The Factors That Influence Twinning Rates

Abstract

In a study carried out in an African population in Western Nigeria and a Caucasian population in Aberdeen, Scotland, it was found that DZ twinning rates varied with maternal age and parity, the MZ twinning rate remaining fairly constant. However, women aged 30–34 were found to have the highest rate in Western Nigeria whereas the peak in Aberdeen population occurred in the older age group, 35–39 years. Other factors that influenced DZ twinning rates were maternal height, social class and ethnicity (in the Nigerian population), and illegitimacy (in the Aberdeen population). No significant association was found between twinning and maternal blood groups or season of the year in either of the two populations. An important factor that also influenced twinning in the two populations was the maternal serum FSH level. The levels were much higher in the Nigerian population than in the Aberdeen population. Furthermore, in the Aberdeen population, twin-prone and non-twin-prone women had similar serum FSH levels, whereas the levels were much higher in twin-prone women in the Nigerian population. This finding is consistent with the fact that the Nigerian population has a much higher twinning incidence (approximately 50 per 1,000 maternities) than Aberdeen population (approximately 12 per 1,000 maternities).

A retrospective study: twin gestation at tertiary care, maternal and fetal outcome

“…[7][8][9][10] Twin gestation can be attributed to multiple factors including genetic and environmental factors like advanced maternal age and increased parity. [4][5][6] There has been an increase in incidence of twins due to multiple reasons such as a rise in the number of women conceiving at an advanced age and in increase in use of assisted reproductive techniques. 11 Women with multiple gestation are more likely to have complications of pregnancy.…”

Twins Birth in Kano, Northern Nigeria

“…Nigeria has long been recognized for a high incidence of multiple pregnancies [6,7,8] The Yoruba people of Nigeria possess a twinning rate more than four-fold that of Caucasian population, and the highest rate in the world [9].…”

Study Of Maternal And Fetal Outcome In Twin Gestation At Tertiary Care Teaching Hospital

“…Globally, the highest burden of multiple births has been found in sub-Saharan Africa, with an average twining rate of 20 per 1,000 deliveries compared to 10 per 1,000 deliveries in Europe or around 5-6 per 1,000 deliveries in Asia. Nigeria has the highest prevalence of multiple births worldwide [1][2][3] . Twining is a multi factorial phenomenon principally attributable to genetic and environmental factors, such as advanced maternal age and increased parity.…”