Pregnancy
Other namesGestation
A woman in the third trimester of pregnancy
SpecialtyObstetrics, midwifery
SymptomsMissed periods, tender breasts, nausea and vomiting, hunger, frequent urination[1]
ComplicationsMiscarriage, high blood pressure of pregnancy, gestational diabetes, iron-deficiency anemia, severe nausea and vomiting[2][3]
Duration~40 weeks from the last menstrual period[4][5]
CausesSexual intercourse, assisted reproductive technology[6]
Diagnostic methodPregnancy test[7]
PreventionBirth control (including emergency contraception)[8]
TreatmentPrenatal care,[9] abortion[8]
MedicationFolic acid, iron supplements[9][10]
Frequency213 million (2012)[11]
DeathsDecrease 230,600 (2016)[12]

Pregnancy, also known as gestation, is the time during which one or more offspring develops inside a woman.[4] A multiple pregnancy involves more than one offspring, such as with twins.[13] Pregnancy usually occurs by sexual intercourse, but can occur through assisted reproductive technology.[6] A pregnancy may end in a live birth, miscarriage, induced abortion, or a stillbirth. Childbirth typically occurs around 40 weeks from the start of the last menstrual period (LMP).[4][5] This is just over nine months – (gestational age) where each month averages 31 days.[4][5] When using fertilization age it is about 38 weeks.[5] An embryo is the developing offspring during the first eight weeks following fertilization, (ten weeks gestational age) after which, the term fetus is used until birth.[5] Symptoms of early pregnancy may include missed periods, tender breasts, nausea and vomiting, hunger, and frequent urination.[1] Pregnancy may be confirmed with a pregnancy test.[7]

Pregnancy is divided into three trimesters, each lasting for approximately 3 months.[4] The first trimester includes conception, which is when the sperm fertilizes the egg.[4] 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.[4] During the first trimester, the possibility of miscarriage (natural death of embryo or fetus) is at its highest.[2] Around the middle of the second trimester, movement of the fetus may be felt.[4] At 28 weeks, more than 90% of babies can survive outside of the uterus if provided with high-quality medical care.[4]

Prenatal care improves pregnancy outcomes.[9] Prenatal care may include taking extra folic acid, avoiding drugs, tobacco smoking, and alcohol, taking regular exercise, having blood tests, and regular physical examinations.[9] Complications of pregnancy may include disorders of high blood pressure, gestational diabetes, iron-deficiency anemia, and severe nausea and vomiting.[3] In the ideal childbirth labor begins on its own when a woman is "at term".[14] Babies born before 37 weeks are "preterm" and at higher risk of health problems such as cerebral palsy.[4] Babies born between weeks 37 and 39 are considered "early term" while those born between weeks 39 and 41 are considered "full term".[4] Babies born between weeks 41 and 42 weeks are considered "late term" while after 42 week they are considered "post term".[4] Delivery before 39 weeks by labor induction or caesarean section is not recommended unless required for other medical reasons.[15]

About 213 million pregnancies occurred in 2012, of which, 190 million (89%) were in the developing world and 23 million (11%) were in the developed world.[11] The number of pregnancies in women aged between 15 and 44 is 133 per 1,000 women.[11] About 10% to 15% of recognized pregnancies end in miscarriage.[2] In 2016, complications of pregnancy resulted in 230,600 maternal deaths, down from 377,000 deaths in 1990.[12] Common causes include bleeding, infections, hypertensive diseases of pregnancy, obstructed labor, and complications associated with miscarriage, abortion, or ectopic pregnancy.[12] Globally, 44% of pregnancies are unplanned.[16] Over half (56%) of unplanned pregnancies are aborted.[16] Among unintended pregnancies in the United States, 60% of the women used birth control to some extent during the month pregnancy occurred.[17]

References edit

  1. ^ a b "What are some common signs of pregnancy?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 12 July 2013. Archived from the original on 19 March 2015. Retrieved 14 March 2015.
  2. ^ a b c The Johns Hopkins Manual of Gynecology and Obstetrics (4 ed.). Lippincott Williams & Wilkins. 2012. p. 438. ISBN 978-1-4511-4801-5. Archived from the original on 10 September 2017.
  3. ^ a b "What are some common complications of pregnancy?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 12 July 2013. Archived from the original on 26 February 2015. Retrieved 14 March 2015.
  4. ^ a b c d e f g h i j k l "Pregnancy: Condition Information". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 19 December 2013. Archived from the original on 19 March 2015. Retrieved 14 March 2015.
  5. ^ a b c d e Abman, Steven H. (2011). Fetal and neonatal physiology (4th ed.). Philadelphia: Elsevier/Saunders. pp. 46–47. ISBN 978-1-4160-3479-7. Archived from the original on 22 May 2021. Retrieved 23 July 2020.
  6. ^ a b Shehan, Constance L. (2016). The Wiley Blackwell Encyclopedia of Family Studies, 4 Volume Set. John Wiley & Sons. p. 406. ISBN 978-0-470-65845-1. Archived from the original on 10 September 2017.
  7. ^ a b "How do I know if I'm pregnant?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 30 November 2012. Archived from the original on 2 April 2015. Retrieved 14 March 2015.
  8. ^ a b Taylor D, James EA (2011). "An evidence-based guideline for unintended pregnancy prevention". Journal of Obstetric, Gynecologic, and Neonatal Nursing. 40 (6): 782–93. doi:10.1111/j.1552-6909.2011.01296.x. PMC 3266470. PMID 22092349.
  9. ^ a b c d "What is prenatal care and why is it important?". Eunice Kennedy Shriver National Institute of Child Health and Human Development. 12 July 2013. Archived from the original on 2 April 2015. Retrieved 14 March 2015.
  10. ^ Keats, EC; Haider, BA; Tam, E; Bhutta, ZA (14 March 2019). "Multiple-micronutrient supplementation for women during pregnancy". The Cochrane Database of Systematic Reviews. 3: CD004905. doi:10.1002/14651858.CD004905.pub6. PMC 6418471. PMID 30873598.
  11. ^ a b c Sedgh G, Singh S, Hussain R (September 2014). "Intended and unintended pregnancies worldwide in 2012 and recent trends". Studies in Family Planning. 45 (3): 301–314. doi:10.1111/j.1728-4465.2014.00393.x. PMC 4727534. PMID 25207494.
  12. ^ a b c GBD 2016 Causes of Death Collaborators (September 2017). "Global, regional, and national age-sex specific mortality for 264 causes of death, 1980–2016: a systematic analysis for the Global Burden of Disease Study 2016". Lancet. 390 (10100): 1151–1210. doi:10.1016/S0140-6736(17)32152-9. PMC 5605883. PMID 28919116. {{cite journal}}: |author1= has generic name (help)CS1 maint: numeric names: authors list (link)
  13. ^ Wylie, Linda (2005). Essential anatomy and physiology in maternity care (Second ed.). Edinburgh: Churchill Livingstone. p. 172. ISBN 978-0-443-10041-3. Archived from the original on 10 September 2017.
  14. ^ American Congress of Obstetricians and Gynecologists (February 2013), "Five Things Physicians and Patients Should Question", Choosing Wisely: an initiative of the ABIM Foundation, American Congress of Obstetricians and Gynecologists, archived from the original on 1 September 2013, retrieved 1 August 2013
  15. ^ World Health Organization (November 2014). "Preterm birth Fact sheet N°363". who.int. Archived from the original on 7 March 2015. Retrieved 6 March 2015.
  16. ^ a b Bearak J, Popinchalk A, Alkema L, Sedgh G (April 2018). "Global, regional, and subregional trends in unintended pregnancy and its outcomes from 1990 to 2014: estimates from a Bayesian hierarchical model". The Lancet. Global Health. 6 (4): e380–e389. doi:10.1016/S2214-109X(18)30029-9. PMC 6055480. PMID 29519649.
  17. ^ Hurt, K Joseph; Guile, Matthew W.; Bienstock, Jessica L.; Fox, Harold E.; Wallach, Edward E. (2012-03-28). The Johns Hopkins manual of gynecology and obstetrics (4th ed.). Philadelphia: Wolters Kluwer Health / Lippincott Williams & Wilkins. p. 382. ISBN 978-1-60547-433-5. Archived from the original on 12 May 2016. Retrieved 23 July 2020.