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.

There are various causes for recurrent miscarriage, and some can be treated. Some couples never have a cause identified, often after extensive investigations. About 50-75% of cases of Recurrent Miscarriage are unexplained.

Fifteen percent of women who have experienced three or more recurring miscarriages have some anatomical reason for the inability to complete the pregnancy. The structure of the uterus has an effect on the ability to carry a child to term. Anatomical differences are common and can be congenital.

Pregnancy, also known as gestation, is the time during which one or more offspring develops inside a woman. A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy can occur by sexual intercourse or assisted reproductive technology. Childbirth typically occurs around 40 weeks from the last menstrual period (LMP). This is just over nine months, where each month averages 29½ days. When measured from conception it is about 38 weeks. An embryo is the developing offspring during the first eight weeks following conception, after which, the term "fetus" is used until birth. Symptoms of early pregnancy may include missed periods, tender breasts, nausea and vomiting, hunger, and frequent urination. Pregnancy may be confirmed with a pregnancy test.

Pregnancy is typically divided into three trimesters. The first trimester is from week one through 12 and includes conception. Conception is when the sperm fertilizes the egg. The fertilized egg then travels down the fallopian tube and attaches to the inside of the uterus, where it begins to form the embryo and placenta. The first trimester carries the highest risk of miscarriage (natural death of embryo or fetus). The second trimester is from week 13 through 28. Around the middle of the second trimester, movement of the fetus may be felt. At 28 weeks, more than 90% of babies can survive outside of the uterus if provided with high-quality medical care. The third trimester is from 29 weeks through 40 weeks.

Prenatal care improves pregnancy outcomes. Prenatal care may include taking extra folic acid, avoiding drugs and alcohol, regular exercise, blood tests, and regular physical examinations. Complications of pregnancy may include disorders of high blood pressure, gestational diabetes, iron-deficiency anemia, and severe nausea and vomiting among others. Term pregnancy is 37 to 41 weeks, with early term being 37 and 38 weeks, full term 39 and 40 weeks, and late term 41 weeks. After 41 weeks, it is known as post term. Babies born before 37 weeks are preterm and are at higher risk of health problems such as cerebral palsy. Delivery before 39 weeks by labor induction or caesarean section is not recommended unless required for other medical reasons.

About 213 million pregnancies occurred in 2012, of which, 190 million were in the developing world and 23 million were in the developed world. The number of pregnancies in women ages 15 to 44 is 133 per 1,000 women. About 10% to 15% of recognized pregnancies end in miscarriage. In 2013, complications of pregnancy resulted in 293,000 deaths, down from 377,000 deaths in 1990. Common causes include maternal bleeding, complications of abortion, high blood pressure of pregnancy, maternal sepsis, and obstructed labor. Globally, 40% of pregnancies are unplanned. Half of unplanned pregnancies are aborted. Among unintended pregnancies in the United States, 60% of the women used birth control to some extent during the month pregnancy occurred.

A heterotopic pregnancy is a rare complication of pregnancy in which both extra-uterine (ectopic pregnancy) and intrauterine pregnancy occur simultaneously. It may also be referred to as a combined ectopic pregnancy, multiple‑sited pregnancy, or coincident pregnancy.

A possible pregnancy must be considered in any woman who has abdominal pain or abnormal vaginal bleeding. A heterotopic pregnancy may have similar signs and symptoms as a normal intrauterine pregnancy, a normal intrauterine pregnancy and a ruptured ovarian cyst, a corpus luteum, or appendicitis. Blood tests and ultrasound can be used to differentiate these conditions.

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.

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.

A Cervical pregnancy is an ectopic pregnancy that has implanted in the uterine endocervix. Such a pregnancy typically aborts within the first trimester, however, if it is implanted closer to the uterine cavity - a so-called cervico-isthmic pregnancy - it may continue longer. Placental removal in a cervical pregnancy may result in major hemorrhage.

The diagnosis is made in asymptomatic pregnant women either by inspection seeing a bluish discolored cervix or, more commonly, by obstetric ultrasonography. A typical non-specific symptom is vaginal bleeding during pregnancy. Ultrasound will show the location of the gestational sac in the cervix, while the uterine cavity is "empty". Cervical pregnancy can be confused with a miscarriage when pregnancy tissue is passing through the cervix.

Histologically the diagnosis has been made by Rubin’s criteria on the surgical specimen: cervical glands are opposite the trophoblastic tissue, the trophoblastic attachment is below the entrance of the uterine vessels to the uterus or the anterior peritoneal reflection, and fetal elements are absent from the uterine corpus. As many pregnancies today are diagnosed early and no hysterectomy is performed, Rubin's criteria can often not be applied.

An interstitial pregnancy is a uterine but ectopic pregnancy; the pregnancy is located outside the uterine cavity in that part of the fallopian tube that penetrates the muscular layer of the uterus. The term cornual pregnancy is sometimes used as a synonym, but remains ambiguous as it is also applied to indicate the presence of a pregnancy located within the cavity in one of the two upper "horns" of a bicornuate uterus. Interstitial pregnancies have a higher mortality than ectopics in general.

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.

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.

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.

Early diagnosis is important and today facilitated by the use of sonography and the quantitative human chorionic gonadotropin (hCG) assay. As in other cases of ectopic pregnancy, risk factors are: previous tubal pregnancy, IVF therapy, tubal surgery, and a history of sexual infection.

Typical symptoms of an interstitial pregnancy are the classic signs of ectopic pregnancy, namely abdominal pain and vaginal bleeding. Hemorrhagic shock is found in almost a quarter of patients.; this explains the relatively high mortality rate.

In pregnant patients, sonography is the primary method to make the diagnosis, even when patients have no symptoms. The paucity of myometrium around the gestational sac is diagnostic, while, in contrast, the angular pregnancy has at least 5 mm of myometrium on all of its sides. Ultrasonic criteria for the diagnosis include an empty uterine cavity, a gestational sac separate from the uterine cavity, and a myometrial thinning of less than 5 mm around the gestational sac; typically the "interstitial line sign"—an echogenic line from the endometrial cavity to the corner next to the gestational mass—is seen. MRI can be used particularly when it is important to distinguish between an interstitial and angular pregnancy.

On average, the gestational age at presentation is about 7–8 weeks. In a 2007 series, 22% of patients presented with rupture and hemorrhagic shock, while a third of the patients were asymptomatic; the remainder had abdominal pain and/or vaginal bleeding. Cases that are not diagnosed until surgery show an asymmetrical bulge in the upper corner of the uterus.

Both are composed of intermediate trophoblast, but their morphological features and clinical presentation can differ significantly.

Exaggerated placental site is a benign, non cancerous lesion with an increased number of implantation site intermediate trophoblastic cells that infiltrate the endometrium and the underlying myometrium. An exaggerated placental site may occur with normal pregnancy, or after an abortion. No specific treatment or follow up is necessary.

Placental site nodules are lesions of chorionic type intermediate trophoblast, usually small. 40 to 50% of placental site nodules are found in the cervix. They almost always are incidental findings after a surgical procedure. No specific treatment or follow up is necessary.

Ovarian pregnancy refers to an ectopic pregnancy that is located in the ovary. Typically the egg cell is not released or picked up at ovulation, but fertilized within the ovary where the pregnancy implants. Such a pregnancy usually does not proceed past the first four weeks of pregnancy. An untreated ovarian pregnancy causes potentially fatal intraabdominal bleeding and thus may become a medical emergency.

Gestational trophoblastic disease (GTD) is a term used for a group of pregnancy-related tumours. These tumours are rare, and they appear when cells in the womb start to proliferate uncontrollably. The cells that form gestational trophoblastic tumours are called trophoblasts and come from tissue that grows to form the placenta during pregnancy.

There are several different types of GTD. Hydatidiform moles are benign in most cases, but sometimes may develop into invasive moles, or, in rare cases, into choriocarcinoma, which is likely to spread quickly, but which is very sensitive to chemotherapy, and has a very good prognosis. Gestational trophoblasts are of particular interest to cell biologists because, like cancer, these cells invade tissue (the uterus), but unlike cancer, they sometimes "know" when to stop.

GTD can simulate pregnancy, because the uterus may contain fetal tissue, albeit abnormal. This tissue may grow at the same rate as a normal pregnancy, and produces chorionic gonadotropin, a hormone which is measured to monitor fetal well-being.

While GTD overwhelmingly affects women of child-bearing age, it may rarely occur in postmenopausal women.

Women with the condition may be asymptomatic and unaware of having a uniconuate uterus; normal pregnancy may occur. In a review of the literature Reichman et al. analyzed the data on pregnancy outcome of 290 women with a unicornuate uterus. 175 women had conceived for a total of 468 pregnancies. They found that about 50% of patients delivered a live baby. The rates for ectopic pregnancy was 2.7%, for miscarriage 34%, and for preterm delivery 20%, while the intrauterine demise rate was 10%. Thus patients with a unicornuate uterus are at a higher risk for pregnancy loss and obstetrical complications.

A unicornuate uterus represents a uterine malformation where the uterus is formed from one only of the paired Müllerian ducts while the other Müllerian duct does not develop or only in a rudimentary fashion. The sometimes called "hemi-uterus" has a single horn linked to the ipsilateral fallopian tube that faces its ovary.

The diagnosis is made in asymptomatic pregnant women by obstetric ultrasonography. On pelvic examination a unilateral adnexal mass may be found. Typical symptoms are abdominal pain and, to a lesser degree, vaginal bleeding during pregnancy. Patients may present with hypovolemia or be in circulatory shock because of internal bleeding.

Ideally, ultrasound will show the location of the gestational sac in the ovary, while the uterine cavity is "empty", and if there is internal bleeding, it can be identified. Because of the proximity of the tube, the sonographic distinction between a tubal and an ovarian pregnancy may be difficult. Serial hCG levels generally show not the normal progressive rise.

In a series of 12 patients the mean gestation age was 45 days.

Histologically, the diagnosis has been made by Spiegelberg criteria on the surgical specimen of the removed ovary and tube. However, the tube and ovary are not usually removed as sonography allows for earlier diagnosis and surgeons strive to preserve the ovary. Prior to the introduction of Spiegelberg's criteria in 1878, the existence of ovarian pregnancy was in doubt; his criteria helped to identify the ovarian pregnancy from other ectopics:

- The gestational sac is located in the region of the ovary.

- The gestational sac is attached to the uterus by the ovarian ligament.

- Ovarian tissue is histologically proven in the wall of the gestational sac.

- The oviduct on the affected side is intact (this criterion, however, holds not true for a longer ongoing ovarian pregnancy).

An ovarian pregnancy can be mistaken for a tubal pregnancy or a hemorrhagic ovarian cyst or corpus luteum prior to surgery. Sometimes, only the presence of trophoblastic tissue during the histologic examination of material of a bleeding ovarian cyst shows that an ovarian pregnancy was the cause of the bleeding.

Confined placental mosaicism (CPM) represents a discrepancy between the chromosomal makeup of the cells in the placenta and the cells in the baby. CPM was first described by Kalousek and Dill in 1983. CPM is diagnosed when some trisomic cells are detected on chorionic villus sampling and only normal cells are found on a subsequent prenatal test, such as amniocentesis or fetal blood sampling. In theory, CPM is when the trisomic cells are found only in the placenta. CPM is detected in approximately 1-2% of ongoing pregnancies that are studied by chorionic villus sampling (CVS) at 10 to 12 weeks of pregnancy. Chorionic villus sampling is a prenatal procedure which involves a placental biopsy. Most commonly when CPM is found it represents a trisomic cell line in the placenta and a normal diploid chromosome complement in the baby. However, the fetus is involved in about 10% of cases.

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.

About 66% of women have both nausea and vomiting while 33% have just nausea.

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.