RT Book, Section
A1 Posner, Glenn D.
A2 Posner, Glenn D.
A2 Black, Amanda Y.
A2 Jones, Griffith
A2 El-Chaâr, Darine
SR Print(0)
ID 1193311568
T1 The Passenger: Fetus
T2 Oxorn-Foote Human Labor & Birth, 7e
YR 2022
FD 2022
PB McGraw-Hill Education
PP New York, NY
SN 9781260019414
LK obgyn.mhmedical.com/content.aspx?aid=1193311568
RD 2024/04/25
AB Resemblance  to  the  adult  human  form  may  be  perceptible  at  the  end  of  8  weeks’  gestation  and  is  obvious  at  the  end  of  12  weeks’  gestationBy  the  end  of  12  weeks  and  sometimes  sooner,  the  sexual  differences  in  the  external  genitalia  may  be  recognized  in  abortusesQuickening  (the  perception  by  the  pregnant  woman  of  fetal  movements  in  utero)  occurs  between  the  16th  and  20th  weeks  of  pregnancy.  The  time  of  quickening  is  too  variable  to  be  of  value  in  determining  the  expected  date  of  confinement  or  when  term  has  been  reached.  Active  intestinal  peristalsis  is  the  most  common  phenomenon  mistaken  for  quickeningDepending  on  maternal  body  habitus,  the  fetal  heart  is  audible  using  a  fetal  Doppler  by  the  12th  to  13th  weeks  of  gestationThe  fetal  heart  is  audible  using  a  stethoscope  by  the  18th  or  20th  weekThe  average  length  of  the  fetus  at  term  is  50  cmWithin  wide  variations,  the  average  boy  in  Canada  (7  pounds,  15  oz  or  ~3600  g)  is  a  little  heavier  at  birth  (based  on  40  weeks’  gestational  age)  than  the  average  girl  (7  pounds,  10  oz  or  ~3500  g)In  premature  babies,  the  circumference  of  the  head  is  relatively  large  compared  with  the  shoulders.  This  fact  is  of  clinical  relevance  when  contemplating  preterm  breech  delivery.  As  the  fetus  matures,  the  body  grows  faster  than  the  head,  so  that  at  term,  the  circumferences  of  the  head  and  the  shoulders  are  nearly  the  same