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Size and date discrepancy of pregnancy. Facilitator: Pawin Puapornpong. Size < date. Inaccurate menstrual period Fetal growth restriction oligohydramnios. Size > date. Elevation of the uterus by a distended bladder Multifetal pregnancy
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Size and date discrepancy of pregnancy Facilitator: Pawin Puapornpong
Size < date • Inaccurate menstrual period • Fetal growth restriction • oligohydramnios
Size > date • Elevation of the uterus by a distended bladder • Multifetal pregnancy • Inaccurate menstrual history • Hydramnios • Hydatidiform mole • Uterine myomas • A closely attached adnexal mass • Fetal macrosomia (late in pregnancy, DM)
Oligohydramnios • Normally, 1L by 36 wks. • Only 100 to 200 mL (postterm) • Diminished volume : oligohydramnios • Amniotic fluid index ( AFI) < 5 cm. • Risk of cord compression, fetal distress
Early onset oligohydramnios • Obstruction of urinary tract or renal agenesis • Preterm delivery and neonatal death • Adhesions between amnion and fetal parts : deformities (amputation) • Pressure to fetus, muscle, skeletal deformities: clubfoot • Pulmonary hypoplasia 15% • Impaired lung growth and development
Oligohydramnios in late pregnancy • Variable deceleration • c/s for fetal distress • 5-minute apgar score < 7 • Amnioinfusion during labor, prevent cord compression
Hydramnios • > 2 L • AFI > 25 cm. • CNS or GI malformation • Anencephaly and esophageal atresia • First half of pregnancy : transfer water and small molecules across amnion and fetal skin • Second trimester : fetus urinate, swallow and inspire amnionic fluid • Maternal diabetes : fetal hyperglycemia, osmotic diuresis, excess amnionic fluid
Symptoms • Overdistended uterus • Dyspnea • Edema : compression of venous system ( lower extremieties, vulva) • Diagnosis : uterine enlargement with difficulty in palpating fetal parts • Differential diagnosis : ascites or a large ovarian cyst by U/S
Pregnancy outcome • Fetal malformation • Preterm delivery • Umbilical cord prolapse • Placental abruption • Uterine dysfunction • PPH • Abnormal fetal presentation
Management • Minor degrees : no Px • Dyspnea or abdominal pain : hospitalization • Bed rest, diuretics and water-salt restriction : ineffective
Therapeutic amniocentesis : relieve maternal distress (only transient) • Membranes rupture : cord prolapse, placental abruption • Indomethacin : impair lung liquid production, enhances absorption, fetal urine production potential for closure of fetal ductus arteriosus
Fetal growth restriction • 3 to 10 % of infants • Small-for-gestational age (SGA) : intrauterine growth retardation • Avoid “retardation” : fetal growth restriction now preferred
definition • SGA : below 10th percentile for their GA • Some are small because of constitutional factors, not pathologically growth restricted. • Others define by +2 SD with normal limits SGA < 3rd percentile, most of them are poor outcomes.
Mortality and morbidity • Fetal demise, birth asphyxia, meconium aspiration, neonatal hypoglycemia and hypothermia • Growth restriction due to congenital, viral, chromosomal or maternal constitutional factors remains small throughout life. • but due to placental insufficiency will often catch-up growth after birth.
symmetrical • Early insult : chemical exposure, viral infection, aneuploidy : proportionate reduction in both head and body.
asymmetrical • Late insult : placental insufficiency from hypertension, diminished glucose transfer and hepatic storage • Fetal abdominal circumference (liver size) is reduced. • Shunting of oxygen and nutrients to the brain : normal brain and head growth. • Increase relative brain size compared with small liver.
Risk factors • Constitutional small mothers • Fetal infections • Rubella and CMV • Hepatitis A and B • Listeriosis, TB, syphilis • Congenital malformations • karyotype abnormalities : trisomy 18, 13 • Not in trisomy 21, Turner and Klinefelter
Chemical teratogens • Cigarette, alcohol, cocaine • Maternal medical complications • Chronic vascular disease • Preeclampsia • Renal disease • High altitude residence • Placental and cord abnormalities • Multiple fetuses
diagnosis • Early confirmation of GA • Maternal weight gain • Uterine fundal growth • Identification of risk factors • Serial sonography • Doppler velocimetry • NST • Biophysical profile
management • Near term : prompt delivery • Remote from term : growth remains normal, expectant until maturity, interval U/S of 2 to 3 wks. • Labor : monitor for evidence of compromise, insufficient placental function aggravated by labor. • Newborn : meconium aspiration, hypothermia, hypoglycemia and polycythemia
Definition(Multi-fetal Gestation) -Twins (two babies) -Monozygotic(Division of 1 ova fertilized by the same sperm) -Dizygotic(Fertilization of 2 ova by 2 sperm) -Triplets (three babies) -Quadruplets (four babies)
Incidence • Twins - 1 in 100 births • African Americans: 1 in 70 • Caucasians: 1 in 88 • Japanese: 1 in 150 • Chinese: 1 in 300 • Triplets are about 1 in 7,500 births • Quadruplets are about 1 in 65,000 births
Causes of Multiple Gestation • Spontaneously • In Vitro fertilization • Intrauterine insemination • Assisted Hatching • GIFT, ZIFT • Frozen Embryo Transfer, Blastocyte Embryo Transfer • Fertility Drugs • Clomiphene citrate (clomid, serrophene) • Gonadotropins
Dizygotic twins (66% ) Dichorionic – separate chorion (placenta) Diamniotic – separate amnion (amniotic sac) Monozygotic twin(33%) Ova division: < 72 hours: Dichorionic, diamniotic 4-8 days:Monchorionic, diamniotic 8-13 days: Monochorionic, monoamniotic > 13 days:conjoined twins
Average age of gestation Number of babiesWeeks of Gestation 1 40 weeks 2 35 1/2 weeks 3 33 weeks 4 29 ½ weeks
Zygosity & Chorionicity • Zygosity refers to the type of conception whereas chorionicity denotes the type of placentation. • Two thirds of all twins are dizygotic. • Approximately 25% of monozygotic twins are dichorionic. • Chorionicity rather than zygosity determines outcome.
HistoryPatient profile: • Etiological factors; with positive pasthistory and family history speciallymaternal (advanced maternal age, highparity, large maternal size) ART • Early pregnancy:Hyperemesis, abnormal bleeding
Mid-pregnancy: Greater weight gain than expected abdominal size > period of amenorrhea, early PIH symptoms. • Late pregnancy: Pressure symptoms (dyspnea, dyspepsia)
Examination • Abdominal: Size > Date especially in midpregnancy • exclude other causes. • Palpation: Multiple fetal parts • Auscultation of FHS: 2 different recordings by 2 observers and a difference > 10 bpm
Ultrasonography • Detect multifetal gestation 99% before 26 weeks. • Confirm fetal number [ 2 sacs or 2 fetal heads in 2 perpendicular planes]. • Confirm fetal lives • Diagnosis of vanishing twin syndrome. • Diagnose type
Conjoined twins or Siamese twins • *Anterior (thoracopagus) • *Posterior (pygopagus) • *Cephalic (craniopagus) • *Caudal (ischiopagus)
Discordant twins • Diagnosis1. US anatomical.2.Fetal weight difference.* wt. of the larger - wt.of smaller wt.of the larger twin >15-25% poor outcome* • Abd circumferences differ >20 mm.
Twin-TwinTransfusionSyndrome • Incidence : 4 - 20% of MC twins It is characterised by an imbalance of bloodflow between the twins The former criterion of > 20% discordance is no longer used in the diagnosis
Twin-TwinTransfusionSyndrome • Monochorionicity. Marked discordance in amniotic fluid volume between the twins. • Discordance in size with the larger twin in the polyhydramniotic sac. • Fetal anomalies are excluded.
Suggested treatment in TTTS • Serial amnioreduction • Amniotic septostomy • Laser ablation • Selective fetocide
Antenatal care protocol First visit • Routine growth scan & AFI • Chorionicity determination • Placental localization • Cord insertions • Doppler study of UA/UV in each • Inspection of chorionic plate for anastomotic vessels
Subsequent visit • As the first visit • Prenatal diagnosis as indicated • No agreement on the ideal frequency of ultrasound examinations in twins. DC : 4 weekly from 24 weeks MC : 2 weekly from 18 weeks • Note any change in anastomotic flow patterns
Delivery bed with lithotomy stirrups • Obstetric forceps (Piper’s forceps if breech delivery planned) or vacuum apparatus • Premixed oxytocin infusion • Methergine, 15-methyl PGF2 , or both • Immediate availability of blood • Capabilities and staff for emergency cesarean section
Uterine overdistension causes hypotonic uterine dysfunction. • Increased risk of postpartum hemorrhage due to uterine atony. • multifetal gestation is not a contraindication to labor induction, but is a condition that warrants special attention.