An observational study in Pregnancy, sponsored by International Maternal Pediatric Adolescent AIDS Clinical Trials Group. Recruiting at 9 sites in 2 countries. Open to female participants. Per ClinicalTrials.gov, last updated 2026-08-06.
Sponsored by International Maternal Pediatric Adolescent AIDS Clinical Trials Group · Observational
IMPAACT 2044 is a study to characterize the pharmacokinetics (PK) and safety of ceftriaxone and benzathine penicillin G during pregnancy. Up to 78 pregnant women receiving (1) ceftriaxone for indications other than syphilis or (2) benzathine penicillin G for treatment of syphilis from non-study clinical care providers will be enrolled at study sites located in the United States. Approximately 22 infants of pregnant participants receiving benzathine penicillin G will also be enrolled.
IMPAACT 2044 is a Phase IV, multi-site, open-label, non-randomized, opportunistic study to characterize the pharmacokinetics (PK) and safety of ceftriaxone and benzathine penicillin G during pregnancy.
The study includes two arms, with Arm 1 subdivided by route of administration:
Arm 1A: Intravenous (IV) ceftriaxone Arm 1B: Intramuscular (IM) ceftriaxone Arm 2: IM benzathine penicillin G
126 studies on the registry are indexed under Syphilis; 34 are open to participants now.
This study's planned enrollment of 110 is below the median of 400 across 39 observational studies indexed under Syphilis.
Browse Syphilis studies →International Maternal Pediatric Adolescent AIDS Clinical Trials Group is the lead sponsor of 27 studies on the registry; 3 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Women receiving or expecting to receive ceftriaxone for indications other than syphilis or benzathine penicillin G for treatment of syphilis during pregnancy in the United States (US). The infants of pregnant participants receiving benzathine penicillin G will also be enrolled.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
At screening, is receiving or expected to receive one of the following drugs under study as prescribed by a clinical care provider and documented in medical records:
Exclusion Criteria:
Has any of the following as determined by the site investigator based on pregnant participant report and available medical records:
Receipt of any of the following prohibited medications within seven days prior to entry as determined by the site investigator based on pregnant participant report and available medical records:
Arm 2: penicillin other than benzathine penicillin G
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Intravenous ceftriaxone
Drug: Ceftriaxon
Intramuscular ceftriaxone
Drug: Ceftriaxon
Intramuscular benzathine penicillin G
Drug: Benzathine penicillin G
Ceftriaxone will not be provided as part of the study. Pregnant participants will receive these drugs as prescribed outside the study by their non-study clinical care provider
Benzathine penicillin G will not be provided as part of the study. Pregnant participants will receive these drugs as prescribed outside the study by their non-study clinical care provider
Geometric mean area under the curve (AUC) during the dosing interval (AUC0-tau) in the first trimester trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Geometric mean terminal elimination half-life (t1/2) in the first trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Geometric mean trough concentration (Ctrough) in the first trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Geometric mean AUC0-tau in the second trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Geometric mean t1/2 in the second trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Geometric mean Ctrough in the second trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Geometric mean AUC0-tau in the third trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Geometric mean t1/2 in the third trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Geometric mean Ctrough in the third trimester
Arm 1A
Time frame: First on-study dose through 24 hours
Median maximum plasma concentration during the dose interval (Cmax) in the first trimester
Arm 1B
Time frame: First on-study dose through up to 24 hours
Median time to Cmax (Tmax) in the first trimester
Arm 1B
Time frame: First on-study dose through up to 24 hours
Median Cmax in the second trimester
Arm 1B
Time frame: First on-study dose through up to 24 hours
Median Tmax in the second trimester
Arm 1B
Time frame: First on-study dose through up to 24 hours
Median Cmax in the third trimester
Arm 1B
Time frame: First on-study dose through up to 24 hours
Median Tmax in the third trimester
Arm 1B
Time frame: First on-study dose through up to 24 hours
Geometric mean AUC at 7 days (AUC 0-7d) in the first trimester
Arm 2
Time frame: First on-study dose through 7 days
Geometric mean AUC at 14 days (AUC0-14d) in the first trimester
Arm 2
Time frame: First on-study dose through 14 days
Geometric mean plasma concentration at 2 hours (C2h) in the first trimester
Arm 2
Time frame: 2 hours post-first on-study dose
Geometric mean plasma concentration at 24 hours (C24h) in the first trimester
Arm 2
Time frame: 24 hours post-first on-study dose
Geometric mean plasma concentration at 4 days (C4d) in the first trimester
Arm 2
Time frame: 4 days post-first on-study dose
Geometric mean plasma concentration at 7 days (C7d) in the first trimester
Arm 2
Time frame: 7 days post-first on-study dose
Geometric mean plasma concentration at 14 days (C14d) in the first trimester
Arm 2
Time frame: 14 days post-first on-study dose
Geometric mean AUC0-7d in the second trimester
Arm 2
Time frame: First on-study dose through 7 days
Geometric mean AUC0-14d in the second trimester
Arm 2
Time frame: First on-study dose through 14 days
Geometric mean C2h in the second trimester
Arm 2 (as defined above)
Time frame: 2 hours post-first on-study dose
Geometric mean C24h in the second trimester
Arm 2 (as defined above)
Time frame: 24 hours post-first on-study dose
Geometric mean C4d in the second trimester
Arm 2 (as defined above)
Time frame: 4 days post-first on-study dose
Geometric mean C7d in the second trimester
Arm 2 (as defined above)
Time frame: 7 days post-first on-study dose
Geometric mean C14d in the second trimester
Arm 2 (as defined above)
Time frame: 14 days post-first on-study dose
Geometric mean AUC0-7d in the third trimester
Arm 2
Time frame: First on-study dose through 7 days
Geometric mean AUC0-14d in the third trimester
Arm 2
Time frame: First on-study dose through 14 days
Geometric mean C2h in the third trimester
Arm 2 (as defined above)
Time frame: 2 hours post-first on-study dose
Geometric mean C24h in the third trimester
Arm 2 (as defined above)
Time frame: 24 hours post-first on-study dose
Geometric mean C4d in the third trimester
Arm 2 (as defined above)
Time frame: 4 days post-first on-study dose
Geometric mean C7d in the third trimester
Arm 2 (as defined above)
Time frame: 7 days post-first on-study dose
Geometric mean C14d in the third trimester
Arm 2 (as defined above)
Time frame: 14 days post-first on-study dose
Proportion of participants with a maternal serious adverse event (SAE)
Arm 1A and Arm 1B
Time frame: First on-study dose through 7 days
Proportion of participants with a maternal SAE assessed as related to drug under study
Arm 1A and Arm 1B
Time frame: First on-study dose through 7 days
Proportion of participants with a maternal SAE
Arm 2
Time frame: First on-study dose through up to 28 days
Proportion of participants with a maternal SAE assessed as related to drug under study
Arm 2
Time frame: First on-study dose through up to 28 days
Proportion of participants with a spontaneous abortion or miscarriage (<20 weeks gestation)
Arm 1A, Arm1B, and Arm 2
Time frame: At pregnancy outcome/delivery/birth
Proportion of participants with a stillbirth (≥20 weeks gestation)
Arm 1A, Arm1B, and Arm 2
Time frame: At pregnancy outcome/delivery/birth
Proportion of participants with an infant small for gestational age (SGA; weight <10th percentile for gestational age, adjusted for sex)
Arm 1A, Arm1B, and Arm 2
Time frame: At pregnancy outcome/delivery/birth
Proportion of participants with a preterm birth (<37 weeks gestation)
Arm 1A, Arm1B, and Arm 2
Time frame: At pregnancy outcome/delivery/birth
Proportion of participants with an infant congenital anomaly consistent with the definition of defect provided by Metropolitan Atlanta Congenital Defects Program (MACDP)
Arm 1A, Arm1B, and Arm 2
Time frame: At pregnancy outcome/delivery/birth
Plan to share: Yes — Individual participant data that underlie results in the publication, after deidentification.
Supporting information: Study protocol, Statistical analysis plan
Time frame: Beginning 3 months following publication and available throughout period of funding of the International Maternal Pediatric Adolescent AIDS Clinical Trial (IMPAACT) Network by NIH.
Access criteria: With whom? Researchers who provide a methodologically sound proposal for use of the data that is approved by the IMPAACT Network. For what types of analyses? To achieve aims in the proposal approved by the IMPAACT Network. By what mechanism will data be made available? Researchers may submit a request for access to data using the IMPAACT "Data Request" form at: https://www.impaactnetwork.org/studies/submit-research-proposal. Researchers of approved proposals will need to sign an IMPAACT Data Use Agreement before receiving the data.
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
International Maternal Pediatric Adolescent AIDS Clinical Trials Group