- Acute Flaccid Myelitis
- Alzheimer’s Disease
- Arteriovenous Malformations
- Attention Deficit Hyperactivity Disorder
- Back Pain
- Brain Aneurysm
- Brain Tumors
- Carpal Tunnel Syndrome
- Childhood Brain Tumors
- Delirium
- Dementia
- Hemorrhagic Stroke
- Ischemic Stroke
- Memory
- Meningitis
- Mild Cognitive Impairment
- Movement Disorders
- Multiple Sclerosis
- Neuroblastoma
- Neuromuscular Disorders
- Parkinson’s Disease
- Polio and Post-Polio Syndrome
- Speech and Language Problems in Children
- Stroke
- Transient Ischemic Attack
- Tremor
- Walking Problems
- West Nile Virus
- A1C
- Blood Glucose
- Diabetes
- Diabetes and Pregnancy
- Diabetes Complications
- Diabetes in Children and Teens
- Diabetes Medicines
- Diabetes Type 1
- Diabetes Type 2
- Diabetic Diet
- Diabetic Eye Problems
- Diabetic Foot
- Diabetic Heart Disease
- Diabetic Kidney Problems
- Diabetic Nerve Problems
- How to Prevent Diabetes
- Hyperglycemia
- Metabolic Syndrome
- Prediabetes
- Abortion
- Breast Cancer
- Breast Diseases
- Breast Reconstruction
- Breastfeeding
- Cervical Cancer
- Cervical Cancer Screening
- Cesarean Delivery
- Childbirth
- Ectopic Pregnancy
- Endometriosis
- Female Infertility
- Health Problems in Pregnancy
- High Blood Pressure in Pregnancy
- HIV and Pregnancy
- Hormone Replacement Therapy
- HPV
- Hysterectomy
- Infections and Pregnancy
- Mammography
- Mastectomy
- Menopause
- Menstruation
- Miscarriage
- Ovarian Cancer
- Ovarian Cysts
- Ovarian Disorders
- Pelvic Floor Disorders
- Pelvic Inflammatory Disease
- Pelvic Pain
- Period Pain
- Polycystic Ovary Syndrome
- Pregnancy
- Pregnancy and Drug Use
- Pregnancy and Opioids
- Premenstrual Syndrome
- Prenatal Care
- Prenatal Testing
- Primary Ovarian Insufficiency
- Sexual Problems in Women
- Stillbirth
- Teenage Pregnancy
- Trichomoniasis
- Tubal Ligation
- Uterine Cancer
- Uterine Diseases
- Uterine Fibroids
- Vaginal Bleeding
- Vaginal Cancer
- Vaginal Diseases
- Vaginitis
- Vulvar Cancer
- Vulvar Disorders
- Yeast Infections
- Alcohol
- Calcium
- Child Nutrition
- Cholesterol
- Cholesterol Levels: What You Need to Know
- Cholesterol Medicines
- DASH Eating Plan
- Eating Disorders
- Food Allergy
- HDL: The “Good” Cholesterol
- High Cholesterol in Children and Teens
- How to Lower Cholesterol
- How to Lower Cholesterol with Diet
- Infant and Newborn Nutrition
- LDL: The “Bad” Cholesterol
- Malabsorption Syndromes
- Nutrition for Older Adults
- Pregnancy and Nutrition
- Toddler Nutrition
- Triglycerides
- VLDL Cholesterol
- Alpha-1 Antitrypsin Deficiency
- Ataxia Telangiectasia
- Brain Malformations
- Cerebral Palsy
- Charcot-Marie-Tooth Disease
- Chiari Malformation
- Cleft Lip and Palate
- Color Blindness
- Congenital Heart Defects
- Craniofacial Abnormalities
- Cystic Fibrosis
- Ehlers-Danlos Syndrome
- Fetal Alcohol Spectrum Disorders
- Friedreich Ataxia
- Genetic Counseling
- Hemophilia
- Huntington’s Disease
- Hydrocephalus
- Muscular Dystrophy
- Neural Tube Defects
- Neurofibromatosis
- Newborn Screening
- Osteogenesis Imperfecta
- Prader-Willi Syndrome
- Pregnancy and Medicines
- Rett Syndrome
- Sickle Cell Disease
- Spina Bifida
- Spinal Muscular Atrophy
- Tay-Sachs Disease
- Tourette Syndrome
- Tuberous Sclerosis
- Usher Syndrome
- Acute Lymphocytic Leukemia
- Allergy
- Animal Bites
- Ankylosing Spondylitis
- Aplastic Anemia
- Asthma
- Asthma in Children
- Childhood Leukemia
- Childhood Vaccines
- Chronic Lymphocytic Leukemia
- COVID-19 Vaccines
- Cryptosporidiosis
- Eosinophilic Disorders
- Eosinophilic Esophagitis
- Giant Cell Arteritis
- Hay Fever
- HIV
- HIV and Infections
- HIV in Women
- Hodgkin Lymphoma
- Infectious Diseases
- Infectious Mononucleosis
- Juvenile Arthritis
- Kawasaki Disease
- Lymphedema
- Lymphoma
- Multiple Myeloma
- Pemphigus
- Pneumocystis Infections
- Rheumatoid Arthritis
- Scleroderma
- Sjogren’s Syndrome
- Tonsillitis
- Vaccines
- Viral Infections
- Adhesions
- Ankle Injuries and Disorders
- Arm Injuries and Disorders
- Back Injuries
- Brachial Plexus Injuries
- Burns
- Chest Injuries and Disorders
- Concussion
- CPR
- Dislocated Shoulder
- Dislocations
- Elbow Injuries and Disorders
- Eye Injuries
- Facial Injuries and Disorders
- Finger Injuries and Disorders
- Foot Injuries and Disorders
- Fractures
- Hand Injuries and Disorders
- Heel Injuries and Disorders
- Hip Injuries and Disorders
- Inhalation Injuries
- Insect Bites and Stings
- Jaw Injuries and Disorders
- Knee Injuries and Disorders
- Leg Injuries and Disorders
- Mosquito Bites
- Neck Injuries and Disorders
- Rotator Cuff Injuries
- Shoulder Injuries and Disorders
- Spinal Cord Injuries
- Sprains and Strains
- Tick Bites
- Toe Injuries and Disorders
- Traumatic Brain Injury
- Wrist Injuries and Disorders
- Acute Bronchitis
- Bird Flu
- Chronic Bronchitis
- COPD
- COVID-19 (Coronavirus Disease 2019)
- Croup
- E-Cigarettes
- Fistulas
- Flu
- Granulomatosis with Polyangiitis
- H1N1 Flu (Swine Flu)
- Legionnaires’ Disease
- Lung Cancer
- Mesothelioma
- Pneumonia
- Pulmonary Hypertension
- Respiratory Syncytial Virus Infections
- Sleep Apnea
- Smoking
- Tuberculosis
- Whooping Cough
- Anatomy
- Assisted Reproductive Technology
- Birth Control
- Chlamydia Infections
- Circumcision
- Erectile Dysfunction
- Genital Herpes
- Genital Warts
- Gonorrhea
- Herpes Simplex
- Infertility
- Male Infertility
- Penis Disorders
- Prostate Cancer
- Prostate Cancer Screening
- Prostate Diseases
- Reproductive Hazards
- Sexual Health
- Sexual Problems in Men
- Sexually Transmitted Diseases
- Syphilis
- Testicular Cancer
- Testicular Disorders
- Vasectomy
- Abdominal Pain
- Bad Breath
- Bleeding
- Breathing Problems
- Bruises
- Chest Pain
- Choking
- Chronic Pain
- Constipation
- Cough
- Diarrhea
- Dizziness and Vertigo
- Edema
- Fainting
- Fever
- Frostbite
- Gas
- Gastrointestinal Bleeding
- Headache
- Heartburn
- Heat Illness
- Hives
- Hypothermia
- Indigestion
- Itching
- Jaundice
- Nausea and Vomiting
- Pain
- Rare Diseases
- Raynaud’s Disease
- Sciatica
- Speech and Communication Disorders
- Stuttering
Fetal Health and Development
Summary
A normal pregnancy lasts nine months. Each three-month period of pregnancy is called a trimester. During each trimester, the fetus grows and develops. Regular medical checkups and prenatal tests are very important. They can:
- Help keep you and your baby healthy
- Spot problems with your baby (if there are any). In some cases, health care professionals can treat the problem before your baby is born. But even when they cannot, it can still be helpful to know about the problem early on. That gives you time to learn about your baby’s condition and prepare for any challenges you may face after the baby is born.
- Prevent problems during delivery. For example, if your baby is breech (bottom first or feet first, instead of head first), you may need to have a Cesarean section to avoid complications.
Besides getting medical care, there are other things you can do to keep your baby as healthy as possible. It’s important not to drink or smoke. Try to eat a healthy diet and make sure to take care of any health problems you have during pregnancy.
Eunice Kennedy Shriver National Institute of Child Health and Human Development
Clinical Trials
- ClinicalTrials.gov: Fetal Development National Institutes of Health
- ClinicalTrials.gov: Fetal Diseases National Institutes of Health
Find an Expert
- Eunice Kennedy Shriver National Institute of Child Health and Human Development Eunice Kennedy Shriver National Institute of Child Health and Human Development
- Find an Ob-Gyn American College of Obstetricians and Gynecologists
- March of Dimes Foundation March of Dimes Foundation
Patient Handouts
- Fetal development Medical Encyclopedia
- Intrauterine growth restriction Medical Encyclopedia
Encyclopedia
- Fetal echocardiography Medical Encyclopedia
- Hydrops fetalis Medical Encyclopedia
Diagnosis and Tests
- Fetal Echocardiography/Your Unborn Baby’s Heart American Heart Association
- Prenatal Testing: MedlinePlus Health Topic National Library of Medicine
Specifics
- Fetal Growth Restriction American Academy of Family Physicians
- Hydrops Fetalis/Erythroblastosis Fetalis Children’s Hospital and Health System, Inc.
Journal Articles
Start Here
- Stages of Pregnancy Department of Health and Human Services, Office on Women’s Health
- Your Baby’s Development: The First Trimester American Academy of Family Physicians
- Your Baby’s Development: The Second Trimester American Academy of Family Physicians
- Your Baby’s Development: The Third Trimester American Academy of Family Physicians
Related Issues
- What Are the Risks of Preeclampsia and Eclampsia to the Fetus? Eunice Kennedy Shriver National Institute of Child Health and Human Development