How do you measure fundal height?
Woman supine w/ straight legs
Empty bladder
Measure from top of symphysis pubis to top of fundus (level of xyphoid process)
Relationship of fundal height with weeks gestation
10-20 weeks: nonpalpable to ~20cm by 20 weeks
20-30 weeks: fundal height about equal to her weeks
20-36 weeks: uterus grows ~3.5cm/month
30-43 weeks: uterine growth slows so she is between 38-40cm by term
DDx Increased Fundal Height
DDX Decreased Fundal Height
EDD
LMP + 280 days = EDD
Factors that effect accuracy of EDD calculation
When can you detect fetal heart tone with doppler?
10-12 weeks from LMP
Ultrasound and EDD
very accurate before 20 weeks, gives due date +/- 5 days
Early US around 10-12 weeks can give +/- 2 or 3 days
Multiple Gestation Types
Identical twins
1 ovum fertilized by one sperm, separates early in development into 2 or more embryos
incomplete separation results in conjoined twins
placentas usu fused w/ 2 umbilical cord, 2 amnions, 1 chorion
Greater incidence of congenital abnormalities in fraternal or identical twins?
Identical
Fraternal twins
2 or more ova fertilized by 2 or more sperm with normal division
placentas sometimes fuse, 2 chorions and 2 amnions
Factors influencing fraternal twins
Triplets
most often associated with fertility agents and in-vitro fertilization
Maternal risks of multiple gestation
Fetal risks of multiple gestation
Dx of multiple gestation: History
Dx of multiple gestation: sxs
2. rapid weight gain
Dx of multiple gestation: signs
Definitive dx of multiple gestation
US!
Triple Test
Multiple gestation test where mom may have increased bHCG, HPL, estriol
Prenatal management of multiple gestation
2. possible bedrest to prolong pregnancy
Criteria for possible hospital vaginal birth w/ multiple gestation
Macrosomia definition
Large for gestational age
>90% greater than 9lb