It is recommended for women planning pregnancy to stop smoking. It is important to examine these effects because smoking before, during and after pregnancy is not an unusual behavior among the general population and can have detrimental health impacts, especially among both mother and child as a result. In 2011, approximately 10% of pregnant women in data collected from 24 states reported smoking during the last three months of their pregnancy.

If one does continue to smoke after giving birth, however, it is still more beneficial to breastfeed than to completely avoid this practice altogether. There is evidence that breastfeeding offers protection against many infectious diseases, especially diarrhea. Even in babies exposed to the harmful effects of nicotine through breast milk, the likelihood of acute respiratory illness is significantly diminished when compared to infants whose mothers smoked but were formula fed. Regardless, the benefits of breastfeeding outweigh the risks of nicotine exposure.

In low-risk pregnancies, the association between cigarette smoking and a reduced risk of pre-eclampsia has been consistent and reproducible across epidemiologic studies. High-risk pregnancies (those with pregestational diabetes, chronic hypertension, history of pre-eclampsia in a previous pregnancy, or multifetal gestation) showed no significant protective effect. The reason for this discrepancy is not definitively known; research supports speculation that the underlying pathology increases the risk of preeclampsia to such a degree that any measurable reduction of risk due to smoking is masked. However, the damaging effects of smoking on overall health and pregnancy outcomes outweighs the benefits in decreasing the incidence of preeclampsia. It is recommended that smoking be stopped prior to, during and after pregnancy.

Studies suggest that marijuana use in the months prior to or during the early stages of pregnancy may interfere with normal placental development and consequently increase the risk of preeclampsia.

Taking aspirin is associated with a 1% to 5% reduction in pre-eclampsia and a 1% to 5% reduction in premature births in women at high risk. The World Health Organization recommends low-dose aspirin for the prevention of pre-eclampsia in women at high risk and recommends it be started before 20 weeks of pregnancy. The United States Preventive Services Task Force recommends a low-dose regimen for women at high risk beginning in the 12th week. Benefits are less if started after 16 weeks.

There are many options available in treating obesity, such as: altering one's diet and exercising regularly. Moderate forms of exercise, such as walking, can lead to healthy weight loss. Some people who are obese turn to gastric bypass surgery in order to reduce their appetites. It is always advised to consult a physician regarding any obesity treatment.

It is recommended that obese women should try to lose weight before becoming pregnant, yet women should not diet during pregnancy because sufficient nutrition is important for pregnant women and women planning pregnancy. Women with gastric banding can have normal pregnancies and better outcomes than women who do not have the surgery, but in most cases, doctors have agreed that pregnancy should wait until surgery-related weight loss has stabilized. Clinicians have been encouraged to talk to women who are pregnant or may become pregnant about getting enough folic acid, quitting smoking, and avoiding alcohol. Women are also recommended to have appropriate calorie intake and exercise adequately.

Pregnant women who ate more sweets, such as candy and processed juices, in early pregnancy were at higher risk of gaining excessive weight. A healthy, well-balanced diet during pregnancy can also help to minimize some pregnancy symptoms such as nausea and constipation.

It is the goal of evolutionary medicine to find treatments for diseases that are informed by the evolutionary history of a disease. It has been suggested that gestational hypertension is linked to insulin resistance during pregnancy. Both the increase in blood sugar that can lead to gestational diabetes and the increase in blood pressure that can lead to gestational hypertension are mechanisms that mean to optimize the amount of nutrients that can be passed from maternal tissue to fetal tissue. It has been suggested that techniques used to combat insulin insensitivity might also prove beneficial to those suffering from gestational hypertension. Measures to avoid insulin resistance include avoiding obesity before pregnancy, minimizing weight gain during pregnancy, eating foods with low glycemic indexes, and exercising.

Education and counselling by physicians of children and adolescents has been found to be effective in decreasing the risk of tobacco use.

The use of recreational drugs in pregnancy can cause various pregnancy complications.

- Ethanol during pregnancy can cause fetal alcohol syndrome and fetal alcohol spectrum disorder. Studies have shown that light to moderate drinking during pregnancy might not pose a risk to the fetus, although no amount of alcohol during pregnancy can be guaranteed to be absolutely safe.

- Tobacco smoking during pregnancy can cause a wide range of behavioral, neurological, and physical difficulties. Smoking during pregnancy causes twice the risk of premature rupture of membranes, placental abruption and placenta previa. Smoking is associated with 30% higher odds of preterm birth.

- Prenatal cocaine exposure is associated with premature birth, birth defects and attention deficit disorder.

- Prenatal methamphetamine exposure can cause premature birth and congenital abnormalities. Short-term neonatal outcomes show small deficits in infant neurobehavioral function and growth restriction. Long-term effects in terms of impaired brain development may also be caused by methamphetamine use.

- Cannabis in pregnancy has been shown to be teratogenic in large doses in animals, but has not shown any teratogenic effects in humans.

Low birthweight, pre-term birth and pre-eclampsia have been associated with maternal periodontitis exposure. But the strength of the observed associations is inconsistent and vary according to the population studied, the means of periodontal assessment and the periodontal disease classification employed. However the best is that the risk of low birth weight can be reduced with very simple therapy. Treatment of periodontal disease during gestation period is safe and reduction in inflammatory burden reduces the risk of preterm birth as well as low birth weight.

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.

A study by the Agency for Healthcare Research and Quality (AHRQ) found that of the 3.8 million births that occurred in the United States in 2011, approximately 6.1% (231,900) were diagnosed with low birth weight (<2,500 g). Approximately 49,300 newborns (1.3%) weighed less than 1,500 grams (VLBW). Infants born at low birth weight are at a higher risk for developing neonatal infection.

Healthy eating can be instituted at any stage of the pregnancy including nutritional adjustments, use of vitamin supplements, and smoking cessation. Calcium supplementation in women who have low dietary calcium reduces the number of negative outcomes including preterm birth, pre-eclampsia, and maternal death. The World Health Organization (WHO) suggests 1.5-2 g of calcium supplements daily, for pregnant women who have low levels calcium in their diet. Supplemental intake of C and E vitamins have not been found to reduce preterm birth rates. Different strategies are used in the administration of prenatal care, and future studies need to determine if the focus can be on screening for high-risk women, or widened support for low-risk women, or to what degree these approaches can be merged. While periodontal infection has been linked with preterm birth, randomized trials have not shown that periodontal care during pregnancy reduces preterm birth rates.

Despite these risks for gestational hypertension, the hemochorial placenta has been favored because of its advantages in the way that it aids in diffusion from mother to fetus later in pregnancy. The bipedal posture that has allowed humans to walk upright has also led to a reduced cardiac output, and it has been suggested that this is what necessitated humans’ aggressive early placental structures. Increased maternal blood pressure can attempt to make up for lower cardiac output, ensuring that the fetus’s growing brain receives enough oxygen and nutrients. The benefits of being able to walk upright and run on land have outweighed the disadvantages that come from bipedalism, including the placental diseases of pregnancy, such as gestational hypertension. Similarly, the advantages of having a large brain size have outweighed the deleterious effects of having a placenta that does not always convert the spiral arteries effectively, leaving humans vulnerable to contracting gestational hypertension. It is speculated that this was not the case with Neanderthals, and that they died out because their cranial capacity increased too much, and their placentae were not equipped to handle the fetal brain development, leading to widespread preeclampsia and maternal and fetal death.

Gestational hypertension in the early stages of pregnancy (trimester 1) has been shown to improve the health of the child both in its first year of life, and its later life. However, when the disease develops later in the pregnancy (subsequent trimesters), or turns into preeclampsia, there begin to be detrimental health effects for the fetus, including low birth-weight. It has been proposed that fetal genes designed to increase the mother’s blood pressure are so beneficial that they outweigh the potential negative effects that can come from preeclampsia. It has also been suggested that gestational hypertension and preeclampsia have remained active traits due to the cultural capacity of humans, and the tendency for midwives or helpers to aid in delivering babies.

Adoption of specific professional policies can immediately reduce risk of preterm birth as the experience in assisted reproduction has shown when the number of embryos during embryo transfer was limited.

Many countries have established specific programs to protect pregnant women from hazardous or night-shift work and to provide them with time for prenatal visits and paid pregnancy-leave. The EUROPOP study showed that preterm birth is not related to type of employment, but to prolonged work (over 42 hours per week) or prolonged standing (over 6 hours per day). Also, night work has been linked to preterm birth. Health policies that take these findings into account can be expected to reduce the rate of preterm birth.

Preconceptional intake of folic acid is recommended to reduce birth defects. There is significant evidence that long-term (> one year) use of folic acid supplement preconceptionally may reduce premature birth. Reducing smoking is expected to benefit pregnant women and their offspring.

Dipping tobacco, commonly referred to as snuff, is also put in the mouth, but it is a flavored powder. it is placed between the cheek and gum. Dipping tobacco doesn't need to be chewed for the nicotine to be absorbed into your body. First-time users of these products often become nauseated and dizzy. Long-term effects include bad breath, yellowed teeth, and an increased risk of oral cancer.

Users of dipping tobacco are believed to face less risk of some cancers than smokers but are still at greater risk than people who do not use any tobacco products. They also have an equal risk of other health problems directly linked to nicotine such as increased rate of atherosclerosis.

Families who are impacted by SIDS should be offered emotional support and grief counseling. The experience and manifestation of grief at the loss of an infant are impacted by cultural and individual differences.

A large investigation into diphtheria-tetanus-pertussis vaccination and potential SIDS association by Berlin School of Public Health, Charité – Universitätsmedizin Berlin concluded: "Increased DTP immunisation coverage is associated with decreased SIDS mortality. Current recommendations on timely DTP immunisation should be emphasised to prevent not only specific infectious diseases but also potentially SIDS."

Many other studies have also reached conclusions that vaccinations reduce the risk of SIDS. Studies generally show that SIDS risk is approximately halved by vaccinations.

Some disorders and conditions can mean that pregnancy is considered high-risk (about 6-8% of pregnancies in the USA) and in extreme cases may be contraindicated. High-risk pregnancies are the main focus of doctors specialising in maternal-fetal medicine.

Serious pre-existing disorders which can reduce a woman's physical ability to survive pregnancy include a range of congenital defects (that is, conditions with which the woman herself was born, for example, those of the heart or , some of which are listed above) and diseases acquired at any time during the woman's life.

A Dutch 2010 research showed that "low-risk" pregnancy in the Netherlands may actually carry a higher risk of perinatal death than a "high-risk" pregnancy.

DES (diethylstilbestrol) is a drug that mimics estrogen, a female hormone. From 1938 until 1971 doctors prescribed this drug to help some pregnant women who had had miscarriages or premature deliveries on the theory that miscarriages and premature births occurred because some pregnant women did not produce enough estrogen naturally to sustain the pregnancy for full term . An estimated 5-10 million pregnant women and the children born during this period were exposed to DES. Currently, DES is known to increase the risk of breast cancer, and cause a variety of birth-related adverse outcomes exposed female offsprings such as spontaneous abortion, second-trimester pregnancy loss, preterm delivery, stillbirth, neonatal death, sub/infertility and cancer of reproductive tissues . DES is an important developmental toxicant which links the fetal basis of adult disease.

Methylmercury and inorganic mercury is excreted in human breast milk and infants are particularly susceptible to toxicity due to this compound. The fetus and infant are especially vulnerable to mercury exposures with special interest in the development of the CNS since it can easily cross across the placental barrier, accumulate within the placenta and fetus as the fetus cannot eliminate mercury and have a negative effect on the fetus even if the mother does not show symptoms. Mercury causes damage to the nervous system resulting from prenatal or early postnatal exposure and is very likely to be permanent.

There are many factors that may influence childbearing age in women, although they are mostly correlations without certain causations.

Two studies show that generous parental leave allowances in Britain encourage young motherhood and that parental-leave allowance reduces postponement in Sweden.

The World Health Organization defines a maternal near-miss case as "a woman who nearly died but survived a complication that occurred during pregnancy, childbirth or within 42 days of termination of pregnancy."

Although the risk of placental abruption cannot be eliminated, it can be reduced. Avoiding tobacco, alcohol and cocaine during pregnancy decreases the risk. Staying away from activities which have a high risk of physical trauma is also important. Women who have high blood pressure or who have had a previous placental abruption and want to conceive must be closely supervised by a doctor.

The risk of placental abruption can be reduced by maintaining a good diet including taking folic acid, regular sleep patterns and correction of pregnancy-induced hypertension.

It is crucial for women to be made aware of the signs of placental abruption, such as vaginal bleeding, and that if they experience such symptoms they must get into contact with their health care provider/the hospital "without any delay".