Pregnancy is not contagious, but it can have a copycat effect –especially among female colleagues. A study by researchers at the State Institute for Family Research at the University of Bamberg (ifb) found that women in particular are influenced by a pregnancy in their immediate professional environment.
The effect is particularly strong among female colleagues of approximately the same age. The probability of pregnancy is almost twice as high in the year after a colleague becomes a mother. The researchers attribute this to mechanisms such as social learning and social support.
Buyukkececi Z et al. Family, Firms, and Fertility: A Study of Social Interaction Effects. Demography 2020;57: 243–266.
DOI: https://doi.org/10.1007/s13524-019–00841‑y
By the way, if the topic of pregnancies brings to mind the connection between birth rates and stork population — here an interesting mathematical background article:
Der Storch bringt die Babys zur Welt (p = 0.008)
http://www3.math.uni-paderborn.de/~agbiehler/sis/sisonline/struktur/jahrgang21-2001/heft2/Langfassungen/2001–2_Matth.pdf