Last updated

Specialty OB/GYN

Tocolytics (also called anti-contraction medications or labor suppressants) are medications used to suppress premature labor (from Greek τόκος tókos, "childbirth", and λύσις lúsis, "loosening"). Preterm birth accounts for 70% of neonatal deaths. [1] Therefore, tocolytic therapy is provided when delivery would result in premature birth, postponing delivery long enough for the administration of glucocorticoids, which accelerate fetal lung maturity but may require one to two days to take effect.


Commonly used tocolytic medications include β2 agonists, calcium channel blockers, NSAIDs, and magnesium sulfate. These can assist in delaying preterm delivery by suppressing uterine muscle contractions and their use is intended to reduce fetal morbidity and mortality associated with preterm birth. [2] The suppression of contractions is often only partial and tocolytics can only be relied on to delay birth for a matter of days. Depending on the tocolytic used, the pregnant woman or fetus may require monitoring (e.g., blood pressure monitoring when nifedipine is used as it reduces blood pressure; cardiotocography to assess fetal well-being). In any case, the risk of preterm labor alone justifies hospitalization.


Tocolytics are used in preterm labor, which refers to when a baby is born too early before 37 weeks of pregnancy. As preterm birth represents one of the leading causes of neonatal morbidity and mortality, the goal is to prevent neonatal morbidity and mortality through delaying delivery and increasing gestational age by gaining more time for other management strategies like corticosteroids therapy that may help with fetus lung maturity. [3] [4] Tocolytics are considered for women with confirmed preterm labor between 24 and 34 weeks of gestation age and used in conjunction with other therapies that may include corticosteroids administration, fetus neuroprotection, and safe transfer to facilities. [5]

Types of agents

There is no clear first-line tocolytic agent. [6] [7] Current evidence suggests that first line treatment with β2 agonists, calcium channel blockers, or NSAIDs to prolong pregnancy for up to 48 hours is the best course of action to allow time for glucocorticoid administration. [1]

Various types of agents are used, with varying success rates and side effects. Some medications are not specifically approved by the U.S. Food and Drug Administration (FDA) for use in stopping uterine contractions in preterm labor, instead being used off-label.[ citation needed ]

According to a 2022 Cochrane review, the most effective tocolytics for delaying preterm birth by 48 hours, and 7 days were the nitric oxide donors, calcium channel blockers, oxytocin receptor antagonists and combinations of tocolytics. [8]

DrugMechanism of actionDescriptionPossible
Maternal side effectsFetal and neonatal side effects
Terbutaline (Brethine) β2 agonist Off-label use, FDA has advised that injectable terbutaline should only be used in urgent situations, and that the oral form of the drug should never be used [9] Cardiac tachyarrhythmias, poorly controlled diabetes mellitus, hyperthyroidism, prolonged tocolysis(>48 to 72 hours) [1] Tachycardia, palpitations, hypotension, dyspnea, chest pain, hypokalemia, hyperglycemia, lipolysis, pulmonary edema, myocardial ischemia [10] Fetal tachycardia, hyperinsulinemia, hypoglycemia, myocardial and septal hypertrophy, myocardial ischemia [11]
Ritodrine (Yutopar) β2 agonist No longer FDA approved [12] Poorly controlled thyroid disease, hypertension, and diabetes [13] Metabolic hyperglycemia, hyperinsulinemia, hypokalemia, antidiuresis, altered thyroid function, physiologic tremor, palpitations, nervousness, nausea or vomiting, fever, hallucinations [14] Neonatal tachycardia, hypoglycemia, hypocalcemia, hyperbilirubinemia, hypotension, intraventricular hemorrhage [14]
Fenoterol β2 agonist Not approved for tocolysis by FDA Diabetes, tachyarrhythmia, hypertrophic obstructive cardiomyopathy, hypersensitivity to fenoterol [15] Palpitations, tachycardia, and chest pain [16] Tachycardia, [17] impaired carbohydrate tolerance, hyperinsulinaemia [18]
Salbutamol (INN) or albuterol (USAN) β2 agonist Shown to be less effective than nifedipine for tocolysis regarding neonatal outcome [19] Diabetes, ischemic cardiopathy, cardiac arrhythmia, placenta praevia, hyperthyroidism, hypersensitivity to salbutamol (albuterol) [20] [21] Headache, palpitations, tachycardia, tremor, sweating, and shortness of breath [22] Fetal tachycardia, hypoglycemia, hyperinsulinaemia [22]
Hexoprenaline (Gynipral) β2 agonist Not FDA approved Hyperthyroidism, cardiovascular diseases, glaucoma, placental abruption, vaginal bleeding, inflammatory diseases of internal genitalia, 1st trimester of pregnancy, breastfeeding [23] [24] Vertigo, anxiety, tremor, hyperhidrosis, tachycardia, hypotension, hyperglycemia, edema Hypoglycemia, bronchospasm, anaphylactic shock [24]
Nifedipine (Procardia, Adalat) Ca2+ channel blocker Is one of the most commonly used tocolytic agents. [25] Hypotension, preload-dependent cardiac disease. [26] It should not be used concomitantly with magnesium sulfate [27] Flushing, headache, dizziness, nausea, transient hypotension. Administration of calcium channel blockers should be used with care in patients with renal disease and hypotension. Concomitant use of calcium channel blockers and magnesium sulfate may result in cardiovascular collapse [28] Calcium channel blockers have the fewest neonatal adverse effects [5]
Atosiban Oxytocin receptor antagonistSafer than both nifedipine and beta agonists; As effective as nifedipine and more effective than beta agonists. [29] Fewer side effects than β2 agonists. [30] Although not FDA approved in the US, atosiban was developed specifically to delay preterm labor. [31] No current contraindicationsNo maternal adverse effects [32] No adverse effects to the baseline fetal heart rate. No significant difference in neonatal side effect compared to other treatments [32]
Indomethacin NSAID Shown to effectively delay premature birth, studies show that it is safer and more effective for pregnant women that are <= 32 weeks of gestation [33] Late pregnancy (ductus arteriosus), significant renal or hepatic impairment [34] Nausea, heartburn [35] Constriction of ductus arteriosus, pulmonary hypertension, reversible decrease in renal function with oligohydramnios, intraventricular hemorrhage, hyperbilirubinemia, necrotizing enterocolitis [36]
Sulindac NSAID Studies show that it has similar efficacy to that of indomethacin and has a milder effect on the fetal ductus arteriousus [37] Coagulation disorders or thrombocytopenia, NSAID-sensitive asthma, other sensitivity to NSAID [38] GI complications such as nausea, vomiting and stomach pain due to COX inhibition [39] NSAIDs have been shown to be associated with constriction of the ductus arteriousus and oligohydramnios [34]
Magnesium sulfate [40] Myosin light chain inhibitorProbably effective in delaying preterm birth by 48 hours. [8] It is used for its neuro-protective effects since it is shown to decrease the risk of cerebral palsy in infants. [41] Absolute contraindication: myasthenia gravis. [42] Use as a tocolytic agent may result in death of the fetus or infant. [40] Flushing, lethargy, headache, muscle weakness, diplopia, dry mouth, pulmonary edema, cardiac arrest [42] Lethargy, hypotonia, respiratory depression, demineralization with prolonged use [42]
Ethanol GABAA receptor PAM Shown to be ineffective: no better than placebo. [22] Source revision needed Was a frequently used tocolytic in the mid-20th century, but later double-blind studies [43] found it was not effective.Pregnancy: no amount of ethanol is safe to the fetus [44] Intoxication, withdrawal [22] Fetal alcohol syndrome: ethanol is a teratogen and can harm fetus [44]

Calcium-channel blockers (such as nifedipine) and oxytocin antagonists (such as atosiban) may delay delivery by 2 to 7 days, depending on how quickly the medication is administered. [45] NSAIDs (such as indomethacin) and calcium channel blockers (such as nifedipine) are the most likely to delay delivery for 48 hours, with the least amount of maternal and neonatal side effects. [46] Otherwise, tocolysis is rarely successful beyond 24 to 48 hours because current medications do not alter the fundamentals of labor activation. [47] However, postponing premature delivery by 48 hours appears sufficient to allow pregnant women to be transferred to a center specialized for management of preterm deliveries, and thus administer corticosteroids for the possibility to reduce neonatal organ immaturity. [46]

The efficacy of β-adrenergic agonists, atosiban, and indomethacin is a decreased odds ratio (OR) of delivery within 24 hours of 0.54 (95% confidence interval (CI): 0.32-0.91) and 0.47 within 48 hours (OR 0.47, 95% CI: 0.30-0.75). [6]

Antibiotics were thought to delay delivery, but no studies have shown any evidence that using antibiotics during preterm labor effectively delays delivery or reduces neonatal morbidity. [41] Antibiotics are used in people with premature rupture of membranes, but this is not characterized as tocolysis. [48]

Contraindications to tocolytics

In addition to drug-specific contraindications, [41] several general factors may contraindicate delaying childbirth with the use of tocolytic medications.

Future direction of tocolytics

Most tocolytics are currently being used off-label. The future direction of the development of tocolytics agents should be directed toward better efficacy in intentionally prolonging pregnancy. This will potentially result in less maternal, fetal, and neonatal adverse effects when delaying preterm childbirth. A few tocolytic alternatives worth pursuing include Barusiban, a last generation of oxytocin receptor antagonists, as well as COX-2 inhibitors. [50] More studies on the use of multiple tocolytics must be directed to research overall health outcomes rather than solely pregnancy prolongation. [51]

See also

Related Research Articles

<span class="mw-page-title-main">Childbirth</span> Expulsion of a fetus from the pregnant mothers uterus

Childbirth, also known as labour, parturition and delivery, is the completion of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million human births globally. In the developed countries, most deliveries occur in hospitals, while in the developing countries most are home births.

<span class="mw-page-title-main">Terbutaline</span> Chemical compound

Terbutaline, sold under the brand names Bricanyl and Marex among others, is a β2 adrenergic receptor agonist, used as a "reliever" inhaler in the management of asthma symptoms and as a tocolytic to delay preterm labor for up to 48 hours. This time can then be used to administer steroid injections to the mother which help fetal lung maturity and reduce complications of prematurity. It should not be used to prevent preterm labor or delay labor more than 48–72 hours. In February 2011, the Food and Drug Administration began requiring a black box warning on the drug's label. Pregnant women should not be given injections of the drug terbutaline for the prevention of preterm labor or for long-term management of preterm labor, and should not be given oral terbutaline for any type of prevention or treatment of preterm labor "due to the potential for serious maternal heart problems and death."

<span class="mw-page-title-main">Preterm birth</span> Birth at less than a specified gestational age

Preterm birth, also known as premature birth, is the birth of a baby at fewer than 37 weeks gestational age, as opposed to full-term delivery at approximately 40 weeks. Extreme preterm is less than 28 weeks, very early preterm birth is between 28 and 32 weeks, early preterm birth occurs between 32 and 34 weeks, late preterm birth is between 34 and 36 weeks' gestation. These babies are also known as premature babies or colloquially preemies or premmies. Symptoms of preterm labor include uterine contractions which occur more often than every ten minutes and/or the leaking of fluid from the vagina before 37 weeks. Premature infants are at greater risk for cerebral palsy, delays in development, hearing problems and problems with their vision. The earlier a baby is born, the greater these risks will be.

<span class="mw-page-title-main">Misoprostol</span> Medication to induce abortion and treat ulcers

Misoprostol is a synthetic prostaglandin medication used to prevent and treat stomach and duodenal ulcers, induce labor, cause an abortion, and treat postpartum bleeding due to poor contraction of the uterus. It is taken by mouth when used to prevent gastric ulcers in people taking nonsteroidal anti-inflammatory drugs (NSAID). For abortions it is used by itself or in conjunction with mifepristone or methotrexate. By itself, effectiveness for abortion is between 66% and 90%. For labor induction or abortion, it is taken by mouth, dissolved in the mouth, or placed in the vagina. For postpartum bleeding it may also be used rectally.

<span class="mw-page-title-main">External cephalic version</span> Process by which a breech baby can sometimes be turned from buttocks or foot first to head first

External cephalic version (ECV) is a process by which a breech baby can sometimes be turned from buttocks or foot first to head first. It is a manual procedure that is recommended by national guidelines for breech presentation of a pregnancy with a single baby, in order to enable vaginal delivery. It is usually performed late in pregnancy, that is, after 36 gestational weeks, preferably 37 weeks, and can even be performed in early labour.

Labor induction is the process or treatment that stimulates childbirth and delivery. Inducing (starting) labor can be accomplished with pharmaceutical or non-pharmaceutical methods. In Western countries, it is estimated that one-quarter of pregnant women have their labor medically induced with drug treatment. Inductions are most often performed either with prostaglandin drug treatment alone, or with a combination of prostaglandin and intravenous oxytocin treatment.

<span class="mw-page-title-main">Indometacin</span> Anti-inflammatory drug

Indometacin, also known as indomethacin, is a nonsteroidal anti-inflammatory drug (NSAID) commonly used as a prescription medication to reduce fever, pain, stiffness, and swelling from inflammation. It works by inhibiting the production of prostaglandins, endogenous signaling molecules known to cause these symptoms. It does this by inhibiting cyclooxygenase, an enzyme that catalyzes the production of prostaglandins.

<span class="mw-page-title-main">Atosiban</span> Chemical compound

Atosiban, sold under the brand name Tractocile among others, is an inhibitor of the hormones oxytocin and vasopressin. It is used as an intravenous medication as a labour repressant (tocolytic) to halt premature labor. It was developed by Ferring Pharmaceuticals in Sweden and first reported in the literature in 1985. Originally marketed by Ferring Pharmaceuticals, it is licensed in proprietary and generic forms for the delay of imminent preterm birth in pregnant adult women.

<span class="mw-page-title-main">Prelabor rupture of membranes</span> Medical condition

Prelabor rupture of membranes (PROM), previously known as premature rupture of membranes, is breakage of the amniotic sac before the onset of labor. Women usually experience a painless gush or a steady leakage of fluid from the vagina. Complications in the baby may include premature birth, cord compression, and infection. Complications in the mother may include placental abruption and postpartum endometritis.

<span class="mw-page-title-main">Cervical effacement</span>

Cervical effacement or cervical ripening refers to the thinning and shortening of the cervix. This process occurs during labor to prepare the cervix for dilation to allow the fetus to pass through the vagina. While this a normal, physiological process that occurs at the later end of pregnancy, it can also be induced through medications and procedures.

<span class="mw-page-title-main">Cervical cerclage</span> Obstetrics medical procedure

Cervical cerclage, also known as a cervical stitch, is a treatment for cervical weakness, when the cervix starts to shorten and open too early during a pregnancy causing either a late miscarriage or preterm birth. In women with a prior spontaneous preterm birth and who are pregnant with one baby, and have shortening of the cervical length less than 25 mm, a cerclage prevents a preterm birth and reduces death and illness in the baby.

Antenatal steroids, also known as antenatal corticosteroids, are medications administered to pregnant women expecting a preterm birth. When administered, these steroids accelerate the maturation of the fetus' lungs, which reduces the likelihood of infant respiratory distress syndrome and infant mortality. The effectiveness of this corticosteroid treatment on humans was first demonstrated in 1972 by Sir Graham Liggins and Ross Howie, during a randomized control trial using betamethasone.

Postterm pregnancy is when a woman has not yet delivered her baby after 42 weeks of gestation, two weeks beyond the typical 40-week duration of pregnancy. Postmature births carry risks for both the mother and the baby, including fetal malnutrition, meconium aspiration syndrome, and stillbirths. After the 42nd week of gestation, the placenta, which supplies the baby with nutrients and oxygen from the mother, starts aging and will eventually fail. Postterm pregnancy is a reason to induce labor.

<span class="mw-page-title-main">Uterine atony</span> Loss of tone in the uterine musculature

Uterine atony is the failure of the uterus to contract adequately following delivery. Contraction of the uterine muscles during labor compresses the blood vessels and slows flow, which helps prevent hemorrhage and facilitates coagulation. Therefore, a lack of uterine muscle contraction can lead to an acute hemorrhage, as the vasculature is not being sufficiently compressed. Uterine atony is the most common cause of postpartum hemorrhage, which is an emergency and potential cause of fatality. Across the globe, postpartum hemorrhage is among the top five causes of maternal death. Recognition of the warning signs of uterine atony in the setting of extensive postpartum bleeding should initiate interventions aimed at regaining stable uterine contraction.

<span class="mw-page-title-main">Postpartum bleeding</span> Loss of blood following childbirth

Postpartum bleeding or postpartum hemorrhage (PPH) is often defined as the loss of more than 500 ml or 1,000 ml of blood following childbirth. Some have added the requirement that there also be signs or symptoms of low blood volume for the condition to exist. Signs and symptoms may initially include: an increased heart rate, feeling faint upon standing, and an increased breathing rate. As more blood is lost, the patient may feel cold, blood pressure may drop, and they may become restless or unconscious. The condition can occur up to six weeks following delivery.

<span class="mw-page-title-main">Vaginal delivery</span> Delivery through the vagina

A vaginal delivery is the birth of offspring in mammals through the vagina. It is the most common method of childbirth worldwide. It is considered the preferred method of delivery, with lower morbidity and mortality than Caesarean sections (C-sections).

A uterotonic, also known as an oxytocic or ecbolic, is a type of medication used to induce contraction or greater tonicity of the uterus. Uterotonics are used both to induce labor and to reduce postpartum hemorrhage.

Amnioinfusion is a method in which isotonic fluid is instilled into the uterine cavity.

Uterine Tachysystole is a condition of excessively frequent uterine contractions during pregnancy. It is most often seen in induced or augmented labor, though it can also occur during spontaneous labor, and this may result in fetal hypoxia and acidosis. This may have serious effects on both the mother and the fetus including hemorrhaging and death. There are still major gaps in understanding treatment as well as clinical outcomes of this condition. Uterine tachysystole is defined as more than 5 contractions in 10 minutes, averaged over a 30-minute period.

<span class="mw-page-title-main">High-risk pregnancy</span> Medical condition

A high-risk pregnancy is one where the mother or the fetus has an increased risk of adverse outcomes compared to uncomplicated pregnancies. No concrete guidelines currently exist for distinguishing “high-risk” pregnancies from “low-risk” pregnancies; however, there are certain studied conditions that have been shown to put the mother or fetus at a higher risk of poor outcomes. These conditions can be classified into three main categories: health problems in the mother that occur before she becomes pregnant, health problems in the mother that occur during pregnancy, and certain health conditions with the fetus.


  1. 1 2 3 American College of Obstetricians Gynecologists' Committee on Practice Bulletins—Obstetrics (2016). "Practice Bulletin No. 171: Management of Preterm Labor". Obstetrics & Gynecology. 128 (4): e155–e164. doi:10.1097/AOG.0000000000001711. ISSN   0029-7844. PMID   27661654. S2CID   5537988.
  2. Mayer, Christopher; Apodaca-Ramos, Irasema (2021), "Tocolysis", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID   32965883 , retrieved 29 July 2021
  3. Ouzounian, Joseph G; Goodwin, T. Murphy; Paulson, Richard J; Montoro, Martin N; Muderspach, Laila I; Roy, Subir (2010). Management of Common Problems in Obstetrics and Gynecology. Blackwell Publishing Ltd. pp. 9–11. ISBN   9781444323030.
  4. Harrison, Margo S.; Goldenberg, Robert L. (2016). "Global burden of prematurity". Seminars in Fetal & Neonatal Medicine. 21 (2): 74–79. doi:10.1016/j.siny.2015.12.007. ISSN   1878-0946. PMID   26740166.
  5. 1 2 Hanley, Margaret; Sayres, Lauren; Reiff, Emily S.; Wood, Amber; Grotegut, Chad A.; Kuller, Jeffrey A. (2019). "Tocolysis: A Review of the Literature". Obstetrical & Gynecological Survey. 74 (1): 50–55. doi:10.1097/OGX.0000000000000635. ISSN   1533-9866. PMID   30648727. S2CID   58563849.
  6. 1 2 Tan TC, Devendra K, Tan LK, Tan HK (May 2006). "Tocolytic treatment for the management of preterm labour: a systematic review". Singapore Med J. 47 (5): 361–6. PMID   16645683.
  7. de Heus R, Mol BW, Erwich JJ, et al. (2009). "Adverse drug reactions to tocolytic treatment for preterm labour: prospective cohort study". BMJ. 338: b744. doi:10.1136/bmj.b744. PMC   2654772 . PMID   19264820.
  8. 1 2 Wilson, Amie; Hodgetts-Morton, Victoria A; Marson, Ella J; Markland, Alexandra D; Larkai, Eva; Papadopoulou, Argyro; Coomarasamy, Arri; Tobias, Aurelio; Chou, Doris; Oladapo, Olufemi T; Price, Malcolm J; Morris, Katie; Gallos, Ioannis D (10 August 2022). "Tocolytics for delaying preterm birth: a network meta-analysis (0924)". Cochrane Database of Systematic Reviews. 2022 (8): CD014978. doi:10.1002/14651858.CD014978.pub2. PMC   9364967 . PMID   35947046.{{cite journal}}: CS1 maint: PMC embargo expired (link)
  9. Why do doctors still use terbutaline to delay preterm labor despite its major health risks? Retrieved on October 20th, 2020
  10. Gyetvai, K.; Hannah, M. E.; Hodnett, E. D.; Ohlsson, A. (1999). "Tocolytics for preterm labor: A systematic review". Obstetrics and Gynecology. 94 (5 Pt 2): 869–877. doi:10.1016/s0029-7844(99)00329-4. PMID   10546776.
  11. Gaudet, Laura M.; Singh, Kavita; Weeks, Laura; Skidmore, Becky; Tsertsvadze, Alexander; Ansari, Mohammed T. (2012). "Effectiveness of Terbutaline Pump for the Prevention of Preterm Birth. A Systematic Review and Meta-Analysis". PLOS ONE. 7 (2): e31679. Bibcode:2012PLoSO...731679G. doi: 10.1371/journal.pone.0031679 . ISSN   1932-6203. PMC   3283660 . PMID   22363704.
  12. "Drugs@FDA: FDA-Approved Drugs".
  13. Pool, Beverly A. Von Der (1998). "Preterm Labor: Diagnosis and Treatment". American Family Physician. 57 (10): 2457–2464. ISSN   0002-838X. PMID   9614414.
  14. 1 2 Modak, Raj K. (2013). Anesthesiology Keywords Review. Lippincott Williams & Wilkins. ISBN   978-1-4511-7782-4.
  15. "Fenoterol drug information | DrugsUpdate India". Retrieved 2 August 2021.
  16. Neilson, James P.; West, Helen M.; Dowswell, Therese (5 February 2014). "Betamimetics for inhibiting preterm labour". The Cochrane Database of Systematic Reviews (2): CD004352. doi:10.1002/14651858.CD004352.pub3. ISSN   1469-493X. PMID   24500892.
  17. Verdurmen, Kim M. J.; Hulsenboom, Alexandra D. J.; van Laar, Judith O. E. H.; Oei, S. Guid (2017). "Effect of tocolytic drugs on fetal heart rate variability: a systematic review". The Journal of Maternal-Fetal & Neonatal Medicine. 30 (20): 2387–2394. doi:10.1080/14767058.2016.1249844. ISSN   1476-4954. PMID   27756155. S2CID   6900277.
  18. Drugs during pregnancy and lactation : treatment options and risk assessment. Christof Schaefer, P. W. J. Peters, Richard K. Miller (Third ed.). London, UK. 2015. ISBN   978-0-12-407901-4. OCLC   892869035.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)
  19. Tsatsaris, V (2001). "Tocolysis with nifedipine or beta-adrenergic agonists: a meta-analysis1". Obstetrics & Gynecology. 97 (5): 840–847. doi:10.1016/S0029-7844(00)01212-6. PMID   11336775.
  20. Johnson, Donavon B.; Merrell, Brigham J.; Bounds, Connor G. (2021), "Albuterol", StatPearls, Treasure Island (FL): StatPearls Publishing, PMID   29489143 , retrieved 2 August 2021
  21. Spirlet, Marina de; Treluyer, Jean-Marc; Chevret, Sylvie; Rey, Elisabeth; Tournaire, Michel; Cabrol, Dominique; Pons, Gérard (2004). Fundamental & Clinical Pharmacology. Oxford, UK: Blackwell Science Ltd. pp. 207–217.
  22. 1 2 3 4 Lamont, Ronald F.; Jørgensen, Jan S. (2019). "Safety and Efficacy of Tocolytics for the Treatment of Spontaneous Preterm Labour". Current Pharmaceutical Design. 25 (5): 577–592. doi:10.2174/1381612825666190329124214. ISSN   1873-4286. PMID   30931850. S2CID   89620227.
  23. "Gynipral (hexoprenaline) Full Prescribing Information". Russian State Register of Medicinal Products (in Russian). Nycomed Austria GmbH. St. Peter-Straße 25, A-4020, Linz, Austria. Retrieved 19 March 2016.
  24. 1 2 "Gynipral (hexoprenaline) Tablets 0.5 mg, Solution for Intravenous Infusion 5 μg/mL (0.0005%)". "RLS" (РЛС): Russian Register of Medical Products (in Russian). Retrieved 19 March 2016.
  25. Welcome to the Women's – The Royal Women's Hospital Victoria Australia
  26. "Nifedipine Monograph for Professionals -". 2015. Archived from the original on 25 December 2015.
  27. Koontz, Stephanie L.; Friedman, Steven A.; Schwartz, Martin L. (2004). "Symptomatic hypocalcemia after tocolytic therapy with magnesium sulfate and nifedipine". American Journal of Obstetrics and Gynecology. 190 (6): 1773–1776. doi:10.1016/j.ajog.2004.02.050. ISSN   0002-9378. PMID   15284796.
  28. Davis, W. B.; Wells, S. R.; Kuller, J. A.; Thorp, J. M. (March 1997). "Analysis of the risks associated with calcium channel blockade: implications for the obstetrician-gynecologist". Obstetrical & Gynecological Survey. 52 (3): 198–201. doi:10.1097/00006254-199703000-00023. ISSN   0029-7828. PMID   9061722.
  29. Lyndrup, Jens; Lamont, Ronald F (2007). "The choice of a tocolytic for the treatment of preterm labor: a critical evaluation of nifedipine versus atosiban". Expert Opinion on Investigational Drugs. 16 (6): 843–853. doi:10.1517/13543784.16.6.843. ISSN   1354-3784. PMID   17501696. S2CID   1012738.
  30. Flenady, Vicki; Reinebrant, Hanna E; Liley, Helen G; Tambimuttu, Eashan G; Papatsonis, Dimitri NM (2014). Cochrane Pregnancy and Childbirth Group (ed.). "Oxytocin receptor antagonists for inhibiting preterm labour". Cochrane Database of Systematic Reviews (6): CD004452. doi:10.1002/14651858.CD004452.pub3. PMID   24903678.
  31. Neilson, J. P. (2007). "Oxytocin Receptor Antagonists for Inhibiting Preterm Labour". Obstetrics & Gynecology. 110 (1): 180–181. doi:10.1097/01.AOG.0000269669.34758.4e. ISSN   0029-7844. PMID   17601917. S2CID   35984198.
  32. 1 2 Tsatsaris, Vassilis; Carbonne, Bruno; Cabrol, Dominique (2004). "Atosiban for Preterm Labour". Drugs. 64 (4): 375–382. doi:10.2165/00003495-200464040-00003. ISSN   0012-6667. PMID   14969573. S2CID   946463.
  33. Macones, George A.; Robinson, Charlah A. (1997). "Is there justification for using indomethacin in preterm labor? An analysis of neonatal risks and benefits". American Journal of Obstetrics and Gynecology. 177 (4): 819–824. doi:10.1016/S0002-9378(97)70275-8. PMID   9369826.
  34. 1 2 Loudon, Jenifer A. Z.; Groom, Kate M.; Bennett, Philip R. (2003). "Prostaglandin inhibitors in preterm labour". Best Practice & Research. Clinical Obstetrics & Gynaecology. 17 (5): 731–744. doi:10.1016/s1521-6934(03)00047-6. ISSN   1521-6934. PMID   12972011.
  35. "Indomethacin Side Effects: Common, Severe, Long Term". Retrieved 30 July 2021.
  36. Management of high-risk pregnancy : a practical approach. S. S. Trivedi, Manju, MD Puri, Swati Agrawal (Second ed.). New Delhi. 2016. ISBN   978-93-5250-046-8. OCLC   946116669.{{cite book}}: CS1 maint: location missing publisher (link) CS1 maint: others (link)
  37. Räsänen, Juha; Jouppila, Pentti (1995). "Fetal cardiac function and ductus arteriosus during indomethacin and sulindac therapy for threatened preterm labor: A randomized study". American Journal of Obstetrics and Gynecology. 173 (1): 20–25. doi:10.1016/0002-9378(95)90163-9. ISSN   0002-9378. PMID   7631682.
  38. Stevenson, Donald D. (2004). "Aspirin and NSAID sensitivity". Immunology and Allergy Clinics of North America. 24 (3): 491–505, vii. doi:10.1016/j.iac.2004.03.001. ISSN   0889-8561. PMID   15242723.
  39. Castellsague, Jordi; Riera-Guardia, Nuria; Calingaert, Brian; Varas-Lorenzo, Cristina; Fourrier-Reglat, Annie; Nicotra, Federica; Sturkenboom, Miriam; Perez-Gutthann, Susana; Safety of Non-Steroidal Anti-Inflammatory Drugs (SOS) Project (1 December 2012). "Individual NSAIDs and upper gastrointestinal complications: a systematic review and meta-analysis of observational studies (the SOS project)". Drug Safety. 35 (12): 1127–1146. doi:10.2165/11633470-000000000-00000. ISSN   1179-1942. PMC   3714137 . PMID   23137151.
  40. 1 2 Crowther, CA; Brown, J; McKinlay, CJ; Middleton, P (2014). "Magnesium sulphate for preventing preterm birth in threatened preterm labour". The Cochrane Database of Systematic Reviews (8): CD001060. doi: 10.1002/14651858.CD001060.pub2 . PMID   25126773.
  41. 1 2 3 4 5 6 Rundell, Kristen; Panchal, Bethany (2017). "Preterm Labor: Prevention and Management". American Family Physician. 95 (6): 366–372. ISSN   0002-838X. PMID   28318214.
  42. 1 2 3 William G. Sayres, Jr (2010). "Preterm Labor". American Family Physician. 81 (4): 477–484. ISSN   0002-838X. PMID   20148502.
  43. Castrén O, Gummerus M, Saarikoski S (1975). "Treatment of imminent premature labour". Acta Obstet Gynecol Scand. 54 (2): 95–100. doi:10.3109/00016347509156739. PMID   1094787. S2CID   22685586.
  44. 1 2 "Committee opinion no. 496: At-risk drinking and alcohol dependence: obstetric and gynecologic implications". Obstetrics and Gynecology. 118 (2 Pt 1): 383–388. 2011. doi:10.1097/AOG.0b013e31822c9906. ISSN   1873-233X. PMID   21775870. S2CID   205474115.
  45. Iams JD, Romero R, Culhane JF, Goldenberg RL (2008). "Primary, secondary, and tertiary interventions to reduce the morbidity and mortality of preterm birth". The Lancet . 371 (9607): 164–175. doi:10.1016/S0140-6736(08)60108-7. PMID   18191687. S2CID   8204299.
  46. 1 2 Haas, David M; Caldwell, Deborah M; Kirkpatrick, Page; McIntosh, Jennifer J; Welton, Nicky J (2012). "Tocolytic therapy for preterm delivery: systematic review and network meta-analysis". The BMJ. 345: e6226. doi:10.1136/bmj.e6226. ISSN   0959-8138. PMC   4688428 . PMID   23048010.
  47. Simhan HN, Caritis SN (2007). "Prevention of Preterm Delivery". New England Journal of Medicine . 357 (5): 477–487. doi:10.1056/NEJMra050435. PMID   17671256.
  48. Kenyon, Sara; Boulvain, Michel; Neilson, James P. (2 December 2013). "Antibiotics for preterm rupture of membranes". The Cochrane Database of Systematic Reviews (12): CD001058. doi:10.1002/14651858.CD001058.pub3. ISSN   1469-493X. PMID   24297389.
  49. 1 2 3 4 5 6 7 8 9 10 11 Wong, D. L.; Perry, S. E.; Hockenberry, M. J.; Lowdermilk, D. L. (2002). Maternal Child Nursing Care. Mosby. ISBN   978-0-323-01399-4.
  50. Hubinont, C.; Debieve, F. (2011). "Prevention of Preterm Labour: 2011 Update on Tocolysis". Journal of Pregnancy. 2011: 941057. doi: 10.1155/2011/941057 . ISSN   2090-2727. PMC   3228310 . PMID   22175022.
  51. Cole, Stephen; Smith, Roger; Giles, Warwick (2004). "Tocolysis: current controversies, future directions". Current Opinion in Investigational Drugs. 5 (4): 424–429. ISSN   1472-4472. PMID   15134284.