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a period of 3 months.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


(trī'mes-tĕr, trī-mes'ter),
A period of 3 months; one third of the length of a pregnancy.
[L. trimestris, of 3-months' duration]
Farlex Partner Medical Dictionary © Farlex 2012


(trī-mĕs′tər, trī′mĕs′-)
1. A period or term of three months.
2. One of three terms into which an academic year is divided in some universities and colleges.

tri·mes′tral (-trəl), tri·mes′tri·al (-trē-əl) adj.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


Obstetrics A period of 3 months, understood to be during pregnancy; the 1st trimester is 1-12 wks; the 2nd trimester is 13-26 wks; the 3rd trimester is 27 wks to delivery
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


A period of 3 months; one third of the length of a pregnancy.
[L. trimestris, of 3-months' duration]
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


The first third or 13 weeks of pregnancy.
Mentioned in: Rubella
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.


A period of 3 months.
[L. trimestris, of 3-months' duration]
Medical Dictionary for the Dental Professions © Farlex 2012

Patient discussion about trimester

Q. My daughter had lost her pregnancy in the second trimester. Something is going wrong with my daughter. She had lost her pregnancy in the second trimester. Something wrong was found in her ultrasound report. The situation was described as a molar pregnancy. After this miscarriage, still she is on regular examination. The very strange part is that they are still taking her hCG tests after her miscarriage. What sort of problem is this?

A. A molar pregnancy is a mass of tissue (hydatidiform mole) that forms an abnormal placenta inside the uterus. Even though it is not an embryo, a mole triggers symptoms of pregnancy. And the pregnancy test will result in positive value also. About 1 out of 1,000 women with early pregnancy symptoms has a molar pregnancy.

A molar pregnancy triggers the same first-trimester symptoms that a normal pregnancy does (a missed menstrual period, breast tenderness, fatigue, increased urination, morning sickness). It may be diagnosed during an early ultrasound test. In addition to normal pregnancy signs, a molar pregnancy usually causes additional symptoms, which can include:

Here are the most characteristic symptoms of a molar pregnancy :
Vaginal bleeding, a bigger size uterus that is abnormally large for the length of the pregnancy, severe nausea and vomiting, pelvic discomfort.

If you are diagnosed with a molar pregnancy, you will need immediate treatment to remove all molar growth fro

Q. I am in the final trimester and my whole stomach got really hard twice and hurt a lot. I am in the final trimester and from yesterday I am having extremely bad mental feeling and cramps and while at departmental store my whole stomach got really hard twice and hurt a lot....scared the hell out of me….it’s a heavy pain now, though I am relaxing now and still the pain seems to be arousing in a slow manner and I want to know what you all think?

A. Liam, since you're in your final trimester, be prepared to deliver your baby. I will suggest you to be more relax, and prepare yourself (physically, mentally, and emotionally) to deliver your baby at anytime.

Here I will share to you some real-labor symptoms :
- you will feel intensified contractions, it becomes stronger and more often
- the contraction will be more painful (that can feel like a cramp)
- you have bloody show (pinkish bloody streak from your down-there)
- you break the amniotic water

Okay, get prepared, and be ready to welcome your babyborn! Stay healthy always..

Q. My wife is pregnant and she is now in the first trimester. Her queasiness is disturbing her a lot. My wife is pregnant and she is now in the first trimester. Her queasiness is disturbing her a lot. She calls it as morning sickness. Almost all the day she feels nauseated whether she vomits or not. But every day she will throw once to have some relief for some time. I worry that this sickness can harm the baby. She does not want to meet the doctor as she says it’s normal with everyone who is pregnant. But I am worried can anyone give some advice?

A. my advice to you is the nausea and vomiting is a common thing that happens in first trimester. but be careful if the nausea and vomiting become more often and worse, by that time you must go to a doctor to find some help and therapy. it is called hyperemesis gravidarum.

so, make sure that what happened to your wife is in normal range, and good luck with her pregnancy! stay healthy always..

More discussions about trimester
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References in periodicals archive ?
The stiffness of carotid arteries of pregnant women has been studied during normal pregnancy using other measurement techniques including PWV, where they concluded that arterial compliance of carotid arteries increased significantly from the first to the second trimester, and then decreased toward baseline at the third trimester [16, 35].
The Journal of Allergy and Clinical Immunology randomised pregnant women in their third trimester into fish oil, placebo and 'no oil' groups.
The researchers observed that 23.3% of women smoked during pregnancy; 6.0% during preconception only and 17.3% smoked through the first trimester, as well.
[9,11] The pattern of GWG is higher in the 2nd trimester at a rate of 0.563 kg/week and birth weight is strongly correlated with weigh gain during that period.
Pregnancy is not itself a contraindication for dental treatment, although all elective dental treatments should be deferred till after the first trimester is over due to the fragile state and vulnerability of the fetus.
One such strategy has focused on eliminating access to abortion after the first trimester by banning one method at a time.
We obtained peripheral blood samples with informed consent and institutional approval from 10 pregnant women from each of the first (12-14 weeks), second (20-23 weeks), and third (38-40 weeks) trimesters and harvested the plasma and maternal buffy coat from each case.
In a second specification, for each trimester t we modeled three dichotomous indicator variables for [PM.sub.10] categorized as 30-49 [micro]g/[m.sup.3] (PM30_49t), 50-69 [micro]g/[m.sup.3] (PM50_69t), and [greater than or equal to] 70 [micro]g/[m.sup.3] (PM70t), with [PM.sub.10] < 30 [micro]g/[m.sup.3] serving as the reference exposure category.
Trimester specification is required as the final digit.
The expectations for the number of employees for the next period are more favorable, the assessment of the current situation regarding orders (contracts) is at the same level as the previous trimester, while the expectations for the total orders for the next 3 months are unfavorable.
Although the success rate increased by higher doses of misoprostol, it seems that this differences may not be beneficial in clinic [32] Several investigators have demonstrated that vaginal misoprostol is a safe and effective medication for pregnancy termination in first trimester [28, 33].