Signs of a miscarriage include vaginal spotting, abdominal pain or cramping, and fluid or tissue passing from the vagina. Bleeding can be a symptom of miscarriage, but many women also have bleeding in early pregnancy and don't miscarry. Bleeding during pregnancy may be referred to as a threatened miscarriage. Of those who seek clinical treatment for bleeding during pregnancy, about half will miscarry. Miscarriage may be detected during an ultrasound exam, or through serial human chorionic gonadotropin (HCG) testing.

Hyperemesis gravidarum is the presence of severe and persistent vomiting, causing dehydration and weight loss. It is more severe than the more common morning sickness and is estimated to affect 0.5–2.0% of pregnant women.

The symptoms and discomforts of pregnancy are those presentations and conditions that result from pregnancy but do not significantly interfere with activities of daily living or pose a threat to the health of the mother or baby. This is in contrast to pregnancy complications. Sometimes a symptom that is considered a discomfort can be considered a complication when it is more severe. For example, nausea (morning sickness) can be a discomfort, but if, in combination with significant vomiting it causes a water-electrolyte imbalance, it is a complication known as hyperemesis gravidarum.

Common symptoms and discomforts of pregnancy include:

- Tiredness.

- Constipation

- Pelvic girdle pain

- Back pain

- Braxton Hicks contractions. Occasional, irregular, and often painless contractions that occur several times per day.

- Edema (swelling). Common complaint in advancing pregnancy. Caused by compression of the inferior vena cava and pelvic veins by the uterus leads to increased hydrostatic pressure in lower extremities.

- Increased urinary frequency. A common complaint, caused by increased intravascular volume, elevated glomerular filtration rate, and compression of the bladder by the expanding uterus.

- Urinary tract infection

- Varicose veins. Common complaint caused by relaxation of the venous smooth muscle and increased intravascular pressure.

- Haemorrhoids (piles). Swollen veins at or inside the anal area. Caused by impaired venous return, straining associated with constipation, or increased intra-abdominal pressure in later pregnancy.

- Regurgitation, heartburn, and nausea.

- Stretch marks

- Breast tenderness is common during the first trimester, and is more common in women who are pregnant at a young age.

In addition, pregnancy may result in pregnancy complication such as deep vein thrombosis or worsening of an intercurrent disease in pregnancy.

Gestational diabetes is when a woman without diabetes develops high blood sugar levels during pregnancy.

Associated terms for pregnancy are "gravid" and "parous". "Gravidus" and "gravid" come from the Latin for "heavy" and a pregnant female is sometimes referred to as a "gravida". Gravidity is a term used to describe the number of times that a female has been pregnant. Similarly, the term "parity" is used for the number of times that a female carries a pregnancy to a viable stage. Twins and other multiple births are counted as one pregnancy and birth. A woman who has never been pregnant is referred to as a "nulligravida." A woman who is (or has been only) pregnant for the first time is referred to as a "primigravida", and a woman in subsequent pregnancies as a "multigravida" or as "multiparous." Therefore, during a second pregnancy a woman would be described as "gravida 2, para 1" and upon live delivery as "gravida 2, para 2." In-progress pregnancies, abortions, miscarriages and/ or stillbirths account for parity values being less than the gravida number. In the case of a multiple birth the gravida number and parity value are increased by one only. Women who have never carried a pregnancy achieving more than 20 weeks of gestation age are referred to as "nulliparous."

The terms "preterm" and "postterm" have largely replaced earlier terms of "premature" and "postmature." "Preterm" and "postterm" are defined above, whereas "premature" and "postmature" have historical meaning and relate more to the infant's size and state of development rather than to the stage of pregnancy.

Miscarriage, also known as spontaneous abortion and pregnancy loss, is the natural death of an embryo or fetus before it is able to survive independently. Some use the cutoff of 20 weeks of gestation, after which fetal death is known as a stillbirth. The most common symptom of a miscarriage is vaginal bleeding with or without pain. Sadness, anxiety and guilt often occur afterwards. Tissue and clot-like material may leave the uterus and pass through and out of the vagina. When a woman keeps having miscarriages, infertility is present.

Risk factors for miscarriage include an older parent, previous miscarriage, exposure to tobacco smoke, obesity, diabetes, thyroid problems, and drug or alcohol use. About 80% of miscarriages occur in the first 12 weeks of pregnancy (the first trimester). The underlying cause in about half of cases involves chromosomal abnormalities. Diagnosis of a miscarriage may involve checking to see if the cervix is open or closed, testing blood levels of human chorionic gonadotropin (hCG), and an ultrasound. Other conditions that can produce similar symptoms include an ectopic pregnancy and implantation bleeding.

Prevention is occasionally possible with good prenatal care. Avoiding drugs, alcohol, infectious diseases, and radiation may prevent miscarriage. No specific treatment is usually needed during the first 7 to 14 days. Most miscarriages will complete without additional interventions. Occasionally the medication misoprostol or a procedure such as vacuum aspiration is used to remove the remaining tissue. Women who have a blood type of rhesus negative (Rh negative) may require Rho(D) immune globulin. Pain medication may be beneficial. Emotional support may help with negative emotions.

Miscarriage is the most common complication of early pregnancy. Among women who know they are pregnant, the miscarriage rate is roughly 10% to 20%, while rates among all fertilisation is around 30% to 50%. In those under the age of 35 the risk is about 10% while it is about 45% in those over the age of 40. Risk begins to increase around the age of 30. About 5% of women have two miscarriages in a row. Some recommend not using the term "abortion" in discussions with those experiencing a miscarriage in an effort to decrease distress.

Symptoms may include abdominal pain or vaginal bleeding during pregnancy. As this is nonspecific in areas where ultrasound is not available the diagnosis was often only discovered during surgery to investigate the abnormal symptoms. They are typically diagnosed later in the developing world than the developed. In about half of cases from a center in the developing world the diagnosis was initially missed.

It is a dangerous condition as there can be bleeding into the abdomen that results in low blood pressure and can be fatal. Other causes of death in people with an abdominal pregnancy include anemia, pulmonary embolus, coagulopathy, and infection.

Preterm birth causes a range of problems.

The main categories of causes of preterm birth are preterm labor induction and spontaneous preterm labor. Signs and symptoms of preterm labor include four or more uterine contractions in one hour. In contrast to false labour, true labor is accompanied by cervical dilatation and effacement. Also, vaginal bleeding in the third trimester, heavy pressure in the pelvis, or abdominal or back pain could be indicators that a preterm birth is about to occur. A watery discharge from the vagina may indicate premature rupture of the membranes that surround the baby. While the rupture of the membranes may not be followed by labor, usually delivery is indicated as infection (chorioamnionitis) is a serious threat to both fetus and mother. In some cases, the cervix dilates prematurely without pain or perceived contractions, so that the mother may not have warning signs until very late in the birthing process.

A review into using uterine monitoring at home to detect contractions and possible preterm births in women at higher risk of having a preterm baby found that it did not reduce the number of preterm births. The research included in the review was poor quality but it showed that home monitoring may increase the number of unplanned antenatal visits and may reduce the number of babies admitted to special care when compared with women receiving normal antenatal care.

Preterm infants usually show physical signs of prematurity in reverse proportion to the gestational age. As a result, they are at risk for numerous medical problems affecting different organ systems.

- Neurological problems include apnea of prematurity, hypoxic-ischemic encephalopathy (HIE), retinopathy of prematurity (ROP), developmental disability, transient hyperammonemia of the newborn, cerebral palsy and intraventricular hemorrhage, the latter affecting 25 percent of babies born preterm, usually before 32 weeks of pregnancy. Mild brain bleeds usually leave no or few lasting complications, but severe bleeds often result in brain damage or even death. Neurodevelopmental problems have been linked to lack of maternal thyroid hormones, at a time when their own thyroid is unable to meet postnatal needs.

- Cardiovascular complications may arise from the failure of the ductus arteriosus to close after birth: patent ductus arteriosus (PDA).

- Respiratory problems are common, specifically the respiratory distress syndrome (RDS or IRDS) (previously called hyaline membrane disease). Another problem can be chronic lung disease (previously called bronchopulmonary dysplasia or BPD).

- Gastrointestinal and metabolic issues can arise from neonatal hypoglycemia, feeding difficulties, rickets of prematurity, hypocalcemia, inguinal hernia, and necrotizing enterocolitis (NEC).

- Hematologic complications include anemia of prematurity, thrombocytopenia, and hyperbilirubinemia (jaundice) that can lead to kernicterus.

- Infection, including sepsis, pneumonia, and urinary tract infection

A study of 241 children born between 22 and 25 weeks who were currently of school age found that 46 percent had severe or moderate disabilities such as cerebral palsy, vision or hearing loss and learning problems. 34 percent were mildly disabled and 20 percent had no disabilities, while 12 percent had disabling cerebral palsy.

Abortion is the ending of pregnancy by removing a fetus or embryo before it can survive outside the uterus. An abortion that occurs spontaneously is also known as a miscarriage. An abortion may be caused purposely and is then called an induced abortion, or less frequently, "induced miscarriage". The word "abortion" is often used to mean only induced abortions. A similar procedure after the fetus could potentially survive outside the womb is known as a "late termination of pregnancy".

When allowed by law, abortion in the developed world is one of the safest procedures in medicine. Modern methods use medication or surgery for abortions. The drug mifepristone in combination with prostaglandin appears to be as safe and effective as surgery during the first and second trimester of pregnancy. Birth control, such as the pill or intrauterine devices, can be used immediately following abortion. When performed legally and safely, induced abortions do not increase the risk of long-term mental or physical problems. In contrast, unsafe abortions (those performed by unskilled individuals, with hazardous equipment, or in unsanitary facilities) cause 47,000 deaths and 5 million hospital admissions each year. The World Health Organization recommends safe and legal abortions be available to all women.

Around 56 million abortions are performed each year in the world, with about 45% done unsafely. Abortion rates changed little between 2003 and 2008, before which they decreased for at least two decades as access to family planning and birth control increased. , 40% of the world's women had access to legal abortions without limits as to reason. Countries that permit abortions have different limits on how late in pregnancy abortion is allowed.

Historically, abortions have been done using herbal medicines, sharp tools, with force, or through other traditional methods. Abortion laws and cultural or religious views of abortions are different around the world. In some areas abortion is legal only in specific cases such as rape, problems with the fetus, poverty, risk to a woman's health, or incest. In many places there is much debate over the moral, ethical, and legal issues of abortion. Those who oppose abortion often maintain that an embryo or fetus is a human with a right to life and may compare abortion to murder. Those who favor the legality of abortion often hold that a woman has a right to make decisions about her own body.

An abdominal pregnancy can be regarded as a form of an ectopic pregnancy where the embryo or fetus is growing and developing outside the womb in the abdomen, but not in the Fallopian tube, ovary or broad ligament.

While rare, abdominal pregnancies have a higher chance of maternal mortality, perinatal mortality and morbidity compared to normal and ectopic pregnancies; on occasion, however, a healthy viable infant can be delivered.

Because tubal, ovarian and broad ligament pregnancies are as difficult to diagnose and treat as abdominal pregnancies, their exclusion from the most common definition of abdominal pregnancy has been debated.

Others—in the minority—are of the view that abdominal pregnancy should be defined by a placenta implanted into the peritoneum.

HELLP syndrome is defined as hemolysis (microangiopathic), elevated liver enzymes (liver dysfunction), and low platelets (thrombocytopenia). This condition may occur in 10–20% of patients with severe pre-eclampsia and eclampsia and is associated with increased maternal and fetal morbidity and mortality. In 50% of instances, HELLP syndrome develops preterm, while 20% of cases develop in late gestation and 30% during the post-partum period.

Swelling (especially in the hands and face) was originally considered an important sign for a diagnosis of pre-eclampsia. However, because swelling is a common occurrence in pregnancy, its utility as a distinguishing factor in pre-eclampsia is not high. Pitting edema (unusual swelling, particularly of the hands, feet, or face, notable by leaving an indentation when pressed on) can be significant, and should be reported to a health care provider.

In general, none of the signs of pre-eclampsia are specific, and even convulsions in pregnancy are more likely to have causes other than eclampsia in modern practice. Further, a symptom such as epigastric pain may be misinterpreted as heartburn. Diagnosis, therefore, depends on finding a coincidence of several pre-eclamptic features, the final proof being their regression after delivery.

Spontaneous abortion, also known as miscarriage, is the unintentional expulsion of an embryo or fetus before the 24th week of gestation. A pregnancy that ends before 37 weeks of gestation resulting in a live-born infant is known as a "premature birth" or a "preterm birth". When a fetus dies in utero after viability, or during delivery, it is usually termed "stillborn". Premature births and stillbirths are generally not considered to be miscarriages although usage of these terms can sometimes overlap.

Only 30% to 50% of conceptions progress past the first trimester. The vast majority of those that do not progress are lost before the woman is aware of the conception, and many pregnancies are lost before medical practitioners can detect an embryo. Between 15% and 30% of known pregnancies end in clinically apparent miscarriage, depending upon the age and health of the pregnant woman. 80% of these spontaneous abortions happen in the first trimester.

The most common cause of spontaneous abortion during the first trimester is chromosomal abnormalities of the embryo or fetus, accounting for at least 50% of sampled early pregnancy losses. Other causes include vascular disease (such as lupus), diabetes, other hormonal problems, infection, and abnormalities of the uterus. Advancing maternal age and a woman's history of previous spontaneous abortions are the two leading factors associated with a greater risk of spontaneous abortion. A spontaneous abortion can also be caused by accidental trauma; intentional trauma or stress to cause miscarriage is considered induced abortion or feticide.

Drug use during pregnancy can have temporary or permanent effects on the fetus. Any drug that acts during embryonic or fetal development to produce a permanent alteration of form or function is known as a teratogen. Drugs may refer to both pharmaceutical drug and recreational drugs.

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.

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.

Breastfeeding and medications is the description of the medications that can be used by a breastfeeding mother with no or few consequences and those medications which are recommended to be avoided. Some medications are excreted in breastmilk. Almost all medicines pass into breastmilk in small amounts. Some have no effect on the baby and can be used while breastfeeding. The National Institutes of Medicine (US) maintains a database containing information on drugs and other chemicals to which breastfeeding mothers may be exposed. It includes information on the levels of such substances in breast milk and infant blood, and the possible adverse effects in the nursing infant. Suggested therapeutic alternatives to those drugs are provided, where appropriate. All data are derived from reliable sources. Some medications and herbal supplements can be of concern. This can be because the drug can accumulate in breastmilk or have effects on the infant and the mother. Those medications of concern are those medications used to treat substance and alcohol addiction. Other medications of concern are those that are used in smoking cessation. Pain medications and antidepressants need evaluation.

Cannabis consumption in pregnancy might be associated with restrictions in growth of the fetus, miscarriage, and cognitive deficits. The American Congress of Obstetricians and Gynecologists recommended that cannabis use be stopped before and during pregnancy, Cannabis is the most commonly used illicit substance

among pregnant women.

Although it is difficult to draw firm conclusions, there is some evidence that prenatal exposure to marijuana may be associated with deficits in language, attention, cognitive performance, and delinquent behaviors. THC exposure in rats during the prenatal developmental phase may cause epigenetic changes in gene expression, but there is limited knowledge about the risk for psychiatric disorders because of ethical barriers to studying the developing human brain. While animal studies cannot take into account factors that could influence the effects of cannabis on human maternal exposure, such as environmental and social factors, a 2011 review of rodent studies by Campolongo "et al." said there was "... increasing evidence from animal studies showing that cannabinoid drugs ... induce enduring neurobehavioral abnormalities in the exposed offspring ..." Campolongo "et al." added that "clinical studies report hyperactivity, cognitive impairments and altered emotionality in humans exposed in utero to cannabis". Martin "et al." investigated recent trends in substance abuse treatment admissions for cannabis use in pregnancy in the US, based on Treatment Episodes Data Set (TEDS) from 1992 to 2012, and discovered that, while the proportion of treatment admissions for pregnant women was stable (about 4%), the admissions for women who were pregnant and reported any marijuana use grew from 29% to 43%. A 2015 review found that cannabis use by pregnant mothers impaired brain maturation in their children, and that it also predisposed their children to neurodevelopmental disorders.

Molar pregnancies usually present with painless vaginal bleeding in the fourth to fifth month of pregnancy. The uterus may be larger than expected, or the ovaries may be enlarged. There may also be more vomiting than would be expected (hyperemesis). Sometimes there is an increase in blood pressure along with protein in the urine. Blood tests will show very high levels of human chorionic gonadotropin (hCG).

HIV in pregnancy is the presence of the HIV virus in a woman while pregnant. There are concerns because women diagnosed with HIV/AIDS may transmit the infection to their child during pregnancy. The infection be transmitted to the infant during the pregnancy, childbirth, or breastfeeding. However, the risk of mother-to-child transmission of HIV may be reduced by the use of HIV medications known as antiretroviral therapy (ART). These medications may be used by women before, during, and after pregnancy. After delivery, children are also given the medication to reduce the risk of infection. Because HIV may be spread through breast milk, mothers with the infection are encouraged to avoid breastfeeding.

Infection with HIV/AIDS is not a contraindication to pregnancy. Women with the disease may choose to become pregnant if they desire, however, they are encouraged to talk with their doctors beforehand. Some women are unaware they have the disease until they become pregnant. In this case, they should begin antiretroviral therapy as soon as possible. With the appropriate treatment, the risk of mother-to-child infection can be reduced to below 1%. Without treatment, the risk of transmission is 15-45%.

There are approximately 1.4 million HIV positive women who become pregnant and contribute to more than 300,000 neonatal and fetal deaths each year. With the use of ART, transmission of HIV from the mother to child has decreased according to reports by the World Health Organization (WHO). In 2009, there were an estimated 400,000 children born with HIV and by 2013, there were 240,000. Countries in Southern Africa are worst affected by the HIV/AIDS pandemic. In 2010, 30% of all pregnancies in the region were affected by HIV. In 2011, HIV was responsible for 50% of the deaths for children below the age of 5. In the United States, fewer than 200 babies are born with HIV every year.

As of 2015, Cuba has become the first country in the world to eradicate mother-to-child transmission of HIV. In 2010, the WHO partnered with the Pan American Health Organization (PAHO) to implement an initiative that would provide early prenatal care and HIV testing for all pregnant women in the country. For women who tested positive, ART was provided for both the mother and child, cesarean sections were performed, and alternatives to breastfeeding were provided. In implementing these measures, the country was successfully able to eradicate HIV transmission during pregnancy.

Symptoms in PID range from none to severe. If there are symptoms, then fever, cervical motion tenderness, lower abdominal pain, new or different discharge, painful intercourse, uterine tenderness, adnexal tenderness, or irregular menstruation may be noted.

Other complications include endometritis, salpingitis, tubo-ovarian abscess, pelvic peritonitis, periappendicitis, and perihepatitis.

It is often characterized by a decrease in flow and duration of bleeding (absence of menstrual bleeding, little menstrual bleeding, or infrequent menstrual bleeding) and become infertile. Menstrual anomalies are often but not always correlated with severity: adhesions restricted to only the cervix or lower uterus may block menstruation. Pain during menstruation and ovulation is sometimes experienced and can be attributed to blockages.

It has been reported that 88% of AS cases occur after a D&C is performed on a recently pregnant uterus, following a missed or incomplete miscarriage, birth, or during an elective termination (abortion) to remove retained products of conception.