- ACTH Adrenocorticotropin hormone
- AFP Alph-afetoprotein
- AMH Anti-Müllerian hormone
- BMI Body mass index
- BV Bacterial vaginosis
- CRH Corticotropin-releasing hormone
- DHEA Dehydroepiandrosterone
- EGF Epidermal growth factor
- fFN Fetal fibronectin
- FGF Fibroblast growth factor
- GDM Gestational diabetes mellitus
- GH Growth hormone
- GnRH Gonadotropin-releasing hormone
- GTN Gestational trophoblastic neoplasia
- hCG human chorionic gonadotropin
- HELLP syndrome Hemolysis, elevated liver enzymes, and low platelets
- hPL Human placental lactogen
- IGF Insulin-like growth factor
- LH luteinizing hormone
- NSAID Nonsteroidal anti-inflammatory drug
- PDGF Platelet-derived growth factor
- PlGF Placental growth factor
- PRL Prolactin
- PROM Premature rupture of membranes
- PTB Preterm birth
- sEng Soluble endoglin
- sFlt-1 Soluble fms-like tyrosine kinase 1
- SHBG Sex hormone–binding globulin
- TRH Thyrotropin-releasing hormone
- TSH Thyroid-stimulating hormone
- VEGF Vascular endothelial growth factor
Throughout pregnancy, the fetal-placental unit secretes protein and steroid hormones that alter the function of every endocrine gland in the mother's body. Both clinically and in the laboratory, pregnancy can mimic hyperthyroidism, Cushing disease, pituitary adenoma, diabetes mellitus, polycystic ovary syndrome, and more.
The endocrine changes associated with pregnancy are adaptive, allowing the mother to nurture the developing fetus. Although maternal reserves are usually adequate, in cases of gestational diabetes or hypertensive disease of pregnancy, a woman may develop overt signs of disease as a direct result of pregnancy.
Aside from creating a satisfactory nutritive environment for fetal development, the placenta serves as an endocrine, respiratory, alimentary, and excretory organ. Measurements of fetal-placental products in the maternal serum provide one means of assessing fetal well being. This chapter will consider the changes in maternal endocrine function in pregnancy and during parturition as well as fetal endocrine development. The chapter concludes with a discussion of some endocrine disorders complicating pregnancy.
In fertile women, ovulation occurs approximately 12 to 16 days after the onset of the previous menses. The ovum must be fertilized within 24 to 48 hours if conception is to result. For about 48 hours around ovulation, cervical mucus is copious, nonviscous, slightly alkaline, and forms a gel matrix that acts as a filter and conduit for sperm. Sperm begin appearing in the outer third of the fallopian tube (the ampulla) 5 to 10 minutes after coitus and continue to migrate to this location from the cervix for about 24 to 48 hours. Of the 200 × 106 sperm that are deposited in the vaginal fornices, only approximately 200 reach the distal tube. Fertilization normally occurs in the ampulla.
Implantation and hCG Production
Embryonic invasion of the uterus occurs during a specific window of implantation 8 to 10 days after ovulation and fertilization, when the conceptus is a blastocyst. Vitronectin, an alpha-v-beta-3 integrin receptor ligand, serves as one of several links between the maternal and embryonic epithelia. The two layers of placental epithelial cells, cytotrophoblasts and syncytiotrophoblasts, develop after the blastocyst invades the endometrium (Figure 16–1). Columns of invading cytotrophoblasts anchor the ...