Assignment focus
Create pharmacology concept maps for commonly used maternal-child medications given to pregnant women and their newborns: prenatal vitamins, oxytocin, nalbuphine, Rh immune globulin, vitamin K injection and erythromycin eye ointment.
Introduction
Maternal-child nursing involves caring for two patients at once, and many medications given to the mother also affect the fetus or newborn. A few medications are given so often in prenatal clinics, labor and delivery, and the newborn nursery that every nursing student should know them well. This guide presents each drug as a concept map. The drug name and class sit at the center, linked to its indications, mechanism of action, dose and route, adverse effects, contraindications and nursing considerations.
Concept maps help students see how a drug’s mechanism explains both its intended effects and its side effects. They also help students turn drug facts into safe nursing actions at the bedside.
Medications covered in this guide
| Medication | Given to | When | Main purpose |
|---|---|---|---|
| Prenatal vitamins | Mother | Before conception → breastfeeding | Prevent neural tube defects and anemia |
| Oxytocin | Mother | Labor and immediately postpartum | Stimulate contractions; prevent and treat PPH |
| Nalbuphine | Mother | Labor | Labor pain relief |
| Rh immune globulin | Rh-negative mother | 28 weeks and within 72 h of birth | Prevent Rh alloimmunization |
| Vitamin K | Newborn | Within 6 h of birth | Prevent vitamin K deficiency bleeding |
| Erythromycin eye ointment | Newborn | Soon after birth | Prevent gonococcal eye infection |
1. Prenatal vitamins
Prenatal vitamins fill the gap between what a typical diet provides and the higher needs of pregnancy. The most important ingredient is folic acid. The neural tube closes 21–28 days after conception, often before a woman knows she is pregnant, so all people who could become pregnant are advised to take 400–800 mcg of folic acid daily (U.S. Preventive Services Task Force [USPSTF], 2023).
Indications
- Prevent neural tube defects (NTDs)
- Prevent iron-deficiency anemia in pregnancy
- Meet higher needs for folate, iron, iodine and vitamin D
- Start ≥1 month before conception; continue through breastfeeding
Mechanism of action
- Folic acid: needed for DNA synthesis and closure of the neural tube (days 21–28)
- Iron: builds hemoglobin for expanded maternal blood volume and fetal stores
- Iodine: fetal thyroid and brain development
Dose & route
- PO, 1 tablet daily
- Folic acid 400–800 mcg/day (4 mg/day if previous NTD-affected pregnancy, as prescribed)
- Iron ~27 mg; iodine ~150 mcg
Adverse effects
- Nausea, GI upset
- Constipation
- Dark/black stools (iron) – expected
- Metallic taste
Contraindications & cautions
- Hypersensitivity to ingredients
- Hemochromatosis / iron overload
- Avoid extra vitamin A (retinol) supplements – teratogenic in high doses
Nursing considerations
- Take at bedtime or with a snack if nausea occurs
- Take with vitamin C; avoid taking with milk, antacids, tea or coffee (reduce iron absorption)
- Increase fluids and fiber for constipation
- Store out of children’s reach – iron overdose is dangerous
Nursing tip: Nausea is the most common reason clients stop taking prenatal vitamins. Suggest taking the vitamin at bedtime or with a snack, or ask the provider about a chewable or gummy form. Gummies often contain no iron, so check the label.
2. Oxytocin (Pitocin)
Oxytocin is one of the most frequently used drugs in obstetrics and is classified as a high-alert medication by the Institute for Safe Medication Practices (ISMP), because dosing errors can cause serious harm to both mother and fetus. It is used to start or strengthen labor contractions and, after birth, to contract the uterus and prevent postpartum hemorrhage, the leading cause of maternal death worldwide.
Indications
- Induction or augmentation of labor
- Prevention and treatment of postpartum hemorrhage (PPH)
- Active management of the third stage of labor
Mechanism of action
- Binds oxytocin receptors in the myometrium
- Increases intracellular calcium → stronger, more frequent contractions
- Stimulates milk ejection (let-down)
- Mild antidiuretic effect
Dose & route
- Labor: IV infusion on a pump as a secondary line, e.g. 0.5–2 mU/min, increased by 1–2 mU/min every 30–60 min per protocol
- PPH: 10 units IM, or 10–40 units in 500–1,000 mL IV fluid
- Never give as an undiluted IV push
Adverse effects
- Uterine tachysystole (>5 contractions in 10 min, averaged over 30 min)
- Fetal distress: late decelerations, bradycardia
- Uterine rupture
- Water intoxication → hyponatremia, seizures
- Hypotension with rapid IV administration
Contraindications & cautions
- Non-reassuring fetal heart rate tracing
- Cephalopelvic disproportion; transverse lie
- Placenta previa or vasa previa
- Previous classical uterine incision
- Active genital herpes
Nursing considerations
- Use an infusion pump; piggyback into the primary line at the port closest to the patient
- Continuous EFM; assess contractions and FHR per protocol
- Tachysystole: stop or reduce infusion, left side-lying position, IV fluid bolus, notify provider; terbutaline as ordered
- Monitor I&O and for headache, confusion (water intoxication)
- Postpartum: assess fundal tone and lochia
Nursing tip: When a labor patient on oxytocin shows uterine tachysystole with an abnormal FHR, the first action is to stop or reduce the oxytocin infusion. Then reposition her, give an IV fluid bolus and notify the provider. Oxytocin has a short half-life (about 1–6 minutes), so stopping the infusion works quickly.
3. Nalbuphine (Nubain)
Nalbuphine is a mixed opioid agonist-antagonist often used for IV labor analgesia when a client does not want, or cannot yet have, an epidural (American College of Obstetricians and Gynecologists [ACOG], 2019). Because it blocks mu receptors, its respiratory depression has a ceiling, which makes it safer than pure opioids. The same action means it can trigger withdrawal in opioid-dependent clients.
Indications
- Moderate to severe pain during labor
- Pain after birth (short term)
- Relief of itching caused by neuraxial (epidural/spinal) opioids
Mechanism of action
- Stimulates kappa opioid receptors → analgesia and sedation
- Blocks/partially activates mu receptors → ceiling effect on respiratory depression
- Less euphoria and lower misuse potential than pure opioids
Dose & route
- 10–20 mg IV or IM every 3–6 h as ordered (labor dosing often 10 mg IV)
- IV onset 2–3 min; duration 3–6 h
- Give IV slowly over several minutes, at the start of a contraction
Adverse effects
- Sedation, dizziness, nausea/vomiting
- Maternal respiratory depression (limited by ceiling effect)
- Fetus: reduced FHR variability
- Newborn: respiratory depression if birth occurs soon after a dose
Contraindications & cautions
- Opioid dependence – can precipitate withdrawal in mother and newborn
- Hypersensitivity
- Respiratory compromise
- Birth expected imminently
Nursing considerations
- Assess pain level, vital signs (hold if RR <12) and FHR before and after the dose
- Fall precautions: bed low, side rails up, call light in reach
- Inform the neonatal team of timing of the last dose
- Have naloxone available (avoid in newborns of opioid-dependent mothers)
- Document pain relief
Nursing tip: Giving an IV opioid at the start of a contraction reduces how much reaches the fetus, because blood flow to the placenta is lower during the contraction. Always tell the neonatal team when the last dose was given if birth is approaching.
4. Rh immune globulin (RhoGAM)
When an Rh-negative mother carries an Rh-positive fetus, fetal red blood cells that enter her circulation can cause her to make anti-D antibodies (sensitization). In a later pregnancy, these antibodies cross the placenta and destroy fetal red cells, causing hemolytic disease of the fetus and newborn. Rh immune globulin prevents this sensitization (ACOG, 2017).
Indications
- Rh(D)-negative, unsensitized pregnant person
- Routinely at 28 weeks’ gestation
- Within 72 h of birth of an Rh(D)-positive infant
- After miscarriage, ectopic pregnancy, abortion, amniocentesis/CVS, abdominal trauma, bleeding or external version
Mechanism of action
- Passive anti-D antibodies attach to Rh-positive fetal red cells in the mother’s blood
- These cells are cleared before the mother’s immune system makes her own antibodies
- Prevents alloimmunization and hemolytic disease of the fetus and newborn in future pregnancies
Dose & route
- 300 mcg IM (deltoid or gluteal) – standard full dose
- Covers about 30 mL of fetal whole blood
- Kleihauer-Betke test after birth determines whether extra doses are needed for a large fetomaternal bleed
Adverse effects
- Pain and tenderness at injection site
- Low-grade fever, malaise
- Rare: hypersensitivity/anaphylaxis
- Rare hemolysis
Contraindications & cautions
- Rh(D)-positive patients
- Already sensitized (positive antibody screen/indirect Coombs)
- IgA deficiency with anti-IgA antibodies
- Never give to the newborn
- Religious objections to blood products – informed consent
Nursing considerations
- Verify maternal Rh-negative status, negative antibody screen and infant Rh-positive (negative direct Coombs)
- Two-nurse verification per facility blood-product policy
- Give within 72 h; document lot number
- Explain purpose; give a wallet card
- Live vaccines (MMR, varicella) postpartum: follow provider/ACIP guidance on timing
Nursing tip: Rh immune globulin works only before the mother is sensitized, so always confirm a negative antibody screen (indirect Coombs). ACOG (2024) now says RhIG may be skipped after abortion or pregnancy loss before 12 weeks; follow your facility’s policy.
5. Vitamin K injection (phytonadione)
Newborns are born with low vitamin K levels, which puts them at risk of vitamin K deficiency bleeding (VKDB). Late VKDB, occurring between 2 and 12 weeks of age, often presents as bleeding in the brain. A single IM dose at birth almost completely prevents it, which is why the American Academy of Pediatrics recommends it for every newborn (Hand et al., 2022).
Indications
- Prevention of vitamin K deficiency bleeding (VKDB) in the newborn
- Recommended for all newborns, including breastfed infants
Mechanism of action
- Needed by the liver to make clotting factors II, VII, IX and X
- Newborns are deficient: sterile gut (no vitamin K–producing bacteria), poor placental transfer and low levels in breast milk
Dose & route
- Single dose of 0.5–1 mg IM
- Anterolateral thigh (vastus lateralis) with a 25-gauge, 5/8-inch needle
- Give within 6 h of birth – may follow the first hour of skin-to-skin and breastfeeding
Adverse effects
- Pain, bruising or small hematoma at the site
- Rare: hypersensitivity reaction
Contraindications & cautions
- Hypersensitivity to phytonadione
- Oral vitamin K is not FDA-approved in the U.S. and is less effective than IM
- Parents who refuse: risk of late VKDB, including brain bleeding, is far higher
Nursing considerations
- Use the vastus lateralis only – not the deltoid or gluteal muscle
- Comfort measures: breastfeeding, skin-to-skin or sucrose during the injection
- Observe for bleeding from cord, circumcision or puncture sites
- Educate parents; document refusal and teaching if declined
Nursing tip: More parents are refusing the vitamin K injection. Explain in plain language that babies who do not receive vitamin K are far more likely to develop late bleeding, which can cause brain damage or death. Document the teaching and any refusal.
6. Erythromycin eye ointment 0.5%
A newborn can be exposed to Neisseria gonorrhoeae during birth, which can cause ophthalmia neonatorum, a rapidly progressing eye infection that can lead to blindness. Erythromycin 0.5% ointment is the only agent recommended for routine prophylaxis in the United States (Workowski et al., 2021), and the USPSTF (2019) gives it an “A” recommendation.
Indications
- Prevention of gonococcal ophthalmia neonatorum, which can cause corneal damage and blindness
- Required by law in most U.S. states
- Given to all newborns, including those born by cesarean
Mechanism of action
- Binds the 50S ribosomal subunit of bacteria
- Inhibits bacterial protein synthesis (bacteriostatic)
- Does not reliably prevent chlamydial conjunctivitis
Dose & route
- 1-cm ribbon into the lower conjunctival sac of each eye
- Single dose, as soon as possible after birth (may be delayed up to about 1 h for bonding)
- Single-use tube for each infant
Adverse effects
- Temporary blurred vision
- Mild chemical conjunctivitis/redness
- Eyelid swelling or irritation
Contraindications & cautions
- Hypersensitivity to erythromycin
- Do not flush the eyes after application
- Do not touch the tube tip to the eye
Nursing considerations
- Wash hands and wear gloves
- Apply from the inner to the outer canthus
- After 1 min, gently wipe off excess with sterile gauze
- Explain to parents that blurred vision is temporary and may affect eye contact
- Document time given or parental refusal
Nursing tip: Delay the eye ointment until after the first hour of skin-to-skin contact and breastfeeding (but give it within the time your facility’s protocol allows), because blurred vision can interfere with early bonding and eye contact.
Quick-reference summary
| Drug | Class | Route / timing | Priority nursing action |
|---|---|---|---|
| Prenatal vitamins | Vitamin/mineral supplement | PO daily, before conception through lactation | Teach how to take iron to reduce nausea and constipation |
| Oxytocin | Oxytocic | IV infusion on a pump (labor); IM or IV (PPH) | Monitor contractions and FHR; stop the infusion for tachysystole |
| Nalbuphine | Opioid agonist-antagonist | IV/IM during labor | Check RR and FHR; fall precautions; inform the neonatal team |
| Rh immune globulin | Immune globulin | IM at 28 weeks and within 72 h of birth | Confirm Rh-negative mother, negative antibody screen, Rh-positive baby |
| Vitamin K | Fat-soluble vitamin | IM, vastus lateralis, within 6 h of birth | Correct site and dose; educate parents |
| Erythromycin ointment | Macrolide antibiotic | Topical, both eyes, soon after birth | Inner to outer canthus; do not flush; wipe excess after 1 min |
Conclusion
Each of these six medications protects mothers and newborns at a key point in childbirth. Prenatal vitamins prevent birth defects and anemia. Oxytocin manages labor and prevents hemorrhage. Nalbuphine relieves labor pain with a built-in safety ceiling. Rh immune globulin protects future pregnancies. Vitamin K and erythromycin protect every newborn from bleeding and blindness. Concept maps link each drug’s mechanism to its effects, risks and nursing actions, which prepares nurses to give these medications safely, recognize complications early and educate families with confidence.
References
American College of Obstetricians and Gynecologists. (2009). Induction of labor (Practice Bulletin No. 107). Obstetrics & Gynecology, 114(2), 386–397.
American College of Obstetricians and Gynecologists. (2017). Prevention of Rh D alloimmunization (Practice Bulletin No. 181). Obstetrics & Gynecology, 130(2), e57–e70.
American College of Obstetricians and Gynecologists. (2019). Obstetric analgesia and anesthesia (Practice Bulletin No. 209). Obstetrics & Gynecology, 133(3), e208–e225.
American College of Obstetricians and Gynecologists. (2024). Rh D immune globulin administration after abortion or pregnancy loss at less than 12 0/7 weeks of gestation (Clinical Practice Update). Obstetrics & Gynecology.
Hand, I., Noble, L., & Abrams, S. A. (2022). Vitamin K and the newborn infant. Pediatrics, 149(3), e2021056036. https://doi.org/10.1542/peds.2021-056036
Institute for Safe Medication Practices. (2024). ISMP list of high-alert medications in acute care settings. https://www.ismp.org
U.S. Preventive Services Task Force. (2019). Ocular prophylaxis for gonococcal ophthalmia neonatorum: US Preventive Services Task Force reaffirmation recommendation statement. JAMA, 321(4), 394–398.
U.S. Preventive Services Task Force. (2023). Folic acid supplementation to prevent neural tube defects: US Preventive Services Task Force reaffirmation recommendation statement. JAMA, 330(5), 454–459.
Workowski, K. A., Bachmann, L. H., Chan, P. A., Johnston, C. M., Muzny, C. A., Park, I., Reno, H., Zenilman, J. M., & Bolan, G. A. (2021). Sexually transmitted infections treatment guidelines, 2021. MMWR Recommendations and Reports, 70(4), 1–187.