Search results
Results From The WOW.Com Content Network
A multiple birth is the culmination of one multiple pregnancy, wherein the mother gives birth to two or more babies. A term most applicable to vertebrate species, multiple births occur in most kinds of mammals , with varying frequencies.
This is a list of multiple births, consisting of notable higher order (4+) multiple births and pregnancies. Twins and triplets are sufficiently common to have their own separate articles. With the use of reproductive technology such as fertility drugs and in vitro fertilization (IVF) such births have become increasingly common. This list ...
A multiple pregnancy (e.g., twins, triplets, etc.) is counted as 1. Parity, or "para", indicates the number of births (including live births and stillbirths) where pregnancies reached viable gestational age. A multiple pregnancy (e.g., twins, triplets, etc.) carried to viable gestational age is still counted as 1. [3]
A litter is the live birth of multiple offspring at one time in animals from the same mother and usually from one set of parents, particularly from three to eight offspring. The word is most often used for the offspring of mammals , but can be used for any animal that gives birth to multiple young.
Triplet and higher multiple births nosedive. In 2004, of the people younger than 35 who gave birth with the help of IVF, 32.7% delivered twins, and 4.9% delivered triplets, according to doctors at ...
Hellin's law, also called Hellin-Zeleny's law, is an empirical observation in demography that the approximate rate of multiple births is one n-tuple birth per 89 n-1 singleton births: twin births occur about once per 89 singleton births, triplets about once per 89 2, quadruplets about once per 89 3, and so on.
Mammals during pregnancy can have one or more gestations at the same time, for example in a multiple birth. [2] The time interval of a gestation is called the gestation period. In obstetrics, gestational age refers to the time since the onset of the last menses, which on average is fertilization age plus two weeks. [3]
Reproductive synchrony is a term used in evolutionary biology and behavioral ecology. Reproductive synchrony—sometimes termed "ovulatory synchrony"—may manifest itself as "breeding seasonality". Where females undergo regular menstruation, "menstrual synchrony" is another possible term. Figure a. Females competing for good genes should avoid ...