Oh gosh, Rochelle, at only 28 weeks your client should be fine. The
uterus grows a lot 32-37 weeks so the placenta should be much further
out of the way at the time of birth.
Here's an article that states 90% of placenta previa diagnosed at 20
weeks (not mere low lying placenta like your client has) resolve
spontaneously during pregnancy. I think the pictures and tables are
particularly effectively at communicating the situation. Just keep in
mind your client has low lying placenta *not* placenta previa.
http://www.aafp.org/afp/20070415/1199.html
I asked a MW apprentice friend of mine about the anterior/posterior
low lying placenta thing. She said much of it depends upon the baby's
position at time of birth but also anterior placentas tend to grow up
the uterus faster than posterior placentas.
I'm including references to two journal articles from my paper files.
If they're not available on line it should be easy enough to get
photocopies from a medical library.
HTH.
Take gentle care,
Cheryl
BJOG. 2003 Sep;110(9):860-4. Links
Placental edge to internal os distance in the late third trimester and
mode of delivery in placenta praevia.Bhide A, Prefumo F, Moore J,
Hollis B, Thilaganathan B.
Fetal Medicine Unit, Academic Department of Obstetrics and Gynaecology,
St George's Hospital Medical School, Cranmer Terrace, London SW17 0RE, UK.
OBJECTIVES: To correlate transvaginal ultrasound findings with mode of
delivery in cases of placenta praevia. DESIGN: Cohort study. SETTING:
A London Teaching Hospital. METHODS: Retrospective review of all cases
of placenta praevia diagnosed by transvaginal ultrasound between
February 1997 and March 2002.
MAIN OUTCOME MEASURES: Likelihood of vaginal delivery and major
obstetric haemorrhage.
RESULTS: A total of 121 pregnancies were studied with a mean
scan-to-delivery interval of 10.5 days. In the 64 women who laboured,
the likelihood of vaginal delivery rose significantly as the placental
edge to internal os distance increased. Caesarean section rate was 90%
when the placental edge-internal os distance was 0.1 to 2.0 cm,
falling to 37% when this measurement was over 2.0 cm (P 2 cm. The term "praevia" should be
restricted to cases where the placental edge is < or =2 cm from the
internal os, as the likelihood of operative delivery and significant
postpartum haemorrhage is high. Cases where the placenta is more than
2 cm from the internal os have a greater than 60% chance of vaginal
delivery and should be defined as "low lying" in order to reduce the
clinician's bias towards operative delivery.
Am J Obstet Gynecol. 1991 Oct;165(4 Pt 1):1036-8. Links
What is a low-lying placenta?Oppenheimer LW, Farine D, Ritchie JW,
Lewinsky RM, Telford J, Fairbanks LA.
Department of Obstetrics and Gynecology, Mount Sinai Hospital,
University of Toronto, Ontario, Canada.
Transvaginal ultrasonography was performed in 127 women thought to
have placenta previa. In all cases of complete previa, placental
location was confirmed at cesarean section. Where the placenta was
situated in the lower segment of the uterus but did not cover the
cervical os the distance from the placental edge to the internal
cervical os was measured. This distance was analyzed in relation to
the route of delivery. No patient with a placental edge greater than 2
cm from the internal cervical os required cesarean section for the
indication of placenta previa, whereas seven of eight patients with a
distance of less than or equal to 2 cm underwent cesarean section
because of bleeding characteristic of aplacenta previa. These
preliminary results suggest that transvaginal ultrasonography
measurement may indicate the optimal delivery route and make the
traditional classification of placenta previa obsolete.