title: Serial transvaginal ultrasound scans and beta-human chorionic gonadotropin levels in early singleton and multiple pregnancies.
abstract: OBJECTIVE
  To determine if serum beta-hCG levels are higher in multiple gestation than in singleton pregnancy at the time of intrauterine sac visualization and the first appearance of fetal heart activity as documented by serial transvaginal ultrasound (US).
  
  
  METHODS
  Prospective analysis of serial transvaginal US findings in 19 pregnancies correlated with serum hCG levels during early gestation.
  
  
  METHODS
  Reproductive endocrinology division of the University of Arkansas for Medical Sciences, Little Rock, Arkansas.
  
  
  METHODS
  Nineteen infertility patients were studied after conceiving. Thirteen underwent IVF or GIFT, 4 received hMG therapy, 1 was treated with clomiphene citrate, and 1 pregnancy followed spontaneous ovulation.
  
  
  METHODS
  Transvaginal US and hCG levels were obtained every Monday, Wednesday, and Friday from 20 to 22 days after ovulation until the appearance of fetal heart activity.
  
  
  RESULTS
  Initial sac visualization occurred at lower serum hCG levels in singleton versus multiple pregnancies (2,180 +/- 1,170 versus 7,028 +/- 4,280 mIU/mL, mean +/- SD). Sacs were always seen when the serum hCG level (mIU/mL) was > or = 1,161 in singleton, 1,556 in twin, 3,372 in triplet, and 9,399 in quadruplet pregnancies.
  
  
  CONCLUSIONS
  Failure to observe an intrauterine sac by transvaginal US in the presence of serum hCG levels in the 1,000 to 2,000 mIU/mL range is not pathognomonic for an ectopic gestation. Clinical symptomatology, risk of multiple pregnancies, and gestational age must also be considered.
authors.affiliation: Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock 72205.
authors.forename: S C
authors.initials: SC
authors.lastname: Keith
authors.forename: S N
authors.initials: SN
authors.lastname: London
authors.forename: G A
authors.initials: GA
authors.lastname: Weitzman
authors.forename: T J
authors.initials: TJ
authors.lastname: O'Brien
authors.forename: M M
authors.initials: MM
authors.lastname: Miller
mesh_terms: D000704:Analysis of Variance; D006063:Chorionic Gonadotropin / Q000097:blood*; D018997:Chorionic Gonadotropin, beta Subunit, Human; D002996:Clomiphene / Q000627:therapeutic use; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005307:Fertilization in Vitro; D015181:Gamete Intrafallopian Transfer; D006801:Humans; D007247:Infertility, Female / Q000000981:diagnostic imaging / Q000628:therapy; D008596:Menotropins / Q000627:therapeutic use; D010060:Ovulation; D010446:Peptide Fragments / Q000097:blood*; D011247:Pregnancy / Q000502:physiology*; D011272:Pregnancy, Multiple / Q000502:physiology*; D014463:Ultrasonography; D014599:Uterus / Q000000981:diagnostic imaging*; D014621:Vagina
chemical_list: D006063:Chorionic Gonadotropin; D018997:Chorionic Gonadotropin, beta Subunit, Human; D010446:Peptide Fragments; D002996:Clomiphene; D008596:Menotropins