Over the counter medications are those medications that do not require a prescription to purchase in the US. Medications that require a prescription to purchase in the US may be available in other countries without a prescription. The following guidelines are recommended:

- taking oral medications after breastfeeding rather than before will allow some of the medication to leave the mother's body through her kidneys between nursings.

- in most women without kidney disease, nonsteroidal anti-inflammatory drugs and paracetamol (acetaminophen) are used safely.

- aspirin can cause rashes and even cause bleeding in infants.

- limit the use of antihistamines for long periods of time. These anti-allergy medications can cause crying, sleep problems, fussiness, exsessive sleepiness in babies. Antihistamines have an effect on the amount of milk the body produces and decrease the supply.

- carefully observe the infant for changes or side effects when first taking a medication to watch for side effects. Side effects indicating that the medication is having an affect on the baby is difficulty breathing, rash and other questionable changes that occurred after the medication was started by the mother.

- many times other young children are in the home and keeping these over the counter medications out of their reach is a safe practice.

Other substances or chemicals have been evaluated regarding their safe use during pregnancy. Hair dye or solutions used for a 'permanent' do not pass to breastmilk. No adverse reports of using oral antihastamines and breastfeeding are found. Some of the older antihistamines used by a nursing mother can cause drowsiness in the infant. This may be a concern if the infant misses feedings by sleeping instead of nursing.

The goal of antiretroviral use during pregnancy is to reduce the risk of transmission of HIV from mother to child. It is important to choose medications that are safe for the mother and the fetus and which are effective at decreasing the total viral load. Some studies have shown an increase in stillbirths, preterm delivery, and delayed fetal growth in women using high doses of antiretroviral drugs during pregnancy. However, the overall benefits of ART are believed to outweigh the risks and all women are encouraged to use ART for the duration of their pregnancy.

Due to physiological changes in the body during pregnancy, it may be necessary to alter the dosing of medications so that they remain effective. Generally, the dose or the frequency of dosing are increased to account for these changes.

The recommended ART regimen for HIV-positive pregnant women consists of drugs from 4 different classes of medications listed below. In the United States, the favored regimen is a three-drug regimen where the first two drugs are NRTIs and the third is either a protease inhibitor, an integrase inhibitor, or an NNRTI.

- Nucleoside reverse transcriptase inhibitors (NRTIs) are considered the "backbone" of ART and 2 medications are generally used in combination. Due to its known safety profile and extensive use in pregnant patients, zidovudine-lamivudine (ZDV/3TC) is the preferred choice as the NRTI backbone. Zidovudine may worsen anemia, so patients with anemia are advised to use an alternative agent. For women who are coinfected with Hepatitis B, tenofovir with either emtricitabine or lamivudine is the preferred NRTI backbone. NRTI use may cause lactic acidosis in some women, so it is important to monitor patients for this complication. Deaths from lactic acidosis and liver failure have been associated with the use of two NRTIs, stavudine and didanosine (Zerit and Videx, respectively); therefore, combinations involving these drugs should be avoided in pregnancy.

- Protease inhibitors (PIs) have been studied extensively in pregnancy and are therefore the preferred third drug in the regimen. Atazanavir-ritonavir and darunavir-ritonavir are two of the most common PIs used during pregnancy. There is conflicting data regarding their association with preterm births, so women who are at a high risk for premature delivery are advised not to use PIs. Some PIs have been associated with hyperglycemia but is unclear whether they add to the risk of developing gestational diabetes. Some PIs have been noted to cause hyperbilirubinemia and nausea, so these side effects should be monitored for closely.

- Integrase inhibitors (IIs) are generally the third drug in the regimen when a PI cannot be used. They rapidly reduce the viral load and for this reason, they are often used in women who are diagnosed with HIV late in the pregnancy. Raltegravir is the most common II used.

- Non-nucleoside reverse transcriptase inhibitors (NNRTIs), the most popular being efavirenz and nevirapine, may be used during pregnancy. However, there are significant toxicities associated with their use, making them a less desirable option.

- Efavirenz (brand name Sustiva, and a component of the combination drug Atripla) is classified as a category D drug by the US Food and Drug Administration indicating there are risks associated with its use during pregnancy. In a study analyzing the use of the drug in pregnant women, 2.3% of births were associated with birth defects. However, a systematic review of the safety of efavirenz use in humans during the first trimester found no increase in birth defects among women using the drug. Given the uncertain potential for risk the U.S. DHHS recommends against using efavirenz in the first trimester of pregnancy or in women who may become pregnant. They instead recommend a protease inhibitor based regimen with lopinavir or atazanavir. However, to simplify regimens and provide a uniform recommendation for HIV-infected individuals during pregnancy, the WHO continues to recommend efavirenz as a first line agent for HIV positive women. Women using efavirenz prior to their pregnancy may continue with the drug as it is more dangerous to stop or change medications during pregnancy because this can result in improper control of the viral load.

- Nevirapine (trade name Viramune) increases the risk of very serious liver damage in women with CD4 counts greater than 250 cells/mm . It is generally avoided in pregnant women. Women taking nevirapine safely prior to pregnancy may continue with the medication because nevirapine-related liver damage has not been seen in women previously using the medication.

No treatment is necessary for a diagnosis of complete miscarriage (so long as ectopic pregnancy is ruled out). In cases of an incomplete miscarriage, empty sac, or missed abortion there are three treatment options: watchful waiting, medical management, and surgical treatment. With no treatment (watchful waiting), most miscarriages (65–80%) will pass naturally within two to six weeks. This treatment avoids the possible side effects and complications of medications and surgery, but increases the risk of mild bleeding, need for unplanned surgical treatment, and incomplete miscarriage. Medical treatment usually consists of using misoprostol (a prostaglandin) to contract the uterus, expelling remaining tissue out of the cervix. This works within a few days in 95% of cases. Vacuum aspiration or sharp curettage can be used, though vacuum aspiration is lower-risk and more common.

Drugs used during pregnancy can have temporary or permanent effects on the fetus. Anything (including drugs) that can cause permanent deformities in the fetus are labeled as teratogens. In the U.S., drugs were classified into categories A, B, C, D and X based on the Food and Drug Administration (FDA) rating system to provide therapeutic guidance based on potential benefits and fetal risks. Drugs, including some multivitamins, that have demonstrated no fetal risks after controlled studies in humans are classified as Category A. On the other hand, drugs like thalidomide with proven fetal risks that outweigh all benefits are classified as Category X.

In delayed or incomplete miscarriage, treatment depends on the amount of tissue remaining in the uterus. Treatment can include surgical removal of the tissue with vacuum aspiration or misoprostol. Some organizations recommend delaying sexual relations immediately after a miscarriage to prevent infection.

The apprehension is not necessarily data driven and is a cautionary response to the lack of clinical studies in pregnant women. The indication is a trade-off between the adverse effects of the drug, the risks associated with intercurrent diseases and pregnancy complications, and the efficiency of the drug to prevent or ameliorate such risks. In some cases, the use of drugs in pregnancy carries benefits that outweigh the risks. For example, high fever is harmful for the fetus in the early months, thus the use of paracetamol (acetaminophen) is generally associated with lower risk than the fever itself. Similarly, diabetes mellitus during pregnancy may need intensive therapy with insulin to prevent complications to mother and baby. Pain management for the mother is another important area where an evaluation of the benefits and risks is needed. NSAIDs such as Ibuprofen and Naproxen are probably safe for use for a short period of time, 48–72 hours, once the mother has reached the second trimester. If taking aspirin for pain management the mother should never take a dose higher than 100 mg.

Nutrition during pregnancy is important to ensure healthy growth of the fetus. Nutrition during pregnancy is different from the non-pregnant state. There are increased energy requirements and specific micronutrient requirements. Women benefit from education to encourage a balanced energy and protein intake during pregnancy. Some women may need professional medical advice if their diet is affected by medical conditions, food allergies, or specific religious/ ethical beliefs.

Adequate periconceptional (time before and right after conception) folic acid (also called folate or Vitamin B) intake has been shown to decrease the risk of fetal neural tube defects, such as spina bifida. The neural tube develops during the first 28 days of pregnancy, a urine pregnancy test is not usually positive until 14 days post-conception, explaining the necessity to guarantee adequate folate intake before conception. Folate is abundant in green leafy vegetables, legumes, and citrus. In the United States and Canada, most wheat products (flour, noodles) are fortified with folic acid.

DHA omega-3 is a major structural fatty acid in the brain and retina, and is naturally found in breast milk. It is important for the woman to consume adequate amounts of DHA during pregnancy and while nursing to support her well-being and the health of her infant. Developing infants cannot produce DHA efficiently, and must receive this vital nutrient from the woman through the placenta during pregnancy and in breast milk after birth.

Several micronutrients are important for the health of the developing fetus, especially in areas of the world where insufficient nutrition is common. Women living in low and middle income countries are suggested to take multiple micronutrient supplements containing iron and folic acid. These supplements have been shown to improve birth outcomes in developing countries, but do not have an effect on perinatal mortality. Adequate intake of folic acid, and iron is often recommended. In developed areas, such as Western Europe and the United States, certain nutrients such as Vitamin D and calcium, required for bone development, may also require supplementation. Vitamin E supplementation has not been shown to improve birth outcomes. Zinc supplementation has been associated with a decrease in preterm birth, but it is unclear whether it is causative. Daily iron supplementation reduces the risk of maternal anemia. Studies of routine daily iron supplementation for pregnant women found improvement in blood iron levels, without a clear clinical benefit. The nutritional needs for women carrying twins or triplets. are higher than those of women carrying one baby.

Women are counseled to avoid certain foods, because of the possibility of contamination with bacteria or parasites that can cause illness. Careful washing of fruits and raw vegetables may remove these pathogens, as may thoroughly cooking leftovers, meat, or processed meat. Unpasteurized dairy and deli meats may contain "Listeria," which can cause neonatal meningitis, stillbirth and miscarriage. Pregnant women are also more prone to "Salmonella" infections, can be in eggs and poultry, which should be thoroughly cooked. Cat feces and undercooked meats may contain the parasite Toxoplasma gondii and can cause toxoplasmosis. Practicing good hygiene in the kitchen can reduce these risks.

Women are also counseled to eat seafood in moderation and to eliminate seafood known to be high in mercury because of the risk of birth defects. Pregnant women are counseled to consume caffeine in moderation, because large amounts of caffeine are associated with miscarriage. However, the relationship between caffeine, birthweight, and preterm birth is unclear.

Vitamin A plays a role in the immune system and is a low-cost intervention that has been suggested to help with preventing mother-to-child transmission of HIV. A Cochrane review summarised the evidence of five trials conducted in Malawi, South Africa, Tanzania and Zimbabwe between 1995 and 2005, where none of the participants received antiretroviral therapy. They found that giving vitamin A supplementation to pregnant women or to women after they delivered a baby probably has little or no effect on mother-to-child transmission of HIV. The intervention has been largely suspended by antiretroviral therapy.

The determination of the safety of a medication can be evaluated by considering the following:

- The age and maturity of the infant. Full term infants are better able to metabolize medications than premature infants

- The weight of the infant.

- The amount and percentage of breastmilk consumed by the infant. An infant taking solid foods with breastfeeding will receive a lower dose of medication.

- The general health of the infant and the general health of the mother.

- The nature of the mother's illness, if present.

- The general information about the drug other literature documenting studies related to the drug and breastfeeding.

- The duration of the drug therapy.

- Is the drug short-acting? A short-acting form of the drug may be a better choice for a breastfeeding mother rather than a longer-acting form that stays in the mother's system for a longer period.

- How is the medication being given?

- Does the drug interfere with lactation?

U.S. Code of Federal Regulations requires that certain drugs and biological products must be labelled very specifically with respect to their effects on pregnant populations, including a definition of a "pregnancy category." These rules are enforced by the Food and Drug Administration (FDA). The FDA does not regulate labelling for all hazardous and non-hazardous substances and some potentially hazardous substances are not assigned a pregnancy category.

Australia’s categorisations system takes into account the birth defects, the effects around the birth or when the mother gives birth, and problems that will arise later in the child's life caused from the drug taken. The system places them into a category of their severity that the drug could cause to the infant when it crosses the placenta(Australian Government, 2014).

The routine administration of antibiotics to all women with threatened preterm labor reduces the risk of the baby to get infected with group B streptococcus and has been shown to reduce related mortality rates.

When membranes rupture prematurely, obstetrical management looks for development of labor and signs of infection. Prophylactic antibiotic administration has been shown to prolong pregnancy and reduced neonatal morbidity with rupture of membranes at less than 34 weeks. Because of concern about necrotizing enterocolitis, amoxicillin or erythromycin has been recommended, but not amoxicillin + clavulanic acid (co-amoxiclav).

A number of medications may be useful to delay delivery including: NSAIDs, calcium channel blockers, beta mimetics, and atosiban. Tocolysis rarely delays delivery beyond 24–48 hours. This delay however may be sufficient to allow the pregnant woman to be transferred to a center specialized for management of preterm deliveries and give administered corticosteroids to reduce neonatal organ immaturity. Meta-analyses indicate that calcium-channel blockers and an oxytocin antagonist can delay delivery by 2–7 days, and β2-agonist drugs delay by 48 hours but carry more side effects. Magnesium sulfate does not appear to be useful and may be harmful when used for this purpose.

The World Health Organization recommends that women with severe hypertension during pregnancy should receive treatment with anti-hypertensive agents. Severe hypertension is generally considered systolic BP of at least 160 or diastolic BP of at least 110. Evidence does not support the use of one anti-hypertensive over another. The choice of which agent to use should be based on the prescribing clinician's experience with a particular agent, its cost, and its availability. Diuretics are not recommended for prevention of preeclampsia and its complications. Labetolol, Hydralazine and Nifedipine are commonly used antihypertensive agents for hypertension in pregnancy. ACE inhibitors and angiotensin receptor blockers are contraindicated as they affect fetal development.

The goal of treatment of severe hypertension in pregnancy is to prevent cardiovascular, kidney, and cerebrovascular complications. The target blood pressure has been proposed to be 140–160 mmHg systolic and 90–105 mmHg diastolic, although values are variable.

The intrapartum and postpartum administration of magnesium sulfate is recommended in severe pre-eclampsia for the prevention of eclampsia. Further, magnesium sulfate is recommended for the treatment of eclampsia over other anticonvulsants. Magnesium sulfate acts by interacting with NMDA receptors.

A number of antiemetics are effective and safe in pregnancy including: pyridoxine/doxylamine, antihistamines (such as diphenhydramine), metoclopramide, and phenothiazines (such as promethazine). With respect to effectiveness it is unknown if one is superior to another. In the United States and Canada, the doxylamine-pyridoxine combination (as Diclegis in US and Diclectin in Canada) is the only approved pregnancy category "A" prescription treatment for nausea and vomiting of pregnancy.

Ondansetron may be beneficial, but there are some concerns regarding an association with cleft palate, and there is little high quality data. Metoclopramide is also used and relatively well tolerated. Evidence for the use of corticosteroids is weak.

Ideally the management of abdominal pregnancy should be done by a team that has medical personnel from multiple specialties. Potential treatments consist of surgery with termination of the pregnancy (removal of the fetus) via laparoscopy or laparotomy, use of methotrexate, embolization, and combinations of these. Sapuri and Klufio indicate that conservative treatment is also possible if the following criteria are met: 1. there are no major congenital malformations; 2. the fetus is alive; 3. there is continuous hospitalization in a well-equipped and well-staffed maternity unit which has immediate blood transfusion facilities; 4. there is careful monitoring of maternal and fetal well being; and 5. placental implantation is in the lower abdomen away from the liver and spleen. The choice is largely dictated by the clinical situation. Generally, treatment is indicated when the diagnosis is made; however, the situation of the advanced abdominal pregnancy is more complicated.

The uterine curettage is generally done under the effect of anesthesia, preferably spinal anesthesia in hemodynamically stable patients. The advantages of spinal anesthesia over general anesthesia include ease of technique, favorable effects on the pulmonary system, safety in patients with hyperthyroidism and non-tocolytic pharmacological properties. Additionally, by maintaining patient’s consciousness one can diagnose the complications like uterine perforation, cardiopulmonary distress and thyroid storm at an earlier stage than when the patient is sedated or is under general anesthesia.

Hydatidiform moles should be treated by evacuating the uterus by uterine suction or by surgical curettage as soon as possible after diagnosis, in order to avoid the risks of choriocarcinoma. Patients are followed up until their serum human chorionic gonadotrophin (hCG) level has fallen to an undetectable level. Invasive or metastatic moles (cancer) may require chemotherapy and often respond well to methotrexate. As they contain paternal antigens, the response to treatment is nearly 100%. Patients are advised not to conceive for half a year after hCG levels have normalized. The chances of having another molar pregnancy are approximately 1%.

Management is more complicated when the mole occurs together with one or more normal fetuses.

The pregnancy category of a medication is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. It does "not" include any risks conferred by pharmaceutical agents or their metabolites in breast milk.

Every drug has specific information listed in its product literature. The British National Formulary used to provide a table of drugs to be avoided or used with caution in pregnancy, and did so using a limited number of key phrases, but now Appendix 4 (which was the Pregnancy table) has been removed. Appendix 4 is now titled "Intravenous Additives". However, information that was previously available in the former Appendix 4 (pregnancy) and Appendix 5 (breast feeding) is now available in the individual drug monographs.

"Taylorella equigenitalis" is susceptible to most antibiotics, although the carrier state in mares is difficult to eliminate. Most mares with acute endometritis recover spontaneously. Recommended therapy is to infuse the uterus with an antibiotic such as penicillin, cleansing the clitoral area with 2% chlorhexidine solution and then applying chlorhexidine or nitrofurazone ointment to the clitoral fossa and sinuses. The entire treatment is repeated daily for five days.

It is relatively easy to eliminate the carrier state in stallions using local disinfectant. With the stallion's penis dropped and the glans extended from the foreskin, the shaft of the penis, including the folds of the prepuce and the urethral fossa, should be cleansed daily for five days with a 2% chlorhexidine solution. After drying, nitrofurazone cream is applied to these areas.

Some studies support the use of ginger, but overall the evidence is limited and inconsistent. Safety concerns have been raised regarding its anticoagulant properties.

Treatment is often started without confirmation of infection because of the serious complications that may result from delayed treatment. Treatment depends on the infectious agent and generally involves the use of antibiotic therapy. If there is no improvement within two to three days, the patient is typically advised to seek further medical attention. Hospitalization sometimes becomes necessary if there are other complications. Treating sexual partners for possible STIs can help in treatment and prevention.

For women with PID of mild to moderate severity, parenteral and oral therapies appear to be effective. It does not matter to their short- or long-term outcome whether antibiotics are administered to them as inpatients or outpatients. Typical regimens include cefoxitin or cefotetan plus doxycycline, and clindamycin plus gentamicin. An alternative parenteral regimen is ampicillin/sulbactam plus doxycycline. Erythromycin-based medications can also be used. Another alternative is to use a parenteral regimen with ceftriaxone or cefoxitin plus doxycycline. Clinical experience guides decisions regarding transition from parenteral to oral therapy, which usually can be initiated within 24–48 hours of clinical improvement.

In places lacking the necessary medical skill for dilation and extraction, or where preferred by practitioners, an abortion can be induced by first inducing labor and then inducing fetal demise if necessary. This is sometimes called "induced miscarriage". This procedure may be performed from 13 weeks gestation to the third trimester. Although it is very uncommon in the United States, more than 80% of induced abortions throughout the second trimester are labor induced abortions in Sweden and other nearby countries.

Only limited data are available comparing this method with dilation and extraction. Unlike D&E, labor induced abortions after 18 weeks may be complicated by the occurrence of brief fetal survival, which may be legally characterized as live birth. For this reason, labor induced abortion is legally risky in the U.S.

The data presented is for comparative and illustrative purposes only, and may have been superseded by updated data.

Miscarriage is the loss of a pregnancy prior to 20 weeks. In the UK miscarriage is defined as the loss of a pregnancy during the first 23 weeks.