Can Macrophage Colony-Stimulating Factor (M-CSF) Be Given During Pregnancy?
Macrophage colony-stimulating factor (M-CSF) does not need to be "given" during pregnancy as it is naturally produced at significantly elevated levels throughout gestation and plays essential physiological roles in placental development and maintenance.
Natural M-CSF Production During Pregnancy
M-CSF is endogenously produced during pregnancy and increases dramatically:
- Maternal serum M-CSF levels are markedly elevated throughout pregnancy, returning to baseline within 3 weeks after delivery 1
- Uterine M-CSF concentrations increase approximately 1,000-fold during pregnancy, with a fivefold elevation by day 5 of pregnancy 2
- Both placental and decidual tissues express M-CSF mRNA (4.7Kb) and its receptor c-fms (3.9Kb), with expression increasing as pregnancy progresses 3
- Fetal cord blood also contains high M-CSF levels, and newborn infants maintain elevated levels for weeks after birth 1
Physiological Role in Pregnancy
M-CSF serves critical functions at the maternal-fetal interface:
- M-CSF is deeply involved in local proliferation and differentiation of cells at the materno-fetal interface through autocrine and paracrine mechanisms 3
- The dramatic uterine M-CSF elevation suggests a role beyond mononuclear phagocyte regulation, potentially affecting other cell types essential for pregnancy maintenance 2
- M-CSF expression in the endometrium is regulated by synergistic action of female sex steroid hormones, as demonstrated in pseudopregnant uterus models 3
Clinical Context: Confusion with G-CSF
If your question concerns granulocyte colony-stimulating factor (G-CSF) rather than M-CSF, the answer differs significantly:
G-CSF can be safely administered during pregnancy when clinically indicated 4
- The 2023 ESMO expert consensus achieved 100% agreement that G-CSF could be used during pregnancy if clinically indicated 4
- Transplacental passage of G-CSF has been demonstrated, but pregnancy outcomes in cancer patients receiving G-CSF are comparable to those without G-CSF administration 4
- No major neurological or functional cardiological abnormalities were found in children almost 2 years after delivery in mothers who received G-CSF 4
- Studies in chronic neutropenia patients found no increased incidence of fetal death or congenital malformation 4
Important Caveat for G-CSF Use
- Neonates born to mothers who received G-CSF shortly before delivery had increased neutrophil counts compared to controls, though this appears to be a transient effect without long-term consequences 4
Bottom Line
M-CSF is naturally produced at high levels during pregnancy and serves essential physiological functions—exogenous administration is not indicated. If you meant G-CSF, it can be safely used when clinically necessary for managing chemotherapy-induced neutropenia or chronic neutropenia during pregnancy.