Background and objective:
Despite concerted efforts to achieve universal and equitable immunization coverage, many children are still missed since they have no formal record of existence, making it difficult to track these ‘invisible’ children. We developed an electronic pregnant women and birth registry (pwbr) module that enrolls pregnant women and newborns visiting birthing facilities into a centralized database connected to the provincial electronic immunization registry (zindagi mehfooz; zm eir) in sindh province, pakistan.

Methods:
We implemented the pwbr module at 15 birthing facilities in 8 ‘super high-risk union councils’ (shrucs) in karachi, based on the prevalence and circulation of poliovirus and low routine immunization coverage. Pregnant women and their newborns were enrolled into the pwbr at the birthing facility through assigning them a unique qr-code based identifier that linked them to the provincial eir. We evaluated the impact of the pwbr on birth dose immunization coverage and timeliness among enrolled newborns.

Results:
Between november 10, 2020, and december 31, 2021, we enrolled 33,335 pregnant women and 99.5% (17,942/18,021) of the children born at the birthing facilities. 88% (15,712/17,945) of the newborns were administered the birth dose of the polio vaccine at the facility, of which 99% (15,666/15,712) were vaccinated within 24-hours of birth. We observed that coverage rate for birth dose polio vaccine (93%) was higher among children enrolled in the eir through pwbr compared to those enrolled through other modalities (immunization centers, outreach, etc.) (43%).Timeliness of subsequent vaccines was also higher for children enrolled through pwbr compared to those enrolled through other modalities.

Conclusion:
A birth registry module integrated in existing lmic health systems can effectively provide newborns with a digital identity and link them to the health system for effectively tracking their immunization status till completion.