As stated above, research on the effects of epidurals on newborn health is somewhat ambiguous and many factors may be contributing to newborn health at the time of birth. How much of an effect these medications will have is difficult to judge and could vary based on dosage, how long labor continues and individual babies. Dosages and medications vary, so concrete information from research is lacking. Studies reveal that some babies may initially have trouble "latching on" among other difficulties with breastfeeding. While in-utero, they may become lethargic and have trouble getting into position for delivery. These medications have been known to cause respiratory depression, and decreased fetal heart rate in newborns. Though the medication may not harm the baby, the baby may experience subtle effects like those mentioned above.
http://www.americanpregnancy.org/labornbirth/epidural.html
...Although many medications, including some vaccines, are avoided during pregnancy because of potential harm to the mother or fetus, some vaccines are actually recommended for pregnant women. Certain immunizations during pregnancy will enhance the mother’s health and others will protect the child by means of the mother’s antibodies that remain in the child for the first 3-6 months of life.
While certain drugs may harm the developing fetus, the risk of a developing fetus being harmed by vaccination of the mother during pregnancy remains only theoretical. Currently, no evidence exists of risk from vaccinating pregnant women with any inactivated viral or bacterial vaccine or toxoid. Live attenuated vaccines, including MMR and varicella, are of greater theoretical concern, so it is recommended that women avoid pregnancy as a precautionary measure for at least 28 days after administration of these vaccines. This 28-day rule is used even though there is no evidence in prior studies of damage to the fetus when the pregnant mother received one of these vaccines.
Pregnant women and health care providers should always consider the risks and benefits of the vaccine as well as the risks of the disease before administering or receiving the vaccine....
Breast-feeding does not interfere with the response to the vaccines recommended for adults. Although rubella vaccine virus has been found in human milk, this and other vaccines provided to the mother during pregnancy or immediately post partum have not been shown to interfere with the immune response of children to the vaccine. Also, no child has developed illness from a vaccine administered to their mother. Human milk contains antibodies and other factors that may help protect infants against many infectious diseases.
The Centers for Disease Control and Prevention (CDC) has published a recommended adult immunization schedule, including for pregnant women.
Influenza. Pregnant women who become infected with influenza viruses are at increased risk of hospitalization, serious medical complications, and adverse pregnancy outcomes. Immunization of the pregnant woman with inactivated influenza virus vaccine is effective at reducing febrile respiratory infections in pregnant woman. Immunizing the mother during pregnancy also protects her newborn because she passes immune antibodies across the placenta (influenza antibodies are actually higher in umbilical cord blood than in the mother’s blood). Infants with influenza virus infection account for many hospitalizations and are predisposed to bacterial respiratory infections. Childhood deaths associated with influenza virus infection occur most frequently in infants less than 6 months of age. Unfortunately, during the first 6 months of life, there are no vaccines or anti-influenza virus drugs available. For these reasons, pregnant women should receive inactivated influenza virus vaccine and those who will be helping to care for the newborn should be vaccinated as well. Studies of influenza vaccination of more than 2,000 pregnant women have demonstrated no adverse effects to the fetus from the vaccine. However, the nasal influenza vaccine should not be given to pregnant women because it is a live virus vaccine.
Tetanus. Tetanus in newborn infants—once common throughout the Americas—is prevented if the mother has been immunized. This is because an immune mother passes antibodies to the baby across the placenta. The mother is immune if she has been immunized before becoming pregnant or during pregnancy. An expectant mother whose tetanus immunization status is uncertain or whose last immunization was more than 10 years ago should be immunized against tetanus. This is usually given combined with diphtheria toxoid vaccine (a product called Td). Recently a new Td vaccine that also contains vaccine for pertussis has been licensed for adults (Tdap) including for use for women in the child-bearing age group. Pregnancy is not a contraindication to Tdap immunization. However, at this time, CDC recommends that pregnant women who received the last tetanus toxoid-containing vaccine less than 10 years ago receive Tdap in the post-partum period according to the routine vaccination recommendations. If the last dose of tetanus toxoid-containing vaccine was more than 10 years before, they prefer that she be immunized with Td during the second and third trimester instead of Tdap.
Generally, live-attenuated vaccines are contraindicated for pregnant women because of the theoretical risk of transmission of the vaccine virus to the fetus. The following live, attenuated vaccines should not be administered during pregnancy except in unusual circumstances:
The following vaccines should be considered for pregnant women who are at risk for acquiring or being exposed to these diseases. Because spontaneous abortion occurs more commonly in the first trimester of pregnancy, some obstetricians prefer to avoid administering vaccines during this time, if possible, to avoid any temporal associations that might occur. Specific recommendations for travel by pregnant women (and others) can be obtained at www.cdc.gov/travel.
http://www.immunizationinfo.org/issues/general/vaccines-pregnant-women