Merck Manual

Please confirm that you are a health care professional

honeypot link

Risk Factors for Pregnancy Complications

By

Antonette T. Dulay

, MD, Main Line Health System

Reviewed/Revised Mar 2024
View PATIENT EDUCATION
Topic Resources

Risk factors for complications during pregnancy include

  • Preexisting maternal medical conditions and characteristics

  • Modifiable risk factors (eg, smoking, substance use)

  • Previous obstetric complications (eg, a previous history of preeclampsia)

Some major risk factors are discussed here. For additional medical conditions that may complicate pregnancy, see Pregnancy Complicated by Disease Pregnancy Complicated by Disease .

Diabetes

Preexisting insulin-dependent diabetes increases the risk of the following:

The incidence of fetal macrosomia is approximately 50% higher in pregnant women with preexisting diabetes than in pregnant women in the general population. The incidence of perinatal fetal or neonatal mortality is also higher.

Tight glucose control before conception and during early pregnancy is essential to prevent fetal malformations.

Insulin requirements usually increase during pregnancy.

Gestational diabetes increases the risk of the following:

Gestational diabetes is routinely screened for at 24 to 28 weeks and, if women have risk factors, during the first trimester. Risk factors include the following:

  • Previous gestational diabetes

  • A macrosomic infant in a previous pregnancy

  • Unexplained fetal losses

  • Prepregnancy body mass index (BMI) > 30 kg/m2

  • Maternal age > 40 years

  • Family history of diabetes

  • Non-Hispanic Asian/Pacific Islander and Hispanic/Latina ethnicity

  • 1-step test: A fasting, 75-g glucose, 2-hour oral glucose tolerance test (GTT). Abnormal results are any of the following: fasting (≥ 92 mg/dL [5.1 mmol/L]); 1 hour (≥ 180 mg/dL [10 mmol/L]); or 2 hour (≥ 153 mg/dL [8.5 mmol/L).

  • 2-step test: A non-fasting, 50-g glucose, 1-hour GTT; if abnormal (≥ 130 mg/dL [7.5 mmol/L] to 140 mg/dL [7.8 mmol/L]), then a fasting, 100-g, 3-hour GTT. For interpretation of results , see table .

The American College of Obstetricians and Gynecologists (ACOG) recommends the 2-step test to diagnosis gestational diabetes. The 1-step approach has been used and promoted by other organizations, including the International Association of Diabetes and Pregnancy Study Group (IADPSG) (6 Diabetes references Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more Diabetes references ).

Table

Optimal treatment of gestational diabetes Treatment Pregnancy makes glycemic control more difficult in preexisting type 1 (insulin-dependent) and type 2 (non–insulin-dependent) diabetes but does not appear to exacerbate diabetic retinopathy,... read more (with dietary modification, exercise, and close monitoring of blood glucose levels and insulin when necessary) reduces risk of adverse maternal, fetal, and neonatal outcomes. Women with gestational diabetes are at a higher lifetime risk of cardiovascular events and, after delivery, should be referred for appropriate cardiovascular risk assessment and follow-up.

Table

Women with gestational diabetes mellitus may have had undiagnosed diabetes mellitus before pregnancy. Thus, they should be screened for diabetes mellitus Screening Diabetes mellitus is impaired insulin secretion and variable degrees of peripheral insulin resistance leading to hyperglycemia. Early symptoms are related to hyperglycemia and include polydipsia... read more 6 to 12 weeks postpartum, using the same testing and criteria used for patients who are not pregnant.

Diabetes references

  • 1. Deputy NP, Kim SY, Conrey EJ, Bullard KM: Prevalence and Changes in Preexisting Diabetes and Gestational Diabetes Among Women Who Had a Live Birth - United States, 2012-2016. MMWR Morb Mortal Wkly Rep 67(43):1201-1207, 2018. Published 2018 Nov 2. doi:10.15585/mmwr.mm6743a2

  • 2. Goya M, Codina M: Diabetes mellitus and pregnancy. Updated clinical practice guideline 2021. Executive summary. Endocrinol Diabetes Nutr (Engl Ed) 70 Suppl 1:1-6, 2023. doi:10.1016/j.endien.2021.12.006

  • 3. Gregory EC, Ely DM: Trends and Characteristics in Gestational Diabetes: United States, 2016-2020. Natl Vital Stat Rep 71(3):1-15, 2022.

  • 4. Artal R: Exercise: The alternative therapeutic intervention for gestational diabetes. Clinical Obstetrics and Gynecology 46 (2):479–487, 2003.

  • 5. Artal R: The role of exercise in reducing the risks of gestational diabetes mellitus in obese women. Best Pract Res Clin Obstet Gynaecol 29 (1):123–4132, 2015.

  • 6. American College of Obstetrics and Gynecology (ACOG): ACOG Practice Bulletin No. 190: Gestational Diabetes Mellitus. Obstet Gynecol. 2018;131(2):e49-e64. doi:10.1097/AOG.0000000000002501

  • 7. American Diabetes Association Professional Practice Committee: 2. Diagnosis and Classification of Diabetes: Standards of Care in Diabetes-2024. Diabetes Care. 2024;47(Suppl 1):S20-S42. doi:10.2337/dc24-S002

Hypertension

  • Chronic hypertension: Present before the pregnancy or developing before 20 weeks of pregnancy

  • Gestational hypertension: New onset of systolic and/or diastolic blood pressure (BP) ≥ 140/≥ 90 mm Hg on 2 occasions at least 4 hours apart after 20 weeks of gestation

  • Preeclampsia Preeclampsia and Eclampsia Preeclampsia is new onset or worsening of existing hypertension with proteinuria after 20 weeks gestation. Eclampsia is unexplained generalized seizures in patients with preeclampsia. Diagnosis... read more : New onset after 20 weeks of gestation of persistent (2 episodes within 4 hours) systolic and/or diastolic BP ≥ 140/≥ 90 mm Hg OR at least 1 measurement of systolic and/or diastolic BP ≥ 160/≥ 110 mm Hg PLUS new unexplained proteinuria (> 300 mg/24 hours or urine protein/creatinine ratio ≥ 0.3 or dipstick reading of 2+; in the absence of proteinuria, new-onset hypertension with new onset of other signs of end-organ damage (eg, thrombocytopenia [platelets < 100,000/mcL], impaired liver function, renal insufficiency, pulmonary edema, new-onset headache [unresponsive to medication and not accounted for by alternative diagnoses], visual symptoms).

  • Preeclampsia with severe features: Preeclampsia with persistent (2 episodes within 4 hours) systolic and/or diastolic BP ≥ 160/≥ 110 mm Hg and/or other signs of end-organ damage

  • HELLP syndrome: A form of severe preeclampsia with hemolysis, elevated liver enzymes, and low platelet count

  • Chronic hypertension plus superimposed preeclampsia: Worsening hypertension and new or worsening proteinuria or other signs of end-organ damage after 20 weeks in a woman with preexisting hypertension

  • Eclampsia: New-onset tonic-clonic, focal, or multifocal seizures not accounted for by other causes

Chronic hypertension increases risk of the following:

Before attempting to become pregnant, women with hypertension should be counseled about risks. Prenatal care should begin as early in pregnancy as possible. Pregnant women with chronic hypertension who require antihypertensive therapy should be started or continued on appropriate medications and referred to a maternal-fetal medicine specialist (2 Hypertension references Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more Hypertension references ).

Management of chronic hypertension during pregnancy Treatment Recommendations regarding classification, diagnosis, and management of hypertensive disorders (including preeclampsia) are available from the American College of Obstetricians and Gynecologists... read more includes measurements of baseline renal function (eg, serum creatinine, blood urea nitrogen [BUN]), funduscopic examination, and directed cardiovascular evaluation (auscultation and sometimes ECG, echocardiography, or both). Each trimester, 24-hour urine protein, serum uric acid, serum creatinine, and hematocrit are measured.

Ultrasonography to monitor fetal growth is done at 28 weeks and every 4 weeks thereafter. Delayed growth is evaluated with multivessel Doppler testing by a maternal-fetal medicine specialist.

Women with a history of preeclampsia or gestational hypertension are at a higher lifetime risk of cardiovascular events and, after delivery, should be referred for appropriate cardiovascular risk assessment and follow-up.

Hypertension references

Thyroid Disorders

Fetal effects vary with the disorder and the medications used for treatment. But generally, untreated or inadequately treated hyperthyroidism can result in

Untreated hypothyroidism can cause

Sexually Transmitted Infections (STIs)

Screening for sexually transmitted infections should be done during pregnancy to make treatment possible and to prevent adverse effects of intrauterine or perinatal transmitted infections to the fetus or neonate. The rate of congenital syphilis Congenital Syphilis Congenital syphilis is a multisystem infection caused by Treponema pallidum and transmitted to the fetus via the placenta. Early signs are characteristic skin lesions, lymphadenopathy... read more Congenital Syphilis in the United States consistently rises (see CDC: National Overview of STDs, 2021).

Routine prenatal care includes screening tests for HIV infection, hepatitis B, hepatitis C (1 STIs references Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more STIs references ), and syphilis and, if < 25 years, for chlamydial infection and gonorrhea at the first prenatal visit. Syphilis testing is repeated during pregnancy and at delivery if risk continues or if the patient resides in an endemic area (2 STIs references Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more STIs references ). Pregnant women who have any of these infections are treated with antimicrobials.

Without treatment, risk of transmission of HIV Transmission Human immunodeficiency virus (HIV) infection results from 1 of 2 similar retroviruses (HIV-1 and HIV-2) that destroy CD4+ lymphocytes and impair cell-mediated immunity, increasing risk of certain... read more Transmission from mother to child is approximately 30% prepartum and approximately 25% intrapartum. Antiretroviral treatment of the pregnant woman before and during pregnancy and of the neonate within 6 to 12 hours of birth reduces risk of HIV transmission to the fetus Prevention Human immunodeficiency virus (HIV) infection is caused by the retrovirus HIV-1 (and less commonly by the related retrovirus HIV-2). Infection leads to progressive immunologic deterioration and... read more Prevention by two thirds; risk is lower (< 2%) with a combination of 2 or 3 highly active antiretrovirals. Highly active antiretrovirals are given to the mother during pregnancy and intrapartum to prevent mother-to-child transmission.

Treatment of bacterial vaginosis, gonorrhea, or chlamydial infection may prolong the interval from rupture of the membranes to delivery and may improve fetal outcome by decreasing fetal inflammation.

STIs references

Female Genital Tract Abnormalities

Structural abnormalities of the uterus and cervix (eg, uterine septum, bicornuate uterus) make the following more likely:

Cervical insufficiency Cervical Insufficiency Cervical insufficiency (formerly called cervical incompetence) is painless cervical dilation resulting in second-trimester pregnancy loss. Transvaginal cervical ultrasonography during the second... read more Cervical Insufficiency (incompetence) makes preterm delivery more likely. The risk of cervical insufficiency is higher in women who have had lacerations or injury of the cervix during a previous procedure (eg, therapeutic abortion, instrumental vaginal deliveries). Cervical insufficiency is treated with surgical intervention (cerclage).

If, before pregnancy, women have had a myomectomy in which the uterine cavity was entered, cesarean delivery is required because uterine rupture Uterine Rupture Uterine rupture is rupture of the myometrium in late pregnancy before labor or during labor, which usually occurs in patients with prior uterine surgery (eg, cesarean delivery or myomectomy)... read more is a risk during subsequent vaginal delivery.

Uterine abnormalities that lead to poor obstetric outcomes often require surgical correction, which is done after delivery.

Substance Use

Alcohol Alcohol Toxicity and Withdrawal Alcohol (ethanol) is a central nervous system depressant. Large amounts consumed rapidly can cause respiratory depression, coma, and death. Large amounts chronically consumed damage the liver... read more is the most commonly used teratogen. Risk is probably related to amount of alcohol consumed, but no amount is known to be risk-free. Binge drinking in particular, possibly as little as 45 mL of pure alcohol (equivalent to about 3 drinks) a day, can cause fetal alcohol syndrome Fetal Alcohol Syndrome Alcohol exposure in utero increases the risk of spontaneous abortion, decreases birth weight, and can cause fetal alcohol syndrome, a constellation of variable physical and cognitive abnormalities... read more , which may result in fetal growth restriction, facial and cardiovascular defects, and neurologic dysfunction.

Clinicians should ask pregnant patients about substance misuse, utilize validated screening tools, and refer to addiction specialists when necessary.

Exposure to Teratogens

Common teratogens (agents that cause fetal malformation) include infections, drugs, and physical agents. Malformations are most likely to result if exposure occurs between the second and eighth week after conception (the fourth to tenth week after the last menstrual period), when organs are forming. Other adverse pregnancy outcomes are also more likely. Pregnant women exposed to teratogens are counseled about increased risks and referred for detailed ultrasound evaluation to detect malformations.

Common infections that may be teratogenic include

Commonly used drugs that may be teratogenic include

Exposure to Mercury

Mercury in seafood can be toxic to the fetus. The FDA (see Advice about Eating Fish For Those Who Might Become or Are Pregnant or Breastfeeding and Children Ages 1–11 Years) recommends the following:

  • Avoiding tilefish from the Gulf of Mexico, shark, swordfish, big-eye tuna, marlin, orange roughy, and king mackerel

  • Limiting albacore tuna to 4 ounces (one average meal)/week

  • Before eating fish caught in local lakes, rivers, and coastal areas, checking local advisories about the safety of such fish and, if levels of mercury are not known to be low, limiting consumption to 4 ounces/week while avoiding other seafood that week

Tilefish from the Gulf of Mexico have the highest levels of mercury of all fish (as tested by the U.S. Food and Drug Administration (FDA); tilefish from the Atlantic Ocean can be safely eaten.

Experts recommend that women who are pregnant or breastfeeding eat 8 to 12 ounces (2 or 3 average meals) per week of a variety of seafood that is lower in mercury. Such seafood includes flounder, shrimp, canned light tuna, salmon, pollock, tilapia, cod, and catfish. Fish has nutrients that are important for fetal growth and development.

Maternal Age

In women ≥ 35 years, the incidence of preeclampsia is increased, as is that of gestational diabetes Diabetes Mellitus in Pregnancy , dysfunctional labor, abruptio placentae Placental Abruption (Abruptio Placentae) Placental abruption (abruptio placentae) is premature separation of the placenta from the uterus, usually after 20 weeks gestation. It can be an obstetric emergency. Manifestations may include... read more , stillbirth Stillbirth Stillbirth is fetal death (fetal demise) at ≥ 20 weeks gestation (> 28 weeks in some definitions). Management is delivery and postpartum care. Maternal and fetal testing is done to determine... read more , and placenta previa Placenta Previa Placenta previa is implantation of the placenta over or near the internal os of the cervix. It typically manifests as painless vaginal bleeding after 20 weeks gestation; the source of bleeding... read more . These women are also more likely to have preexisting disorders (eg, chronic hypertension Hypertension Hypertension is sustained elevation of resting systolic blood pressure (≥ 130 mm Hg), diastolic blood pressure (≥ 80 mm Hg), or both. Hypertension with no known cause (primary; formerly, essential... read more Hypertension , diabetes Diabetes Mellitus (DM) Diabetes mellitus is impaired insulin secretion and variable degrees of peripheral insulin resistance leading to hyperglycemia. Early symptoms are related to hyperglycemia and include polydipsia... read more ). Because risk of fetal chromosomal abnormalities Overview of Chromosomal Abnormalities Chromosomal abnormalities cause various disorders. Abnormalities that affect autosomes (the 22 paired chromosomes that are alike in males and females) are more common than those that affect... read more increases as maternal age increases, genetic screening and testing Preconception or Prenatal Carrier Testing of Parents Carrier testing is part of routine prenatal care and is ideally done before conception. The extent of carrier testing is related to how the woman and her partner weigh factors such as The probability... read more and detailed ultrasound screening for fetal malformations should be offered.

The most common chromosomal abnormality is autosomal trisomy Overview of Chromosomal Abnormalities Chromosomal abnormalities cause various disorders. Abnormalities that affect autosomes (the 22 paired chromosomes that are alike in males and females) are more common than those that affect... read more . The United States National Birth Defects Prevention Study (NBDPS) found that children of women > 40 years are at increased risk of cardiac abnormalities Overview of Congenital Cardiovascular Anomalies Congenital heart disease is the most common congenital anomaly, occurring in almost 1% of live births ( 1). Among birth defects, congenital heart disease is the leading cause of infant mortality... read more Overview of Congenital Cardiovascular Anomalies , esophageal atresia Overview of Congenital Cardiovascular Anomalies Congenital heart disease is the most common congenital anomaly, occurring in almost 1% of live births ( 1). Among birth defects, congenital heart disease is the leading cause of infant mortality... read more Overview of Congenital Cardiovascular Anomalies , hypospadias Hypospadias Congenital anomalies of the urethra in boys usually involve anatomic abnormalities of the penis and vice versa. In girls, urethral anomalies may exist without other external genital abnormalities... read more Hypospadias , and craniosynostosis Craniosynostosis Craniosynostosis is premature fusion of one or more calvarial sutures. (See also Introduction to Congenital Craniofacial and Musculoskeletal Disorders and Overview of Congenital Craniofacial... read more Craniosynostosis (1 Maternal age reference Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more Maternal age reference ).

Maternal age reference

  • 1. Gill SK, Broussard C, Devine O, et al: Association between maternal age and birth defects of unknown etiology: United States, 1997-2007. Birth Defects Res A Clin Mol Teratol 94 (12):1010–1018, 2012. doi: 10.1002/bdra.23049

Maternal Weight

Pregnant women whose body mass index (BMI) was < 18.5 kg/m2 before pregnancy are considered underweight, which predisposes to low birth weight (< 2.5 kg) in neonates. Such women are encouraged to gain at least 12.5 kg during pregnancy.

Pregnant women whose BMI was 25 to 29.9 kg/m2 (overweight) or ≥ 30 kg/m2 (obese) before pregnancy are at risk of maternal hypertension Hypertension in Pregnancy Recommendations regarding classification, diagnosis, and management of hypertensive disorders (including preeclampsia) are available from the American College of Obstetricians and Gynecologists... read more and diabetes Diabetes Mellitus in Pregnancy Pregnancy makes glycemic control more difficult in preexisting type 1 (insulin-dependent) and type 2 (non–insulin-dependent) diabetes but does not appear to exacerbate diabetic retinopathy,... read more , postterm pregnancy Postterm Pregnancy Postterm pregnancy refers to gestation that lasts ≥ 42 (> 41 6/7) weeks. Late-term pregnancy is defined as 41 0/7 to 41 6/7 weeks. Antenatal surveillance should be considered at 41 weeks. Induction... read more , pregnancy loss Spontaneous Abortion Spontaneous abortion is pregnancy loss before 20 weeks gestation. Diagnosis is by pelvic examination, measurement of beta subunit of human chorionic gonadotropin, and ultrasonography. Treatment... read more , fetal macrosomia Large-for-Gestational-Age (LGA) Infant Infants whose weight is > the 90th percentile for gestational age are classified as large for gestational age. Macrosomia is birthweight > 4000 g in a term infant. The predominant cause is... read more , congenital malformations, intrauterine growth restriction Small-for-Gestational-Age (SGA) Infant Infants whose weight is < the 10th percentile for gestational age are classified as small for gestational age. Complications include perinatal asphyxia, meconium aspiration, polycythemia... read more , preeclampsia Preeclampsia and Eclampsia Preeclampsia is new onset or worsening of existing hypertension with proteinuria after 20 weeks gestation. Eclampsia is unexplained generalized seizures in patients with preeclampsia. Diagnosis... read more , and the need for cesarean delivery Cesarean Delivery Cesarean delivery is surgical delivery by incision into the uterus. The rate of cesarean delivery was 32% in the United States in 2021 (see March of Dimes: Delivery Method). The rate has fluctuated... read more . Ideally, weight loss should begin before pregnancy, first by trying lifestyle modifications (eg, increased physical activity, dietary changes). Women with overweight or obesity are encouraged to limit weight gain during pregnancy, ideally by modifying their lifestyle. The Institute of Medicine (IOM) uses the following guidelines:

  • Overweight: Weight gain limited to 6.8 to 11.3 kg (15 to 25 lb)

  • Obese: Weight gain limited to < 5 to 9 kg (11 to 20 lb)

However, not all experts agree with IOM recommendations. Many experts recommend an individualized approach that can include more limited weight gain plus lifestyle modifications (eg, increased physical activity, dietary changes), particularly for women with obesity (1 Maternal weight references Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more Maternal weight references ). During pregnancy, most women should be encouraged to exercise at least 3 times a week for a total of 150 minutes each week (2 Maternal weight references Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more Maternal weight references ).

For pregnant women with overweight or obesity, lifestyle modifications during pregnancy reduce the risk of gestational diabetes and preeclampsia.

Discussing appropriate weight gain, diet, and exercise at the initial visit and periodically throughout the pregnancy is important.

Maternal weight references

  • 1. Artal R, Lockwood CJ, Brown HL: Weight gain recommendations in pregnancy and the obesity epidemic. Obstet Gynecol 115 (1):152–155, 2010. doi: 10.1097/AOG.0b013e3181c51908

  • 2. Mottola MF, Davenport MH, Ruchat SM, et al: 2019 Canadian guideline for physical activity throughout pregnancy. Br J Sports Med 52 (21):1339–1346, 2018. doi: 10.1136/bjsports-2018-100056

Multiple Gestation

Multiple gestation reference

Prior Neonate With a Genetic or Congenital Disorder

Risk of having a fetus with a chromosomal disorder Risk Factors for Genetic Disorders or Congenital Anomalies Prenatal genetic counseling is provided for all prospective parents, ideally before conception, to assess risk factors for genetic disorders. In addition, prenatal counseling provides information... read more is increased for most couples who have had a fetus or neonate with a chromosomal disorder (recognized or missed). Recurrence risk for most genetic disorders is unknown. Most congenital malformations are multifactorial; risk of having a subsequent fetus with malformations varies based on the defect itself.

If couples have had a neonate with a genetic or chromosomal disorder, genetic consultation and screening Preconception or Prenatal Carrier Testing of Parents Carrier testing is part of routine prenatal care and is ideally done before conception. The extent of carrier testing is related to how the woman and her partner weigh factors such as The probability... read more is recommended. If couples have had a neonate with a congenital malformation, genetic screening, high-resolution ultrasonography, and evaluation by a maternal-fetal medicine specialist is recommended.

Prior Stillbirth

Stillbirth Stillbirth Stillbirth is fetal death (fetal demise) at ≥ 20 weeks gestation (> 28 weeks in some definitions). Management is delivery and postpartum care. Maternal and fetal testing is done to determine... read more is death of a fetus at ≥ 20 weeks gestation before or during delivery, as defined by the Centers for Disease Control and Prevention (CDC [ 1 Prior stillbirth references Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more Prior stillbirth references ]), or at > 28 weeks, as defined by the World Health Organization (2 Prior stillbirth references Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more Prior stillbirth references ). Fetal death during late pregnancy may have maternal, placental, or fetal anatomic or genetic causes (see table ). Having had a stillbirth or late abortion (ie, at 16 to 20 weeks) increases risk of fetal death in subsequent pregnancies. Degree of risk varies depending on the cause of a previous stillbirth. Fetal surveillance using antepartum testing (eg, nonstress testing, biophysical profile) is recommended.

Treatment of maternal disorders (eg, chronic hypertension, diabetes, infections) may lower risk of stillbirth in a current pregnancy.

Prior stillbirth references

Prior Preterm Delivery

Preterm delivery Preterm Labor Labor (regular uterine contractions resulting in cervical change) that begins before 37 weeks gestation is considered preterm. Risk factors include prelabor rupture of membranes, uterine abnormalities... read more is delivery before 37 weeks. Previous preterm delivery due to preterm labor is associated with an increased risk of future preterm deliveries. Preterm delivery is also sometimes medically indicated due to certain pregnancy complications (eg, severe preeclampsia or symptomatic placenta previa). These diseases are not independent risk factors for preterm delivery, but they may recur, and appropriate monitoring or preventive measures should be done.

Women with prior preterm delivery due to unexplained preterm labor should be closely monitored at 2-week intervals beginning at 15 to 16 weeks gestation, up to 23 to 24 weeks. Evaluation may include (1 Prior preterm delivery reference Risk factors for complications during pregnancy include Preexisting maternal medical conditions and characteristics Modifiable risk factors (eg, smoking, substance use) Previous obstetric complications... read more Prior preterm delivery reference )

Prior preterm delivery reference

Prior Birth Injury

Most cerebral palsy Cerebral Palsy (CP) Cerebral palsy refers to a group of nonprogressive conditions characterized by impaired voluntary movement or posture and resulting from prenatal developmental malformations or perinatal or... read more and neurodevelopmental disorders are caused by factors unrelated to a birth injury. Injuries such as brachial plexus damage can result from procedures such as forceps or vacuum extractor delivery but often result from intrauterine forces during labor or malposition during the last weeks of pregnancy.

Previous shoulder dystocia Shoulder Dystocia Shoulder dystocia occurs during an attempted vaginal delivery (in the second stage of labor [pushing]) when the fetal head delivers but delivery does not progress because the anterior shoulder... read more is a risk factor for future dystocia, and the delivery records should be reviewed for potentially modifiable risk factors (eg, fetal macrosomia, operative vaginal delivery) that may have predisposed to the injury.

Drugs Mentioned In This Article

Drug Name Select Trade
Aluvea , BP-50% Urea , BP-K50, Carmol, CEM-Urea, Cerovel, DermacinRx Urea, Epimide-50, Gord Urea, Gordons Urea, Hydro 35 , Hydro 40, Kerafoam, Kerafoam 42, Keralac, Keralac Nailstik, Keratol, Keratol Plus, Kerol, Kerol AD, Kerol ZX, Latrix, Mectalyte, Nutraplus, RE Urea 40, RE Urea 50 , Rea Lo, Remeven, RE-U40, RYNODERM , U40, U-Kera, Ultra Mide 25, Ultralytic-2, Umecta, Umecta Nail Film, URALISS, Uramaxin , Uramaxin GT, Urea, Ureacin-10, Ureacin-20, Urealac , Ureaphil, Uredeb, URE-K , Uremez-40, Ure-Na, Uresol, Utopic, Vanamide, Xurea, X-VIATE
Anacin Adult Low Strength, Aspergum, Aspir-Low, Aspirtab , Aspir-Trin , Bayer Advanced Aspirin, Bayer Aspirin, Bayer Aspirin Extra Strength, Bayer Aspirin Plus, Bayer Aspirin Regimen, Bayer Children's Aspirin, Bayer Extra Strength, Bayer Extra Strength Plus, Bayer Genuine Aspirin, Bayer Low Dose Aspirin Regimen, Bayer Womens Aspirin , BeneHealth Aspirin, Bufferin, Bufferin Extra Strength, Bufferin Low Dose, DURLAZA, Easprin , Ecotrin, Ecotrin Low Strength, Genacote, Halfprin, MiniPrin, St. Joseph Adult Low Strength, St. Joseph Aspirin, VAZALORE, Zero Order Release Aspirin, ZORprin
Cafcit, NoDoz, Stay Awake, Vivarin
GOPRELTO, NUMBRINO
View PATIENT EDUCATION
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
quiz link

Test your knowledge

Take a Quiz! 
iOS ANDROID
iOS ANDROID
iOS ANDROID
TOP