Editing Obstetrics (section)

==== First trimester ====
Routine tests in the first [[Trimester (pregnancy)|trimester]] of pregnancy generally include:
* [[Complete blood count]]
* [[Blood type]]
** [[Rh blood group system|Rh-negative]] antenatal patients should receive [[Rho(D) immune globulin|RhoGAM]] at 28 weeks to prevent [[Rh disease]].
* [[Coombs test#Indirect Coombs test|Indirect Coombs test]] (AGT) to assess risk of [[hemolytic disease of the newborn]]<ref>{{Cite web | vauthors = Rath L |title=What Is a Coombs Test? |url=https://www.webmd.com/a-to-z-guides/antibody-coombs-test |access-date=2022-04-29 |website=WebMD |language=en}}</ref>
* [[Rapid plasma reagin]] test to screen for [[syphilis]]
* [[Rubella]] antibody screen<ref>{{Cite web | vauthors = Rath L |title=Why Do I Need a Rubella Test? |url=https://www.webmd.com/a-to-z-guides/rubella-test-antibodies |access-date=2022-04-29 |website=WebMD |language=en}}</ref>
* [[HBsAg]] test to screen for [[hepatitis B]]<ref>{{Cite journal|date=2021-04-03 | vauthors = Mekaroonkamol P, Hashemi N | veditors = Staros EB |title=Hepatitis B Test: Reference Range, Interpretation, Collection and Panels |url=https://emedicine.medscape.com/article/2109144-overview | journal = Medscape }}</ref>
* Testing for [[chlamydia]] (and [[gonorrhea]] when indicated<ref name="pmid24548498">{{cite journal | vauthors = Fontenot HB, George ER | title = Sexually transmitted infections in pregnancy | journal = Nursing for Women's Health | volume = 18 | issue = 1 | pages = 67–72 | date = 2014 | pmid = 24548498 | doi = 10.1111/1751-486X.12095 }}</ref>
* [[Mantoux test]] for [[tuberculosis]]<ref>{{Cite web |last=CDCTB |date=2020-12-16 |title=Tuberculosis (TB) Fact Sheets- Tuberculin Skin Testing |url=https://www.cdc.gov/tb/publications/factsheets/testing/skintesting.htm |access-date=2022-04-29 |website=Centers for Disease Control and Prevention |language=en-us}}</ref>
* [[Urinalysis]] and culture<ref>{{Cite web |title=Urinalysis: What It Is, Purpose, Types & Results |url=https://my.clevelandclinic.org/health/diagnostics/17893-urinalysis |access-date=2022-04-29 |website=Cleveland Clinic}}</ref>
* [[HIV]] screen

Genetic screening for [[Down syndrome]] (trisomy 21) and [[Edwards syndrome]] (trisomy 18), the national standard in the United States, is rapidly evolving away from the AFP-[[quad screen]], done typically in the second trimester at 16–18 weeks.<ref>{{cite journal | vauthors = Cereda A, Carey JC | title = The trisomy 18 syndrome | journal = Orphanet Journal of Rare Diseases | volume = 7 | pages = 81 | date = October 2012 | pmid = 23088440 | pmc = 3520824 | doi = 10.1186/1750-1172-7-81 | doi-access = free }}</ref> The newer integrated screen (formerly called F.A.S.T.E.R for First And Second Trimester Early Results) can be done at 10 plus weeks to 13 plus weeks with an [[ultrasound]] of the fetal neck (thicker nuchal skin correlates with higher risk of Down syndrome being present) and two chemicals (analytes), [[pregnancy-associated plasma protein A]] and [[human chorionic gonadotropin]] (pregnancy hormone level itself<ref>{{cite journal | vauthors = Malone FD, Canick JA, Ball RH, Nyberg DA, Comstock CH, Bukowski R, Berkowitz RL, Gross SJ, Dugoff L, Craigo SD, Timor-Tritsch IE, Carr SR, Wolfe HM, Dukes K, Bianchi DW, Rudnicka AR, Hackshaw AK, Lambert-Messerlian G, Wald NJ, D'Alton ME | display-authors = 6 | title = First-trimester or second-trimester screening, or both, for Down's syndrome | journal = The New England Journal of Medicine | volume = 353 | issue = 19 | pages = 2001–2011 | date = November 2005 | pmid = 16282175 | doi = 10.1056/NEJMoa043693 | doi-access = free }}</ref>). It gives an accurate risk profile very early. A second blood screen at 15 to 20 weeks refines the risk more accurately.<ref>{{Cite web |date=2021-08-08 |title=Common Tests During Pregnancy |url=https://www.hopkinsmedicine.org/health/wellness-and-prevention/common-tests-during-pregnancy |access-date=2022-04-29 |website=www.hopkinsmedicine.org |language=en}}</ref> The cost is higher than an "AFP-quad" screen due to the ultrasound and second blood test, but it is quoted to have a 93% pick up rate as opposed to 88% for the standard AFP/QS. This is an evolving standard of care in the United States.<ref name="Carlson2017">{{cite journal | vauthors = Carlson LM, Vora NL | title = Prenatal Diagnosis: Screening and Diagnostic Tools | journal = Obstetrics and Gynecology Clinics of North America | volume = 44 | issue = 2 | pages = 245–256 | date = June 2017 | pmid = 28499534 | pmc = 5548328 | doi = 10.1016/j.ogc.2017.02.004 }}</ref><ref name="Zhang2019">{{cite journal | vauthors = Zhang W, Mohammadi T, Sou J, Anis AH | title = Cost-effectiveness of prenatal screening and diagnostic strategies for Down syndrome: A microsimulation modeling analysis | journal = PLOS ONE | volume = 14 | issue = 12 | pages = e0225281 | date = 2019 | pmid = 31800591 | pmc = 6892535 | doi = 10.1371/journal.pone.0225281 | doi-access = free | bibcode = 2019PLoSO..1425281Z }}</ref><ref name="Common Tests During Pregnancy">{{Cite web |date=2021-08-08 |title=Common Tests During Pregnancy |url=https://www.hopkinsmedicine.org/health/wellness-and-prevention/common-tests-during-pregnancy |access-date=2022-04-28 |website=www.hopkinsmedicine.org |language=en}}</ref>
[[File:Down Syndrome karyotype.png|thumb|Down syndrome karyotype]]