• 10-12 weeks
• "fetal cardiac activity" can be detected by US at 6-7 weeks).

• Fetal crown-rump length (CRL) can be measured to assess GA at 12 weeks
• Biparietal diameter (BPD), femur length, and abdominal circumference can be used from 13 weeks.
• US measurement of GA is most reliable during 1st trimetster.

hCG (produced by placenta) peaks (100K mlU) by 10 weeks, decreases throughout 2nd trimester, and levels off in 3rd trimester.

hCG levels should increase by 66% every 48 hours during early pregnancy.

1. Renal flow - increases 25-50%
2. GFR - increases early, then plateaus during 2nd trimester.

• Uterine weight increases from 60-70 g to about 900-1200 g.
• Body weight - average 11 kg (25 lb) increase (between 1 to 1.5 kg/mo).

• HR - increases 20%
• SV - increases to max @ 10 weeks, then plateaus
• CO -increases rapidly by 20%, then gradually increases by an additional 10% by 28 wks.
• BP - decreases 10% by 34 wks, then increases to pre-prepregnancy values
• Peripheral vascular resistance - progressive decrease 

• RR - unchanged
• Tidal volume - increases 30 - 40%
• ERV - decreases
• Respiratory minute volume - increases ~40%
• VC - unchanged

• Blood volume - increases by 50% in 2nd trimester
• Hematocrit - slight decrease
• Fibrinogen - increases

• Sphincter tone decreases
• Gastric emptying time increases

*constipation is common

1. PAPP-A
2. beta hCG
3. nuchal translucency (CVS can be done during this time)

• Glucose challenge test (done earlier if obese or high risk for GDM)
• GBS, repeat H&H
•  chlamydia, gonorrhea cultures, HIV, and RPR in high risk pts.

1. Open NT defects
2. Abdominal wall defects
3. Multiple gestation
4. Incorrect gestational dating
5. Fetal death
6. Placental abnormalities.

1. Trisomies 21 and 18
2. Fetal demise
3. Incorrect gestational dating

• Trisomy 21 - 2 up, 2 down: inhibin A and hCG up, MSAFP and estriol down
• Trisomy - all down (18 is UNDERage)

1. Implant (progestin-only) - inhibits ovulation, increased cervical mucus viscosity, decidualizes endometrium
2. IUD (either with progestin or copper). Progestin IUD causes cervical thickening and endometrial decidualization. May interfere with transport of ovum. Copper has spermicidal effect. Both are foreign bodies --> inflammation.
3. Surgical sterilization

• IUD with progestin - effective for up to 5 years. Pros: Lighter periods, less cramping. Cons: spotting up to 6 mo.
• Copper IUD - Pros: effective for up to 10 years. Cons: increased cramping and bleeding.
• Both are safe with breastfeeding, both have immediate return to fertility once removed, and both have same risk of uterine puncture (1/1000).

• IM injecction every 3 mo
• 90-99% effective (same for patch, ring, OCP, minipill)
• Pros: lighter or no periods, each shot works for 3 mo, safe with breastfeeding.
• Cons: irregular bleeding, weight gain, decreased bone density (reversible), delayed fertility after discontinuation (up to 10 months)

• combined low-dose progestin and estrogen vaginal ring
• Pros: can make periods more regular. 3 wks continuous, 1 week - no ring. Safe to use continuously.
• Cons: may increase vaginal discharge. Spotting in first 1-2 mo.

• Inhibit FSH/LH, suppressing ovulation; thicken cervical mucus; decidualize endometrium
• Pros: decreased risk of ovarian and endometrial cancers and benign breast dz; predictable, light, less painful menses; may improve acne; immediate fertility upon cessation
• Cons: daily compliance necessary; breakthrough bleeding in 10-30%, thromboembolism risk

• Thicken cervical mucus
• Pro: Safe with breastfeeding (preferred over combined OCP)
• Con: Requires strict compliance with daily timing.

1. Pregnancy
2. H/o stroke or DVT
3. Breast cancer
4. Undiagnosed abnormal vaginal bleeding
5. ER-dependent cancer
6. benign or malignant liver neoplasm
7. current tobacco use AND age > 35

1. Pregnancy
2. Undiagnosed vaginal bleeding
3. Current purulent cervicitis
4. PID in past 3 mo
5. Confirmed, symptomatic actinomycosis culture
6. Bicornuate or septate uterus
7. Cervical or uterine CA
8. Pap with squamous intraepithelial lesion or 2 atypical pap smears
9. H/o of heart valve replacement or artificial joints.

• Copper only - copper allergy, Wilson dz, severe dysmenorrhea/menorrhagia
• Mirena  only - levonorgestrel allergy, breast CA, acute liver dz, or liver tumor.

1. Good screen for low-risk (<35) women
2. Available earlier than CVS and less invasive than CVS.

• Done at 10 - 12 weeks GA.
• Transcervical or transabdominal aspiration of placental tissue
• Pros: genetically diagnostic, available at early GA
• Cons: 1% risk of fetal loss, cannot detect open NT defects, limb defect are assoc with CVS at < 9 wks.

• Done at 15-20 wks GA
• Transabdominal aspiration of amniotic fluid using ultrasound-guided needle
• Pro: genetically diagnostic
• Con: PROM, chorioamnionitis, fetal-maternal hemorrhage

1. Women who wil be > 35 yo at time of delivery
2. In conjunction with abnormal quad screen
3. In Rh-sensitized pregnancy to obtain fetal blood type or to detect fetal hemolysis
4. To evaluate fetal lung maturity with L:S ratio (=/>2.5) or to detect phosphatidylglycerol (done in 3rd trimester).

1. bowel atresias
2. congenital malformations of heart, limbs, face, and GU tract
3. microcephaly
4. IUGR
5. cerebral infarctions

1. nasal hypoplasia
2. stippled bone epiphyses
3. developmental delay
4. IUGR
5. ophthalmologic abnormalities

• Toxoplasmosis - hydrocephalus, intracranial calcifications, chorioretinitis, ring-enhancing MRI lesion
• Other: parvovirus, varicella, listeria, TB, malaria, fungi
• Rubella - blueberry muffin rash, cataracts, MR, hearing loss, PDA
• CMV - petechial rash and periventricular calcifcations
• HSV - skin, eye, mouth infxns; life-threatening CNS/systemic infxn
• HIV - Often no sx; failure to thrive, increased incidences of RTIs
• Syphilis - maculopapular skin rash, lymphadenopathy, hepatosplenomegaly, mucopurulent rhinitis, osteitis. Late congenital syphilis: Saber shins, Saddle nose, CNS involvement, Hutchison's triad: peg-shaped central incisors, deafness, interstitial keratitis. 

1. Chromosomal abnormalities (MC cause, 1st trimester)
2. Maternal factors
3. Environmental factors (tobacco, alcohol)
4. Fetal factors (anatomic malformation)

1. Inheritied thrombophilias (ex. factor V Leiden)
2. Immunologic (ex. antiphospholipid Ab's)
3. Anatomic (ex. uterine or cervical abnormalities, LEEP, DES, etc.)
4. Endocrine (DM, hypothyroidism, progesterone defiency)
5. Other: maternal trauma, advanced maternal age, infxn, dietary defiency

• s/s: POC are expelled. Pain ceases, spotting may persist.
• dx: Closed os. US shows empty uterus
• tx: follow hCG levels until negative (should halve every 48-72 hrs). 

• s/s: Some POC expelled. Bleeding, mild cramping, visible tissue on exam. Uterus continues to contract in an effort to expel the retained tissue.
• dx: Open os. US shows retained POC
• tx: manual uterine aspiration or D&C

• s/s: no POC expelled. Uterine bleeding before 20 weeks. +/- abdominal pain.
• dx: Closed os, intact membrane, + fetal cardiac motion on US
• tx: pelvic rest for 24-48 hr, f/u US and hCG to assess viability (up to 50% miscarry)

• s/s: No POC expelled, uterine bleeding and cramps
• dx: Open os. +/- ROM
• tx: manual uterine aspiration, D&C, misoprostol, or expectant mgmnt

• s/s: No POC expelled. No fetal cardiac motion, no uterine bleeding or cramping. +/- Brownish vaginal discharge
• dx: Closed os. Retained POC on US.
• tx: MUA, D&C, or misoprostol

• s/s: endometritis leading to septicemia. Maternal mortality is 10-15%.
• dx: Hypotension, hypothermia, elevated WBCs
• tx: MUA, D&C, and IV abx

• s/s: absence of fetal cardiac activity
• dx: uterus small for GA, no FHT or FM on US.
• tx: Induce labor; evacuate uterus (D&E) to prevent DIC at GA>16 w.

• If early in pregnancy, often d/t chromosomal abnormalities.
• If later in pregnancy, often d/t hypercoaguable state (inherited thrombophilia in mother0
• Incompetent cervix should be suspected with h/o painless dilation of cervix and delivery of normal fetus between 18-32 weeks.

• Karyotyping both parents
• Hypercoaguability work-up of mother
• Evaluate for uterine abnormalities.

• Oral mifepristone (low dose) + oral/vaginal misoprostol - up to 49 days GA
• iM/oral MTX + oral/vaginal misoprostol - up to 49 days GA.
• Vaginal or sublingual or buccal misoprostol (high dose), up to 3x. Up to 13 weeks GA.

• Vaginal spotting, absence of FHTs, uterus size greater than dates, and markedly elevated hCG levels
• Dx is made by US which reveals a "snow storm' pattern in the uterus.
• Tx is curretage followed by weekly monitoring of hCG levels.

• In inevitable abortion uterine ctx cause cervical dilation. 
• In incompetent cervix, the cervix dilates without uteirne ctx (painless dilation).
• Tx of incompetent cervix is cerclage = surgical ligature of the internal os. 

• Cervical conization
• Congenital problems (short cervix, collagen d/o)
• Trauma to the cervix
• Prolonged 2nd stage of labor
• Uterine overdistension as with a multiple pregnancy