TY - JOUR
T1 - Twin chorionicity and zygosity both vary with maternal age
AU - Yeaton-Massey, Amanda
AU - Sparks, Teresa N.
AU - Norton, Mary E.
AU - Jelliffe-Pawlowski, Laura
AU - Currier, Robert J.
N1 - Publisher Copyright:
© 2021 John Wiley & Sons Ltd.
PY - 2021/8
Y1 - 2021/8
N2 - Objective: To determine the ratio of dichorionic (DC) to monochorionic (MC) twins by maternal age. Methods: We reviewed all twin pregnancies undergoing first trimester screening (FTS) with nuchal translucency from April 2009 to December 2012 with sonographic determination of chorionicity. Cases were linked to newborn screening (NBS) results and zygosity estimated based on rates of fetal sex discordance. The ratio of DC to MC placentation by maternal age was calculated. Results: We identified 11,351 twin pregnancies with FTS and documented chorionicity. Among these, 7861 (64.2%) had linked data on FTS and NBS to allow estimation of zygosity based on neonatal sex. Of these, 1464 (18.6%) were MC and 6406 (81.4%) DC. The MC twin rate remained constant while the DC twin rate increased with maternal age until 40 years. At <20 years, 55% of twin pregnancies were monozygotic (MZ), as compared to 29% at > 40 years. Of MZ twins, 38% were DC at < 20years, while 53% were DC at >40 years. Conclusions: Our data suggest a relationship of both zygosity and chorionicity with maternal age. DZ twinning increased with maternal age, while among MZ twins, the proportion that were DC also increased with maternal age.
AB - Objective: To determine the ratio of dichorionic (DC) to monochorionic (MC) twins by maternal age. Methods: We reviewed all twin pregnancies undergoing first trimester screening (FTS) with nuchal translucency from April 2009 to December 2012 with sonographic determination of chorionicity. Cases were linked to newborn screening (NBS) results and zygosity estimated based on rates of fetal sex discordance. The ratio of DC to MC placentation by maternal age was calculated. Results: We identified 11,351 twin pregnancies with FTS and documented chorionicity. Among these, 7861 (64.2%) had linked data on FTS and NBS to allow estimation of zygosity based on neonatal sex. Of these, 1464 (18.6%) were MC and 6406 (81.4%) DC. The MC twin rate remained constant while the DC twin rate increased with maternal age until 40 years. At <20 years, 55% of twin pregnancies were monozygotic (MZ), as compared to 29% at > 40 years. Of MZ twins, 38% were DC at < 20years, while 53% were DC at >40 years. Conclusions: Our data suggest a relationship of both zygosity and chorionicity with maternal age. DZ twinning increased with maternal age, while among MZ twins, the proportion that were DC also increased with maternal age.
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U2 - 10.1002/pd.5997
DO - 10.1002/pd.5997
M3 - Article
C2 - 35280337
AN - SCOPUS:85110041285
SN - 0197-3851
VL - 41
SP - 1074
EP - 1079
JO - Prenatal Diagnosis
JF - Prenatal Diagnosis
IS - 9
ER -