Please select the eligibility criteria that correspond to the clinical trial below.
Title: Breastfeeding and Oral Contraceptives: a Randomized, Controlled Trial
Brief Summary: Objectives

To clarify the relationship between postpartum (2 weeks) use of progestin-only vs. combined oral contraceptive pills and the outcomes of breastfeeding continuation, infant growth, contraceptive method continuation, and pregnancy rates in breastfeeding women. Specific research questions:

1. To determine whether there is a difference in rates of breastfeeding continuation at 2 months and 4 months between postpartum breastfeeding women using progestin-only pills vs. combined pills.
2. To determine whether there is a difference in infant growth at 2 weeks and 8 weeks between postpartum breastfeeding women using progestin-only pills vs. combined pills.
3. To determine whether there is a difference in birth control method continuation at 2 months and 4 months between postpartum breastfeeding women using progestin-only pills vs. combined pills.

Hypothesis

Combined oral contraceptive pills, when initiated by postpartum breastfeeding women, will cause a differential in continuation of breastfeeding: 35% continuation in the combined pill group vs. 60% in the progestin-only pill group at 8 weeks.


Options:
A: Inclusion Criteria:

* Age greater than or equal to 18 years
* Greater than or equal to 24 0/7 weeks pregnant at time of enrollment
* Anticipates undergoing a vaginal delivery
* Desires to use the LNG-IUD (Mirena) for postpartum contraception
* Willing and able to sign an informed consent in English
* Willing to comply with the study protocol

Exclusion Criteria:

* Planning to undergo a scheduled cesarean section
* Allergy to either polyethylene or levonorgestrel or other contraindications to use of the LNG-IUD
* Exposure to or treatment for gonorrhea, chlamydia, or trichomoniasis during the pregnancy
* Presence of one or more leiomyomata greater than 3 centimeters in diameter
* Uterine anomaly (other than a repaired septate uterus)
* Current cervical cancer or carcinoma in-situ
* Desires repeat pregnancy within one year of delivery
B: Inclusion Criteria:

* women at the day 42th of post-partum fully breastfeeding-

Exclusion Criteria:

* baby premature
* diabetes
* blood hypertension
* not breastfeeding or partial breastfeeding
C: Inclusion Criteria: Patients on the postpartum ward at University Hospital will be offered inclusion in the study if they are:

* healthy,
* 18-40 years old,
* delivered a healthy term infant,
* intend to breastfeed,
* desire Implanon as their method of contraception, and
* agree to be randomized to early versus standard postpartum insertion.

Exclusion Criteria:

* obstetric complications including anemia with hematocrit\<30,
* transfusion,
* infection,
* severe pregnancy induced hypertension,
* prolonged hospitalization,
* coagulopathy,
* liver disease,
* undiagnosed genital bleeding,
* or other relative contraindication to Implanon® insertion (known or suspected pregnancy, known, suspected, or history of breast cancer, or hypersensitivity to any of the components in Implanon®).
* Women taking drugs that are potent inducers of hepatic enzymes will also be excluded, including barbiturates, griseofulvin, rifampin, phenylbutazone, phenytoin, carbamazepine, felbamate, oxcarbazepine, topiramate, modafinil, protease inhibitors, and herbal products including St. John's Wort.
D: Inclusion Criteria:

* able to give informed consent
* postpartum women delivering at the University of New Mexico Hospital
* Intend to breastfeed
* Plan to use oral contraceptives as her family planning method
* Willing to be randomized to either progestin-only pills or combined pills

Exclusion Criteria:

* medical contraindications to combined pills including history of thromboembolism, uncontrolled hypertension or complex migraine headaches
* preterm birth (\<37 weeks)
* small for gestational age infant (\<2500 grams)
* large for gestational age infant (\>4500 grams)
* infant with major congenital anomaly

Answer: D