gestation period

Also found in: Dictionary, Thesaurus, Legal, Encyclopedia, Wikipedia.


the period of development of the young in viviparous animals, from the time of fertilization of the oocyte (ovum) to birth; see also pregnancy.
gestation period the duration of pregnancy; in the human female, the average length, calculated from the first day of the last normal menstrual period, is 280 days, or 6 lunar months. The normal limits of the human gestation period are from 37 weeks (259 days) to 42 weeks (293 days); days and weeks are counted as completed days and weeks. If one counts from the moment of conception, the length of time is 266 days (280−14 days).


an interval or division of time; the time for the regular recurrence of a phenomenon.
absolute refractory period the part of the refractory period from phase 0 to approximately −60 mV during phase 3; during this time it is impossible for the myocardium to respond with a propagated action potential, even with a strong stimulus. Called also effective refractory period.
blanking period a period of time during and after a pacemaker stimulus when the unstimulated chamber is insensitive to avoid sensing the electronic event in the stimulated chamber.
effective refractory period absolute refractory period.
ejection period the second phase of ventricular systole (0.21 to 0.30 sec), between the opening and closing of the semilunar valves, while the blood is discharged into the aorta and pulmonary artery. Called also sphygmic period.
gestation period see gestation period.
incubation period see incubation period.
isoelectric period the moment in muscular contraction when no deflection of the galvanometer is produced.
latency period
latent period a seemingly inactive period, as that between exposure to an infection and the onset of illness (incubation period) or that between the instant of stimulation and the beginning of response (latency, def. 2).
refractory period the period of depolarization and repolarization of the cell membrane after excitation; during the first portion (absolute refractory period), the nerve or muscle fiber cannot respond to a second stimulus, whereas during the relative refractory period it can respond only to a strong stimulus.
relative refractory period the part of the refractory period from approximately −60 mV during phase 3 to the end of phase 3; during this time a depressed response to a strong stimulus is possible.
safe period the period during the menstrual cycle when conception is considered least likely to occur; it comprises approximately the ten days after menstruation begins and the ten days preceding menstruation. See the section on fertility awareness methods, under contraception.
sphygmic period ejection period.
supernormal period in electrocardiography, a period at the end of phase 3 of the action potential during which activation can be initiated with a milder stimulus than is required at maximal repolarization, because at this time the cell is excitable and closer to threshold than at maximal diastolic potential.
vulnerable period that time at the peak of the T wave during which serious arrhythmias are likely to result if a stimulus occurs.
Wenckebach's period a usually repetitive sequence seen in partial heart block, marked by progressive lengthening of the P–R interval; see also dropped beat.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

gestation period

The period from fertilization of the egg (ovum) to the birth of the child. The human gestation period is 40 weeks, plus or minus 2 weeks.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
Think about how long the gestation period would be in securing a conviction for death penalty.
Intraspecific variation in the mammalian gestation period. Journal of Mammalogy, 63(4), 646-652.
Moreover, research estimating parameters including gestation period, number of offspring, weaning age, and weight can provide useful information for the management of captive pangolins.
The gestation period is often longer than a parliament, but a country with no discovery research (and government laboratories are best suited to do it) will have no innovation offspring to celebrate and use to develop its economy.
In the second phase, the consortium will build Afghanistan's first steel plant -- a project that has a gestation period of about a decade.
Officials at the LEO Zoological Conservation Center tell the Greenwich Time ( ) they had removed the only male anteater from the enclosure in August, long before the six-month gestation period for baby Archie would have begun.
Tapirs give birth to a single youngster after a gestation period of about 13 months.
"Such projects have a long gestation period, but one has to start somewhere," the newspaper quoted an anonymous official as saying in its report headlined: "Soon: Bullet trains for tortoise tracks".
Since the intake of grilled meat did not affect the duration of pregnancy, the reduced birth weight was not due to a shortened gestation period.
They found that after a ten week gestation period, the treated plots contained nine per cent less carbon in the soil.
Economic down turn, high cost of biopharmaceuticals, long gestation period of biopharmaceutical drugs and the quality of the reagents are factors restricting the market.