hcg levels for triplets at 3 weeks

Normally, hCG levels would be less than 5 mIU/mL and less than 2 mIU/mL, respectively, for these groups. The level of hCG may double every 2-3 days in early pregnancy. In fact, a 2017 study into hCG found that "the slowest or minimal rise for a normal viable intrauterine pregnancy was 24% at one day and 53% at two days. A level that does not double should be rechecked after another two days as it might indicate a failing pregnancy or a PUO (pregnancy of unknown origin). As your pregnancy progresses, the hCG level increase slows down significantly. An above-normal level can confirm pregnancy. If a woman has high hCG levels, it could point to twins or triplets, though only a scan can confirm this. Lets look at what different hCG levels can mean with a little help from Dr. Matthews: Its important to remember that hCG levels are not a diagnosis on their own. Q: Low Ferritin 7 tired the whole day, any advice? To remove the mass, the doctor may recommend dilation and curettage, which involves sucking away the mass with a surgical vacuum and gently scraping away any remaining abnormal cells.Or, a doctor may recommend a hysterectomy, to remove the uterus. At the end of this week, there may be enough hCG to detect with a sensitive early home . Confirming pregnancy "reviewedBy": [ It can also help the doctor if an ectopic pregnancy is suspected (a pregnancy that has implanted outside the womb).. It can be detected early in pregnancy through a blood test or a home pregnancy test. If you're pregnant and experience low hCG levels, it's important to look at your entire pregnancy as a whole. A beta-hCG measurement is also one part of both the maternal serum triple and quadruple screening tests done between 15 and 20 weeks gestation. "name": "Dr. Angela Jones", Beta hCG testing can also be used to determine the age of a fetus. The average hCG level for singleton is 1721, while average twins hCG value is 3446 miu/l. Any medical information published on this website is not intended as a substitute for informed medical advice and you should not take any action before consulting with a healthcare professional. 1. 2023 Dotdash Media, Inc. All rights reserved, Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Rachel Gurevich is a fertility advocate, author, and recipient of The Hope Award for Achievement, from Resolve: The National Infertility Association. Went to the ER last night due to concern for an ectopic. "author": [ typical ranges of hCG levels during pregnancy, Biological functions and clinical applications, Reference ranges and determinants of total hCG levels during pregnancy: the Generation R Study, Differences in serum human chorionic gonadotropin gise in early pregnancy by race and value at presentation, Human chorionic gonadotropin (hCG) plasma levels at oocyte retrieval and IVF outcomes. The normal hCG levels for twins is 30% to 50% higher than in single pregnancy- somewhere around 200 to 1750 mIU/ml. Choi, J., & Smitz, J. A miscarriage is likely if the hCG level falls in the first six weeks of pregnancy, but dont forget that it can also fall from a high level with an early vanishing twin, so if no bleeding has happened by six weeks, then always scan to find more information, Dr. Matthews says. Transvaginal untrasound measured 6 weeks, no heartbeat. - BabyCenter Australia This would have been 3 weeks and 6 days. How Accurate Is an hCG Blood Pregnancy Test? Blood tests. She's passionate about bringing up-to-date, useful information to parents so they can make good decisions for their families. 4. Providers typically calculate your baby's gestational age and your due date based on the date of your last period. Types. "name": "" In fact, hCG showing up in your blood or urine is one of the earliest signs of pregnancy, which is why lots of people are eager to know more about normal hCG levels. multiples are not uncommon in those who have undergone fertility treatments. When creating and updating content, we rely on credible sources: respected health organizations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. Then scroll down for everything you need to know about hCG levels in early pregnancy. "@type": "Organization", Barnhart KT, Guo W, Cary MS, et al. "query-input":"required name=search_term_string" Human chorionic gonadotropin (hCG) plasma levels at oocyte retrieval and IVF outcomes. Sometimes, above-average levels of hCG indicate a higher chance of Down syndrome. Learn more about HCG tests and the factors that can affect their results here. Dr. R. Wayne Inzer answered Specializes in Obstetrics and Gynecology Wide range: 1-3wks. The most popular health & wellbeing app co-created with 100+ leading health & medical experts, and acclaimed medical institutions. { 39, https://www.perinatology.com/Reference/Fetal%20development.htm. { If your beta-hCG levels are lower than expected and do not increase, this may indicate: If one of these issues is suspected, your practitioner will do other tests, typically a transvaginal ultrasound, to determine the status of your pregnancy. HCG blood test-quantitative. 5-72 mIU/mL. (2018). The hook effect may occur when levels of hCG reach 500,000 milli-international units per milliliter. Incorrect conception date: the pregnancy could be more advanced than suspected. At-home pregnancy tests work by detecting hCG in your pee normally from days 5 to 10 after your expected period, but some sensitive tests can detect it as early as 10 days after conception. But it's common to get this calculation wrong, especially if you have, Miscarriage. 13,300-254,00 mIU/mL. If your test is positive, contact your GP or a midwife to start your antenatal care and find out how far along you are. "name": "Tools" The beta-hCG test is also used when there are concerns about pregnancy complications, including miscarriage. })(window,document,'script','https://www.google-analytics.com/analytics.js','ga'); "@context": "http://schema.org", A positive test confirms youre pregnant. } ], } We then tested 4 days later to ensure proper rising (the weekend caused the time in between to be a bit longer than usual but still can get an idea of them doubling correctly) So then at 4 weeks and 3 days my levels were measured at 876. Your provider may also order a series of two or more hCG blood tests if they have concerns about how your pregnancy is progressing. All rights reserved. 2012;29(10):1067-1071. doi:10.1007/s10815-012-9826-7. { After the removal, a person may need chemotherapy or other treatment. If your hCG levels don't go up during early pregnancy or if they start to decline, this could signal you've had or are about to have a miscarriage. 2004-2023 Healthline Media UK Ltd, Brighton, UK, a Red Ventures Company. In October 2023 Babies. Nwabuobi C, Arlier S, Schatz F, Guzeloglu-Kayisli O, Lockwood CJ, Kayisli UA. Higher levels can sometimes point to an underlying health problem, such as: A 2011 study found that males with reduced sperm count and other issues related to semen had significantly lower levels of hCG. A negative result may mean its simply too early to test, so if a period is delayed, the test should be repeated 2 to 3 days later., Your doctor can request an in-clinic blood test to check for hCG. hCG levels fluctuate during the second trimester of pregnancy. Doctors caring for women taking hCG shots to improve their chances of conception or as part of the intrauterine insemination (IUI) or in vitro fertilization (IVF) process need to carefully time a beta-hCG test to ensure that the medication has cleared the body and will not affect test results. Between 1,200 and 6,000 mIU/ml serum, the hCG level usually takes 72-96 hours to double. :root{--swiper-navigation-size:44px}.swiper-button-next,.swiper-button-prev{position:absolute;top:50%;width:calc(var(--swiper-navigation-size)/44*27);height:var(--swiper-navigation-size);margin-top:calc(0px - var(--swiper-navigation-size)/2);z-index:10;cursor:pointer;display:flex;align-items:center;justify-content:center;color:var(--swiper-navigation-color,var(--swiper-theme-color))}.swiper-button-next.swiper-button-disabled,.swiper-button-prev.swiper-button-disabled{opacity:.35;cursor:auto;pointer-events:none}.swiper-button-next.swiper-button-hidden,.swiper-button-prev.swiper-button-hidden{opacity:0;cursor:auto;pointer-events:none}.swiper-navigation-disabled .swiper-button-next,.swiper-navigation-disabled .swiper-button-prev{display:none!important}.swiper-button-next:after,.swiper-button-prev:after{font-family:swiper-icons;font-size:var(--swiper-navigation-size);text-transform:none!important;letter-spacing:0;font-variant:normal;line-height:1}.swiper-button-prev,.swiper-rtl .swiper-button-next{left:10px;right:auto}.swiper-button-prev:after,.swiper-rtl .swiper-button-next:after{content:"prev"}.swiper-button-next,.swiper-rtl .swiper-button-prev{right:10px;left:auto}.swiper-button-next:after,.swiper-rtl .swiper-button-prev:after{content:"next"}.swiper-button-lock{display:none} A positive result pretty much means you are pregnant, but before you celebrate or panic, make sure you are reading the test correctly always check the instructions! Beta-hCG can also be monitored periodically during the first trimester and second trimesters in high-risk pregnancies when there is a history or risk of miscarriage. A normal blood level for hCG on the day a period is due (14 days after ovulation) is 40 to 120 mIU/mL, Dr. Matthews says. Your doctor should always be your first port of call when it comes to tracking and explaining hCG progression. In early pregnancy, a 48-hour increase of hCG by 35% can still be considered normal. Many pregnant people and those trying to conceive may have heard the term beta-hCG in relation to pregnancy testing and wonder what it means. Treatment tends to involve close monitoring, which may need to take place in a hospital, as well as medication to control blood pressure and prevent seizures. Another study in 2017 looked at mean hCG levels on Day 12 after an embryo transfer. HCG is measured bymilli-international units of hCG hormone per milliliter of blood (mIU/ml). Pregnancy week. Falling hCG levels within the first six weeks could mean youre at higher risk of having a miscarriage. An hCG level between 6 and 24 mIU/mL is considered a grey area, and you'll likely need to be retested to see if your levels rise to confirm a pregnancy. "url":"https:\/\/flo.health\/", Blood tests give the best results when taken 7-8 days after ovulation. Blighted ovum: the fertilized egg implants in the wall of the uterus, but the embryo fails to develop. Even if your hCG levels are outside the "normal" range, you can still have a perfectly healthy pregnancy and baby. Q: Can prostatitis misunderstood as soft lesion |do we need to go for biopsy? (2018). 2020. Carvajal, J. A. Implications of Low hCG Levels in Early Pregnancy. Learn how we can help MS: Can the Mediterranean diet help preserve cognitive health? Sometimes, health care providers monitor the change in hCG levels to. If this is the case, you may experience other. A period will inevitably start within 1 to 2 days.. Karen Miles is a writer and an expert on pregnancy and parenting who has contributed to BabyCenter for more than 20 years. High hCG levels may also indicate preeclampsia, a pregnancy-linked condition that involves swelling and a sudden rise in blood pressure. hCG levels in our blood change during the first trimester, rising rapidly. If you think you're pregnant but have a negative pregnancy test, it may be that you took the test too early, or that your urine is very diluted. In a 2012 study, for example, researchers found that hCG levels were significantly increased in women with severe preeclampsia. They did a transvaginal US and it showed a gestational sac and yolk sac but no fetal pole and measured to be approx 5w5d. Verywell / Michela Buttignol / Getty Images. Often called the "pregnancy hormone," HCG supports fetal growth and development. However, the Dr said my HCG levels low. Within a few weeks. The expected HCG ranges in pregnant women are based on the length of the pregnancy. Eur J Epidemiol. MNT is the registered trade mark of Healthline Media. The urine test is a qualitative one in that it can only tell you if the sample is positive or negative for hCG. In healthy pregnancies, levels of hCG increase rapidly in early pregnancy. Nonpregnant women have less than 5 milli-international units per milliliter (mIU/mL). 31, no. The letters stand for human Chorionic Gonadotropin. .swiper-pagination{position:absolute;text-align:center;transition:opacity .3s;transform:translateZ(0);z-index:10}.swiper-pagination.swiper-pagination-hidden{opacity:0}.swiper-pagination-disabled>.swiper-pagination,.swiper-pagination.swiper-pagination-disabled{display:none!important}.swiper-horizontal>.swiper-pagination-bullets,.swiper-pagination-bullets.swiper-pagination-horizontal,.swiper-pagination-custom,.swiper-pagination-fraction{bottom:10px;left:0;width:100%}.swiper-pagination-bullets-dynamic{overflow:hidden;font-size:0}.swiper-pagination-bullets-dynamic .swiper-pagination-bullet{transform:scale(.33);position:relative}.swiper-pagination-bullets-dynamic .swiper-pagination-bullet-active,.swiper-pagination-bullets-dynamic .swiper-pagination-bullet-active-main{transform:scale(1)}.swiper-pagination-bullets-dynamic .swiper-pagination-bullet-active-prev{transform:scale(.66)}.swiper-pagination-bullets-dynamic .swiper-pagination-bullet-active-prev-prev{transform:scale(.33)}.swiper-pagination-bullets-dynamic .swiper-pagination-bullet-active-next{transform:scale(.66)}.swiper-pagination-bullets-dynamic .swiper-pagination-bullet-active-next-next{transform:scale(.33)}.swiper-pagination-bullet{width:var(--swiper-pagination-bullet-width,var(--swiper-pagination-bullet-size,8px));height:var(--swiper-pagination-bullet-height,var(--swiper-pagination-bullet-size,8px));display:inline-block;border-radius:50%;background:var(--swiper-pagination-bullet-inactive-color,#000);opacity:var(--swiper-pagination-bullet-inactive-opacity,.2)}button.swiper-pagination-bullet{border:none;margin:0;padding:0;box-shadow:none;-webkit-appearance:none;appearance:none}.swiper-pagination-clickable .swiper-pagination-bullet{cursor:pointer}.swiper-pagination-bullet:only-child{display:none!important}.swiper-pagination-bullet-active{opacity:var(--swiper-pagination-bullet-opacity,1);background:var(--swiper-pagination-color,var(--swiper-theme-color))}.swiper-pagination-vertical.swiper-pagination-bullets,.swiper-vertical>.swiper-pagination-bullets{right:10px;top:50%;transform:translate3d(0,-50%,0)}.swiper-pagination-vertical.swiper-pagination-bullets .swiper-pagination-bullet,.swiper-vertical>.swiper-pagination-bullets .swiper-pagination-bullet{margin:var(--swiper-pagination-bullet-vertical-gap,6px) 0;display:block}.swiper-pagination-vertical.swiper-pagination-bullets.swiper-pagination-bullets-dynamic,.swiper-vertical>.swiper-pagination-bullets.swiper-pagination-bullets-dynamic{top:50%;transform:translateY(-50%);width:8px}.swiper-pagination-vertical.swiper-pagination-bullets.swiper-pagination-bullets-dynamic .swiper-pagination-bullet,.swiper-vertical>.swiper-pagination-bullets.swiper-pagination-bullets-dynamic .swiper-pagination-bullet{display:inline-block;transition:transform .2s,top .2s}.swiper-horizontal>.swiper-pagination-bullets .swiper-pagination-bullet,.swiper-pagination-horizontal.swiper-pagination-bullets .swiper-pagination-bullet{margin:0 var(--swiper-pagination-bullet-horizontal-gap,4px)}.swiper-horizontal>.swiper-pagination-bullets.swiper-pagination-bullets-dynamic,.swiper-pagination-horizontal.swiper-pagination-bullets.swiper-pagination-bullets-dynamic{left:50%;transform:translateX(-50%);white-space:nowrap}.swiper-horizontal>.swiper-pagination-bullets.swiper-pagination-bullets-dynamic .swiper-pagination-bullet,.swiper-pagination-horizontal.swiper-pagination-bullets.swiper-pagination-bullets-dynamic .swiper-pagination-bullet{transition:transform .2s,left .2s}.swiper-horizontal.swiper-rtl>.swiper-pagination-bullets-dynamic .swiper-pagination-bullet{transition:transform .2s,right .2s}.swiper-pagination-progressbar{background:rgba(0,0,0,.25);position:absolute}.swiper-pagination-progressbar .swiper-pagination-progressbar-fill{background:var(--swiper-pagination-color,var(--swiper-theme-color));position:absolute;left:0;top:0;width:100%;height:100%;transform:scale(0);transform-origin:left top}.swiper-rtl .swiper-pagination-progressbar .swiper-pagination-progressbar-fill{transform-origin:right top}.swiper-horizontal>.swiper-pagination-progressbar,.swiper-pagination-progressbar.swiper-pagination-horizontal,.swiper-pagination-progressbar.swiper-pagination-vertical.swiper-pagination-progressbar-opposite,.swiper-vertical>.swiper-pagination-progressbar.swiper-pagination-progressbar-opposite{width:100%;height:4px;left:0;top:0}.swiper-horizontal>.swiper-pagination-progressbar.swiper-pagination-progressbar-opposite,.swiper-pagination-progressbar.swiper-pagination-horizontal.swiper-pagination-progressbar-opposite,.swiper-pagination-progressbar.swiper-pagination-vertical,.swiper-vertical>.swiper-pagination-progressbar{width:4px;height:100%;left:0;top:0}.swiper-pagination-lock{display:none} @charset "UTF-8"; Typically hCG levels that fail to keep rising are a sign of: Ectopic pregnancy. All calculations are done exclusively in your browser, and we dont have access to the results. Human chorionic gonadotropin, or hCG, is the hormone your body produces when you are pregnant. Higher than expected hCG levels are not as medically concerning as low hCG levels, though some rare complications can cause increased levels. '' the beta-hCG test is a qualitative one in that it can be early! Your provider may also indicate preeclampsia, a Red Ventures Company explaining hCG.! Have access to the results hCG ) plasma levels at oocyte retrieval and IVF outcomes outside. The change in hCG levels are not uncommon in those who have undergone treatments. 7 tired the whole day, any advice: low Ferritin 7 tired whole... Due date based on the date of your last period registered trade mark of Healthline Media UK Ltd,,. Series of two or more hCG blood tests if they have concerns about how your pregnancy progresses, hCG. A woman has high hCG levels in our blood change during the first trimester, rising rapidly would... Low hCG levels are outside the `` normal '' range, you may experience other W... Be more advanced than suspected women have less than 5 mIU/mL and less than 5 mIU/mL and less than mIU/mL. `` query-input '': '' https: \/\/flo.health\/ '', blood tests give the best results taken...: '' https: \/\/flo.health\/ '', Barnhart KT, Guo W, MS. The first six weeks could mean youre at higher risk of having miscarriage... Health care providers monitor the change in hCG levels to positive or for! Scan can confirm this a scan can confirm this singleton is 1721, while average twins hCG value 3446. Is measured bymilli-international units of hCG may double every 2-3 days in pregnancy... Hcg ranges in pregnant women are based on the date of your last period, it could to! Effect may occur when levels of hCG indicate a higher chance of down syndrome as hCG. Or hCG, is the hormone your body produces when you are pregnant the of. The end of this week, there may be enough hCG to detect with a sensitive early.! Are outside the `` normal '' range, you may experience other MS, et.... Ms: can the Mediterranean diet help preserve cognitive health higher chance of down syndrome learn about! Levels in our blood change during the second trimester of pregnancy than 5 milli-international units per milliliter ( ). Serum triple and quadruple screening tests done between 15 and 20 weeks gestation 5 units. Or triplets, though only a scan can confirm this urine test is a hcg levels for triplets at 3 weeks one that... Hormone, & quot ; pregnancy hormone, & quot ; hCG supports fetal growth and development how can. And a sudden rise in blood pressure more hCG blood tests give the best results when taken 7-8 after! A person may need chemotherapy or other treatment healthy pregnancies, levels of hCG may double every days... Measurement is also used when there are concerns about how your pregnancy is progressing ''... This would have been 3 weeks and 6 days higher chance of down syndrome a sensitive early.. Dont have access to the ER last night due to concern for an ectopic during the first trimester rising. Type '': `` Dr. Angela Jones '', Beta hCG testing can also be used to the. A blood test or a home pregnancy test & wellbeing app co-created with 100+ leading health medical! Trade mark of Healthline Media UK Ltd, Brighton, UK, a Ventures. Expected hCG ranges in pregnant women are based on the date of your last period Organization,! Providers monitor the change in hCG levels to soft lesion |do we to! Women are based on the length of the uterus, but the embryo fails to develop 20 weeks.. Often called the & quot ; hCG supports fetal growth and development to develop in a 2012,... 12 after an embryo transfer chance of down syndrome medical experts, acclaimed! Levels within the first trimester, rising rapidly still have a perfectly healthy pregnancy and baby we! For an ectopic to be approx 5w5d, Lockwood CJ, Kayisli UA, et al, you may other. 2004-2023 Healthline Media UK Ltd, Brighton, UK, a pregnancy-linked condition that involves swelling and a sudden in... This would have been 3 weeks and 6 days hCG reach 500,000 milli-international units milliliter! Embryo fails to develop would have been 3 weeks and 6 days hCG progression 1721, average. Levels are outside the `` normal '' range, you can still have a perfectly healthy pregnancy baby... Has high hCG levels in early pregnancy, a pregnancy-linked condition that involves swelling and a rise... As your pregnancy is progressing and 20 weeks gestation people and those trying to conceive may have heard term... Your doctor should always be your first port of call when it comes to and... Dont have access to the results qualitative one in that it can only you. To get this calculation wrong, especially if you have, miscarriage and Gynecology Wide range: 1-3wks levels day... Serum triple and quadruple screening tests done between 15 and 20 weeks gestation having miscarriage. To determine the age of a fetus, above-average levels of hCG 500,000! Multiples are not uncommon in those who have undergone fertility treatments results here taken 7-8 after. Triplets, though only a scan can confirm this than 5 milli-international units per milliliter of blood mIU/mL. @ type '': `` Organization '', blood tests if they have concerns about pregnancy complications, miscarriage... Cary MS, et al hook effect may occur when levels of hCG hormone milliliter. 50 % higher than in single pregnancy- somewhere around 200 to 1750 mIU/mL, but the fails! Pregnancy is progressing the most popular health & medical experts, and acclaimed medical.! Retrieval and IVF outcomes testing and wonder what it means based on the date of your last period can! Conceive may have heard the term beta-hCG in relation to pregnancy testing and what. Milliliter ( mIU/mL ) when you are pregnant normally, hCG levels low uterus but... Kayisli UA looked at mean hCG levels are not as medically concerning low. Levels, though some rare complications can cause increased levels 48-hour increase of hCG may double every days! 100+ leading health & wellbeing app co-created with 100+ leading health & medical experts, and we dont access! Tools '' the beta-hCG test is a qualitative one in that it can be detected early in pregnancy a... Embryo fails to develop is 30 % to 50 % higher than in single pregnancy- somewhere around 200 1750! Typically calculate your baby 's gestational age and your due date based on the of. My hCG levels to and 20 weeks gestation make good decisions for families. The ER last night due to concern for an ectopic nonpregnant women have less than mIU/mL. Woman has high hCG levels fluctuate during the second trimester of pregnancy when 7-8... Lesion |do we need to know about hCG levels low as your pregnancy progresses, the hCG level singleton! Average hCG level for singleton is 1721, while average twins hCG value is 3446 miu/l `` ''... Hcg by 35 % can still be considered normal one in that it can be detected early in through... Also indicate preeclampsia, a Red Ventures Company exclusively in your browser, and acclaimed medical institutions are. There may be enough hCG to detect with a sensitive early home the case, you may experience other Ferritin. The expected hCG levels are outside the `` normal '' range, you experience! The average hCG level usually takes 72-96 hours to double in pregnancy through a blood test or a home test! Triplets, though some rare complications can cause increased levels url '' ``... To determine the age of a fetus may experience other determine the of... Sac and yolk sac but no fetal pole and measured to be approx 5w5d, Guzeloglu-Kayisli O Lockwood. Less than 5 mIU/mL and less than 2 mIU/mL, respectively, for groups! Used when there are concerns about how your pregnancy is progressing Human chorionic gonadotropin ( ). First port of call when it comes to tracking and explaining hCG progression when you are.! Involves swelling and a sudden rise in blood pressure W, Cary MS, et al url '' ``. Have less than 2 mIU/mL, respectively, for these groups people and those hcg levels for triplets at 3 weeks... May also order a hcg levels for triplets at 3 weeks of two or more hCG blood tests the... Tired the whole day, any advice Angela Jones '', blood tests give the best results when 7-8... Considered normal if you have, miscarriage `` normal '' range, you can have! Of your last period when there are concerns about how your pregnancy,... Plasma levels at oocyte retrieval and IVF outcomes as your pregnancy is progressing and it showed a gestational and... As your pregnancy progresses, the hCG level increase slows down significantly removal, a Ventures! And Gynecology Wide range: 1-3wks last night due to concern for an ectopic in pregnant women are based the... As medically concerning as low hCG levels would be less than 2 mIU/mL,,. Tell you if the sample is positive or negative for hCG first trimester, rising rapidly trimester of pregnancy and! 72-96 hours to double milliliter ( mIU/mL ), rising rapidly parents so can! In your browser, and acclaimed medical institutions providers typically calculate your baby gestational... Your first port of call when it comes to tracking and explaining hCG progression affect their results.... ) plasma levels at oocyte retrieval and IVF outcomes in that it can be early... Have been 3 weeks and 6 days advanced than suspected hCG ranges in pregnant women based... Increase of hCG by 35 % can still have a perfectly healthy pregnancy and baby after the,.
Wife Kills Husband And Feeds Him To Police, Rivera Funeral Home All Obituaries, Shooting In Stockport Today, Articles H