Obstetrics Exam Notes
Urinary Tract Infections (UTIs)
Most common infections in pregnant and nonpregnant women.
Acute cystitis:
Occurs in about 1% to 2% of pregnant women.
Signs and symptoms: urgency, frequency, hematuria, pyuria, and dysuria.
UTIs are characterized as:
Asymptomatic (e.g., asymptomatic bacteriuria).
Symptomatic (e.g., lower [cystitis] or upper [pyelonephritis]).
Escherichia coli is the primary cause of infection in 70% to 80% of cases.
Other gram-negative rods (Enterobacter, Klebsiella, and Proteus) and Group B Streptococcus (GBS) account for some infections.
The presence of GBS in the urine indicates heavy colonization of the genitourinary tract, increasing the risk for GBS infection in the newborn.
Incidence of asymptomatic bacteriuria ranges from 2% to 10%. Untreated, bacteriuria progresses to pyelonephritis in approximately 40% of pregnant women.
Screening pregnant women for asymptomatic bacteriuria should occur early in pregnancy, up to 16 weeks gestation, with urine culture as the gold standard.
Rapid screening tests (dipsticks) should be avoided due to the potential for false-negative results.
UTI Treatment
Treatment of asymptomatic bacteriuria and acute cystitis is necessary to prevent pyelonephritis and preterm delivery.
Treatment courses for asymptomatic bacteriuria and cystitis are commonly 3 to 7 days.
Beta-lactams (penicillins and cephalosporins) have been widely used.
Increasing resistance to ampicillin and amoxicillin limits their use as single agents.
Nitrofurantoin:
Considered first-line by ACOG.
Not active against Proteus species.
Should not be used after week 37 in patients with glucose-6-phosphate dehydrogenase deficiency because of a theoretical risk for hemolytic anemia in the neonate.
Sulfa-containing drugs:
Can contribute to the development of newborn kernicterus; avoid during the last weeks of gestation.
Trimethoprim is a folate antagonist and is relatively contraindicated during the first trimester due to associations with cardiovascular malformations.
Fluoroquinolones and tetracyclines are contraindicated because of potential associations with impaired cartilage development and deciduous teeth discoloration (if given after 5 months of gestation, respectively).
Pregnancy Considerations (Sulfamethoxazole and Trimethoprim)
Sulfamethoxazole and trimethoprim cross the placenta.
Increased risk of congenital malformations (neural tube defects, cardiovascular malformations, urinary tract defects, oral clefts, club foot) has been observed following maternal use.
Trimethoprim interferes with folic acid metabolism, decreasing maternal levels.
Adequate maternal folic acid supplementation may decrease the risk of some birth defects.
Due to theoretical concerns that sulfonamides cross the placenta and may cause kernicterus in the newborn, neonatal health care providers should be informed if maternal sulfonamide therapy is used near the time of delivery.
Avoidance of sulfamethoxazole/trimethoprim during the third trimester is recommended by some guidelines.
The pharmacokinetics of sulfamethoxazole and trimethoprim are similar to nonpregnant pharmacokinetic values in early pregnancy.
Recommended for treatment and prophylaxis of Pneumocystis jirovecii pneumonia (PCP) in pregnant patients with HIV because of the considerable maternal benefits of therapy.
Supplemental folic acid at high doses (>0.4 mg/day) may be considered during the first trimester only.
Fetal ultrasound is recommended at 18 to 20 weeks' gestation to evaluate fetal anatomy.
Recommended for primary treatment of symptomatic Isospora belli infection and secondary prophylaxis in pregnant patients with HIV.
Treatment for secondary prophylaxis can be withheld during the first trimester due to concerns of birth defects.
Recommended for primary prophylaxis of Toxoplasma gondii encephalitis (TE) in pregnant patients with HIV.
The risks of fetal exposure should be balanced with the risk of TE.
Recommended for the acute treatment of Q fever (Coxiella burnetii) in pregnant patients.
Untreated first trimester maternal infection may lead to miscarriage; premature delivery may occur when infection occurs later in pregnancy.
Treatment decreases the risk of adverse pregnancy outcomes and adverse events in subsequent pregnancies.
Treatment with sulfamethoxazole/trimethoprim is recommended throughout pregnancy up to 32 weeks' gestation.
Monitoring should continue for 24 months after delivery to evaluate possible progression to chronic disease.
Approved for the treatment of urinary tract infections (UTIs) in adults.
Some guidelines prefer alternative antibiotics for UTIs in pregnancy and avoiding use in the third trimester.
Not recommended for the treatment of granuloma inguinale during pregnancy.
May be used as part of a treatment regimen when brucellosis is diagnosed during pregnancy.
Treatment with sulfamethoxazole/trimethoprim is not recommended after 36 weeks' gestation due to the risk of kernicterus.
Used in the management of plague (Yersinia pestis).
Treatment and prophylaxis can be used regardless of trimester.
Pregnancy Considerations (Nitrofurantoin)
Nitrofurantoin crosses the placenta.
Studies evaluating maternal use of nitrofurantoin during pregnancy and the development of congenital anomalies have had mixed results.
An increased risk of neonatal jaundice was observed following maternal nitrofurantoin use during the last 30 days of pregnancy.
Pregnancy-induced physiologic changes may alter some pharmacokinetic properties of nitrofurantoin.
Maternal serum concentrations may be decreased and urine concentrations may be increased during pregnancy.
Treatment with a targeted antibiotic is recommended when asymptomatic bacteriuria or acute cystitis are diagnosed.
According to the manufacturer, nitrofurantoin is contraindicated in pregnant patients at term (38 to 42 weeks' gestation), during labor and delivery, or when the onset of labor is imminent due to the possibility of hemolytic anemia in the newborn.
Nitrofurantoin may be used in the first trimester when alternative antibiotics cannot be used and may be considered as a first-line antibiotic in the second and third trimesters.
Avoid use in pregnant patients with G6PD deficiency.
Pyelonephritis
Patients usually present with bacteriuria and systemic symptoms of:
Costovertebral angle tenderness, dysuria, fever, flank pain, nausea, and vomiting.
Complications include:
Premature delivery, low infant birth weight, and maternal morbidity (e.g., hypertension, anemia, acute kidney injury, sepsis, and acute respiratory distress syndrome).
Hospitalization is standard of care for pregnant women with pyelonephritis.
Inpatient therapy has included parenteral administration of:
Second- or third-generation cephalosporins (e.g., cefuroxime and ceftriaxone), ampicillin plus gentamicin, or ampicillin–sulbactam.
Switching to an oral antibiotic can be considered after the patient has been afebrile for 48 hours; nitrofurantoin should be avoided because it does not achieve therapeutic levels outside of the urine.
Outpatient antibiotic therapy can be considered after initial inpatient observation in women who are afebrile and less than 24 weeks of gestation.
The total duration of antibiotic therapy for acute pyelonephritis is controversial, with some recommending 7 to 14 days and others recommending 10 to 14 days.
Treatment of acute cystitis is similar to that of asymptomatic bacteriuria; duration is 7-10 days.
Acute pyelonephritis complicates 1-2% of pregnancies.
Usually, hospitalization + parenteral cephalosporins (e.g., cefazolin or ceftriaxone), ampicillin with gentamicin, or ampicillin-sulbactam.
Outpatient antibiotic therapy (cephalexin) can be considered if a woman has been afebrile for 48 hrs & symptoms have resolved.
Total duration of antibiotic therapy for acute pyelonephritis is 10-14 days.
Up to 23% of women may experience recurrence → suppression therapy with nitrofurantoin 100 mg nightly is recommended for the duration of pregnancy.
Epilepsy
When possible, antiepileptic drug monotherapy is recommended with medication regimen optimization occurring before conception.
If gradual drug withdrawal is attempted because of epilepsy remission, it should be fully completed and evaluated before trying to conceive.
Medication change to avoid use of valproic acid and phenobarbital is suggested; however, if either is used during pregnancy because of treatment failure with other medications, the lowest effective dose should be used.
All women taking antiepileptic drugs should receive folic acid supplementation: 4 to 5 mg daily starting before pregnancy and continuing through at least the first trimester, but preferably through the entire pregnancy.
Asthma
Risks of medication use to the fetus are lower than the risks of untreated asthma; therefore, use of medications to achieve and maintain control is warranted.
Treatment recommendations are divided into multiple steps based on symptom control and follow a stepwise approach.
Once control is achieved, maintenance of control at the lowest controlling step is the overall goal; however, stepping down may be delayed until after delivery because of the potential effects of exacerbation on pregnancy outcomes.
Budesonide is the preferred ICS, but any may be used; alternatives are cromolyn (less effective), leukotriene receptor antagonists (less experience in pregnancy), and theophylline (more potential toxicity).
Systemic corticosteroids recommended to gain control in patients with most severe disease.
Allergic Rhinitis
Pre-existing or newly developed allergic rhinitis occurs during pregnancy.
Nasal congestion can be caused by pregnancy because of vascular engorgement in the nasal passages and hormonal effects on mucus secretion.
Treatment strategies for allergic rhinitis during pregnancy are similar to those used in nonpregnant women and include avoidance of allergens, immunotherapy, and pharmacotherapy.
Oral antihistamines and leukotriene receptor antagonists, as well as intranasal antihistamines, decongestants (limit duration because of the risk for drug-induced rhinitis), cromones, and corticosteroids can be used. Oral corticosteroids should be of short duration to limit exposure to the fetus.
Immunotherapy is not contraindicated in pregnancy, but dose increases during pregnancy are not advised in order to lessen the risk for anaphylaxis.
Preterm Labor
Preterm labor occurs between 20 and 37 weeks of gestation when changes in cervical dilation and/or effacement happen along with regular uterine contractions, or when the initial presentation includes regular contractions and cervical dilation of at least 2 cm.
Bed rest and hydration do not decrease the risk of preterm birth and should not be recommended routinely as they carry risks of VTE, bone demineralization, and deconditioning.
The purposes of tocolytic therapy are threefold:
(a) postpone delivery long enough to allow for the maximum effect of antenatal corticosteroid administration; (b) allow for transportation of the mother to a facility equipped to deal with high-risk deliveries; and (c) prolongation of pregnancy when there are underlying, self-limited conditions that can cause labor, such as pyelonephritis or abdominal surgery, that are unlikely to cause recurrent preterm labor.
Four classes of tocolytics are available in the United States:
β-agonists, magnesium, calcium channel blockers, prostaglandin inhibitors (i.e., NSAIDs).
All four therapies prolong pregnancy between 48 hours to 1 week; however, this prolongation is not associated with a statistically significant reduction in overall rates of respiratory distress syndrome, neonatal death, or preterm birth before 37 weeks of gestation.
Prostaglandin inhibitors and calcium channel blockers may be preferable based on the probability of delaying delivery and improving neonatal outcomes.
Nifedipine is associated with fewer side effects than magnesium or β-agonist therapy and decreases the risk of delivery within 7 days compared to β-agonists.
NSAIDs, such as indomethacin, have been used effectively for tocolysis.
An increased rate of premature constriction of the ductus arteriosus has been noted in infants with indomethacin use after 32 weeks of gestation and with use exceeding 48 hours.
Indomethacin may be used when tocolysis is needed despite treatment with magnesium for neuroprotection because other agents, such as calcium channel blockers and β-agonists, can cause hypotension when administered concurrently with magnesium.
If a patient experiences preterm premature rupture of membranes (PPROM) before 34 weeks of gestation, prophylactic antibiotics should be initiated because a reduction in major morbidities (i.e., death, respiratory distress syndrome, early sepsis, severe intraventricular hemorrhage, and necrotizing enterocolitis) was demonstrated.
A 7-day course of broad-spectrum antibiotics should be used with the intent to prolong latency, which is the time from ruptured membranes to delivery.
One recommended regimen is ampicillin (2 g IV every 6 hours) plus erythromycin (250 mg IV every 6 hours) for 48 hours, followed by amoxicillin (250 mg orally three times daily) and erythromycin base (333 mg orally every 8 hours), although multiple regimens have shown benefit.
Induction of labor is recommended at 34 weeks gestation as prolonging delivery may increase the risk of chorioamnionitis.
Progesterone administration in the setting of prior preterm birth is based upon its effects to:
diminish cervical ripening (softening of the cervix necessary for cervical dilation before birth
reduce uterine wall contractility,
and modulate inflammation.
Use of intramuscular 17-α-hydroxyprogesterone weekly (250 mg) starting between weeks 16 and 24 continued through week 36 in women with a previous spontaneous preterm birth is recommended.
Group B Streptococcus (GBS) Intrapartum Prophylaxis
Between 10 & 30% of pregnant women are colonized with group B Streptococcus (GBS).
Maternal infection with GBS is associated with invasive disease in the newborn (bacteremia, pneumonia, meningitis, & fatality).
Mortality rate for GBS is 5-20%.
GBS infection causes maternal UTI, amnionitis, endometriosis, & wound infection.
Recommendations for prevention of GBS infection were last updated in 2010.
Universal prenatal screening for GBS colonization is recommended.
Antibiotics are given if the woman previously gave birth to an infant with invasive GBS disease or in the presence of GBS bacteriuria.
All other pregnant women should have a vaginal/rectal culture at 35 to 37 weeks of gestation. If negative, antibiotics are not indicated.
If a woman presents in labor and no screening information is available, antibiotics are given for fever greater than 100.4°F (°C), membrane rupture at least 18 hours prior, or gestation under 37 weeks.
Penicillin G 5 million units given IV, followed by 2.5 million units given every 4 hours until delivery is the recommended treatment regimen.
Alternatively, ampicillin 2 g can be given IV, followed by 1 g every 4 hours.
For women with penicillin allergy but not at risk for anaphylaxis, cefazolin 2 g IV, followed by 1 g every 8 hours, is recommended.
In women at high risk for anaphylaxis, clindamycin 900 mg IV every 8 hours is recommended.
For penicillin-allergic women, GBS cultures should be sent for sensitivities. If resistant to clindamycin or erythromycin, vancomycin 1 g IV every 12 hours until delivery is appropriate.
Antenatal Corticosteroids
Use of antenatal corticosteroids for fetal lung maturation to prevent respiratory distress syndrome, intraventricular hemorrhage, necrotizing enterocolitis, and death in infants delivered prematurely is recommended by ACOG.
The current clinical recommendation is to administer betamethasone 12 mg intramuscularly every 24 hours for two doses or dexamethasone 6 mg intramuscularly every 12 hours for four doses to pregnant women between 24 and 34 weeks of gestation who are at risk for preterm delivery within the next 7 days.
The greatest benefit from antenatal steroids is seen at 2 to 7 days after the initial dose.
Stages of Labor
Weak, irregular, rhythmic contractions (“false labor”) may happen for weeks before the onset of true labor.
1st stage begins with the start of regular uterine contractions & ends with complete cervical dilation, from 3-4 cm to usually 10 cm.
2nd stage starts with complete cervical dilation & ends with delivery of the fetus.
3rd stage: time between delivery of the fetus & delivery of the placenta.
Labor Induction
Indications: when continuation of pregnancy jeopardizes maternal or fetal health (e.g., preeclampsia, chorioamnionitis [infection of fetal membranes], fetal demise, IUGR, Rho(D) alloimmunization, maternal medical problems, post-term pregnancy.
Contraindications (= to those for spontaneous labor & vaginal delivery), e.g., active genital herpes infection, placenta previa (abnormally implanted placenta), prior classic uterine incision, transverse fetal lie, prolapsed umbilical cord.
If uterine activity is monitored, induced labor yields similar outcomes to spontaneous labor.
Assessment of both mother & fetus before inducing labor
Previous labor complications or cesarean deliveries should be considered.
Fetal maturity must be assessed accurately to avoid inadvertent delivery of a preterm fetus.
Every attempt should be made to ensure fetal lung maturation before inducing labor when termination of pregnancy is necessary before 34 weeks‘ gestation, & antenatal corticosteroids should be administered.
Success of labor induction depends on the degree of cervical ripeness → the cervix is assessed using a pelvic scoring method.
Cervical Ripening and Labor Induction
Scoring systems have been used to determine the likelihood of successful labor induction.
The Bishop scoring system is most commonly used and is based on five parameters:
cervical dilation,
cervical effacement (thinning),
station of the baby’s head,
consistency of the cervix,
and position of the cervix.
A Bishop score under 6 indicates the need for cervical ripening while a score above 8 corresponds to a likely successful vaginal delivery.
Use of a Foley catheter placed in an unfavorable cervix for ripening has been found as effective as prostaglandin E2.
Membrane stripping and amniotomy can also be performed and increase contractions via the release of prostaglandins.
Prostaglandin E2 analogs (eg, dinoprostone [Prepidil gel, Cervidil vaginal insert]) are commonly used for cervical ripening.
Misoprostol, a prostaglandin E1 analog, is an effective and inexpensive drug for cervical ripening and labor induction. Intravaginal administration of 25 mcg misoprostol (oral tablets are split to obtain dose) given every 3 to 6 hours is at least as effective as other prostaglandin agents and results in a shorter time to delivery. Use of misoprostol is contraindicated in women with a previous uterine scar because of its association with uterine rupture, a catastrophic medical event.
Oxytocin is the most commonly used agent for labor induction after cervical ripening. By the end of pregnancy, the number of oxytocin receptors has increased by 300-fold. A solution of 10 mU/mL is used for infusion. Oxytocin is effective in both low-dose (physiologic) and high-dose (pharmacologic) regimens.
Labor Analgesia
During 1st phase of labor, women perceive visceral pain associated with uterine contractions.
During 2nd phase of labor, pain is associated with perineal stretching.
Pain perception is variable among women.
The first phase of labor occurs from the onset of labor to complete cervical dilation while the second phase of labor is the period of time between complete cervical dilation and delivery.
Nonpharmacologic Approaches
Warm water baths, intradermal injections of sterile water in the sacral area provide temporary pain relief but have not been shown to ↓ the use of pharmacologic pain treatments.
Acupuncture: sound studies are sparse.
Women who receive continuous support from women trained in labor support have: fewer operative vaginal deliveries, cesarean deliveries, and requests for pain medication.
Intradermal injections of sterile water in the sacral area provide short-term decreases in back pain during labor; however, requests for pain medication did not decrease in studies.
Acupuncture has also been used for pain relief decreases the need for analgesia, but more methodologically sound studies are needed.
The use of visualization and breathing techniques, yoga postures, massage, acupressure, and facilitated partner support show more women delivering vaginally, and they have been shown to reduce epidural use and shorten the second stage of labor.
Use of audioanalgesia (music or white noise), relaxation and breathing techniques, application of heat and cold, aromatherapy, acupressure, transcutaneous electrical nerve stimulation (TENS), and hypnosis have little to no evidence of effectiveness derived from randomized, controlled trials.
Pharmacologic Approaches to Labor Pain Management
Maternal request alone is a sufficient medical indication for labor analgesia.
Parenteral opioids are commonly used to alleviate labor pain. They are less effective than epidural analgesia, have more side effects, and possibly less reliable pain response.
Epidural analgesia: A catheter is introduced into the epidural space, and an opioid and/or an anesthetic (e.g., fentanyl and/or bupivacaine) is administered.
Combined spinal-epidural analgesia consists of injecting a single opioid bolus into the subarachnoid space to provide instant pain relief with additional use of a local anesthetic epidural. Compared with traditional epidurals, combined spinal-epidural anesthesia has a slightly shorter mean time to onset of effective analgesia.
Patient-controlled epidural analgesia allows the patient to control the amount and timing of the anesthetic. It results in a lower total dose of local anesthetics used over the course of labor compared with continuous epidural infusions and allows a reduction in the time between the onset of pain and administration of analgesia.
Nitrous oxide, as a 50% mixture with oxygen, can be employed in women desiring a non-medicated labor. It is less effective than epidural anesthesia, but is quickly reversible and does not limit the woman’s mobility.
Side effects of regional anesthesia include hypotension, pruritus, and inability to void.
Epidural analgesia is associated with prolongation of the second stages of labor, but it does not lead to higher numbers of instrumental deliveries, cesarean sections (for fetal distress), or maternal fever when compared to intravenous opioid therapy.
A rare complication of epidural anesthesia is puncture of the subarachnoid space leading to a severe headache, which occurs in approximately 1% of women. Other complications include hypotension, nausea, vomiting, itching, and urinary retention. Low back pain has not been associated with the use of epidural analgesia.
Postpartum Hemorrhage
The placenta is delivered after the delivery of the baby and is referred to as the third stage of labor.
Postpartum hemorrhage (PPH) is an obstetrical emergency and is a major cause of morbidity and mortality worldwide.
The traditional definition of PPH is loss of more than 500 mL of blood within 24 hours of a vaginal delivery or more than 1,000 mL after a cesarean section; however, ACOG now defines PPH as a cumulated blood loss of more than 1,000 mL regardless of delivery method or blood loss accompanied with signs and symptoms of hypovolemia within 24 hours after delivery.
Risk factors include prior PPH, previous cesarean delivery, a macrosomic fetus (birth weight of more than 4,000 g) or multiple gestation, preeclampsia, operative vaginal delivery, chorioamnionitis, abnormal placentation, and prolonged or augmented labor.
A stepwise approach to the treatment of PPH is advised. After the exclusion of retained products of conception and cervical and vaginal lacerations, attention should be turned to the management of uterine atony, if present, as this is the most common cause of PPH.
Administration of oxytocin should be initiated before placental delivery to institute active management of labor after all uncomplicated vaginal deliveries, as this practice results in reduced maternal blood loss, fewer cases of PPH, and a shorter third stage of labor.
Other uterotonic agents should be used if an inadequate response is attained with oxytocin alone. Methylergonovine, carboprost, and rectal, sublingual, or oral misoprostol can all be used as second-line agents; none has been shown to be more effective than another.
Tranexamic acid (TXA), an antifibrinolytic agent, has been shown to reduce maternal deaths from obstetric hemorrhage if given within 3 hours of delivery.
If uterotonic drug therapies fail to control the bleeding, uterine artery embolization, intrauterine balloon catheters, or a variety of different surgical techniques can be used.
Postpartum Hemorrhage Prevention
Uterine atony is the most common cause of postpartum hemorrhage.
Oxytocin is administered routinely following delivery of the placenta to promote uterine contraction & vasoconstriction.
Risks for atony: induction with oxytocin, prolonged labor, overdistended uterus, & previous postpartum hemorrhage.
Oxytocin is given 10-20 U IM or diluted in 0.5-1 L of parenteral fluid & given as IV infusion of 200 mU/min until the uterus is firmly contracted.
Should never be administered undiluted as a bolus dose (severe hypotension & cardiac dysrhythmias)
Misoprostol 400-600 mcg can be used PO in the 3rd stage of labor.
Was marginally but statistically < effective & had > ADRs.
Also can be administered rectally (<fever & shivering)
If no response to oxytocin → ergonovine maleate (Ergotrate) & its semisynthetic derivative, methylergonovine maleate (Methergine) can be used.
IM administration is associated with < frequent ADEs (N&V, HTN, HA, chest pain, dizziness, tinnitus, diaphoresis) than IV route.
Should be avoided in HTN & eclamptic patients (potential for arrhythmias, seizures, CVA, &, rarely, MI).
Dose of both drugs is 0.2 mg IM Q 2 hours as needed.
→ 0.2-0.4 mg administered PO 2-4 TD for 2-7 days to promote involution of the uterus
15-Methyl Prostaglandin F2 (Carboprost Tromethamine) (Hemabate)
Also used in the treatment of bleeding caused by uterine atony unresponsive to oxytocin.
Initial dose 0.25 mg IM followed by 0.25 mg Q 15-90 min.
The dose may be ↑ to 0.5 mg if the patient does not respond adequately to several 0.25-mg IM doses.
Total cumulative dose should not exceed 2 mg.
Is effective in 60-85% of women with uterine atony who have failed standard treatment.
ADRs: N&V, diarrhea, flushing & fever- frequently.
HTN - rare, in pre-existing HTN or pre-eclampsia.
Can cause uterine rupture, pulmonary & cardiac problems.
Contraindicated in women with active pulmonary, cardiac, renal, or hepatic disease, acute pelvic inflammatory disease.
Drug Use During Lactation—General Concepts
A wide variety of benefits (e.g., health, nutritional, immunologic, psychological, economic, developmental, and social) are imparted by breastfeeding, not only to the infants but also to mothers and the family.
Women should breastfeed exclusively for 6 months and continue until at least 12 months of age while other foods are introduced.
Adequate milk removal from the breast by breastfeeding or pumping is necessary to maintain or increase milk production.
Relactation is the process of increasing the breast milk supply for women whose milk has not “come in,” who have inadequate milk production despite appropriate breastfeeding frequency or pumping, or who have weaned or never breastfed after delivery.
Metoclopramide can be used if nonpharmacologic measures are ineffective due to its stimulation of prolactin secretion. The most common dose is 10 mg orally three times daily for 7 to 14 days. Breast milk production may decrease after metoclopramide therapy is stopped, but production will continue if lactation has been established successfully.
Most drugs transfer into breast milk, but breastfeeding may be continued in most circumstances.
Healthcare providers should encourage breastfeeding women who require medications to continue breastfeeding whenever possible.
Strategies for reducing the risk to the infant include:
selection of medications that would be considered safe for use in the infant. Drugs with shorter half-lives accumulate less, and those that are more protein bound do not cross into breast milk as well as those that are less protein bound.
When choosing between different pharmacotherapies, drugs with lower oral bioavailability and lower lipid solubility may be better choices to reduce infant exposure.
If the mother is using a once-daily medication, administration before the infant’s longest sleep period may be advised to increase the interval to the next feeding.
For medications taken multiple times per day, administration immediately after breastfeeding provides the longest interval for back diffusion of drug from the breast milk to the mother’s serum.
During short-term drug therapy, the mother can pump and discard milk to preserve her milk-producing capability if the necessary medication is not considered compatible with breastfeeding.
Mastitis
Mastitis is inflammation of the breast that occurs in 3% to 20% of lactating women.
It can be infectious or noninfectious and the most common cause is milk stasis.
Signs and symptoms include breast tenderness, redness, warmth, flulike symptoms, and fever (temperature 101.3°F [38.5°C] or greater).
Risk factors for developing mastitis include breast engorgement, plugged milk ducts, oversupply of milk, and cracked nipples.
Penicillin-resistant Staphylococcus aureus is the most common bacterial cause of mastitis; E. coli and Streptococcus have also been implicated.
A 10- to 14-day course of antibiotics is usually given for the treatment of mastitis; penicillinase-resistant penicillins (e.g., dicloxacillin, oxacillin) and cephalosporins (e.g., cephalexin) are frequently prescribed.
Antiinflammatory drugs, such as ibuprofen, may provide some pain relief.
Application of heat may also be helpful along with direct massage of the affected area, if tolerated.
Affected women should be counseled to continue breastfeeding from both breasts throughout treatment and to pump if breasts are not emptied completely with feedings.
Mood disorders in the postpartum period
Mood disorders in the postpartum period may include postpartum blues, postpartum depression, and postpartum psychosis.
Postpartum blues (“baby blues”) is common, usually affecting 15% to 85% of new mothers within the first 10 days of delivery, and generally does not require treatment.
Symptoms include anxiety, anger, fatigue, insomnia, tearfulness, and sadness.
Postpartum psychosis is more severe and can present as mania, psychotic depression, or schizophrenia but is rare, affecting less than 1% of new mothers; hospitalization is usually indicated.
Postpartum depression affects up to 13% of women, with almost 5% experiencing major depression.
Symptoms may develop during pregnancy or up to 6 months after delivery, although the strict definition for major depressive disorder after delivery specifies symptom occurrence within 4 to 6 weeks.
Psychotherapy, including interpersonal psychotherapy, cognitive behavioral therapy, and group/family therapy, has been shown to be effective for the treatment of postpartum depression.
Some suggest that the benefits of breastfeeding to the infant exceed the risks of antidepressant exposure in mothers with postpartum depression.
In cases where pharmacotherapy is warranted, the selection of medication with low transfer to breast milk is desirable. Sertraline, paroxetine, fluoxetine, and nortriptyline are the most studied in the postpartum period.
Given that long-term effects of exposure to antidepressants are largely unknown, monitoring growth and neurodevelopment should be considered for children exposed to antidepressants present in breast milk.