrosomia is not a contraindication to an attempt at vaginal delivery following cesarean section.

·         Second-trimester oligogyhydramnios can lead to fatal pulmonary hypoplasia.

·         The layer of fibrinoid degeneration between the invading trophoblasts and the decidua basalis is called Nitabuch's layer.

·         If there is widespread extravasation of blood into the uterine musculature and beneath the serosa, giving the uterus a bluish color at the time of laparotomy, this is termed a Couvelaire uterus. Such collections of blood rarely disrupt uterine contraction enough to cause postpartum hemorrhage and are not an indication for hysterectomy.

·         In Placenta Abruption, Ischemic necrosis of the kidney may take the form of acute tubular necrosis (ATN) or bilateral cortical necrosis. Both ATN and bilateral cortical necrosis are characterized by oliguria or anuria. However, bilateral cortical necrosis results in death from uremia within 1-2 weeks unless dialysis is instituted, whereas ATN usually resolves spontaneously.

·         Absent or reversed end-diastolic flow in Doppler velocimetry studies is concerning and warrants inpatient surveillance or delivery.

·         Fetal heart rate accelerations signify normal fetal pH and an intact CNS.

·         Decelerations are characterized based on timing with contractions-early (head compression), late (uteroplacental insufficiency), variable (cord compression).

·         The knee-chest position is sometimes more useful than the left lateral position when there is a nonreassuring fetal heart rate pattern, especially a severe variable deceleration.

·         Susceptibility of the conceptus to teratogenic agents depends on the developmental stage at the time of exposure:

1. Resistant period. From day 0 to day 11 of gestation (postovulation), the fetus exhibits the â??all or noneâ? phenomenon with regard to major anomalies.
2. Maximum susceptibility (embryonic period). From days 11 to 57 of gestation, the fetus is undergoing organ differentiation and, at this time, is most susceptible to the adverse effects of teratogens.
3. Lowered susceptibility (fetal period). After 57 days (8 weeks) of gestation, the organs have formed and are increasing in size. A teratogen at this stage may cause a reduction in cell size and number.

·         Maternal virilizing tumor during pregnancy (luteoma of pregnancy): This condition may result in masculinization of the female fetus. The clinical picture and therapy are similar to those for the maternal ingestion of androgenic substances. Psychological development and mental capacity are consistent with chronologic age. Reproductive potential is not adversely affected, and the patient can become pregnant.

Pregnancy

·         In a normal pregnancy, ß-hCG levels approximately double every 48 hours, and serum progesterone is typically greater than 10 ng/mL.

·         Pregnancy is a hypercoagulable state due to increased clotting factors and venous stasis.

·         To decrease group B streptococcal neonatal sepsis, the CDC recommends screening with vaginal and rectal cultures in the late third trimester and prophylaxis in labor for patients who carry the bacteria.

·         In Hyperemesis gravidarum, for women with severe, prolonged vomiting, supplemental thiamine should be given to prevent Wernicke's encephalopathy.

·         RULES OF 15:

15% of the obstetric population have abnormal glucose load test (GLT)

15% of patients with abnormal GLT have abnormal OGTT

15% of patients with abnormal OGTT require insulin

15% of all patients with GDM have infants > 4000 gm

Capillary levels are about 15% higher than plasma levels after meals.

·         Screening for GDM is done with the 1-hour 50 gm glucose tolerance test at ~28 weeks, gestation, and diagnosis is made with the 3-hour 100-gm glucose tolerance test if the 1-hour screen is positive.

If a woman has a history of GDM, her lifetime risk of developing type 2 DM is 36%, which is why a 2-hour 75-gm glucose tolerance test is recommended 6 weeks postpartum.

·         The sulfonylurea glyburide does not cross the placenta in significant quantity.

·         PTU is the first-line treatment for hyperthyroidism because methimazole is associated with a risk of aplasia cutis.

·         "Trimethadione syndrome" consists of developmental delay, low-set ears, palate anomalies, irregular teeth, speech disturbances, and V-shaped eyebrows. Intrauterine growth retardation, short stature, cardiac anomalies, ocular defects, simian creases, hypospadias, and microcephaly are also often present. Up to two-thirds of exposed fetuses will manifest congenital defects. Because trimethadione is associated with a greater risk of anomalies compared with other anticonvulsants, its use should be abandoned.

·         Do not forget subacute bacterial endocarditis prophylaxis at the time of delivery in women with cardiac valvular disease and ventricular septal defects.

·         Peripartum cardiomyopathy:

1.       Heart failure within the last month of pregnancy or 5 months postpartum

2.       Absence of prior heart disease

3.       No determinable cause

4.       Echocardiographic indication of left ventricular dysfunction: ejection fraction < 45%, fractional shortening < 30%, or left ventricular end-diastolic dimension > 2.7cm/m2.

·         Women with myasthenia gravis should not receive magnesium sulfate.

·         The main fetal risk of maternal ITP is that of intracranial hemorrhage (ICH).

·         Conditions Specific to pregnancy presenting as ruq pain:

Severe preeclampsia-nausea, vomiting, and right upper quadrant pain may all be present.

Hepatic capsule rupture-a dramatic complication of severe preeclampsia/HELLP syndrome, marked by sudden onset of upper abdominal pain, nausea, vomiting, and fever. Rupture may be heralded by shock and hypotension; the diagnosis is rarely made prior to emergent laparotomy. Maternal mortality has historically exceeded 60%, but is thought to be decreasing secondary to advances in imaging techniques and heightened awareness.

Acute fatty liver of pregnancy-newly associated with a heterozygous deficiency of long-chain 3-hydroxyacyl-CoA dehydrogenase and the patient carrying an affected (homozygous) fetus. In this rare condition (approximately 1 in 1000 deliveries), the patient presents with acute liver failure, renal failure, hypoglycemia which may lead to coma, bleeding diatheses, and metabolic acidosis. The maternal and fetal mortality is approximately 25%.

·         The most common risk factor for Premature Cervical Dilation (PCD) is a history of previous PCD. Congenital cervical hypoplasia and intrauterine diethylstilbestrol (DES) exposure have been reported as risk factors for PCD. Acquired risk factors include previous trauma to the cervix. Cervical conization, amputation, obstetric laceration, and forceful dilatation are examples of such traumas.

·         Fetal fibronectin assays of cervical samples have a high negative predictive value and therefore are used to rule out preterm labor.

Preterm labor does not occur at an increased frequency in diabetic women.

·         Face presentations can deliver vaginally if mentum anterior, but brow presentations are unstable and convert either to face or vertex presentation.

·         An initial spontaneous abortion, irrespective of the karyotype or sex of the child, does not change the risk of recurrence in a future pregnancy. The rate is commonly quoted as 15% of all known pregnancies.

In spontaneous losses, trisomy 16 is the most common trisomy, with 45,X the most common single  abnormality found. At term, trisomy 16 is never seen and 45,X is seen in approximately 1 in 2000 births. It is estimated that 99% of 45,X and 75% of trisomy 21 conceptuses are lost before term.

·         EXERCISE & PREGNANCY:

Women with uncomplicated pregnancies can continue to exercise during pregnancy if they had previously been accustomed to exercising prior to becoming pregnant. Studies indicate that well-conditioned women who maintain an antepartum exercise program consisting of aerobics or running have improved pregnancy outcomes in terms of shorter active labors, fewer cesarean section deliveries, less meconium-stained amniotic fluid, and less fetal distress in labor. On average, women who run regularly during pregnancy have babies that weigh 310 g less than women who do not exercise during pregnancy. Even though birth weight is reduced in exercising pregnant women, there is not an increased incidence of intrauterine growth retardation. The American College of Obstetricians and Gynecologists recommends that women avoid exercising while in the supine position to avoid a decrease in venous return to the heart, which results in decreased cardiac output. In addition, women should modify their exercise based on symptoms. There is not set pulse above which exercise is to be avoided; rather, women should decrease exercise intensity when experiencing symptoms of fatigue. Non-weight-bearing exercises will minimize the risk of injury. Since the physiologic changes associated with pregnancy will persist from 4 to 6 weeks following delivery, women should not resume the intensity of prepregnancy exercise regimens immediately following delivery.

·         This significant arterial hypotension resulting from inferior vena cava compression is known as supine hypotensive syndrome or inferior vena cava syndrome. Therefore, it is not recommended that women remain in the supine position for any prolonged period of time in the latter part of pregnancy. When patients describe symptoms of the supine hypotensive syndrome, there is no need to proceed with additional cardiac or pulmonary workup.

·         ROUND LIGAMENT PAIN: Each round ligament extends from the lateral portion of the uterus below the oviduct and travels in a fold of peritoneum downward to the inguinal canal and inserts in the upper portion of the labium majus. During pregnancy, these ligaments stretch as the gravid uterus grows further out of the pelvis and can thereby cause sharp pains, particularly with sudden movements. Round ligament pain is usually more frequently experienced on the right side due to the dextrorotation of the uterus that commonly occurs in pregnancy. Usually this pain is greatly improved by avoiding sudden movements and by rising and sitting down gradually. Local heat and analgesics may also help with pain control.

·         ECV has an average success rate of about 60%; it is most successful in parous women with an unengaged breech and a normal amount of amniotic fluid (all conditions that exist in the patient described).

·         A biophysical profile (BPP) is another type of antepartum surveillance test and involves using a real-time ultrasound device and Doppler ultrasound to record fetal heart rate. The BPP looks at the following variables: fetal heart rate accelerations (NST), fetal breathing, fetal movements, fetal tone, and amniotic fluid volume. To achieve a perfect score, the fetus must have a reactive NST, at least one episode of breathing lasting longer than 30 s within 30 min, at least three discrete body movements within 30 min, at least one extension-flexion movement of a limb within 30 min, and a single vertical pocket of amniotic fluid measuring 2 cm. A modified BPP entails performing an NST and assessing the amniotic fluid index; a reactive NST and an AFI greater than 5 is a normal or negative test. The false-negative rate for BPP and modified BPP is 0.8 in 1000.

·         The therapeutic range of serum magnesium to prevent seizures is 4 to 7 mg/dL. At levels between 8 and 12 mg/dL, patellar reflexes are lost. At 10 to 12 mg/dL, somnolence and slurred speech commonly occur. Muscle paralysis and respiratory difficulty occur at 15 to 17 mg/dL, and cardiac arrest occurs at levels greater than 30 mg/dL.

·         Spectinomycin is the treatment of choice for pregnant women who have asymptomatic N. gonorrhoeae infections and who are allergic to penicillin. Erythromycin is another drug that is effective in treating asymptomatic gonorrhea.

·         Pruritic urticarial papules and plaques of pregnancy (PUPPP) is the most common dermatologic condition of pregnancy. It is more common in nulliparous women and occurs most often in the second and third trimesters of pregnancy. PUPPP is characterized by erythematous papules and plaques that are intensely pruritic and appear first on the abdomen. The lesions then commonly spread to the buttocks, thighs, and extremities with sparing of the face. The first-line treatment for PUPPP is oral antihistamines and topical corticosteroids. If these treatments do not give relief, oral steroids should be administered. The rash will resolve quickly following delivery, but delivery would not be the first-line treatment.

Herpes gestationis is a blistering skin eruption that occurs more commonly in multiparous patients in the second or third trimester of pregnancy. The presence of vesicles and bullae help differentiate this skin condition from PUPPP.

Prurigo gestationis is a very rare dermatosis of pregnancy that is characterized by small, pruritic excoriated lesions that occur between 25 and 30 weeks. The lesions first appear on the trunk and forearms and can spread throughout the body as well.

In cases of intrahepatic cholestasis of pregnancy, bile acids are cleared incompletely and accumulate in the dermis, which causes intense itching. These patients develop pruritus in late pregnancy; there are no characteristic skin changes or rashes except in women who develop excoriations from scratching.

Impetigo herpetiformis is a rare pustular eruption that forms along the margins of erythematous patches. This skin condition usually occurs in late pregnancy. The skin lesions usually begin at points of flexure and extend peripherally; mucous membranes are commonly involved. Patients with impetigo herpetiformis usually do not have intense pruritus, but more commonly have systemic symptoms of nausea, vomiting, diarrhea, chills, and fever.

·         Three techniques for cervical cerclage are used today.

1. Shirodkar technique. In the more complicated of the two procedures using a vaginal approach, the suture is almost completely buried beneath the vaginal mucosa at the level of the internal os. It can be left in place for subsequent pregnancies if a cesarean section is performed. This procedure requires dissection of the bladder and is associated with an increased blood loss.
2. McDonald technique. This procedure is a simple purse-string suture of the cervix and is simpler, incurring less trauma to the cervix and less blood loss than the Shirodkar procedure (Fig. 12-4).
3. Abdominal placement. This uncommon, permanent procedure is used in women with a short or amputated cervix or in those in whom a vaginal procedure has failed. Cesarean birth is necessary for delivery.

·         When tocolysis requires multiple agents, chorioamnionitis must be considered.

·         Current IUD use, not past IUD use, places the patient at risk for ectopic pregnancy. Chronic endometritis is not associated with ectopic pregnancy because this inflammation does not involve the fallopian tubes. Age is not a risk factor for ectopic pregnancy

Prenatal Care

·         Estrogen activates oxytocin secretion and myometrial gap junction formation.

Progesterone suppresses production of maternal lymphocytic cytokines, which contribute to immune rejection of the fetus. Progesterone produced by the corpus luteum is essential for pregnancy maintenance until the eighth week. Progesterone suppositories are prescribed during the first 8 weeks of gestation in women with suspected corpus luteum deficiency.

hCG regulates fetal testicular testosterone production, which is critical for the development of male external genitalia. Elevated hCG is the most sensitive serum marker for Down syndrome. Abnormally high levels of hCG are seen in multiple gestation (twins).

hPL induces lipolysis, which provides energy for the mother in the form of fatty acids. hPL also provides energy for the fetus by elevating ketone levels.

Prolactin is produced not only by the decidual tissue of the uterus, but also by the maternal and fetal pituitary glands. Lactation does not occur during pregnancy because estrogen inhibits the action of prolactin on the breast.

Low levels of estriol are associated with placental sulfatase deficiency.

 Anencephaly contributes to lack of ACTH production; therefore, the fetal adrenal cortex is not stimulated properly to convert pregnenolone to DHEA and DHEAS, which are essential in the production of estriol.

·         The differential diagnosis of recurrent spontaneous abortions in women includes deficiencies of protein C and protein S, and the presence of the lupus anticoagulant, which is part of the anti-phospholipid syndrome.

·         It is not uncommon for patients with osteogenesis imperfecta type II—the lethal form—to have dozens of fractures before birth. Osteogenesis imperfecta types I and III, which are compatible with life and may cause blue scleras (type I), are often not detectable before birth.

·         Anencephaly is, of course, incompatible with life and is the only condition for which a termination of pregnancy is generally permissible at any gestational age.

The incidence of neural tube defects in the general population is approximately 1.4 to 2.0/1000. It is a multifactorial defect and is not influenced by maternal age. Women who have a previously affected child have a neural tube defect recurrence risk of about 3 to 4%. A chorionic villus sampling will determine a fetus’s chromosomal makeup but will give no information regarding AFP levels or risk for a neural tube defect. Hyperthermia at the time of neural tube formation in the embryo, as can occur with maternal fever or sauna baths, can increase the relative risk of a neural tube defect up to sixfold.

·         Vaccines for measles and mumps are generally considered to be contraindicated in pregnancy as these are live viruses, although the rubella vaccine, which is known to have been administered inadvertently to over 1000 pregnant women, has never caused a problem and in fact can be used in selected circumstances of exposure. No cases of congenital rubella syndrome have been reported in this group of patients.

Administration of rabies vaccine is unaffected by pregnancy.

Immunization for yellow fever is recommended before travel to a high-risk area. ( confusion ??)

·         Moderate consumption of coffee has not been associated with any fetal risks. Consumption of more than five cups of coffee a day has been shown to be associated with a slightly increased risk of spontaneous abortion in some studies. Cocaine use has been associated with an increased incidence of placental abruption and a constellation of congenital anomalies (skull defects, disruptions in urinary tract development, limb defects, and cardiac anomalies). Marijuana has not been associated with any adverse fetal effects. Lysergic acid diethylamide (LSD) has not been found to be a human teratogen. Tobacco use has been associated with a number of adverse pregnancy outcomes including spontaneous abortion, preterm labor, growth restriction, placental abruption, placenta previa, and attention deficit disorder and behavior and learning problems.

·         Chorionic villus sampling performed at a gestational age of less than 9 weeks has been associated with fetal limb reduction defects.

·         A high level of hCG in the second trimester is the most sensitive marker for Down syndrome. A high level of hCG in the first trimester is suggestive of molar pregnancy. hCG is part of the quadruple screen in the second trimester, not the first trimester. A low level of hCG is suggestive of ectopic pregnancy. hCG stimulates production of TSH, not TRH, leading to hyperthyroidism.

·         Ultrasound examination in the first trimester provides the most accurate dating. Measurement of the crown-rump length (CRL) is accurate to within 5 to 7 days of the actual gestational age. Second- and third-trimester ultrasound uses several parameters for determining gestational age. These parameters include the biparietal diameter (BPD), the femur length (FL), and the abdominal circumference (AC). In the second trimester, the BPD is the most accurate but only to within 14 days of the actual gestational age. Measurements in the third trimester may have an error up to ±21 days of the actual gestational age.