Illness & Infections

Infectious Disease in Pregnancy

Antibacterials: Even more so than for other patients, antibacterials should not be given without strong evidence of a bacterial infection. Generally, penicillins, cephalosporins, macrolides, and sulfonamides are considered safe. Use of any antibacterial during pregnancy should be based on whether benefits outweigh risk, which varies by trimester. Severity of the infection and other options for treatment are also considered.

Most common maternal infections (eg, UTIs, skin and respiratory tract infections) are usually not serious problems during pregnancy, although some genital infections (bacterial vaginosis and genital herpes) affect labor or choice of delivery method. Thus, the main issue is usually use and safety of antimicrobial drugs. However, certain maternal infections can damage the fetus.

Bacterial vaginosis and possibly genital chlamydial infection predispose to premature rupture of the membranes and preterm labor. Tests for these infections are done during routine prenatal evaluations or if symptoms develop.

Genital herpes can be transmitted to the neonate during delivery, particularly if women have visible herpetic lesions or known infection with prodromal symptoms or if herpes infection first occurs during the late 3rd trimester (when the virus is likely to be excreted from the cervix at delivery). In such cases, delivery by cesarean section is preferred. If visible lesions or prodrome is absent, even in women with recurrent infections, risk is low, and vaginal delivery is possible. If women are asymptomatic, serial antepartum cultures do not help identify those at risk of transmission. If women have recurrent herpes infections during pregnancy but no other risk factors for transmission, delivery can sometimes be induced to occur between recurrences. When delivery is vaginal, cervical and neonatal herpesvirus cultures are done.


Diabetes Mellitus in Pregnancy
   
Gestational diabetes occurs in 1 to 3% of all pregnancies, but the rate may be much higher in certain groups (eg, Mexican Americans, American Indians, Asians, Indians, Pacific Islanders).

Diabetes during pregnancy increases fetal and maternal morbidity and mortality. Neonates are at risk of respiratory distress, hypoglycemia, hypocalcemia, hyperbilirubinemia, polycythemia, and hyperviscosity. Poor control of preexisting or gestational diabetes that occurs during organogenesis (up to about 10 wk gestation) increases risk of major congenital malformations. Gestational diabetes can result in fetal macrosomia (fetal weight > 4500 g at birth) even if plasma glucose is kept nearly normal.

Treatment

Preconception counseling and optimal control of diabetes before, during, and after pregnancy minimize maternal and fetal risks, including congenital malformations. Because malformations may develop before pregnancy is diagnosed, the need for constant, strict control of glucose levels is stressed to women who have diabetes and who are considering pregnancy (or not using contraception). Also, all pregnant women are screened for gestational diabetes.

Risks are minimized by involving a diabetes team (eg, physicians, nurses, nutritionists, social workers) and a pediatrician; by promptly diagnosing and treating complications of pregnancy, no matter how trivial; by planning for delivery and having an experienced pediatrician present; and by ensuring that neonatal intensive care is available. In regional perinatal centers, specialists in management of diabetic complications are available.

During pregnancy: Treatment can vary, but some general management guidelines are useful. Women with type 1 or 2 should monitor their plasma glucose levels at home. During pregnancy, normal fasting plasma glucose levels are about 76 mg/dL (4.2 mmol/L); treatment aims to keep fasting plasma glucose levels at < 95 mg/dL.



Urinary Tract Infection in Pregnancy

UTI is common during pregnancy, apparently because of urinary stasis, which results from hormonal ureteral dilation, hormonal ureteral hypoperistalsis, and pressure of the expanding uterus against the ureters. Asymptomatic bacteriuria occurs in about 15% of pregnancies and sometimes progresses to symptomatic cystitis or pyelonephritis. Frank UTI is not always preceded by asymptomatic bacteriuria. Asymptomatic bacteriuria, UTI, and pyelonephritis increase risk of preterm labor and premature rupture of the membranes.

Urinalysis and culture at initial evaluation are routinely done to check for asymptomatic UTI. Diagnosis and treatment of symptomatic UTI is not changed by pregnancy, except drugs that may harm the fetus are avoided.  Antibacterial drug selection is based on individual and local susceptibility and resistance patterns, but are usually good initial empiric choices. After treatment, proof-of-cure cultures are required. Women who have pyelonephritis or have had 1 UTI may require suppressive therapy
In women who have bacteriuria with or without UTI or pyelonephritis, urine should be cultured monthly.