<PAGE>
                                                                  EXHIBIT 10.24


                            PEDIATRIX MEDICAL GROUP

                     AMENDED AND RESTATED CREDIT AGREEMENT



                      Originally Dated as of June 27, 1996
                 As Amended and Restated as of November 1, 2000
                 As Amended and Restated as of August 14, 2001
                As Amended and Restated as of November 22, 2002

                                Amendment No. 4

                           Dated as of April 21, 2003



                     FLEET NATIONAL BANK, AGENT AND LENDER
          U.S. BANK NATIONAL ASSOCIATION, SYNDICATION AGENT AND LENDER
                 HSBC BANK USA, DOCUMENTATION AGENT AND LENDER
                        FLEET SECURITIES, INC., ARRANGER


<PAGE>
                             AMENDMENT NUMBER 4 TO
                     AMENDED AND RESTATED CREDIT AGREEMENT

                           Dated as of April 21, 2003


         This agreement, dated as of April 21, 2003 (this "Amendment"), is
among Pediatrix Medical Group, Inc., a Florida corporation, the Material
Related Entities of Pediatrix Medical Group, Inc. from time to time party
hereto, and the Lenders from time to time party hereto including Fleet National
Bank, formerly known as The First National Bank of Boston, both in its capacity
as a Lender and in its capacity as an Agent, U.S. Bank National Association,
formerly known as Firstar Bank N.A., both in its capacity as a Lender and in
its capacity as Syndication Agent, and HSBC Bank USA, both in its capacity as a
Lender and in its capacity as Documentation Agent. The parties agree as
follows:

         1.       Credit Agreement; Definitions.

                  1.1.     Credit Agreement. This Amendment amends the Credit
         Agreement originally dated as of June 27, 1996, as amended and
         restated as of November 1, 2000, as further amended and restated as of
         August 14, 2001, as amended as of August 29, 2001, as amended as of
         June 28, 2002 and as further amended as of November 22, 2002 among the
         parties hereto (as in effect prior to giving effect to this Amendment,
         the "Credit Agreement").

                  1.2.     Definitions. Terms used in this Amendment but not
         defined herein are used as defined in the Credit Agreement.

         2.       Amendments. Effective upon the date hereof, the Credit
Agreement is amended as follows:

                  2.1.     Section 6.10. Section 6.10 of the Credit Agreement
         is hereby amended to read in its entirety as follows:

                           "6.10. Distributions. None of the Borrowers shall
                  make any Distribution except the following: (i) Distributions
                  in respect of the redemption of capital stock of the Company
                  from employees of any Borrower; provided, however, that the
                  amount of all such Distributions shall not exceed $500,000 in
                  the aggregate in any fiscal year; (ii) other Distributions in
                  respect of the redemption of capital stock of the Company;
                  provided, however, that the amount of all such Distributions
                  shall not exceed $150,000,000 in the aggregate during the
                  lifetime of this agreement; (iii) Distributions to the
                  Company by its Subsidiaries; (iv) regularly scheduled
                  payments of interest to the holders of the Subordinated Notes
                  in accordance with the terms of such Subordinated Notes; and
                  (v) regularly scheduled payments of interest to the holders
                  of Approved Subordinated Debt or Approved Contingent Debt in
                  accordance with the terms of such Approved Subordinated Debt
                  or Approved Contingent Debt."


                                      -1-
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         3.       Representation and Warranty. In order to induce the Agent and
the Lenders to enter into this Amendment, each of the Obligors jointly and
severally represents and warrants that, after giving effect to this Amendment,
no Default exists.

         4.       Payment of Agent's Legal Expenses. Upon or prior to the
effectiveness of this Amendment, each of the Borrowers jointly and severally
agrees to pay the reasonable legal fees and expenses of the Agent with respect
to this Amendment and the transactions contemplated hereby.

         5.       Miscellaneous. The Credit Agreement as amended by this
Amendment (the "Amended Credit Agreement") and all of the Credit Documents are
each confirmed as being in full force and effect. This Amendment, the Amended
Credit Agreement and the other Credit Documents referred to herein or therein
constitute the entire understanding of the parties with respect to the subject
matter hereof and thereof and supersede all prior and current understandings
and agreements, whether written or oral. Each of this Amendment and the Amended
Credit Agreement is a Credit Document and may be executed in any number of
counterparts, which together shall constitute one instrument, and shall bind
and inure to the benefit of the parties and their respective successors and
assigns, including as such successors and assigns all holders of any Credit
Obligation. This Amendment shall be governed by and construed in accordance
with the laws (other than the conflict of law rules) of The Commonwealth of
Massachusetts.


            [The remainder of this page intentionally left blank.]


                                      -2-
<PAGE>
                                     Amendment No. 4 to Pediatrix Medical Group
                                          Amended and Restated Credit Agreement


         IN WITNESS WHEREOF, each of the undersigned has duly executed this
Amendment (or caused this Amendment to be executed on its behalf by its officer
or representative thereunto duly authorized) under seal as of the date first
written above.


                           PEDIATRIX MEDICAL GROUP, INC. (Florida)


                           By: /s/ Karl B. Wagner
                               ------------------------------------------------
                               Karl B. Wagner, Chief Financial Officer


                           ALASKA NEONATOLOGY ASSOCIATES, INC.
                           AUGUSTA NEONATOLOGY ASSOCIATES, P.C.
                           DES MOINES PERINATAL CENTER, P.C.
                           FOOTHILL MEDICAL GROUP, INC.
                           FORT WORTH NEONATAL ASSOCIATES, P.A.
                           OBSTETRIX MEDICAL GROUP OF CALIFORNIA, A
                                PROFESSIONAL CORPORATION
                           MAGELLA HEALTHCARE GROUP, L.P.
                           MAGELLA MEDICAL ASSOCIATES, P.A.
                           MAGELLA MEDICAL ASSOCIATES OF GEORGIA, P.C.
                           MAGELLA MEDICAL ASSOCIATES MIDWEST, P.C.
                           MAGELLA MEDICAL GROUP, INC. (d/b/a MAGELLA
                                MEDICAL GROUP, A MEDICAL CORPORATION)
                           MAGELLA NEVADA, LLC
                           MAGELLA TEXAS, LLC
                           MARCIA J. PERNOLL, M.D. PROF. CORP. d/b/a OBSTETRIX
                                MEDICAL GROUP OF NEVADA, LTD.
                           MOUNTAIN STATES NEONATOLOGY, INC.
                           NEONATAL AND PEDIATRIC INTENSIVE CARE
                                MEDICAL GROUP, INC.
                           NEONATOLOGY ASSOCIATES, P.A.
                           NEONATOLOGY-CARDIOLOGY ASSOCIATES, P.A.
                           NEWBORN SPECIALISTS, P.C.
                           OBSTETRIX MEDICAL GROUP OF COLORADO, P.C.
                           OBSTETRIX MEDICAL GROUP OF KANSAS AND
                                MISSOURI, P.A.
                           OBSTETRIX MEDICAL GROUP OF TEXAS, P.A.
                           OZARK NEONATAL ASSOCIATES, INC.


                           By: /s/ Karl B. Wagner
                               ------------------------------------------------
                               Karl B. Wagner, Attorney-in-Fact


<PAGE>
                                     Amendment No. 4 to Pediatrix Medical Group
                                          Amended and Restated Credit Agreement


                           PEDIATRIX MEDICAL GROUP OF ARKANSAS, P.A.
                           PEDIATRIX MEDICAL GROUP OF CALIFORNIA, A
                                PROFESSIONAL CORPORATION
                           PEDIATRIX MEDICAL GROUP OF COLORADO, P.C.
                           PEDIATRIX MEDICAL GROUP OF GEORGIA, P.C.
                           PEDIATRIX MEDICAL GROUP OF INDIANA, P.C.
                           PEDIATRIX MEDICAL GROUP OF KANSAS, P.A.
                           PEDIATRIX MEDICAL GROUP OF MISSOURI, P.C.
                           PEDIATRIX MEDICAL GROUP OF OKLAHOMA, P.C.
                           PEDIATRIX MEDICAL GROUP OF PENNSYLVANIA, P.C.
                           PEDIATRIX MEDICAL GROUP OF PUERTO RICO, P.S.C.
                           PEDIATRIX MEDICAL GROUP OF TEXAS, P.A.
                           PEDIATRIX MEDICAL GROUP NEONATOLOGY AND
                                PEDIATRIC INTENSIVE CARE SPECIALISTS
                                OF NEW YORK, P.C.
                           PEDIATRIX MEDICAL GROUP
                           PEDIATRIX OF MARYLAND, P.A.
                           PERINATAL PEDIATRICS, P.A.
                           PERNOLL MEDICAL GROUP OF NEVADA, LTD.
                                d/b/a PEDIATRIX MEDICAL GROUP OF NEVADA
                           SAVANNAH NEONATOLOGY, INC.
                           ST. JOSEPH NEONATOLOGY CONSULTANTS, P.A.
                           TEXAS MATERNAL FETAL MEDICINE, P.A.


                           By: /s/ Karl B. Wagner
                               ------------------------------------------------
                               Karl B. Wagner, Attorney-in-Fact


                           PEDIATRIX MEDICAL GROUP OF OHIO CORP.


                           By: /s/ Karl B. Wagner
                               ------------------------------------------------
                               Karl B. Wagner, Secretary


<PAGE>
                                     Amendment No. 4 to Pediatrix Medical Group
                                          Amended and Restated Credit Agreement


                           ASSOCIATES IN NEONATOLOGY, INC.
                           BNA ACQUISITION COMPANY, INC.
                           CENTRAL OKLAHOMA NEONATOLOGY
                                ASSOCIATES, INC.
                           FLORIDA REGIONAL NEONATAL ASSOCIATES, P.A.
                           GNPA ACQUISITION COMPANY, INC.
                           MAGELLA HEALTHCARE CORPORATION
                           MNPC ACQUISITION COMPANY, INC.
                           NACF ACQUISITION COMPANY, INC.
                           NEONATAL SPECIALISTS, LTD.
                           NSPA ACQUISITION COMPANY, INC.
                           OBSTETRIX MEDICAL GROUP OF ARIZONA, P.C.
                           OBSTETRIX MEDICAL GROUP OF DELAWARE, INC.
                           OBSTETRIX MEDICAL GROUP OF PENNSYLVANIA, P.C.
                           OBSTETRIX MEDICAL GROUP OF PHOENIX, P.C.
                           OBSTETRIX MEDICAL GROUP OF
                                WASHINGTON, INC., P.S.
                           OBSTETRIX MEDICAL GROUP, INC.
                           PALM BEACH NEO ACQUISITIONS, INC.
                           PASCV ACQUISITION COMPANY, INC.
                           PEDIATRIX MEDICAL GROUP OF DELAWARE, INC.
                           PEDIATRIX MEDICAL GROUP OF FLORIDA, INC.
                           PEDIATRIX MEDICAL GROUP OF NEW MEXICO, P.C.
                           PEDIATRIX MEDICAL GROUP OF SOUTH CAROLINA, P.A.
                           PEDIATRIX MEDICAL GROUP OF TENNESSEE, P.C.
                           PEDIATRIX MEDICAL GROUP OF WASHINGTON, INC., P.S.
                           PEDIATRIX MEDICAL GROUP, INC. (Utah)
                           PEDIATRIX MEDICAL GROUP, P.A.
                           PEDIATRIX MEDICAL GROUP, P.C. (Virginia)
                           PEDIATRIX MEDICAL GROUP, P.C. (West Virginia)
                           PMG ACQUISITION CORP.
                           PNA ACQUISITION CO., INC.
                           RPNA ACQUISITION COMPANY, INC.
                           SCPMC ACQUISITION CO.
                           SNCA ACQUISITION COMPANY, INC.


                           By: /s/ Karl B. Wagner
                               ------------------------------------------------
                               Karl B. Wagner, Treasurer


<PAGE>
                                     Amendment No. 4 to Pediatrix Medical Group
                                          Amended and Restated Credit Agreement


                           FLEET NATIONAL BANK


                           By: /s/ Virginia C. Stolzenthaler
                               ------------------------------------------------
                               Virginia C. Stolzenthaler, Managing Director


<PAGE>
                                     Amendment No. 4 to Pediatrix Medical Group
                                          Amended and Restated Credit Agreement


                           U.S. BANK NATIONAL ASSOCIATION


                           By: /s/ Walker S. Choppin
                               ------------------------------------------------
                               Walker S. Choppin, Senior Vice President


<PAGE>
                                     Amendment No. 4 to Pediatrix Medical Group
                                          Amended and Restated Credit Agreement


                           HSBC BANK USA


                           By: /s/ Christopher Harrocks
                               ------------------------------------------------
                               Christopher Harrocks, Vice President


<PAGE>
                                     Amendment No. 4 to Pediatrix Medical Group
                                          Amended and Restated Credit Agreement


                           UBS AG, STAMFORD BRANCH


                           By: /s/ Wilfred V. Saint
                               ------------------------------------------------
                               Wilfred V. Saint, Associate Director
                               Banking Products Services, US


                           By: /s/ Susan Brunner
                               ------------------------------------------------
                               Susan Brunner, Associate Director
                               Banking Products Services, US


<PAGE>
                                     Amendment No. 4 to Pediatrix Medical Group
                                          Amended and Restated Credit Agreement


                           THE INTERNATIONAL BANK OF MIAMI, N.A.


                           By: /s/ Eduardo Hornero
                               ------------------------------------------------
                               Eduardo Hornero, Vice President


                           By: /s/ Jorge Maklouf
                               ------------------------------------------------
                               Jorge Maklouf, Senior Vice President