Preeclampsia is a significant medical condition occurring in 3-8% of pregnancies and impacts deleteriously both maternal and fetal health. An important discovery has been made by Dr Craig D Scoville showing that early Tdap vaccinations in pregnancy can reduce the incidence of preeclampsia by more than 50%. A prospective clinical research trial is proposed and urgently needed to validate this finding and thereby make a significant contribution in reducing the incidence of this common and severe complication of pregnancy.

A double blinded randomized prospective clinical research study is proposed to validate the hypothesis that Tdap vaccinations at week 28 in pregnancy can reduce the incidence of preeclampsia by more than 50%. This project will recruit 1600 pregnant women with appropriate informed consent in the first trimester of pregnancy, obtain detailed obstetric and health history, and then randomize these subjects so 800 women receive Tdap at week 28, and 800 women receive Tdap at week 36, and all women will be followed during their pregnancies using standard of care with special attention to preeclampsia and fetal outcomes. Blood samples will be obtained at weeks 12, 20, and 36 in order to test the anti-tetanus toxoid antibody levels, anti-diptheria antibody levels, anti-pertussis antibody levels, and also maternal cytokines (IL-2, IL-4, IL-6, IL-10, TNFa, IL-17, and IFNg), and placental biomarkers (sFlt-1, sEng, and PIGF) for preeclampsia on those patients who develop preeclampsia and compare to those who didn't and thereby better understand the biomarkers of preeclampsia and devise a better formula for positive prediction for preeclampsia. To make this change in clinical practice and save lives, this study is asking for funding from NICHD PA-18-480.

Inclusion Criteria:

1. confirmed pregnancy at week 12
2. Age 18 to 42
3. Willing to participate and sign informed consent documentation
4. willing to follow study procedures with regards to randomization of Tdap and attend all routine clinic visits per obstetrician and standard of care
5. accept Tdap vaccination either at week 28 or week 36

Exclusion Criteria:

1. no history of allergic reaction or intolerance to Tdap vaccination
2. No history of cancer in past 5 years prior to this study (except for non melanoma localized skin cancers or cancer in situ) -

Pregnant women

Data acquired in this project will be shared through presentations at scientific meetings and published peer reviewed publications. In order to disseminate the data, we will maintain a data archive where all information is stored and can be distributed. Data requests may be sent to the PI and reasonable requests will be granted. However a particular data set in the archives will only be shared after a manuscript describing the main findings has been accepted for publication. Also any proprietary information will not be shared until legal restrictions make it permissible

see Plan Description and no time limit once the data is made available to the public

contact Institute of Arthritis Research at scovilleclinic.com

Each study site will designate an "injection nurse" who will be responsible for preparing both placebo and Tdap administration and will be the only one knowing when a patient gets either Tdap injection at week 28 or placebo injection at week 28, or gets Tdap injection at week 36 or placebo injection at week 36. This person will be the only one at each site who will know the randomization of each subject and is the only one who will administer the injection. Every subject will receive Tdap either at week 28 or week 36 and receive placebo injection on the other injection time.