< 14 hours Highly variable > 1.2 cm/'lir dilation 5-30 munîtes 0-30 minutes Up lo 48 hours

Protraction disorder: occurs once true labor has begun if the mother takes longer than she shouldaccording to the above table. Arrest disorder occurs oikv true labor has begun if no change in dilation (as opposed to the slow change of protraction disorder) occurs over 2 hours or if no change occ urs in descent: over 1 hour. First, rule out abnormal lie or cepbalopeivic dis proportion. If everything is okay, treat with labor augmentation (oxytocin, prostaglandin gel, atrmiotomy). If this approach does not work, manage expectantly and do a cesarean section at the first sign of trouble. The most common canst: of failure to progress (protraction or arrest disorder), also known as dystocia (difficult birth), is ceph.alopel.vic disproportion, defined as disparity between the size of the infant's head and the mother's pelvis. Labor augmentât ton is con irai ndicated in thi s set ting.

True labor: normal contractions occur at least every 3 minutes, are fairly regular, and are asso -eiated with cervical changes (effacement and dilation). False labor (Braxton Flicks contractions) is characterized by irregular contract ions with no cervical changes. You may try oxytocin to augment ineffective uferine contractions. Watch out for uterine hypi-rst¡initiation (painful, overly frequent, arid poorly coordinated uterine contractions), uterine rupture, fetal heart rate decelerations, and water intoxication (from the antidiuretic hormone like1 effect of oxytocin). Treat all of these symptoms by first discontinuing oxytocin infusion (half- life ~ < 10 minutes), Prostaglandin E2 (dinoprostone) also may be used locally to induce ("ripen") the cervix and is highly effective in combination with (often before) oxytocin. Prostaglandin E2 also may cause uterine hyperstimulation. Amniotomy hastens labor but exposes the fetus and uterine cavity to possible infection if labor does not occur.

Contraindications to labor induction and augmentation (similar to contraindications to vaginal delivery) :

® Placenta or vasa previa

» Umbilical cord prolapse or presentation a Prior classic uterine cesarean section incision ii Transverse fetal lie m Active genital lu-rpes sa Known cervical cancer

« Known cepbalopeivic disproportion

Abortion; defined as termination of a pregnancy at < 20 weeks (fetus < 500 gm).The follow ing specific terms also imply (hat the event occurs at < 20 weeks' gestation:

1. Threatened abortion; uterine bleeding without cervical dilation and no expulsion of tissue. Treat with IV fluids (or blood, if needed), bedrest, pelvic rest, and Rhogam if the patient is Rh- negative. Do dilatation and curettage if thé fetus dies.

2. Inevitable abortion: uterine bleeding with cervical dilation, and erampy abdominal pain and no tissue expulsion.Treat with IV fluids, Rhogam if the patient is Rh negative, and di latation and curettage.

3. Incomplete abortion: passage of some products of conception through the cervix. Treat with IV fluids, Rhogam if the patient is Rh-negative, and dilatation and curettage.

4. Complete abortion: expulsion of all products of conception from the uterus. Treat with serial HC.'G testing to make sure that HCG drops to zero, do dilatation and curettage, and give Rhogam if the patient is Rh-negative.

5. Missed abortion: fetal death with no expulsion of tissue (often for several weeks). Treat with dilatation and curettage if less than 14 weeks, attempted delivery if greater than I 4 weeks. Give Rhogam if the patient is Kh negative.

S. Induced abortion: intentional termination of pregnane y < 20 weeks; may be elective (requested by patient) or therapeutic (to maintain the health of the mother). 1. Recurrent abortion: two or three successive unplanned abortions. History and physical exam may show:

» Infectious etiology (Listeria, Mycoplasma, or Toxoplasma s pp., syphilis) a Environmental (alcohol, tobacco, drugs) « Diabetes mellitus » Hypothyroi di sm

Systemic lupus erythematosus (especially with positive antiphospbolipid/lupus autieo agulant antibodies)

s Cervical incompetence (watch for history of patient s mother taking diethylstilbestrol during pregnancy and patient with recurrent second-trimester abortions; treat future pregnancies with a cervical cerclage at 14 16 weeks)

® Congenital female tract abnormalities (correct if possible to restore fertility) h Fi broids (remove tliem)

m Chromosomal abnormalities (e.g., ma tenia l/paternal translocations)

HCG roughly doubles every two days in the first trimester of pregnancy. An HCG t hat stays the same or increases only slowly with serial testing indicates a fetus in trouble or fetal demise. A rapidly increasing HCG or one that does not decrease after delivery may indicate: a hydatiform mole or choriocarcinoma.The standard HCG home pregnancy test heroines positive roughly 2 weeks after conception.

Transvaginal ultrasound: detects intrauterine gestational sac: at roughly 5 weeks, fetal image at 6-7 weeks, and a beating heart at 8 weeks. Use this information in trying to determine the possibility of an ectopic pregnancy. If the patient's last menstrual period (I..VII') was 4 weeks ago and the pregnancy test is positive, you cannot rule out a uterine pregnancy with ultra sound. If, however, the patient's I,MP was 10 weeks ago and an ultrasound of the uterus shows no gestational sac, think of ectopic pregnancy. If I ICG is > 2000 mlU, you should be able to visualize a gestational sac with transvaginal ultrasound.

The major risk factor for ectopic pregnancy is a history of pelvic inflammatory disease (10-fold increase in ectopic pregnancies). Other risk factors include previous ectopic pregnancy, history of tubal sterilization or tuboplasty, pregnancy that occurs with an intrauterine device in place, and diethylstilbestrol exposure (which may cause tubal abnormalities in women ex posed in utero).

Classic symptoms of ectopic pregnancy are amenorrhea, vaginal bleeding, and abdominal pain. Patients also have positive HCG test. If you palpate an adnexal mass, yon may be palpating an ectopic pregnancy or a corpus luteum cyst, which may coexist with a tubal pregnancy or a threatened abortion (both may have similar symptoms). When in doubt and the patient is doing poorly (hypovolemia, shock, severe abdominal pain, or rebound tenderness), do a la -paroscopy for definitive diagnosis and treatment, if necessary. On rare occasions, euldocentc-sis is done in a stable patient to check for blood in the pouch of Douglas (with a ruptured ectopic pregnancy), but it has a high false negative rate. When culdocentesis is negative, la-paroscopy is still required. Therefore, do not choose culdocentesis unless laparoscopy is not a choice.

Tubal pregnancy, if stable and less than 3 cm in greatest diameter, can be treated with salpin gostomy and removal, leaving the tube open to heal on its own. If the patient is unstable- or the ectopic pregnancy has ruptured or is greater than 3 cm, salpingectomy is required. Give Rhogam after treatment for Kb negative patients.

Pregnancy and diabetes mellitus:

1. Problems with diabetic mothers in pregnancy: polyhydramnios, preeclampsia, and complications of d iabetes.

2. Problems in infants born to diabetic mothers: macrosomia and IUGR; respiratory distress syndrome; cardiovascular, colon, craniofacial, and neural tube defects; caudal regression syndrome (lower half of body incompletely formed). and postdelivery hypoglycemia in the fetus (from fetal islet cell hypertrophy due to maternal and thus fetal hyperglycemia). After birth, the infant is cut off'from the mother's glucose and the hypergly cemia goes away, but islet cells still overproduce insulin and cause hypoglycemia. Treat with IV glucose.

3. Treat diabetes mellitus with diet, exercise, and/or insulin (no oral hypoglycemics).Tighter control results in better outcomes for mother and infant. Check HbAlc to determine compliance and glucose fluctuations.

4. In evaluating amniotic fluid to determine fetal lung maturity, phosphatidylglycerol concentration is much better than the lecithin:sphingomyelin ratio when the mother is diabetic.

Fetal heart monitoring: routinely done, but its benefit is controversial. Fetal heart tones can be heard with Doppler at 10 -12 weeks and with a stethoscope at 16 20 weeks. At term the normal heart rate is 12.0- 160 bpm. Any value outside this range is worrisome. Know what a basic fetal heart strip with uterine contraction patterns looks like, and know the following abnormalities:

1. Early deceleration: peaks match up (fetal heart deceleration nadir and uterine contraction peak). Early deceleration signifies head compression (probable vagal response) and is normal.

2. Variable deceleration: variable with relation to uterine contractions. The most commonly encountered abnormality, variable deceleration signifies cord compression. Place the mother in a lateral decubitus position, administer oxygen by face mask, and. stop any oxytocin infusion. If bradycardia is severe (< 80-90 BPM) or does not resolve, measure fetal scalp pH.

3. Late deceleration: fetal heart deceleration comes after uterine contraction. Late deceleration signifies uteroplacental insufficiency and is the most worrisome pattern. First, place the mother in a lateral decubitus position, give oxygen by face mask, and stop oxytocin if it is being given. Next, give a tocolytic (beta,) agonist such as ritodrine or magnesium sulfate) and IV fluids if the mother is hypotensive (especially with epidural anesthesia). If late decelerations persist, measure fetal scalp pH.

4. Short-term variability (beat-to-beat variability): reflects the interval between successive heart beats. The normal value is 5 25 bpm. Variability consistently less than 5 bpm is worrisome, especially when combined with decelerations. Measure fetal scalp pH.

5. Long-term variability: a l -minute strip normally shows changes in the. baseline heart; rate. Less than 3 cycles per minute is worrisome, especially when combined with decelerations. Measure fetal scalp pH. Special warn my: long-term variability is decreased normally during fetal sleep.

6. Fetal tachycardia: > 1 60 bpm. Poor indicator of fetal distress unless prolonged or marked. Often associated with oxytocin administration, maternal fever, or intrauterine infection.

Mote: Any fetal scalp pH < 7.2 is an indication for immediate cesarean delivery. If pH > 7.2, continue to observe.

When shoulder dystocia occurs, tire first step is McRobert's maneuver (see figure, top of next page). Ask the mother to flex her thighs sharply against her abdomen.This maneuver may free the impacted shoulder. If it does not work, options are hunted. A cesarean section is usually the procedure of choice (after pushing the infant's head back up into the birth canal).

Third-trimester bleeding (very high yield): always do an ultrasound before a pelvic exam. Always do an ultrasound before a pelvic exam (written twice on purpose). The differential diagnosis includes the following:

1« Placenta previa: predisposing factors include mull ¡parity, increasing age, multiple gestation, and prior previa. This condition is why you always do an ultrasound before a pelvic exam. Bleeding is painless and may be profuse. Ultrasound is 95-1 00% accurate in diagnosis.

A, McRobert's maneuver with legs flexed on the maternal abdomen and chest. Angle of inclination of the pelvic area is increased when the legs are flexed (C) compared tu the legs being extended in lithotomy fS/;thiis, the shoulder of the infant may become disengaged. (From Ratcliffe SD, Byrd JE, Sakurnbut EL: Handbook of Pregnancy and Perinatal Care m Family Practice. Philadelphia, Hanley & Belfus, 1996, with permission.)

Cesarean section is mandatory for delivery, but you may try to admit with bed. and pelvic rest and tocolysis if the. patient is preterm and stable and. the bleeding stops.

2. Abruptio placentae: predisposing factors include hypertension (with or without preeclampsia), trauma, polyhydramnios with rapid decompression after membrane rupture, cocaine/tobacco use, and preterm premature rupture of membranes. Do not forget that the patient can have this condition without visible bleeding (blood contained behind placenta). Patients have pain, uterine tenderness, and increased uterine tone with hyperactive contraction pattern. Fetal distress also is present. Abruptio placentae may cause disseminated intravascular coagulation if fetal products enter the "maternal circulation. Ultrasound detects only 2% of cases. Treat with IV fluids (and blood if needed) and rapid delivery (vaginalpreferred).

3. Uterine rupture: predisposing factors include previous uterine surgery, trauma, oxytocin, grand multiparity (several previous deliveries), excessive uterine distention (e.g., multiple gestation, polyhydramnios), abnormal fetal lie, cephalopelvic disproportion, and shoulder dystocia. Uterine rupture is characterized by extreme pain of sudden onset and often associated with maternal hypotension or shock. Fetal parts may be felt in the abdomen, or the abdominal contour may change. Treat with immediate laparotomy and usually hysterectomy after delivery.

4. Fetal bleeding: usually from vasa previa or velamentous insertion of the cord. The major risk factor is multiple gestation (the higher the number of fetuses, the higher the risk). Bleeding is painless, and the mother is completely stable while the fetus shows worsening distress (tachycardia initially, then bradycardia as the fetus decompensates).The Apt test is positive on uterine blood and differentiates fetal from maternal blood, Treat with immediate cesarean section.

5. Cervical/"vaginal lesions: examples include herpes simplex virus, gonorrhea, chlamydial or candidal, infection.

6. Cervical/vaginal trauma: usually from intercourse.

1. Bleeding disorder: rarely presents before delivery (more common after delivery).

i. Cervical cancer: may occur in pregnant patients too!

9. "Bloody show": with cervical effacement, a blood-tinged mucous plug may be released from the cervical canal and heralds the onset of labor. This event" is normal and a diagnosis of exclusion.

Treatment: in all patients with third-trimester bleeding, start IV fluids and give blood, if needed. Give oxygen, and get complete blood count, coagulation profiles, and ultrasound. Set up fetal and maternal monitoring. Do drug screen if you are suspicious (cocaine causes placental abruption). Give Rlrogam if the mother is Rh-negative. The Kleibauer-Betke test quantifies fetal blood in maternal circulation and is used to calculate the dose of Rlrogam.

Preterm labor: defined as labor between 20- -37 weeks.Treat with lateral decubitus position, bed and pelvic rest, oral or IV fluids, and oxygen administration (all may stop the contractions). Then give a tocolytic: (beta■ agonist or magnesium sulfate) if no contraindications are present (heart disease, hypertension, diabetes niellitus, hemorrhage, ruptured membranes, cervix dilated > 4 cm). Patients may be discharged on oral tocolytic. Do not tocolyze the mother if it is dangerous to do so (preeclampsia, severe hemorrhage, chorioamnionitis, IIJGR, fetal demise, or fetal anomalies incompatible with survival). Often steroids are given with toeolysis (if the infant is 24-34 weeks old) to hasten fetal lung maturity.

Important points:

1. Quickening (when the mother first detects fetal movements) usually occurs at 18 -20 weeks in a primigrávida and I 6 -18 weeks in a multigravida.

2. Order of labor positions: descent, flexion, internal rotation, extension, external rotation, and expulsion

3. IgG is the only maternal antibody that crosses the placenta. An elevated neonatal IgM con cent rat ion is never normal, whereas an elevated neonatal IgG often represents maternal antibodies.

Rh incompatibility and hemolytic disease of the newborn: occur when the mother is Rh negative and the infant is Rh-positive. If both mother and lather are Rh-negative, there is nothing to worry about—-the infant will be Rh-negative. If the lather is Rh-positive, the infant has a SO/50 chance of being Rh-positive. If the potential for hemolytic disease exists, check maternal Rh antibody titers every month., starting in the seventh month. Give R ho gam automatically at 28 weeks and within 72 hours after delivery as well as alter any procedures that may cause transplacental hemorrhage (e.g., amniocentesis). An important point is that development of disease requires previous sensitization. In other words, if a nutiiparous mot her has never received. blood products, her first Rh-positive infant will not be affected by hemolytic disease (except in the rare case of sensitization during the first pregnancy from undetected fetomater-nal bleeding, which usually occurs later in the pregnancy and can be prevented by Rlrogam ad ministration at 28 weeks in most instances).The second Rh-positive infant, however, will be affected—unless you, the astute board taker/physician, administer Rhogam at 28 weeks and within 72 hours after delivery during the first pregnancy. Any history of blood transfusion, abortion, ectopic pregnancy, stillbirth, or delivery can cause sensitization. If you check mater nal Rh antibodies and they are strongly positive, Rhogam is worthless, because sensitization Iras already occurred. Rhogam administration is a good example of primary prevention.

® If not detected and prevented, Rh incompatibility leads to fetal hydrops (edema, ascites, pleural and pericardial effusions).

b Amniotic fluid spec irophoiomeiry gauges the severity of fetal hemolysis.

a Treatment of hemolytic di sease invol ves delivery if the fetus is mature-. Check lung maturity with the lecithin sphingomyelin ratio. Intrauterine transfusion is risky; pheuoba rbital helps the fetal liver to break down bilirubin by inducing enzymes.

m ABO blood group incompatibility also may cause hemolytic; disease of the newborn when (lie mother is type O and the infant is type A, B, or AB. Previous .sensitization is not required, because IgG antibodies, which can cross the placenta, occur naturally in patients with blood type O. Usually the disease is less severe than with Rh incompatibility, but treatment is the same. Other minor blood antigens also cause a reaction in rare cases.

Summary: Give Rhogam only when the mother is Rh-negative and the lather's blood type is unknown or Rh -positive. During routine prenatal care, check for Rh antibodies at the first visit, lithe test is positive, do not give Rhogam—you are too late. Otherwise, give routinely at 28 weeks and immediately after delivery. Also give Rhogam after an abortion, stillbirth, ectopic pregnancy, amniocentesis, chorionic: villus sampling, and any other invasive procedure during pregnancy that, may cause transplacental bleeding.

Note: ff fetal lungs are immature (lecithinsphingomyelin ratio <2:1 or prostaglandin-negative) and the fetus is between 24-34- weeks, corticosteroid administration may hasten lung maturity and thus reduce the risk of respiratory distress syndrome,

Premature rupture of membranes (PROM): rupture of the amniotic sac before the onset of labor. Diagnosis of rupture of the membranes (whether premature or not) is based on. history and sterile speculum exam, which will show (1) pooling of amniotic fl uid, (2) iertiiug pattern when the fluid is placed on a microscopic slide and allowed to dry, and/or (3) positive ni trazine test (nitrazine paper turns blue in presence of amniotic fluid). Ultrasound also should be done to assess amniotic fluid volume (as well as gestational age and any anomalies that may be present). Spontaneous labor often follows membrane rupture. If labor does not occur within 6 8 hours and the patient is at term, labor should be induced. If"the cervix is highly unfavorable, you can wait 24 hours to attempt induction. PROM carries an increased risk of infection, both to the mother (chorioamnionitis) and infant (neonatal sepsis, pneumonia, meningitis), usually from group B streptococci, Escherichia colt, or Listeria sp.

Preterm premature rupture of membranes (FPROM): PROM that occurs before. 36-37 weeks. Risk of infection increases with the duration of ruptured membranes. Do a culture and Gram stain of amniotic fluid. If they are negative, treat with pelvic and bed rest and frequent; follow-up. If positive for group B streptococci, treat the mother with penicillin, even if she is asymptomatic.

Chorioamnionitis: presents with fever and tender, irritable uterus (usually postpartum but may be antepartum in patients with PROM or PPROM). Do a culture and Gram stain of amniotic fluid, and treat with ampicillin while awaiting culture results.

Postpartum hemorrhage: defined as estimated blood loss > 500 ml during a vaginal delivery (> 1000 ml during cesarean section).The most common cause is uterine atony (75--80% of cases). Hemorrhage also may be caused by lacerations, retained placental tissue (placenta acc-reta, increta, or percreta), coagulation disorders (e.g.. disseminated intravascular coagulation, von Wiliebrand disease), low placental implantation, and uterine inversion. The major risk factor for retained placental tissue is previous uterine surgery or cesarean section. Treatment is usually a hysterectomy.

Uterine atony: caused by overdistention of the uterus (multiple gestation, polyhydramnios, macrosomia), prolonged labor, oxytocin usage, grand.multipar.ity (history of 5 or more deliveries), and precipitous labor (< 3 hr),Treat with dilute oxytocin infusion, and use bimanual compression and massage of the uter us while the infusion is running. If this approach fails, try ergonovine or another ergot drug (contraindicated with maternal hypertension) or prostaglandin I;2<x. If this approach also fails, do a hysterectomy (ligate the uterine vessels if the patient wants fertility).

With retained products of conception (which is probably the most common cause ofdduyd postpartum hemorrhage), remove the placenta manually to stop Weeding; then do curettage in the operating room under anesthesia. If placenta accreta or percreta is present (placental tissue grows into/through the myometrium), a hysterectomy is usually necessary to stop the bleeding.

With uterine inversion (the uterus inverts and can be seen outside the vagina, usually as a result of pulling too hard on the cord), put the uterus back in place manually (anesthesia maybe needed) and give IV fluids and oxytocin.

Postpartum fever: defined as temperature >100.4°F (38°C) for at least two consecutive days. Postpartum fever usually is due to endometritis. Important predisposing factors are PROM/PPROM, prolonged labor, frecprent vaginal exams during labor, and manual removal of placenta or retained placental fragments (good culture medium). Patients with endometritis have a tender uterus in addition to fever. Anaerobes usually are involved. Treat with broad-spectrum penicillin or cephalosporin; add clindamycin, metronidazole, and gentamicin if the patient is doing poorly. Before antibiotics, do cultures of endometrium, vagina, blood, and urine. Do not forget the easy causes of postpartum fever, such as urinary tract infection or atelectasis and pneumonia, especially after cesarean section.

■ if a postpartum fever does not resolve with broad-spectrum antibiotics, there are two main, possibilities: progression to pelvic abscess or pelvic thrombophlebitis. Get a CT scan, winch will show an abscess. If an abscess is present, it needs to be drained, if no abscess is seen on CT, think of pelvic thrombophlebitis, which presents with persistent spiking fevers and lack of response to antibiotics. Give heparin, for an easy cure (and diagnosis in retrospect).

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