The twinning rate during a twenty-year period (1965-1985) was investigated at five-year intervals in four Brazilian hospitals. During this period the twinning rate has decreased significantly (from 10.68‰ to 8.11‰), being highly negatively correlated with the five-year intervals (r = -0.97). This change was due mainly to the decline in dizygotic twinning, since the incidence of DZ twins has fallen from around 7‰ in 1965 to around 3.6‰ in 1985. The detected decline in DZ twinning seems to be due to the remotion of the fertility advantage of the more fecundable DZ twin-prone women by the introduction of effective birth control at the present, while some other mechanisms are causing the decline irrespective of the type of twinning.381-2576
Twin births are an important public health issue due to health complications for both mother and chi...
CONTEXT: Epidemiological studies on twin births have been motivated mostly by the positive correlati...
During the 1960s and 1970s, the maternal age-specific twinning rates were declining in England and W...
The twinning rate during a twenty-year period (1965-1985) was investigated at five-year intervals in...
A retrospective study was carried out on a sample consisting of 89,491 deliveries occurred from 1979...
3To whom correspondence should be addressed There is widespread concern about a possible decline in ...
<div><p>Twin births are an important public health issue due to health complications for both mother...
Twin births are an important public health issue due to health complications for both mother and chi...
BACKGROUND: In the wide-ranging debate about the potential monitors of population fertility, twinnin...
The twinning rate has increased dramatically over the last four decades in developed countries. Two ...
The twinning rate has increased dramatically over the last four decades in developed countries. Two ...
The twinning rate has increased dramatically over the last four decades in developed countries becau...
BACKGROUND: In the wide-ranging debate about the potential monitors of population fertility, twinnin...
BACKGROUND. Decreased fecundity has been hypothesized as one of the causes of the widespread decline...
Twinning rates in developed countries have recently registered an increase. At the end of the 1970s,...
Twin births are an important public health issue due to health complications for both mother and chi...
CONTEXT: Epidemiological studies on twin births have been motivated mostly by the positive correlati...
During the 1960s and 1970s, the maternal age-specific twinning rates were declining in England and W...
The twinning rate during a twenty-year period (1965-1985) was investigated at five-year intervals in...
A retrospective study was carried out on a sample consisting of 89,491 deliveries occurred from 1979...
3To whom correspondence should be addressed There is widespread concern about a possible decline in ...
<div><p>Twin births are an important public health issue due to health complications for both mother...
Twin births are an important public health issue due to health complications for both mother and chi...
BACKGROUND: In the wide-ranging debate about the potential monitors of population fertility, twinnin...
The twinning rate has increased dramatically over the last four decades in developed countries. Two ...
The twinning rate has increased dramatically over the last four decades in developed countries. Two ...
The twinning rate has increased dramatically over the last four decades in developed countries becau...
BACKGROUND: In the wide-ranging debate about the potential monitors of population fertility, twinnin...
BACKGROUND. Decreased fecundity has been hypothesized as one of the causes of the widespread decline...
Twinning rates in developed countries have recently registered an increase. At the end of the 1970s,...
Twin births are an important public health issue due to health complications for both mother and chi...
CONTEXT: Epidemiological studies on twin births have been motivated mostly by the positive correlati...
During the 1960s and 1970s, the maternal age-specific twinning rates were declining in England and W...