Biomaterials in Obstetrics and Gynecology - Biomaterials Science: An Integrated Clinical and Engineering Approach - page 158

elastic silicone rubber shell filled with sterile saline solution or cohesive sili-
cone gel.
Ever since the beginning of breast implant use, there have been concerns
raised regarding potential damaging effects on children born of mothers
with breast implants. Whether silicone crosses the placenta has not been
evaluated in women, but there is little evidence of any elevation of blood or
serum silicon concentrations in women with silicone breast implants. There
are also no studies of teratologic effects of silicone in humans. A review of
the published literature suggests that the information is insufficient to show
definitive conclusions [19].
“A Time to Be Born”
The use of Biomaterials during labor and delivery
Labor and delivery is a natural process that we strive to keep natural.
Nevertheless, in the developed world it is usually done under medical
supervision in order to be able to provide medical assistance and to respond
promptly to complications during or after labor. As a natural process with
minimal intervention, very few biomaterials are used during labor. In this
chapter we will present one biomaterial used for induction of labor.
Induction of labor is a medical intervention meant to initiate the process
of labor in order to deliver the baby earlier than expected. Indications for
induction may include high-risk conditions in pregnancy, such as post-
term, gestational hypertensive disorders and pre-eclampsia, and diabetes.
Non-medical and sometimes controversial indications may include planned
delivery because of the patient's or doctor's wishes.
Parturition, or the initiation of labor, is a complex process involving both
maternal and fetal signals that is not fully understood. It does include a local
secretion of prostaglandins, mainly prostaglandin E2 (PGE2), in the cervix
in a process called cervical ripening . Cervical ripening includes softening,
some shortening, and initial dilatation of the cervix preparing for labor.
Prostaglandins also increase the concentration of receptors to the hormone
oxytocin in the uterine muscle to enable effective contractions.
Prostaglandins can be given directly into the cervix or vagina in a form of
gel, tablets, or a vaginal insert of controlled released PGE2 (Propess ® ). While
drugs are beyond the scope of this chapter, we will focus on a mechanical
method for cervical ripening: Laminaria .
Laminaria japonicum is a type of kelp or seaweed that is extensively culti-
vated in China, Japan, and Korea. It acts as a hygroscopic or osmotic cervical
dilator by absorbing local fluids in the cervix and expanding, thus provid-
ing controlled mechanical pressure inside the cervical canal. This, in turn,