The purpose of the Twinrix Pregnancy Registry is to prospectively collect data describing exposure to Twinrix before or during pregnancy, potential confounding factors (such as exposure to other medications) and information related to the outcome of the pregnancy. This is a prospective, voluntary, observational, exposure-registration study. Twinrix is designated as Food and Drug Administration (FDA) Pregnancy Category C, which means that its safety in human pregnancy has not been determined. The Registry is intended to provide an early signal of potential risks in advance of results from formal epidemiologic studies. Registry statistics can supplement animal reproductive toxicology studies and assist clinicians in evaluating the potential risks and benefits of vaccination for individual patients.
The Twinrix Pregnancy Registry will be maintained by GSK Vaccines Clinical Safety and Pharmacovigilance. Enrolment in the Registry will begin at the time of commercial launch of Twinrix in the United States (US). At the time of initiation of the Registry, pre-existing reports of pregnancy from clinical trials will be evaluated and enrolled when the criteria for registration are met. Reporting of exposed pregnancies is voluntary. Pregnancies will be registered following maternal exposure to Twinrix within 28 days prior to conception or during pregnancy. Registration of pregnancies is prospective, i.e., reported during pregnancy before the pregnancy outcome is known. Retrospective reports, in which the pregnancy outcomes are known at the time of reporting, will also be reviewed to assist in the detection of any unusual patterns that may exist among the reported birth defects. However, because there is no denominator from which risk can be calculated, these reports will be excluded from the analysis.
Study Type
OBSERVATIONAL
Enrollment
245
When the pregnancy is reported prospectively, the Registry will collect registration data from the reporter through telephone interview or a short registration form. In the month of the estimated date of delivery, follow-up will be sought by telephone contact or a form mailed to the health professional. Information about maternal events throughout the pregnancy, pregnancy outcome, and neonatal health is requested. Additional follow-up is not sought from subsequent health care providers.
Number of Outcomes From Pregnancies With Reported Exposure Within 28 Days of Last Menstrual Period
Participants were followed from registration upon exposure to Twinrix within 28 days prior to conception until data on pregnancy outcome was obtained. Follow-up via telephone or a form mailed to the contact was sought in the month of the estimated date of delivery. Pregnancy outcomes were stratified by the trimester of exposure, with an additional stratum for preconception exposure with no subsequent administration during pregnancy; multiple exposures were classified by the earliest trimester of exposure. Gestational weeks were counted from the date of the last menstrual period. The second trimester was considered to begin at week 14, and the third trimester beginning at week 28. Pregnancy outcomes were dichotomized according to the presence or absence of birth defects and further categorized as: Live births, Spontaneous abortions (i.e., pregnancy losses), Induced abortions and Fetal deaths.
Time frame: From the date of registration until the date of documentation of pregnancy outcome (up to 10 months i.e. 28 days prior to conception till the month of estimated date of delivery)
Number of Outcomes From Pregnancies With Earliest Reported Exposure During the First Trimester
Participants were followed from registration upon exposure to Twinrix during first trimester of pregnancy until data on pregnancy outcome was obtained. Follow-up via telephone or a form mailed to the contact was sought in the month of the estimated date of delivery. Pregnancy outcomes were stratified by the trimester of exposure, with an additional stratum for preconception exposure with no subsequent administration during pregnancy; multiple exposures were classified by the earliest trimester of exposure. Gestational weeks were counted from the date of the last menstrual period. The second trimester was considered to begin at week 14, and the third trimester beginning at week 28. Pregnancy outcomes were dichotomized according to the presence or absence of birth defects and further categorized as: Live births, Spontaneous abortions (i.e., pregnancy losses), Induced abortions and Fetal deaths.
Time frame: From the date of registration until the date of documentation of pregnancy outcome (up to 10 months i.e. 28 days prior to conception till the month of estimated date of delivery)
Number of Outcomes From Pregnancies With Earliest Reported Exposure During the Second Trimester
Participants were followed from registration upon exposure to Twinrix during second trimester of pregnancy until data on pregnancy outcome was obtained. Follow-up via telephone or a form mailed to the contact was sought in the month of the estimated date of delivery. Pregnancy outcomes were stratified by the trimester of exposure, with an additional stratum for preconception exposure with no subsequent administration during pregnancy; multiple exposures were classified by the earliest trimester of exposure. Gestational weeks were counted from the date of the last menstrual period. The second trimester was considered to begin at week 14, and the third trimester beginning at week 28. Pregnancy outcomes were dichotomized according to the presence or absence of birth defects and further categorized as: Live births, Spontaneous abortions (i.e., pregnancy losses), Induced abortions and Fetal deaths.
Time frame: From the date of registration until the date of documentation of pregnancy outcome (up to 10 months i.e. 28 days prior to conception till the month of estimated date of delivery)
Number of Outcomes From Pregnancies With Earliest Reported Exposure During the Third Trimester
Participants were followed from registration upon exposure to Twinrix during third trimester of pregnancy until data on pregnancy outcome was obtained. Follow-up via telephone or a form mailed to the contact was sought in the month of the estimated date of delivery. Pregnancy outcomes were stratified by the trimester of exposure, with an additional stratum for preconception exposure with no subsequent administration during pregnancy; multiple exposures were classified by the earliest trimester of exposure. Gestational weeks were counted from the date of the last menstrual period. The second trimester was considered to begin at week 14, and the third trimester beginning at week 28. Pregnancy outcomes were dichotomized according to the presence or absence of birth defects and further categorized as: Live births, Spontaneous abortions (i.e., pregnancy losses), Induced abortions and Fetal deaths.
Time frame: From the date of registration until the date of documentation of pregnancy outcome (up to 10 months i.e. 28 days prior to conception till the month of estimated date of delivery)
Number of Outcomes From Pregnancies With Reported Exposure During an Unspecified Trimester
Participants were followed from registration upon exposure to Twinrix during unspecified trimester of pregnancy until data on pregnancy outcome was obtained. Follow-up via telephone or a form mailed to the contact was sought in the month of the estimated date of delivery. Pregnancy outcomes were stratified by the trimester of exposure, with an additional stratum for preconception exposure with no subsequent administration during pregnancy; multiple exposures were classified by the earliest trimester of exposure. Gestational weeks were counted from the date of the last menstrual period. The second trimester was considered to begin at week 14, and the third trimester beginning at week 28. Pregnancy outcomes were dichotomized according to the presence or absence of birth defects and further categorized as: Live births, Spontaneous abortions (i.e., pregnancy losses), Induced abortions and Fetal deaths.
Time frame: From the date of registration until the date of documentation of pregnancy outcome (up to 10 months i.e. 28 days prior to conception till the month of estimated date of delivery)
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