1971•Annals of Human GeneticsRequires access
Placentation and zygosity ot triplets and higher multiple births in Ibadan, Nigeria
P. P. S. Nylander, G. CORNEY
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Abstract
SUMMARY Placentation and zygosity were studied in forty‐four sets of triplets and 1 set of quadruplets in Ibadan, Western Nigeria, between January 1967 and December 1969. Amongst those triplet sets with known placentation, 1 (2–5%) was monochorionic, 10 (25‐0%) were dichorionic and 29 (72‐5%) were trichorionic. Zygosity was determined by sex, type of placentation and genetically determined characters in red cells and placental tissue. It was possible to determine the zygosity of forty sets of triplets and of these 2 (5‐0%) were likely to be MZ, 14 (35‐0%) were likely to be DZ and 24 (60‐0%) were TZ. The high proportion of TZ sets is consistent with previous reports of a high rate of DZ twinning in the same population as compared with other Negro and Caucasian populations.