Estimating Gestational Age and Counseling Antenatal Care Clients in the Context of Zika

The Maternal and Child Survival Program (MCSP) Zika Pregnancy Wheel is a tool designed to help health providers and their clients understand how far along a pregnancy has progressed. Accurate and precise gestational age estimation contributes to better diagnosis of preterm birth and facilitates birth preparedness and complication readiness. The MCSP Zika Pregnancy Wheel is a job aid for counseling clients on key aspects of Zika infection prevention and management, as well as for estimating gestational age. The wheel includes counseling points related to prevention of Zika virus infection, such as using window screens or staying in air-conditioned rooms, using insect repellent, covering arms and legs with clothing, decreasing the opportunities for mosquitoes to reproduce in nearby resting water sources, and practicing safer sex. Practicing safer sex includes using a condom when having vaginal, oral, and anal sex or abstaining from sexual activity during pregnancy. Counseling clients on the potential effects and symptoms of Zika virus infection is also an essential component of care. Zika virus infection can pass from a pregnant woman to her fetus and cause malformations such as microcephaly, eye malformations, hearing problems, problems with brain function, and other serious impacts on normal development. Providers should counsel clients on how to prevent Zika virus infection and unintended pregnancy, as about 80% of Zika virus infections are asymptomatic. To estimate gestational age from the last normal menstrual period, health providers can use a pregnancy wheel. The wheel consists of two overlapping discs: the top rotating disc is the gestational age and expected date of delivery calculator, and the bottom stationary disc is the calendar wheel. To estimate gestational age, the provider determines the date of the first day of the most recent normal menstrual period and turns the top rotating disc so that the arrow labeled "FIRST DAY OF LAST MENSTRUAL PERIOD" points to the month and day of the LMP on the stationary calendar disc. The provider then finds the number indicating the last completed week on the rotating disc and counts the number of small marks (days) up until today's date on the stationary disc, which gives the gestational age in weeks and days. The provider also finds the arrow pointing to week 40 on the stationary disc, which gives the expected date of delivery. The MCSP Zika Pregnancy Wheel is a valuable tool for health providers working in areas where pregnant women are at risk for Zika virus infection. By using the wheel, providers can estimate gestational age and expected date of delivery, counsel clients on prevention of Zika virus infection, and provide essential information on the potential effects and symptoms of Zika virus infection. The wheel can be incorporated into existing antenatal care training strategies for providers working in areas where pregnant women are at risk for Zika virus infection.