A pre-existing disease in pregnancy is a disease that is not directly caused by the

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ca ...

, in contrast to various

complications of pregnancy Complications of pregnancy are health problems that are related to pregnancy. Complications that occur primarily during childbirth are termed obstetric labor complications, and problems that occur primarily after childbirth are termed puerperal di ...

, but which may become worse or be a potential risk to the pregnancy (such as causing pregnancy complications). A major component of this risk can result from necessary use of

drugs in pregnancy Drugs and medications should be avoided while pregnant. Women should speak to their doctor or healthcare professional before starting or stopping any medications while pregnant. Tobacco, alcohol, marijuana, and illicit drug use while pregnant may ...

to manage the disease. In such circumstances, women who wish to continue with a pregnancy require extra medical care, often from an interdisciplinary team. Such a team might include (besides an obstetrician) a specialist in the disorder and other practitioners (for example, maternal-fetal specialists or obstetric physicians,

dietician A dietitian, medical dietitian, or dietician is an expert in identifying and treating disease-related malnutrition and in conducting medical nutrition therapy, for example designing an enteral tube feeding regimen or mitigating the effects of ca ...

s, etc.).

Chronic hypertension

Chronic hypertension in pregnancy can lead to increased complications for both the mother and fetus. Maternal complications include superimposed pre-eclampsia and caesarean delivery. Fetal complications include preterm delivery, low birth weight, and death. Increasing rates of obesity and metabolic syndrome play a key role in the increased prevalence of chronic hypertension and associated complications. While high blood pressure treatment has been shown to decrease the incidence of severe hypertension during pregnancy, there was no significant difference in pregnancy complications (for example, superimposed pre-eclampsia, stillbrith/neonatal death, small for gestational age).

Endocrine disorders

Diabetes mellitus

Diabetes mellitus and pregnancy For pregnant women with diabetes, some particular challenges exist for both mother and child. If the pregnant woman has diabetes as a pre-existing disorder, it can cause early labor, birth defects, and larger than average infants. Therefore, e ...

deals with the interactions of

diabetes mellitus Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...

(not restricted to

gestational diabetes Gestational diabetes is a condition in which a woman without diabetes develops high blood sugar levels during pregnancy. Gestational diabetes generally results in few symptoms; however, it increases the risk of pre-eclampsia, depression, and of ...

) and pregnancy. Risks for the child include miscarriage, growth restriction, growth acceleration, fetal obesity (macrosomia), polyhydramnios and birth defects.

Thyroid disease

Thyroid disease in pregnancy Thyroid disease in pregnancy can affect the health of the mother as well as the child before and after delivery. Thyroid disorders are prevalent in women of child-bearing age and for this reason commonly present as a pre-existing disease in pregnan ...

can, if uncorrected, cause adverse effects on fetal and maternal well-being. The deleterious effects of thyroid dysfunction can also extend beyond pregnancy and delivery to affect neurointellectual development in the early life of the child. Demand for thyroid hormones is increased during pregnancy which may cause a previously unnoticed thyroid disorder to worsen. The most effective way of screening for thyroid dysfunction is not known. A review found that more women were diagnosed with thyroid dysfunction when all pregnant women were tested instead of just testing those at 'high-risk' of thyroid problems (those with family history, signs or symptoms). Finding more women with thyroid dysfunction meant that the women could have treatment and management through their pregnancies. However the outcomes of the pregnancies were surprisingly similar so more research is needed to look at the effects of screening all pregnant women for thyroid problems.

Hypercoagulability

Hypercoagulability in pregnancy is the propensity of pregnant women to develop thrombosis (blood clots) such as a deep vein thrombosis with a potential subsequent pulmonary embolism. Pregnancy itself is a factor of hypercoagulability (pregnancy-induced hypercoaguability), as a physiologically adaptive mechanism to prevent postpartum hemorrhage, ''post partum'' bleeding. The pregnancy associated hypercoaguability is attributed to an increased synthesis of coagulation factors, such as fibrinogen, by the liver through the effects of estrogen. When combined with any additional underlying hypercoagulable state, the risk of thrombosis or embolism may become substantial.Page 264 in: Multiple pre-existing genetic disorders can worsen the hypercoaguable state observed in pregnancy. Examples include: * Factor V Leiden * Prothrombin G20210A * Protein C deficiency * Protein S deficiency * Antithrombin III deficiency

Infections

Vertically transmitted infections

Many infectious diseases have a risk of vertical transmission to the fetus, known as TORCH infections. Examples based on the TORCHES acronym include: * Toxoplasma gondii, Toxoplasma * Other: Parvovirus B19, Zika virus, Zika, Chickenpox * Rubella * Cytomegalovirus * Herpes simplex or Neonatal herpes simplex * HIV * Syphilis Infections in pregnancy also raise particular concerns about whether or not to use

(that is, antibiotics or Antiviral drug, antivirals) to treat them. For example, pregnant women who contract H1N1 influenza infection are recommended to receive antiviral therapy with either oseltamivir (which is the preferred medication) or zanamivir.Health Care Guideline: Routine Prenatal Care. Fourteenth Edition.
By the Institute for Clinical Systems Improvement. July 2010. Both amantadine and rimantadine have been found to be teratogenic and embryotoxic when given at high doses in animal studies.

Candidal vulvovaginitis

In pregnancy, changes in the levels of female sex hormones, such as estrogen, make a woman more likely to develop candidal vulvovaginitis. During pregnancy, the ''Candida'' fungus is more prevalent (common), and recurrent infection is also more likely. There is no clear evidence that treatment of asymptomatic candidal vulvovaginitis in pregnancy reduces the risk of preterm birth. Candidal vulvovaginitis in pregnancy should be treated with intravaginal clotrimazole or nystatin for at least 7 days.

Bacterial vaginosis

Bacterial vaginosis is an imbalance of naturally occurring bacterial flora in the vagina. Bacterial vaginosis occurring during pregnancy may increase the risk of pregnancy complications, most notably premature birth or miscarriage. However, this risk is small overall and appears more significant in women who have had such complications in an earlier pregnancy.

Valvular heart disease

In case of valvular heart disease in pregnancy, the maternal physiological changes in pregnancy confer additional load on the heart and may lead to complications. In individuals who require an artificial heart valve, consideration must be made for deterioration of the valve over time (for bioprosthetic valves) versus the risks of hypercoagulability in pregnancy, blood clotting in pregnancy with mechanical valves with the resultant need of

in the form of anticoagulants.

Other autoimmune disorders

Celiac disease

Untreated celiac disease can cause miscarriage, spontaneous abortion (miscarriage), intrauterine growth restriction, small for gestational age, low birthweight and preterm birth. Often reproductive disorders are the only manifestation of undiagnosed celiac disease and most cases are not recognized. Complications or failures of pregnancy cannot be explained simply by malabsorption, but by the autoimmune response elicited by the exposure to gluten, which causes damage to the placenta. The gluten-free diet avoids or reduces the risk of developing reproductive disorders in pregnant women with celiac disease. Also, pregnancy can be a trigger for the development of celiac disease in genetically susceptible women who are consuming gluten.

Systemic lupus erythematosus

Systemic lupus erythematosus and pregnancy confers an increased rate of fetal death ''in utero'' and spontaneous abortion (miscarriage), as well as of neonatal lupus.

Behçet's disease

Pregnancy does not have an adverse effect on the course of Behçet's disease and may possibly ameliorate its course. Still, there is a substantial variability in clinical course between patients and even for different pregnancies in the same patient. Also, the other way around, Behçet's disease confers an increased risk of pregnancy complications, miscarriage and Cesarean section.

Multiple sclerosis

Being pregnant decreases the risk of relapse in multiple sclerosis; however, during the first months after delivery the risk increases. Overall, pregnancy does not seem to influence long-term disability. Multiple sclerosis does not increase the risk of congenital abnormality or miscarriage.Multiple Sclerosis: Pregnancy Q&A
from Cleveland Clinic, retrieved January 2014.

Mental health

Depression in pregnancy

The effects of depression during pregnancy are difficult to parse from depression before pregnancy as the symptoms of the two overlap. However, the biggest risk factor of depression during pregnancy is a prior history of depression. Most of the research is focused on the consequences of untreated depression regardless if the depression developed during pregnancy or if it was there before conception. Untreated depression has been linked to premature birth, low birth weight, fetal growth restriction, and postnatal complications. On the other hand, however, anti-depressant medications also come with a small risk of pre-term birth, low birth weight, and persistent pulmonary hypertension.

Respiratory disease

Asthma

In the United States, the prevalence of asthma among pregnant women is between 8.4% and 8.8%. Asthma in pregnant women is strongly associated with multiple adverse health outcomes, including pre-eclampsia, preterm birth, and low birth weight. Other conditions such as gestational diabetes, placenta previa, and hemorrhage are inconsistently correlated to asthma. Poorly controlled and severe asthma may exacerbate conditions associated with maternal and neonate morbidity and mortality. Asthma treatment recommendations during pregnancy are similar to those in non-pregnant women.

Structural (congenital) abnormalities of the uterus

Structural abnormalities of the uterus include conditions like septate uterus, bicornuate uterus, arcuate uterus, and didelphys uterus. Most of these abnormalities occur when the Müllerian ducts are fused improperly or incompletely. Women with these congenital abnormalities are usually unaware as these conditions do not usually do not present any symptoms. During pregnancy, these conditions are associated with infertility, preterm birth, fetal malpresentation, and early miscarriages. Among these uterine abnormalities, those with canalization defects, i.e., not having a normal uterine canal such as septate defects have the worse pregnancy outcomes. Surgical treatment is only recommended for individuals who have had recurrent miscarriages and have a septate uterus; however, the risks of surgery, especially scarring of the womb should be considered. Further evidence from randomized controlled trials are required to establish conclusively whether surgery is the better option when its risks and rewards are compared with the risks of the adverse pregnancy outcomes.

Others

The following conditions may also become worse or be a potential risk to the pregnancy: * Cancer * Chronic hypertension * Cirrhosis * Congenital defect, Congenital disorders that may be passed on to offspring * Heart defects, especially primary pulmonary hypertension and Eisenmenger's syndrome * Kidney disorders * Mental health. ** Depression has been linked to higher rates of preterm delivery. * Respiratory system#Disease, Respiratory disorders and diseases (associated, for example, with placental abruption) ** Asthma * Seizure disorders * Structural abnormalities in the cervix * Structural abnormalities in the uterus * Viral hepatitis

References

{{Reflist, group=MMHE Health issues in pregnancy, *