Table 2.

Definitions applied to estimation of absolute risk of primary fetal and infant outcomes

Outcome	Numerator	Denominator
Miscarriage	Number of miscarriages (pregnancy loss prior to 20 weeks gestation)	Total number of pregnancies
Early fetal death	Number of pregnancies lost between 20 and 27 weeks gestation	Total number of pregnancies carried to 20 weeks gestation
Late fetal death	Number or pregnancies lost at or following 28 weeks gestation	Total number of pregnancies carried to 28 weeks gestation
Microcephaly	Number of microcephaly cases	Total number of pregnancies carried to ≥24 weeks gestation, when microcephaly can be assessed by ultrasound in ZIKV-infected mothers,38 we will consider all pregnancies regardless of whether the pregnancy results in a live birth

ZIKV, Zika virus.